WO2026040026A1 - Wireless communication methods, terminal devices, and network devices - Google Patents

Abstract

Provided are wireless communication methods, terminal devices, and network devices. The method comprises: a terminal device receiving first information sent by a network device, the first information being used for configuring a plurality of preamble formats for a first cell. In the embodiments of the present application, a network device can configure a plurality of different preamble formats for a first cell. When compared to a conventional solution in which one cell corresponds to one preamble format, this helps to achieve a balance among a variety of performance aspects.

Description

Wireless communication methods, terminal equipment and network equipment Technical Field

This application relates to the field of communication technology, and more specifically, to wireless communication methods, terminal devices, and network devices.

Background Technology

Currently, for a given cell, the network configures a preamble format that matches the cell's coverage size and high/low speed characteristics. This preamble format is suitable for the coverage performance and capacity of the physical random access channel (PRACH) within the cell. The selection of the preamble format often considers the most extreme cases for the cell. For example, the guard time (GT) length of the preamble format is determined based on the transmission delay difference between PRACH transmissions by terminal equipment at the cell edge and terminal equipment at the cell center. Alternatively, the preamble format for the cell can be determined based on parameters such as the PRACH detection performance and multipath delay of terminal equipment at the cell edge.

This method of selecting the preamble format sacrifices other performance aspects in order to ensure PRACH performance. For example, the preamble format determined in this way may consume more transmission resources, leading to increased PRACH resource overhead and latency. As another example, the preamble format determined in this way typically uses a smaller subcarrier spacing to minimize the channel bandwidth occupied by the PRACH, thereby ensuring a larger power spectrum for PRACH transmission and thus guaranteeing cell coverage with a larger cell radius. However, a smaller subcarrier spacing corresponds to a longer preamble symbol, resulting in increased PRACH resource overhead and latency.

Summary of the Invention

This application provides a wireless communication method, a terminal device, and a network device. The various aspects covered in this application are described below.

In a first aspect, a wireless communication method is provided, comprising: a terminal device receiving first information sent by a network device, the first information being used to configure multiple preamble formats for a first cell.

In a second aspect, a wireless communication method is provided, comprising: a network device sending first information to a terminal device, the first information being used to configure multiple preamble formats for a first cell.

Thirdly, a terminal device is provided, including: a receiving unit for receiving first information sent by a network device, the first information being used to configure multiple preamble formats for a first cell.

Fourthly, a network device is provided, comprising: a transmitting unit for transmitting first information to a terminal device, the first information being used to configure multiple preamble formats for a first cell.

Fifthly, a terminal device is provided, including a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to invoke the computer programs in the memory, causing the terminal device to perform some or all of the steps in the method of the first aspect.

In a sixth aspect, a network device is provided, including a processor, a memory, and a transceiver, wherein the memory is used to store one or more computer programs, and the processor is used to invoke the computer programs in the memory to cause the network device to perform some or all of the steps in the method of the second aspect.

Seventhly, embodiments of this application provide a communication system including the aforementioned terminal device and/or network device. In another possible design, the system may further include other devices that interact with the terminal device or network device as described in the embodiments of this application.

Eighthly, embodiments of this application provide a computer-readable storage medium storing a computer program that causes a communication device (e.g., a terminal device or a network device) to perform some or all of the steps in the methods described above.

Ninthly, embodiments of this application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program operable to cause a communication device (e.g., a terminal device or a network device) to perform some or all of the steps of the methods described in the foregoing aspects. In some implementations, the computer program product may be a software installation package.

In a tenth aspect, embodiments of this application provide a chip including a memory and a processor, the processor being able to call and run a computer program from the memory to implement some or all of the steps described in the methods of the foregoing aspects.

In this embodiment of the application, the network device can configure different preamble formats for the first cell. Compared with the traditional scheme where one cell corresponds to one preamble format, this helps to balance various performance aspects.

Attached Figure Description

Figure 1 shows the wireless communication system 100 used in an embodiment of this application.

Figure 2 is a schematic diagram of the PRACH frequency domain location.

Figure 3 is a schematic diagram of the mapping relationship between the synchronization signal/PBCH (SSB) and the PRACH occasion.

Figure 4 is a schematic diagram of the structure of the PRACH applicable to the embodiments of this application.

Figures 5 and 6 illustrate schematic diagrams showing the correspondence between various preamble formats and multiple area ranges of the first cell according to embodiments of this application.

Figure 7 is a schematic diagram of frequency domain resources corresponding to various preamble formats in the embodiments of this application.

Figure 8 is a schematic diagram of PRACH repetitive transmission applicable to the embodiments of this application.

Figure 9 is a schematic flowchart of a wireless communication method according to an embodiment of this application.

Figure 10 is a schematic flowchart of the random access procedure applicable to the embodiments of this application.

Figure 11 is a schematic diagram of multiple beams covering a cell, applicable to an embodiment of this application.

Figure 12 is a schematic diagram of a terminal device according to an embodiment of this application.

Figure 13 is a schematic diagram of a network device according to an embodiment of this application.

Figure 14 is a schematic structural diagram of a communication device according to an embodiment of this application.

Detailed Implementation

The technical solutions in this application will now be described with reference to the accompanying drawings.

Figure 1 illustrates a wireless communication system 100 according to an embodiment of this application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographical area and may communicate with the terminal device 120 located within that coverage area.

Figure 1 illustrates an exemplary network device and two terminals. Optionally, the wireless communication system 100 may include multiple network devices, and each network device may include other terminal devices within its coverage area. This application embodiment does not limit this.

Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, which is not limited in this embodiment.

It should be understood that the technical solutions of the embodiments of this application can be applied to various communication systems, such as: 5th generation (5G) systems or new radio (NR), long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, etc. The technical solutions provided in this application can also be applied to future communication systems, such as 6th generation mobile communication systems, satellite communication systems, and so on.

The terminal device in this application embodiment can also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device in this application embodiment can be a device that provides voice and/or data connectivity to a user, and can be used to connect people, objects, and machines, such as a handheld device with wireless connectivity, vehicle-mounted device, etc. The terminal devices in the embodiments of this application can be mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, self-driving, remote medical surgery, smart grids, transportation safety, smart cities, and smart homes, etc. Optionally, the UE can act as a base station. For example, the UE can act as a scheduling entity, providing sidelink signals between UEs in V2X or D2D, etc. For example, cellular phones and cars communicate with each other using sidelink signals. Cellular phones and smart home devices communicate without relaying communication signals through a base station.

The network device in this application embodiment can be a device for communicating with a terminal device. This network device can also be called an access network device or a wireless access network device, such as a base station. In this application embodiment, the network device can refer to a radio access network (RAN) node (or device) that connects the terminal device to the wireless network. A base station can broadly encompass, or be replaced by, various names including: NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, transmitting and receiving point (TRP), transmitting point (TP), master MeNB, auxiliary SeNB, multi-mode radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or similar, or a combination thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. Base stations can also be mobile switching centers, devices that perform base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, network-side devices in 6G networks, and devices that perform base station functions in future communication systems. Base stations can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the network equipment.

Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station. In other examples, a helicopter or drone can be configured as a device to communicate with another base station.

In some deployments, the network device in this application embodiment may refer to a CU or a DU, or the network device may include both a CU and a DU. The gNB may also include an AAU.

Network devices and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located.

It should be understood that all or part of the functions of the communication device in this application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (e.g., a cloud platform).

PRACH during random access procedure

In NR technology, PRACH resources are defined for access terminal equipment, including 256 configurations. The PRACH resource configuration information used by the cell is indicated to the access terminal equipment in system messages. Each PRACH resource configuration includes the preamble format, period, radio frame offset y, subframe number, starting symbol, number of PRACH slots within a subframe, and number of PRACH opportunities within a PRACH slot. and PRACH timing duration The time, frequency, and code information of the PRACH resource can be determined using this information. As shown in Table 1, the PRACH Configuration Index has a value of 86, which indicates the preamble format, the radio frame, subframe, start symbol, and duration of the PRACH event.

Table 1: Random Access Configurations for FR2 and Unpaired Spectrum

In addition to the time-domain resource location of RACH resources, the frequency-domain resource location of RACH resources is indicated by the parameter message 1-FrequencyStart and message 1-FDM in the higher-layer signaling "RACH-ConfigGeneric". The msg1-FrequencyStart determines the offset of the starting position of the resource block (RB) of PRACH occasion number 0 relative to the frequency-domain starting position of the uplink common bandwidth part (BWP) (i.e., BWP 0), that is, it determines the frequency-domain starting position of the RACH resource. The value of msg1-FDM is {1,2,4,8}, which determines the number of PRACH opportunities in the frequency domain. The number of RBs occupied by PRACH on the traffic channel is determined by the preamble sequence indicated by the parameter "prach-RootSequenceIndex" and Δf _RA (see Table 6.3.3.2-1 of 3GPP TS38.211). The schematic diagram of its PRACH frequency domain position is shown in Figure 2, where msg1-FDM = 8.

For terminal devices, in addition to the RACH resource configuration indicated by the system message, the association between SSBs and PRACH resources is also indicated. This allows the terminal device to determine the RACH resources it can use based on the detected SSBs and this association. Each SSB is associated with one or more PRACH opportunities and also with multiple contention-based preambles. That is, each SSB index is associated with a specific set of resources in the RACH resource configuration indicated in the system message.

In some implementations, the upper layer configures N (ssb-perRACH-Occasion) SSBs to associate with a PRACH opportunity through the parameter "ssb-perRACH-OccasionAndCB-PreamblesPerSSB", and each SSB is based on the competition-based preamble (CB-PreamblesPerSSB) for each valid PRACH opportunity.

If N < 1, then an SSB is mapped to 1/N consecutive valid PRACH opportunities. For example, if N = 1/4, then an SSB is mapped to 4 PRACH opportunities, and R consecutive indexes are mapped to SSB n, where 0 <= n <= N-1, and each valid PRACH opportunity starts from index 0.

If N>=1, the leader of R consecutive indices is mapped to SSB n, 0<=n<=N-1, and each valid PRACH opportunity is derived from the leader index. Begin. For example: N=2, Two SSBs map to one PRACH opportunity. For these two SSBs n, n = 0, 1, when n = 0, the leader index of SSB 0 starts from 0; when n = 1, the leader index of SSB 1 starts from 32. The leader index on SSB 0 is 0~31, and the leader index on SSB 1 is 32~the configured contention leader - 1. One valid PRACH opportunity corresponds to the entire contention leader count. In this case, one valid PRACH opportunity covers two SSBs, so each SSB occupies a portion of the leader, which is different from N<1. Configured by the parameter "totalNumberOfRA-Preambles" and is an integer multiple of N.

The relevant signaling examples are as follows:

ssb-perRACH-OccasionAndCB-PreamblesPerSSB CHOICE{

oneFourth ENUMERATED{n4,n8,n12,n16,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},

This signaling indicates that one SSB is associated with 4 PRACH opportunities, where n4 indicates that one SSB is associated with 4 contention-based preambles, and so on. The total number of contention-based preambles in one PRACH opportunity is CB-preambles-per-SSB*max(1,SSB-per-rach-occasion).

In some implementations, the mapping from SSB to PRACH timing should follow the following order: First, the order of the preamble index within a PRACH timing is ascending; second, the order of the frequency resource indexes of a frequency-multiplexed PRACH timing is ascending; third, the order of the time-domain resource indexes of a time-domain-multiplexed PRACH timing within a PRACH slot is ascending; and fourth, the order of the PRACH slot indexes is ascending.

The following example illustrates the mapping relationship between the two. For instance, the number of SSBs is 8 (numbered 0 to 7), msg1-FDM = 4 (representing the number of frequency domain PRACH occasions). ssb-perRACH-Occasion = 1/4, and the mapping between SSBs and PRACH occasions is shown in Figure 3.

PRACH format and leader sequence

In some communication systems (e.g., 5G NR), PRACH is primarily used to carry random access preambles from terminal equipment to access network equipment (5G NR base stations). 5G NR random access preambles use ZC (ZaddOff Chu) sequences and support two different preamble sequence lengths: 839 and 139.

In some implementations, the 839 long sequence uses four preamble formats for FR1. Table 2 shows the SCS, CP length, sequence length, GT length, and application scenarios for each preamble format. Referring to Table 2, format 0 is used for typical macrocell coverage, format 1 for ultra-large cell coverage, format 2 uses more sequence repetition for coverage enhancement, and format 3 is applied to high-speed mobile scenarios, such as high-speed rail. Long sequences can use subcarrier spacing of 1.25 kHz or 5 kHz.

Table 2

In some implementations, the 139 short sequence supports nine preamble formats across three series (A, B, and C) to suit different application scenarios. Table 3 shows the number of sequences, CP length, sequence length, GT length, maximum cell radius, and application scenarios for each preamble format. In FR1, the preamble formats shown in Table 3 support subcarrier spacing of 15kHz or 30kHz, while in FR2, the preamble formats shown in Table 3 support subcarrier spacing of 60kHz or 120kHz.

Table 3

In some implementations, subcarrier spacings of 480kHz and 960kHz can also be supported in the 71GHz high-frequency band. In the Rel-16 standardized NR-U and Rel-17 standardized 71GHz band extension features, two additional sequence lengths of 1151 and 571 are introduced among these nine preamble formats, each corresponding to a specific subcarrier spacing, as shown in Table 4. In Table 4, the sequence length corresponding to the same preamble format can be configured via the network, such as through SIB1 indication. Table 4 shows the preamble sequence lengths L_{_RA}, Δf_{_RA}, _Nu , and CP length corresponding to each preamble format. And support for restricted sets.

Table 4

In some implementations, the preamble format consists of two parts: a cyclic prefix (CP) and a preamble sequence. Different preamble formats contain different numbers of preamble sequences to achieve different coverage performance. To prevent interference to other signals caused by inaccurate uplink positioning during initial access of the terminal device, a ground plane (GT) is usually reserved after the preamble, as shown in Figure 4.

In some implementations, the preamble sequence length is a crucial factor affecting coverage in wireless communication systems. A longer sequence results in a larger cell coverage area. This is because a longer preamble provides a longer correlation window, improving signal detection capabilities and maintaining good communication quality even with weak signals or long propagation distances. Simultaneously, a longer sequence provides a sufficient number of preambles, increasing system capacity. For FR2, a shorter preamble sequence should be used to control the bandwidth occupied by the PRACH channel while meeting the needs of cells with small coverage areas. Therefore, long sequences are primarily used in large-cell deployment scenarios, while short sequences are more suitable for small/ordinary cells and indoor deployment scenarios.

In some implementations, the ground truth (GT) in the preamble format is used to offset the differences in transmission latency among different users. The larger the cell coverage area, the longer the transmission latency, and the larger the required GT. The transmission latency of users at the cell edge needs to be within the GT to ensure that PRACH can be received normally without interfering with other subframes. The reserved GT needs to support a transmission distance of twice the cell radius to ensure that users at the cell edge have enough time to send in advance after obtaining downlink synchronization (cell search). The GT length determines the supported access radius: cell coverage distance L1 = L _GT × ^c 2, where c is the speed of light.

In some implementations, the preamble (CP) can overcome inter-symbol interference (ISI) and subcarrier orthogonality disruption caused by multipath delay spread. When the length of the CP is greater than the longest channel delay, it can be guaranteed that the symbol received by the receiver will not overlap with the previous symbol. Multipath delay spread is related to the wireless environment, such as terrain, ground features, and obstructions, and is also related to the cell radius, but there is no absolute correspondence.

In some implementations, the primary consideration in selecting the preamble subcarrier spacing is to counteract Doppler frequency offset. Therefore, in high-speed scenarios, a larger subcarrier spacing is required. For example, a 5kHz preamble subcarrier spacing in FR1 can support terminal device movement speeds of 500km/h. A smaller preamble subcarrier spacing allows the PRACH to occupy less channel bandwidth, thus ensuring a larger PRACH power spectrum and consequently, cell coverage with a larger cell radius. Conversely, a larger subcarrier spacing uses shorter preamble symbols, effectively saving resources while adapting to small cell coverage. The shorter signal length also makes PRACH multiplexing with other channels and beam scanning more advantageous.

In some implementations, different preamble formats are combinations of the aforementioned sequence length, subcarrier spacing, CP length, and GP length, suitable for different cell types and scenarios, such as super-large cells, small cell coverage, high-speed scenarios, and medium-to-low-speed scenarios. At the same time, the selection of the preamble format also takes into account resource overhead.

Currently, for a given cell, the network configures a preamble format that matches the cell's coverage size and high/low speed characteristics. This preamble format is suitable for the coverage performance and capacity of PRACH within the cell. The selection of the preamble format often considers the most extreme cases for that cell. For example, the GT length of the preamble format is determined based on the transmission delay difference between PRACH transmissions from terminal equipment at the cell edge and terminal equipment at the cell center. Alternatively, the preamble format for that cell is determined based on parameters such as PRACH detection performance and multipath delay of terminal equipment at the cell edge.

This method of selecting the preamble format sacrifices other performance aspects in order to ensure PRACH performance. For example, the preamble format determined in this way may consume more transmission resources, leading to increased PRACH resource overhead and latency. As another example, the preamble format determined in this way typically uses a smaller subcarrier spacing to minimize the channel bandwidth occupied by the PRACH, thereby ensuring a larger power spectrum for PRACH transmission and thus guaranteeing cell coverage with a larger cell radius. However, a smaller subcarrier spacing corresponds to a longer preamble symbol, resulting in increased PRACH resource overhead and latency.

Therefore, to address the aforementioned problems, this application provides a wireless communication method in which a single cell (also known as a first cell) can correspond to multiple different preamble formats. Compared to the traditional approach where one cell corresponds to one preamble format, this method helps to balance various performance aspects. For example, for terminal devices located at the cell edge, a preamble with a longer GT length among the multiple preamble formats can be used. The format helps the terminal device receive PRACH normally without interfering with other subframes. For example, for a terminal device located in the center of a cell, using a preamble format with a shorter GT length among various preamble formats helps the terminal device receive PRACH normally and reduces the transmission resources occupied by PRACH transmission. The following describes various preamble formats corresponding to the first cell in the embodiments of this application. Here, the various preamble formats corresponding to the first cell can be understood as various preamble formats that can be used in the first cell.

In some implementations, multiple preamble formats satisfy one or more of the following: different preamble formats have different preamble sequence lengths; different preamble formats have different subcarrier spacings; different preamble formats have different ground truth (GT) lengths; different preamble formats have different CP lengths; and different preamble formats have different number of repetitions of the preamble sequence.

As mentioned earlier, the length of the preamble sequence is a crucial factor affecting coverage in a wireless communication system. A longer preamble sequence results in a larger cell coverage area, while a shorter preamble sequence, although leading to a smaller cell coverage area, helps reduce the resources required for preamble transmission. Therefore, in this embodiment, different preamble formats correspond to different preamble sequence lengths, which helps to accommodate the communication needs of different terminal devices in the first cell.

Assume there are multiple preamble formats, including preamble format 1 and preamble format 2, where the preamble sequence length of preamble format 1 is longer than that of preamble format 2. For terminal devices located at the cell edge, preamble format 1 can be used to extend the cell's coverage area, which helps improve the signal detection capability of terminal devices located at the cell edge. For terminal devices located closer to the cell center, preamble format 2 can be used to reduce the amount of resources required to transmit the preamble.

In this embodiment, the length of the preamble sequence is not limited. Generally, the longer preamble sequence among multiple preamble sequences can be called a "long sequence," and correspondingly, the shorter preamble sequence among multiple preamble sequences can be called a "short sequence." In some implementations, the lengths of the multiple preamble sequences corresponding to multiple preamble formats can include both long and short sequences. For example, the lengths of the multiple preamble sequences can include two sequence lengths: 1151 and 571. Another example is that the lengths of the multiple preamble sequences can include two sequence lengths: 839 and 139. Of course, in this embodiment, the lengths of the multiple preamble sequences can include multiple different short sequences, or the lengths of the multiple preamble sequences can include multiple different long sequences.

As mentioned earlier, the primary consideration in selecting subcarrier spacing is to counteract Doppler frequency offset. Generally, a larger Doppler frequency offset requires a larger subcarrier spacing, which helps reduce the resources required for the transmission preamble. Conversely, a smaller Doppler frequency offset requires a smaller subcarrier spacing, which helps ensure cell coverage with a larger cell radius. Therefore, in this embodiment, different preamble formats correspond to different subcarrier spacings, which helps to accommodate the communication needs of different terminal devices in the first cell.

Assume there are multiple preamble formats, including preamble format 1 and preamble format 2, where the subcarrier spacing of preamble format 1 is greater than that of preamble format 2. For terminal devices with a large Doppler frequency offset, preamble format 1 can be used. For terminal devices with a small Doppler frequency offset, preamble format 2 can be used.

As mentioned earlier, the ground truth (GT) in the preamble format is used to offset the differences in transmission latency among different users. Generally, the larger the cell coverage area, the longer the transmission latency, and a longer GT length can be used. Conversely, the smaller the cell coverage area, the shorter the transmission latency, and a shorter GT length can be used, which helps to reduce the amount of resources occupied by the transmission preamble. Therefore, in the embodiments of this application, different GT lengths correspond to different preamble formats, which helps to take into account the communication needs of different terminal devices in the first cell.

Assume there are multiple preamble formats, including preamble format 1 and preamble format 2, where the ground truth (GT) length of preamble format 1 is greater than that of preamble format 2. For terminal devices located at the cell edge, the transmission latency is typically higher; therefore, preamble format 1 can be used. For terminal devices located near the cell center, the transmission latency is typically lower; therefore, preamble format 2 can be used.

In this embodiment, the GT length is not limited. In some implementations, it is assumed that the first cell can be divided into multiple regions, and the GT length corresponding to each region can be determined based on the distance between the corresponding region and the network device. For example, if the distance between the first region and the network device is a first distance, then the GT length corresponding to the first region needs to ensure that the GT supports a transmission distance twice the first distance. As another example, if the distance between the first region and the network device is L1, then the GT length _LGT corresponding to the first region can be determined according to the formula: L1 = _LGT × ^c² , where ^c represents the speed of light. Of course, in this embodiment, the GT length can be determined based on other methods.

As mentioned above, the CP in the preamble format can overcome the inter-symbol interference (ISI) and subcarrier orthogonality disruption problems caused by multipath delay spread. Typically, for areas with strong ISI in the first cell, a longer CP length can be used, which helps to reduce the probability of the received symbol overlapping with the previous symbol. Conversely, for areas with weak ISI in the first cell, a shorter CP length can be used, which helps to reduce the amount of resources occupied by the transmission preamble. Therefore, in the embodiments of this application, different CP lengths correspond to different preamble formats, which helps to accommodate the communication needs of different terminal devices in the first cell.

Assume there are multiple preamble formats, including preamble format 1 and preamble format 2, where the CP length of preamble format 1 is greater than the CP length of preamble format 2. For terminal devices located in areas with strong ISI, preamble format 1 can be used. For terminal devices located in areas with weak ISI, preamble format 2 can be used.

In some scenarios, the number of repetitions in the preamble sequence is related to the signal detection performance. That is, the more repetitions the preamble sequence has, the better the signal detection performance, thus helping to improve PRACH coverage. Conversely, the fewer repetitions the preamble sequence has, the worse the signal detection performance. The relative decrease, but it helps reduce the amount of resources needed to transmit PRACH.

Assume there are multiple preamble formats, including preamble format 1 and preamble format 2, where the number of repetitions of the preamble sequence corresponding to preamble format 1 is greater than the number of repetitions of the preamble sequence corresponding to preamble format 2. For terminal devices located at the cell edge, preamble format 1 can be used. For terminal devices located near the cell center, preamble format 2 can be used.

It should be noted that the above describes the implementation methods of various preamble formats in the embodiments of this application. The implementation methods described above can be used individually or in combination. For ease of understanding, several examples of combining the above implementation methods are introduced below. In some implementation methods, the lengths of the preamble sequences, the GT length, and the CP lengths corresponding to different preamble formats are all different, but the repetition counts of the preamble sequences corresponding to different preamble formats are the same. For example, the various preamble formats may include preamble format 2 and preamble format 3 as shown in Table 2.

In other implementations, the ground truth (GT) length, the number of repetitions of the leader sequence, and the commutative sequence (CP) length differ among the various leader formats, but the length of the leader sequence corresponding to the different leader formats is the same. For example, the various leader formats may include leader format 0, leader format 1, and leader format 2 as shown in Table 2. As another example, the various leader formats may include leader format A, leader format B, and leader format C as shown in Table 3.

In other implementations, the GT length, the length of the preamble sequence, and the CP length are all the same for different preamble formats, but the number of repetitions of the preamble sequence for different preamble formats are different.

It should be noted that the various preamble formats in the embodiments of this application may be some or all of the preamble formats specified in known communication systems (for example, see the preamble formats shown in Tables 2, 3 and 4). Of course, the various preamble formats in the embodiments of this application may also be preamble formats newly introduced in future communication systems.

The preceding text introduced various preamble formats in the embodiments of this application. The following text describes how to use these various preamble formats in the embodiments of this application.

In some implementations, multiple preamble formats correspond to different areas within the first cell. Typically, different areas within the first cell have different parameters, including path loss, transmission delay, coverage area, delay spread, and Doppler frequency offset. Therefore, different areas can correspond to different preamble formats, which helps to balance various aspects of performance when communicating in different areas within the first cell.

Taking the example that different regions have different path losses, path loss is also called signal transmission loss in some scenarios.

Assume the first cell includes region 1 and region 2, where the path loss for region 1 is greater than that for region 2. Accordingly, the preamble format 1 for region 1 and the preamble format 2 for region 2 satisfy one or more of the following: the length of the preamble sequence for preamble format 1 is greater than the length of the preamble sequence for preamble format 2; the ground truth (GT) length for preamble format 1 is greater than the GT length for preamble format 2; the commutation length (CP) for preamble format 1 is greater than the CP length for preamble format 2; and the number of repetitions of the preamble sequence for preamble format 1 is greater than the number of repetitions of the preamble sequence for preamble format 2.

Taking the example of different transmission delays corresponding to different regions, assume that the first cell includes region 1 and region 2, where the transmission delay corresponding to region 1 is greater than the transmission delay corresponding to region 2. Accordingly, the preamble format 1 corresponding to region 1 and the preamble format 2 corresponding to region 2 satisfy the following condition: the GT length corresponding to preamble format 1 is greater than the GT length corresponding to preamble format 2.

Taking the example of different coverage areas corresponding to different regions, in some implementations, the distance between different regions and network devices varies. Assume the first cell includes region 1 and region 2, where the distance between region 1 and the network device is greater than the distance between region 2 and the network device. Correspondingly, the preamble format 1 corresponding to region 1 and the preamble format 2 corresponding to region 2 satisfy one or more of the following: the length of the preamble sequence corresponding to preamble format 1 is greater than the length of the preamble sequence corresponding to preamble format 2; the ground truth (GT) length corresponding to preamble format 1 is greater than the GT length corresponding to preamble format 2; the commutation length (CP) of preamble format 1 is greater than the CP length corresponding to preamble format 2; and the number of repetitions of the preamble sequence corresponding to preamble format 1 is greater than the number of repetitions of the preamble sequence corresponding to preamble format 2.

Taking the example of different delay spreads (also known as multipath delay spreads) corresponding to different area ranges, assume that the first cell includes area range 1 and area range 2, where the delay spread corresponding to area range 1 is greater than the delay spread corresponding to area range 2. Accordingly, the preamble format 1 corresponding to area range 1 and the preamble format 2 corresponding to area range 2 satisfy the following: the CP length corresponding to preamble format 1 is greater than the CP length corresponding to preamble format 2.

Taking the example of different Doppler frequency offsets corresponding to different regions, assume that the first cell includes region 1 and region 2, where the Doppler frequency offset corresponding to region 1 is greater than that corresponding to region 2. Accordingly, the preamble format 1 corresponding to region 1 and the preamble format 2 corresponding to region 2 satisfy the following condition: the subcarrier spacing corresponding to preamble format 1 is greater than the subcarrier spacing corresponding to preamble format 2.

Of course, in the embodiments of the application, different preamble formats can correspond to the parameters of the terminal device. For example, different preamble formats can correspond to different moving speeds of the terminal device. Assume that the multiple preamble formats include preamble format 1 and preamble format 2, wherein the subcarrier spacing corresponding to preamble format 1 is greater than the subcarrier spacing corresponding to preamble format 2. Accordingly, terminal device 1 can use preamble format 1, and terminal device 2 can use preamble format 2, wherein the moving speed of terminal device 1 is higher than the moving speed of terminal device 2.

For example, different preamble formats can correspond to different path losses in terminal devices. Suppose that there are multiple preamble formats, including preamble format 1 (e.g., preamble format 0 shown in Table 2) and preamble format 2 (e.g., preamble format 1 shown in Table 2). Preamble format 2 repeats the preamble sequence four times, resulting in a larger time-domain length for the entire PRACH. It is suitable for scenarios with small delay spread and large signal propagation loss, such as deep learning. Therefore, preamble format 2 can be used for terminal devices with high path loss. Additionally, preamble format 1 does not repeat the preamble sequence, making it suitable for scenarios with low signal propagation loss; therefore, preamble format 1 can be used for terminal devices with low path loss.

It should be noted that the various preamble formats described above can be used individually, or they can be used in combination. For ease of understanding, the following section, with reference to Figures 5 and 6, uses the correspondence between various preamble formats and multiple area ranges of the first cell as an example to illustrate the usage of various preamble formats in the embodiments of this application.

Referring to Figure 5, the coverage area of the first cell includes area 1 (also known as the outer ring) and area 2 (also known as the inner ring). Area 1 can be understood as the maximum coverage area of the first cell, and the coverage area corresponding to area 2 is smaller than the coverage area corresponding to area 1. Terminal devices located in area 1 include terminal device 1 and terminal device 2, and terminal devices located in area 2 include terminal device 3 and terminal device 4.

In implementation method 1, the preamble format corresponding to the first cell includes preamble format 1 and preamble format 2. The preamble sequence of preamble format 1 is a long sequence with a length of 839, and the preamble sequence of preamble format 2 is a short sequence with a length of 139. In addition, the CP length of preamble format 1 is greater than the CP length of preamble format 2, and the GT length of preamble format 1 is greater than the GT length of preamble format 2.

Accordingly, for implementation method 1, region 2 can correspond to preamble format 2, meaning that terminal devices 3 and 4 can use preamble format 2. Thus, terminal devices 3 and 4 can use a short-sequence preamble format instead of a long-sequence preamble format. The short-sequence preamble format allows for a larger subcarrier spacing, resulting in shorter symbols occupied by the preamble and helping to reduce the transmission time of the preamble. Region 1 can correspond to preamble format 1, meaning that terminal devices 1 and 2 can use preamble format 1. Preamble format 1 has a long preamble sequence with longer CP and GT, which helps to accommodate larger transmission delays and multipath delays.

In implementation method 2, the preamble format corresponding to the first cell includes preamble format 1 (e.g., format 1 shown in Table 2) and preamble format 2 (e.g., format 0 shown in Table 2). The number of repetitions of the preamble sequence corresponding to preamble format 1 is N, where N is a positive integer greater than or equal to 2. The number of repetitions of the preamble sequence corresponding to preamble format 2 is 0, meaning that preamble format 2 does not use preamble sequence repetition. Furthermore, the preamble sequences of both preamble format 1 and preamble format 2 are long sequences of 839. The CP length of preamble format 1 is greater than the CP length of preamble format 2, and the GT length of preamble format 1 is greater than the GT length of preamble format 2.

Accordingly, for implementation method 2, region 2 can correspond to preamble format 2, meaning that terminal device 3 and terminal device 4 can use preamble format 2, which helps reduce the transmission time of the preamble. Region 1 can correspond to preamble format 1, meaning that terminal device 1 and terminal device 2 can use preamble format 1. The preamble sequence of preamble format 1 is a long sequence with relatively long CP and GT, which helps to adapt to larger transmission delays and multipath delays.

Referring to Figure 6, the coverage area of the first cell includes area 1 (also known as the outer ring), area 2 (also known as the middle ring), and area 3 (also known as the inner ring). Area 1 can be understood as the maximum coverage area of the first cell. The coverage area of area 2 is smaller than that of area 1, and the coverage area of area 2 is larger than that of area 3. Terminal devices located in area 1 include terminal device 1, terminal devices located in area 2 include terminal device 2, and terminal devices located in area 3 include terminal device 3 and terminal device 4.

In one implementation, the preamble format corresponding to the first cell includes preamble format 1, preamble format 2, and preamble format 3. Preamble format 1 and preamble format 2 have a preamble sequence length of 839, while preamble format 3 has a preamble sequence length of 139. Furthermore, the CP length corresponding to preamble format 1 is greater than that corresponding to preamble format 2, and the CP length corresponding to preamble format 2 is greater than that corresponding to preamble format 3. The GT length corresponding to preamble format 1 is greater than that corresponding to preamble format 2, and the GT length corresponding to preamble format 2 is greater than that corresponding to preamble format 3.

Accordingly, region 3 can correspond to preamble format 3, meaning that terminal devices 3 and 4 can use preamble format 3. Thus, terminal devices 3 and 4 can use a short-sequence preamble format instead of a long-sequence preamble format. The short-sequence preamble format allows for a larger subcarrier spacing, resulting in shorter symbols occupied by the preamble and helping to reduce the transmission time. Region 2 can correspond to preamble format 2, meaning that terminal device 2 can use preamble format 2. Preamble format 2 has a long preamble sequence with shorter CP and GT, which helps to reduce the transmission time required for the preamble to some extent and accommodates certain transmission delays and multipath delays. Region 1 can correspond to preamble format 1, meaning that terminal device 1 can use preamble format 1. Preamble format 1 has a long preamble sequence with longer CP and GT, which helps to accommodate larger transmission delays and multipath delays.

As mentioned above, the preamble format corresponds to the configuration index of PRACH (for example, see Table 1). Therefore, in the embodiments of this application, different preamble formats correspond to different configuration indices of PRACH.

Typically, when network devices detect preambles, they detect only one preamble format on the same PRACH resource (e.g., PRACH timing). This helps ensure orthogonality between different preambles using the same preamble format, thereby improving preamble detection performance. Therefore, to ensure preamble detection performance, in this embodiment, the PRACH resources corresponding to different preamble formats can be configured to not overlap.

In some implementations, the time-domain resources and/or frequency-domain resources of PRACH corresponding to different preamble formats in multiple preamble formats do not overlap.

In some implementations, the non-overlapping temporal resources of PRACH corresponding to different preamble formats in multiple preamble formats include: different parameters of one or more of the following for different preamble formats: PRACH period, radio frame offset corresponding to PRACH, subframe number within the radio frame corresponding to PRACH, start symbol within the subframe corresponding to PRACH, number of time slots occupied by PRACH within a subframe, number of PRACH opportunities within a time slot, and duration of PRACH opportunity.

As mentioned above, different preamble formats can correspond to different PRACH configuration indices. Accordingly, different PRACH configuration indices indicate one or more of the following parameters: PRACH period, radio frame offset corresponding to PRACH, subframe number within the radio frame corresponding to PRACH, start symbol within the subframe corresponding to PRACH, number of time slots occupied by PRACH within a subframe, number of PRACH opportunities within a time slot, and duration of PRACH opportunity.

For ease of understanding, the following section, in conjunction with Table 5, describes the leading format corresponding to the different PRACH configuration indexes in the embodiments of this application.

Table 5

Referring to Table 5, the configuration indices for PRACH include 0 and 87. Configuration parameters corresponding to PRACH configuration index 0 indicate: the preamble format is preamble format 0; the parameter x used to determine the radio frame corresponding to the PRACH is 16; the parameter y used to determine the radio frame corresponding to the PRACH is 1; the subframe number within the radio frame corresponding to the PRACH is 1; the start symbol within the subframe corresponding to the PRACH is 0; the number of time slots occupied by the PRACH within the subframe is the default; and the number of PRACH events within the PRACH time slot. The default value is the duration of the PRACH event. The configuration parameters corresponding to PRACH configuration index 87 are 0. The preamble format is preamble format A1; the parameter x used to determine the radio frame corresponding to PRACH is 16; the parameter y used to determine the radio frame corresponding to PRACH is 0; the subframe numbers within the radio frame corresponding to PRACH are 4 and 9; the start symbol within the subframe corresponding to PRACH is 0; the number of time slots occupied by PRACH within the subframe is 1; and the number of PRACH opportunities within the PRACH time slot is... The value is 6, which represents the duration of the PRACH timing. The value is 2.

Therefore, the two preamble formats shown in Table 5, preamble format 0 and preamble format A1 (i.e., the length column and the short sequence), correspond to PRACH configuration indices 0 and 87, respectively. Judging from their PRACH resource configurations, their PRACH resources are located on different radio frames, thus avoiding overlap.

In some implementations, the non-overlapping frequency domain resources of PRACH corresponding to different preamble formats in multiple preamble formats include: the starting frequency domain position of the PRACH timings corresponding to different preamble formats and/or the number of PRACH timings in the frequency domain being different. The starting frequency domain position of the PRACH timing can be represented, for example, by the parameter "msg1-FrequencyStart", which determines the offset of the starting position of the RB of PRACH timing 0 relative to the frequency domain starting position of the uplink common BWP (i.e., BWP 0). The number of PRACH timings in the frequency domain can be represented, for example, by the parameter "msg1-FDM". Typically, this parameter takes values of {1, 2, 4, 8}.

In some scenarios, the above parameters can be configured via the higher-level signaling "RACH-ConfigGeneric", which can be represented as follows:

RACH-ConfigGeneric::=SEQUENCE{

prach-ConfigurationIndex INTEGER(0..255),

msg1-FDM ENUMERATED{one,two,four,eight},

msg1-FrequencyStart INTEGER(0..maxNrofPhysicalResourceBlocks-1),

...

It should be noted that the above signaling only lists one set of parameters (msg1-FDM and msg1-FrequencyStart) as an example. For scenarios with multiple preamble formats, the signaling may include multiple sets of parameters (msg1-FDM and msg1-FrequencyStart) to correspond to different preamble formats respectively.

For ease of understanding, the frequency domain resources corresponding to various preamble formats in this application embodiment are described below with reference to Figure 7. As shown in Figure 7, the various preamble formats include preamble format 1 and preamble format 2. The frequency domain resources corresponding to preamble format 1 are determined according to the parameters msg1-FrequencyStart1 and msg1-FDM1, and the frequency domain resources corresponding to preamble format 2 are determined according to the parameters msg1-FrequencyStart2 and msg1-FDM2. The number of PRACH timings indicated by msg1-FDM1 and msg1-FDM2 is 4.

It should be noted that, in the embodiments of this application, the non-overlapping of PRACH resources corresponding to different preamble formats can be achieved solely through the non-overlapping of time-domain resources of the PRACH resources corresponding to different preamble formats, or through the non-overlapping of frequency-domain resources of the PRACH resources corresponding to different preamble formats. Of course, in the embodiments of this application, the non-overlapping of PRACH resources corresponding to different preamble formats can be achieved by ensuring that both the time-domain and frequency-domain resources of the PRACH resources corresponding to different preamble formats do not overlap.

In some implementations, time-domain and frequency-domain resources for PRACH are configured separately for different preamble formats, ensuring that at least one of the PRACH resources for each preamble format is different in the time and/or frequency domains. To achieve this, the network may configure multiple different PRACH configuration indices and multiple sets of msg1-FrequencyStart and msg1-FDM parameters.

In some scenarios, there is an association between downlink reference signals (e.g., SSB) and PRACH resources. Thus, the terminal device can determine which PRACH resource associated with the downlink reference signal to use for random access based on the measurement results of the downlink reference signal. When the network configures multiple preamble formats and corresponding PRACH resources for the first cell, the PRACH resources corresponding to each preamble format can be associated (or mapped) with the downlink reference signal respectively.

In this application, the mapping relationship between PRACH resources corresponding to various preamble formats and downlink reference signals is not limited. In some implementations, the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to various preamble formats is different. In other implementations, the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to various preamble formats is the same.

In some implementations, the downlink reference signal includes an SSB, and the corresponding mapping relationship is determined based on one or more of the following parameters: the number of SSBs associated with a PRACH timing; and the number of contention-based preambles corresponding to each SSB at each valid PRACH timing. The number of SSBs associated with a PRACH timing can be determined, for example, by the parameter "ssb-perRACH-OccasionAndCB-PreamblesPerSSB", and the number of contention-based preambles corresponding to each SSB at each valid PRACH timing can be determined based on the parameter "CB-preamblesPerSSB".

Accordingly, if different PRACH resources among multiple PRACH resources have different mapping relationships with downlink reference signals, the network device can configure a set of parameters (parameter "ssb-perRACH-OccasionAndCB-PreamblesPerSSB" and/or parameter "CB-preamblesPerSSB") for each of the different PRACH resources. If different PRACH resources among multiple PRACH resources have the same mapping relationship with downlink reference signals, the network can configure a set of the same parameters (parameter "ssb-perRACH-OccasionAndCB-PreamblesPerSSB" and/or parameter "CB-preamblesPerSSB") for the multiple PRACH resources.

In this embodiment, the mapping rules between the downlink reference signal, PRACH SSB, and PRACH timing are not limited. In some implementations, the mapping rules may follow the following order: First, the order of the preamble index within a PRACH timing is ascending; second, the order of the frequency domain resource indexes of frequency-domain multiplexed PRACH timings is ascending; third, the order of the time domain resource indexes of time-domain multiplexed PRACH timings within a PRACH slot is ascending; fourth, the order of the PRACH slot indexes is ascending.

In some implementations, network devices can configure PRACH resources and associated parameters for various preamble formats for the first cell via system messages (such as system information blocks (SIBs)1). In other implementations, network devices can configure PRACH resources and associated parameters for various preamble formats for the first cell via common RRC signaling. The associated parameters may include, for example, the parameters "ssb-perRACH-OccasionAndCB-PreamblesPerSSB" and/or "CB-preamblesPerSSB".

During random access, after a terminal device sends a PRACH, it can receive the RAR sent by the network device within the random access response (RAR) receive window. If the terminal device does not receive the RAR, it will resend the PRACH on the next available PRACH resource, increasing the PRACH power by one step. However, under limited coverage, the terminal device cannot indefinitely increase the probability of the network device detecting the PRACH by increasing its power. Therefore, to improve PRACH coverage performance, some standards (e.g., R18) have introduced PRACH retransmission. As shown in Figure 8, PRACH retransmission corresponds to the same Msg2 RAR window (also known as the "RAR receive window"). The network device can merge and receive retransmitted PRACH within the RAR receive window to improve detection performance, thereby improving PRACH coverage.

Therefore, in order to continue using the PRACH retransmission mechanism in this embodiment, different preamble formats among various preamble formats can correspond to a first measurement threshold, wherein the first measurement threshold is used to determine whether the terminal device performs PRACH retransmission. For example, if the measurement result of the terminal device meets the first measurement threshold, the terminal device performs PRACH retransmission, and/or if the measurement result of the terminal device does not meet the first measurement threshold, the terminal device does not perform PRACH retransmission.

In some scenarios, the first measurement threshold can be called the "PRACH retransmission measurement threshold", denoted as "ThresholdMsg1".

In this embodiment, the number of first measurement thresholds associated with a preamble format is not limited. In some implementations, a preamble format can correspond to multiple first measurement thresholds, each corresponding to a different number of repetitions. For example, the first measurement thresholds corresponding to preamble format 1 include: ThresholdMsg1-RepetitionNum2, ThresholdMsg1-RepetitionNum4, and ThresholdMsg1-RepetitionNum8, which correspond to 2, 4, and 8 repetitions of PRACH retransmission, respectively. That is, if the measurement result of the terminal device satisfies ThresholdMsg1-RepetitionNum2, the terminal device performs PRACH retransmission, and the repetition count is 2. If the measurement result of the terminal device satisfies ThresholdMsg1-RepetitionNum4, the terminal device performs PRACH retransmission, and the repetition count is 4. If the measurement result of the terminal device satisfies ThresholdMsg1-RepetitionNum8, the terminal device performs PRACH retransmission, and the repetition count is 8.

As mentioned above, the configuration index of PRACH differs for different preamble formats. Accordingly, various preambles... Different preamble formats in the format can correspond to the first measurement threshold. This can be understood as the configuration index of PRACH corresponding to multiple preamble formats corresponding to the first measurement threshold.

In some implementations, the first measurement threshold corresponding to different preamble formats among multiple preamble formats is configured by the network device. For example, the network device can configure the first measurement threshold corresponding to multiple preamble formats for the first cell through system messages (such as SIB1). In other implementations, the network device can configure the first measurement threshold corresponding to multiple preamble formats for the first cell through common RRC signaling.

The foregoing section introduced various preamble formats in the embodiments of this application. The following section describes the communication process based on these various preamble formats in the embodiments of this application. The following sections will describe the preamble transmission process and the configuration process of various preamble formats, in conjunction with scenarios 1 and 2.

In scenario 1, the wireless communication method of this application embodiment includes: a terminal device sending a preamble to a network device based on a first preamble format, wherein the first preamble format is one of a variety of preamble formats corresponding to a first cell.

In scenario 2, the wireless communication method of this application embodiment includes: a network device sending first information to a terminal device, the first information being used to configure multiple preamble formats for a first cell, see step S910 in FIG9.

In some implementations, different preamble formats can correspond to different PRACH configuration indices. Accordingly, the first information can be replaced with multiple PRACH configuration indices for configuring the first cell, where different PRACH configuration indices correspond to different preamble formats.

In some implementations, the first information is carried in system information (such as SIB1) or RRC signaling.

It should be noted that Scenario 1 and Scenario 2 can be used independently or in combination. When Scenario 1 is used alone, this embodiment does not limit the configuration process for multiple preamble formats. When Scenario 2 is used alone, this embodiment does not limit the transmission process for preambles based on multiple preamble formats. When Scenario 1 and Scenario 2 are used in combination, the terminal device can be configured with multiple preamble formats for the first cell according to the scheme in Scenario 2. Correspondingly, the terminal device can transmit the preamble based on the first preamble format according to the method in Scenario 1.

The preceding text described the communication process based on multiple preamble formats in the embodiments of this application. The following text describes the scheme for selecting a first preamble format from multiple preamble formats in the embodiments of this application. The first preamble format can be the preamble format used by the terminal device for subsequent preamble transmission. Of course, in the embodiments of this application, there is no limitation on whether the terminal device transmits the preamble based on the first preamble format.

In this embodiment of the application, the scheme of selecting the first preamble format can be executed by the terminal device or by the network device, which will be described below in conjunction with implementation method 1 and implementation method 2 respectively.

In implementation method 1, the scheme of selecting the first preamble format can be executed by the terminal device.

In other words, the above method also includes: the terminal device determining a first preamble format from multiple preamble formats.

In some implementations, the first preamble format is used in a contention-based RACH process. Typically, a contention-based RACH process occurs when the terminal device is in an idle or connectionless state, where there is no available connection between the terminal device and the network device. In this situation, the network device may not be able to obtain the terminal device's communication status (e.g., the network device cannot obtain the downlink signal measurement results of the terminal device and select a preamble format based on these measurements). Therefore, the network device may not be able to help the terminal device select a suitable preamble format. In this case, allowing the terminal device to autonomously select the preamble format helps improve the rationality of the preamble format selection.

In implementation method 2, the scheme of selecting the first preamble format can be executed by the network device.

In other words, the above method also includes: a second message sent by the network device to the terminal device, the second message being used to indicate the first preamble format from a variety of preamble formats.

In some implementations, multiple preamble formats correspond to multiple PRACH configuration indices. Accordingly, the second information is used to indicate a first PRACH configuration index from among the multiple PRACH configuration indices, wherein the first PRACH configuration index corresponds to a first preamble format.

In some implementations, the second information can be carried in downlink control information (DCI). In other implementations, the second information can also be carried in higher-layer signaling, such as RRC signaling.

In some implementations, the second information is dynamic indication information or semi-static configuration information. That is, the network device can dynamically indicate the preamble format to the terminal device from multiple preamble formats, which helps improve the rationality of the network device's preamble format configuration for the terminal device. Alternatively, the network device can semi-statically configure the preamble format for the terminal device from multiple preamble formats, which helps reduce the signaling overhead required for the network device to configure the preamble format for the terminal device.

In known technologies, a contention-free RACH procedure can be initiated by a network device. The network device triggers a contention-free random access procedure via a PDCCH order. The network device uses DCI format 1_0 to indicate to the terminal device the RA-preamble index, SSB index, PRACH mask index, and UL/SUL indication (indicating UL or SUL) to be used. Accordingly, the terminal device initiates a random access procedure on the uplink carrier (determined based on the UL/SUL indication) at the PRACH timing (based on the PRACH mask index indication) on the PRACH resources associated with the indicated preamble index and SSB index.

In some scenarios, the random access process can be illustrated in Figure 10. In step S1010, the network device sends an RA preamble assignment to the terminal device. In step S1020, the terminal device sends a random access preamble to the network device. In step S1030, the network device sends a random access response to the terminal device.

Therefore, in this embodiment, the scheme of the network device indicating the first preamble format to the terminal device can be applied to a contention-free RACH process. That is, the aforementioned first preamble format is used in a contention-free RACH process. Typically, a contention-free RACH process occurs when the terminal device is in a connected state. At this time, there is an available connection between the terminal device and the network device. The network device can obtain the communication status of the terminal device (for example, the network device can obtain the measurement results of the downlink signal of the terminal device, which are used to select the preamble format). Therefore, the network device can help the terminal device select a suitable preamble format, which helps to reduce the complexity of the terminal device in selecting the preamble format.

For example, the first cell corresponds to two preamble formats: preamble format 1 and preamble format 2. In this case, the network device can send DCI to the terminal device. If the value of DCI is the first value, it instructs the terminal device to use preamble format 1; if the value of DCI is the second value, it instructs the terminal device to use preamble format 2.

For example, the first cell has two preamble formats: preamble format 1 and preamble format 2. These two preamble formats correspond to PRACH configuration index 1 and PRACH configuration index 2, respectively. In this case, the network device can send DCI to the terminal device. If the value of DCI is the first value, it instructs the terminal device to use the preamble format corresponding to PRACH configuration index 1; if the value of DCI is the second value, it instructs the terminal device to use the preamble format 2 corresponding to PRACH configuration index 2.

The foregoing section described the preamble format selection scheme in this application embodiment in conjunction with implementation methods 1 and 2. The following section describes a scheme for selecting the preamble format based on the measurement results of the downlink signal. It should be understood that this scheme applies to both implementation methods 1 and 2. When this scheme is combined with implementation method 2, the terminal device can send the downlink signal measurement results to the network device. Specifically, the terminal device can send the measurement results of all downlink signals to the network device, or the terminal device can send the measurement results of the downlink signals that meet the requirements (e.g., the first measurement result described below) to the network device.

In the embodiments of this application, the measurement results (including the first measurement result) are not limited. In some implementations, the measurement results may include one or more of the following: reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), signal-to-noise ratio, and path loss.

In some implementations, the first preamble format is selected from multiple preamble formats based on a first measurement result of the downlink signal. For example, the terminal device or network device can determine the area range of the terminal device in the first cell based on the first measurement result, and then select the first preamble format from multiple preamble formats based on the area range and the preamble format corresponding to the area range.

In this application embodiment, the downlink signal is not limited. In some implementations, the downlink signal may include a downlink synchronization signal and/or a downlink reference signal. Taking the downlink signal as the downlink reference signal as an example, the downlink reference signal may include one or more of the following: SSB, channel status information reference signal (CSI-RS), demodulation reference signal (DMRS).

In some scenarios (e.g., high-frequency scenarios), downlink signals can be transmitted using beam scanning. Measuring the downlink signal by the terminal device can be understood as measuring the downlink signal corresponding to each beam. Generally, the measurement result of the downlink signal corresponding to the beam with the best measurement result can be used to determine which preamble format to use. That is, the beam corresponding to the first measurement result belongs to the first beam among multiple beams, and the first measurement result is higher than or equal to the measurement results corresponding to other beams among multiple beams, which are beams other than the first beam.

For example, as shown in Figure 11, assume that the first cell is covered by 8 beams, where terminal device 1 is located within the coverage area of beam 1, terminal device 4 is located within the coverage area of beam 4, terminal device 2 is located within the coverage area of beam 5, and terminal device 3 is located within the coverage area of beam 7.

For terminal device 1, the measurement result of the downlink signal corresponding to beam 1 is the best. Therefore, terminal device 1 can use the measurement result of this downlink signal (i.e., the first measurement result) as the measurement result to determine which preamble format to use. For terminal device 4, the measurement result of the downlink signal corresponding to beam 4 is the best. Therefore, terminal device 4 can use the measurement result of this downlink signal (i.e., the first measurement result) as the measurement result to determine which preamble format to use. For terminal device 2, the measurement result of the downlink signal corresponding to beam 5 is the best. Therefore, terminal device 2 can use the measurement result of this downlink signal (i.e., the first measurement result) as the measurement result to determine which preamble format to use. For terminal device 3, the measurement result of the downlink signal corresponding to beam 7 is the best. Therefore, terminal device 3 can use the measurement result of this downlink signal (i.e., the first measurement result) as the measurement result to determine which preamble format to use.

In some implementations, each of the multiple preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format. Alternatively, multiple preamble formats correspond to multiple PRACH configuration indices, each PRACH configuration index corresponds to a measurement result interval, the first measurement result belongs to the measurement result interval corresponding to the first PRACH configuration index, and the first PRACH configuration index corresponds to the first preamble format. Of course, in the embodiments of this application, each preamble format may correspond to one or more discrete measurement results.

In some implementations, the measurement result intervals corresponding to each of the multiple preamble formats may not overlap. However, in the embodiments of this application, at least two measurement result intervals corresponding to each preamble format may partially or completely overlap.

In some implementations, if at least two measurement result intervals can partially or completely overlap, then the selection of the leading format is appropriate. The method is not limited. For example, a preamble format can be randomly selected from multiple preamble formats corresponding to the measurement result interval as the first preamble format. Alternatively, the preamble format that occupies the least amount of transmission resources can be selected from multiple preamble formats corresponding to the measurement result interval as the first preamble format.

In some implementations, the measurement result intervals corresponding to different preamble formats among multiple preamble formats are configured based on the first information. That is, when configuring multiple preamble formats, the network device configures the measurement result intervals corresponding to each preamble format for the terminal device. For example, if the first information is a system message (such as SIB1), the network device can configure multiple preamble formats and their corresponding measurement result intervals for the first cell using the system message. Similarly, if the first information is a system message (such as SIB1), the network device can configure multiple PRACH configuration indices and their corresponding measurement result intervals for the first cell using the system message. Furthermore, if the first information is a common RRC signaling, the network device can configure multiple preamble formats and their corresponding measurement result intervals for the first cell using the RRC signaling. Finally, if the first information is a common RRC signaling, the network device can configure multiple PRACH configuration indices and their corresponding measurement result intervals for the first cell using the RRC signaling.

Of course, in this embodiment, the measurement result intervals corresponding to the various preamble formats can be predefined. In this case, the network device can configure the various preamble formats using the first information without configuring the measurement result intervals corresponding to the various preamble formats. Accordingly, the measurement result intervals corresponding to the various preamble formats can be determined based on the predefined information.

In this application embodiment, the implementation method of the measurement result intervals corresponding to the various preamble formats is not limited. For example, different preamble formats among the various preamble formats can each correspond to two measurement threshold values, which can be used as the upper and lower limits of the measurement result interval, as detailed in Example 1 below. As another example, various preamble formats correspond to various measurement result intervals, and correspondingly, two adjacent measurement result intervals among the various measurement result intervals can share a single measurement threshold, as detailed in Example 2 below. The following description, in conjunction with Examples 1 and 2, uses the example of a terminal device autonomously selecting a first preamble format.

Example 1: Assume a network device is configured with two preamble formats for a cell: preamble format 1 and preamble format 2. Preamble format 1 corresponds to measurement result interval 1, which includes an upper limit value of 1 and a lower limit value of 2. Preamble format 2 corresponds to measurement result interval 2, which includes an upper limit value of 3 and a lower limit value of 4. If the terminal device's first measurement result belongs to measurement result interval 1, the terminal device uses preamble format 1. If the terminal device's first measurement result belongs to measurement result interval 2, the terminal device uses preamble format 2.

Example 2: Suppose the network device configures two preamble formats for a cell: preamble format 1 and preamble format 2, where preamble format 1 and preamble format 2 correspond to a first measurement threshold. When the terminal device's first measurement result is less than the first measurement threshold, the terminal device uses preamble format 1. Conversely, when the terminal device's first measurement result is greater than (or equal to) the first measurement threshold, the terminal device uses preamble format 2.

In some scenarios, changes in channel conditions during RACH initiation by a terminal device may lead to changes in measurement results. For example, the measurement results of its downlink signal may change while the terminal device is moving. Therefore, how the terminal device can communicate based on multiple preamble formats is a pressing issue. To address this problem, this application proposes two implementation methods.

In implementation method 1, the first measurement result is used to determine the preamble format used in the first RACH process. That is, regardless of whether the measurement result changes during the first RACH process, the terminal device communicates based on the preamble format determined by the first measurement result. In other words, the terminal device only determines the preamble format based on the measurement result at the time the RACH process is initiated (the first measurement result). During the RACH process, the PRACH preamble format does not change, which helps simplify the complexity of the first RACH process. The measurement result at the time the RACH process is initiated can be understood as the measurement result for message 2 (Msg2) and/or message 4 (Msg4) during the RACH process.

For example, if the first measurement result is the optimal measurement result, the terminal device determines to use preamble format 1 among multiple preamble formats based on the first measurement result, and continues to retransmit PRACH based on preamble format 1 and the PRACH resources corresponding to preamble format 1 in the subsequent RACH process, regardless of whether the measurement result of the terminal device changes.

In implementation method 2, the first measurement result is used to determine the preamble format used for the first PRACH transmission during the first RACH process. Here, the first PRACH refers to a specific PRACH transmission within the first RACH process; that is, the first measurement result is used to determine the preamble format used for a specific PRACH transmission during the first RACH process. Alternatively, if the measurement result of the downlink signal changes during the first RACH process, and the preamble format corresponding to the measurement result interval to which the changed measurement result belongs differs from the preamble format corresponding to the measurement result interval to which the terminal device initiated the RACH process, then the terminal device switches the preamble format based on the measurement result and performs the next PRACH transmission based on the switched preamble format. The measurement result at the time of initiating the RACH process can be understood as the measurement result for message 2 (Msg2) and/or message 4 (Msg4) during the RACH process.

For example, the RACH process includes a first PRACH transmission and a second PRACH transmission. When the first terminal device initiates the RACH process, its measurement result belongs to measurement result interval 1, which corresponds to preamble format 1. At this time, the terminal device sends the first PRACH based on preamble format 1. Subsequently, the terminal device's measurement result changes, and the changed measurement result belongs to measurement result interval 2, which corresponds to preamble format 2, where preamble format 1 and preamble format 2 are different. At this time, the terminal device sends the second PRACH based on preamble format 2.

The method embodiments of this application have been described in detail above with reference to Figures 1 to 11. The apparatus embodiments of this application will be described in detail below with reference to Figures 12 to 14. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the apparatus embodiments; therefore, any parts not described in detail can be referred to the preceding method embodiments.

Figure 12 is a schematic diagram of a terminal device according to an embodiment of this application. The terminal device 1200 shown in Figure 12 includes a receiving unit 1210.

The receiving unit 1210 is used to receive first information sent by the network device, the first information being used to configure multiple preamble formats for the first cell.

In some implementations, the multiple preamble formats satisfy one or more of the following: the length of the preamble sequence corresponding to different preamble formats is different; the subcarrier spacing corresponding to different preamble formats is different; the guard interval GT length corresponding to different preamble formats is different; the cyclic prefix CP length corresponding to different preamble formats is different; and the number of repetitions of the preamble sequence corresponding to different preamble formats is different.

In some implementations, the configuration index of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats is different.

In some implementations, the multiple preamble formats correspond to different regional ranges within the first cell, wherein the distance between the different regional ranges within the first cell and the network device is different.

In some implementations, the first information is carried in system information or Radio Resource Control (RRC) signaling.

In some implementations, the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap.

In some implementations, the time-domain and/or frequency-domain resources of the PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap.

In some implementations, the non-overlapping temporal resources of PRACH corresponding to different preamble formats among the multiple preamble formats include: different one or more of the following parameters for different preamble formats among the multiple preamble formats: PRACH period, radio frame offset corresponding to PRACH, subframe number within the radio frame corresponding to PRACH, start symbol within the subframe corresponding to PRACH, number of time slots occupied by PRACH within a subframe, number of PRACH opportunities within a time slot, and duration of PRACH opportunity.

In some implementations, the non-overlapping frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats include: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different.

In some implementations, the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is different, or the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is the same.

In some implementations, the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping is determined based on one or more of the following parameters: the number of SSBs associated with a PRACH timing; and the number of contention-based preambles corresponding to each SSB in each valid PRACH timing.

In some implementations, different preamble formats among the multiple preamble formats correspond to a first measurement threshold, which is used to determine whether the terminal device performs PRACH retransmission.

In some implementations, the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device.

In some implementations, the terminal device further includes a processing unit for determining a first preamble format from the plurality of preamble formats.

In some implementations, the first preamble format is used for a competition-based RACH process.

In some implementations, the receiving unit is configured to receive second information sent by the network device, the second information being used to indicate a first preamble format from among the multiple preamble formats.

In some implementations, the second information is dynamic indication information or semi-static configuration information.

In some implementations, the first preamble format is used for a non-contested RACH procedure.

In some implementations, the first preamble format is selected from the plurality of preamble formats based on a first measurement result of the downlink signal.

In some implementations, the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, and the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, wherein the other beams are beams other than the first beam among the plurality of beams.

In some implementations, each of the multiple preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format.

In some implementations, the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information.

In some implementations, the first measurement result is used to determine the preamble format used in the first RACH process; or the first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process.

Figure 13 is a schematic diagram of a network device according to an embodiment of this application. The network device 1300 shown in Figure 13 includes: a transmitting unit 1310.

The sending unit 1310 is used to send first information to the terminal device, the first information being used to configure multiple preamble formats for the first cell.

In some implementations, the multiple preamble formats satisfy one or more of the following: the length of the preamble sequence corresponding to different preamble formats is different; the subcarrier spacing corresponding to different preamble formats is different; the guard interval GT length corresponding to different preamble formats is different; the cyclic prefix CP length corresponding to different preamble formats is different; and the number of repetitions of the preamble sequence corresponding to different preamble formats is different.

In some implementations, the configuration index of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats is different.

In some implementations, the multiple preamble formats correspond to different regional ranges within the first cell, wherein the distance between the different regional ranges within the first cell and the network device is different.

In some implementations, the first information is carried in system information or Radio Resource Control (RRC) signaling.

In some implementations, the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap.

In some implementations, the time-domain resources and/or frequency-domain resources of PRACH corresponding to different preamble formats in the multiple preamble formats do not overlap.

In some implementations, the non-overlapping temporal resources of PRACH corresponding to different preamble formats among the multiple preamble formats include: different one or more of the following parameters for different preamble formats among the multiple preamble formats: PRACH period, radio frame offset corresponding to PRACH, subframe number within the radio frame corresponding to PRACH, start symbol within the subframe corresponding to PRACH, number of time slots occupied by PRACH within a subframe, number of PRACH opportunities within a time slot, and duration of PRACH opportunity.

In some implementations, the non-overlapping frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats include: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different.

In some implementations, the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is different, or the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is the same.

In some implementations, the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping is determined based on one or more of the following parameters: the number of SSBs associated with a PRACH timing; and the number of contention-based preambles corresponding to each SSB in each valid PRACH timing.

In some implementations, different preamble formats among the multiple preamble formats correspond to a first measurement threshold, which is used to determine whether the terminal device performs PRACH retransmission.

In some implementations, the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device.

In some implementations, the sending unit is further configured to send second information to the terminal device, the second information being used to indicate a first preamble format from among the multiple preamble formats.

In some implementations, the second information is dynamic indication information or semi-static configuration information.

In some implementations, the first preamble format is used for a non-contested RACH procedure.

In some implementations, the first preamble format is selected from the plurality of preamble formats based on a first measurement result of the downlink signal.

In some implementations, the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, and the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, wherein the other beams are beams other than the first beam among the plurality of beams.

In some implementations, each of the multiple preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format.

In some implementations, the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information.

In some implementations, the first measurement result is used to determine the preamble format used in the first RACH process; or the first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process.

In an optional embodiment, the receiving unit 1210 may be a transceiver 1430. The terminal device 1200 may also include a processor 1410 and a memory 1420, as shown in FIG14.

In an optional embodiment, the transmitting unit 1310 may be a transceiver 1430. The network device 1300 may also include a processor 1410 and a memory 1420, as shown in FIG14.

Figure 14 is a schematic structural diagram of a communication device according to an embodiment of this application. The dashed lines in Figure 14 indicate that the unit or module is optional. This device 1400 can be used to implement the methods described in the above method embodiments. Device 1400 can be a chip, a terminal device, or a network device.

Apparatus 1400 may include one or more processors 1410. The processors 1410 may support apparatus 1400 in implementing the methods described in the preceding method embodiments. The processor 1410 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be other general-purpose processors, digital signal processors (DSPs), etc. Signal processors, DSPs, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors can be microprocessors or any conventional processor.

The apparatus 1400 may further include one or more memories 1420. The memories 1420 store a program that can be executed by the processor 1410, causing the processor 1410 to perform the methods described in the preceding method embodiments. The memories 1420 may be independent of the processor 1410 or integrated within the processor 1410.

The device 1400 may also include a transceiver 1430. The processor 1410 can communicate with other devices or chips via the transceiver 1430. For example, the processor 1410 can send and receive data with other devices or chips via the transceiver 1430.

This application also provides a computer-readable storage medium for storing a program. This computer-readable storage medium can be applied to a terminal or network device provided in this application, and the program causes a computer to execute the methods performed by the terminal or network device in various embodiments of this application.

This application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in this application embodiment, and the program causes a computer to execute the methods performed by the terminal or network device in various embodiments of this application.

This application also provides a computer program. This computer program can be applied to the terminal or network device provided in this application, and the computer program causes the computer to execute the methods performed by the terminal or network device in various embodiments of this application.

It should be understood that the terms "system" and "network" in this application can be used interchangeably. Furthermore, the terminology used in this application is only for explaining specific embodiments of the application and is not intended to limit the application. The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

In the embodiments of this application, the term "instruction" can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

In the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and/or other information.

In the embodiments of this application, the term "correspondence" can indicate a direct or indirect correspondence between two things, or an association between two things, or a relationship such as instruction and being instructed, configuration and being configured.

In this application embodiment, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

In this application embodiment, the "protocol" may refer to a standard protocol in the field of communication, such as the LTE protocol, the NR protocol, and related protocols applied to future communication systems. This application does not limit this.

In the embodiments of this application, the term "and/or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and/or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character "/" in this document generally indicates that the preceding and following related objects have an "or" relationship.

In the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any usable medium that a computer can read, or a data storage device such as a server or data center that integrates one or more usable media. The usable medium can be magnetic media (e.g., floppy disk, hard disk, magnetic tape), optical media (e.g., digital video disc (DVD)), or semiconductor media (e.g., solid-state disk (SSD)).

The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims (95)

A method for wireless communication, characterized in that it includes: The terminal device receives first information sent by the network device, the first information being used to configure multiple preamble formats for the first cell. The method as described in claim 1, wherein the plurality of preamble formats satisfies one or more of the following: The different preamble formats have different preamble sequence lengths. The different preamble formats correspond to different subcarrier spacings; The different guard interval GT lengths correspond to different guard formats among the various guard formats; The different preamble formats have different cyclic prefix (CP) lengths; The different number of repetitions of the leader sequence correspond to different leader formats among the various leader formats. The method as described in claim 1 or 2 is characterized in that the configuration indexes of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats are different. The method according to any one of claims 1-3 is characterized in that the multiple preamble formats correspond to different regional ranges within the first cell, wherein the different regional ranges within the first cell are at different distances from the network device. The method according to any one of claims 1-4, wherein the first information is carried in system information or Radio Resource Control (RRC) signaling. The method as described in any one of claims 1-5 is characterized in that the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap. The method as described in claim 6 is characterized in that the time-domain resources and/or frequency-domain resources of the PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap. The method as described in claim 6 or 7, characterized in that the non-overlapping temporal resources of PRACH corresponding to different preamble formats among the plurality of preamble formats include: one or more of the following parameters being different for different preamble formats among the plurality of preamble formats: The PRACH period, the radio frame offset corresponding to the PRACH, the subframe number within the radio frame corresponding to the PRACH, the start symbol within the subframe corresponding to the PRACH, the number of time slots occupied by the PRACH within a subframe, the number of PRACH opportunities within a time slot, and the duration of the PRACH opportunity. The method as described in any one of claims 6-8 is characterized in that the frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap, including: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different. The method as described in any one of claims 6-9, characterized in that the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is different, or The mapping relationship between different PRACH resources and downlink reference signals is the same among the multiple PRACH resources corresponding to the various preamble formats. The method of claim 10, wherein the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping relationship is determined based on one or more of the following parameters: The number of SSBs associated with a PRACH event; The number of contention-based preambles corresponding to each SSB at each valid PRACH time. The method according to any one of claims 1-11 is characterized in that different preamble formats in the plurality of preamble formats correspond to a first measurement threshold, and the first measurement threshold is used to determine whether the terminal device performs PRACH repeated transmission. The method as described in claim 12, wherein the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device. The method according to any one of claims 1-13, characterized in that the method further comprises: The terminal device determines a first preamble format from the multiple preamble formats. The method as described in claim 14, wherein the first preamble format is used for a competition-based RACH process. The method according to any one of claims 1-13, characterized in that the method further comprises: The terminal device receives second information sent by the network device, the second information being used to indicate a first preamble format from among the multiple preamble formats. The method as described in claim 16, wherein the second information is dynamic indication information or semi-static configuration information. The method as described in claim 16 or 17, wherein the first preamble format is used for a non-contested RACH process. The method according to any one of claims 14-18, wherein the first preamble format is selected from the plurality of preamble formats based on a first measurement result of the downlink signal. The method as described in claim 19, wherein the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, and the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, wherein the other beams are the plurality of beams. The beams in the beam other than the first beam. The method as described in claim 19 or 20 is characterized in that each of the plurality of preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format. The method as described in claim 21 is characterized in that the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information. The method as described in any one of claims 19-22, characterized in that the first measurement result is used to determine the preamble format used in the first RACH process; or The first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process. A method for wireless communication, characterized in that it includes: The network device sends first information to the terminal device, the first information being used to configure multiple preamble formats for the first cell. The method as described in claim 24, wherein the plurality of preamble formats satisfies one or more of the following: The different preamble formats have different preamble sequence lengths. The different preamble formats correspond to different subcarrier spacings; The different guard interval GT lengths correspond to different guard formats among the various guard formats; The different preamble formats have different cyclic prefix (CP) lengths; The different number of repetitions of the leader sequence correspond to different leader formats among the various leader formats. The method as described in claim 24 or 25 is characterized in that the configuration indexes of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats are different. The method according to any one of claims 24-26 is characterized in that the multiple preamble formats correspond to different regional ranges within the first cell, wherein the different regional ranges within the first cell are at different distances from the network device. The method according to any one of claims 24-27, wherein the first information is carried in system information or Radio Resource Control (RRC) signaling. The method as described in any one of claims 24-28 is characterized in that the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap. The method as described in claim 29 is characterized in that the time-domain resources and/or frequency-domain resources of the PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap. The method as described in claim 29 or 30, characterized in that the non-overlapping temporal resources of PRACH corresponding to different preamble formats among the plurality of preamble formats include: one or more of the following parameters being different for different preamble formats among the plurality of preamble formats: The PRACH period, the radio frame offset corresponding to the PRACH, the subframe number within the radio frame corresponding to the PRACH, the start symbol within the subframe corresponding to the PRACH, the number of time slots occupied by the PRACH within a subframe, the number of PRACH opportunities within a time slot, and the duration of the PRACH opportunity. The method as described in any one of claims 29-31 is characterized in that the frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap, including: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different. The method as described in any one of claims 29-32 is characterized in that the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is different, or The mapping relationship between different PRACH resources and downlink reference signals is the same among the multiple PRACH resources corresponding to the various preamble formats. The method of claim 33, wherein the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping relationship is determined based on one or more of the following parameters: The number of SSBs associated with a PRACH event; The number of contention-based preambles corresponding to each SSB at each valid PRACH time. The method according to any one of claims 24-34 is characterized in that different preamble formats in the plurality of preamble formats correspond to a first measurement threshold, and the first measurement threshold is used to determine whether the terminal device performs PRACH repeated transmission. The method as described in claim 35, wherein the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device. The method according to any one of claims 24-36, characterized in that the method further comprises: The network device sends second information to the terminal device, the second information being used to indicate a first preamble format from among the multiple preamble formats. The method as described in claim 37, wherein the second information is dynamic indication information or semi-static configuration information. The method as described in claim 37 or 38, wherein the first preamble format is used for a non-contested RACH process. The method as described in any one of claims 37-39, characterized in that the first preamble format is based on the downlink signal's... A measurement result is selected from the various leading formats. The method as described in claim 40, wherein the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, and the other beams are beams other than the first beam among the plurality of beams. The method as described in claim 40 or 41 is characterized in that each of the plurality of preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format. The method as described in claim 42 is characterized in that the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information. The method as described in any one of claims 40-43, characterized in that the first measurement result is used to determine the preamble format used in the first RACH process; or The first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process. A terminal device, characterized in that it comprises: The receiving unit is used to receive first information sent by the network device, the first information being used to configure multiple preamble formats for the first cell. The terminal device as described in claim 45, wherein the plurality of preamble formats satisfies one or more of the following: The different preamble formats have different preamble sequence lengths. The different preamble formats correspond to different subcarrier spacings; The different guard interval GT lengths correspond to different guard formats among the various guard formats; The different preamble formats have different cyclic prefix (CP) lengths; The different number of repetitions of the leader sequence correspond to different leader formats among the various leader formats. The terminal device as described in claim 45 or 46 is characterized in that the configuration indexes of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats are different. The terminal device as described in any one of claims 45-47 is characterized in that the multiple preamble formats correspond to different regional ranges within the first cell, wherein the distance between the different regional ranges within the first cell and the network device is different. The terminal device as described in any one of claims 45-48 is characterized in that the first information is carried in system information or Radio Resource Control (RRC) signaling. The terminal device as described in any one of claims 45-49 is characterized in that the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap. The terminal device as described in claim 50 is characterized in that the time-domain resources and/or frequency-domain resources of the PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap. The terminal device as described in claim 50 or 51, characterized in that the non-overlapping temporal resources of the PRACH corresponding to different preamble formats among the multiple preamble formats include: one or more of the following parameters being different for the different preamble formats among the multiple preamble formats: The PRACH period, the radio frame offset corresponding to the PRACH, the subframe number within the radio frame corresponding to the PRACH, the start symbol within the subframe corresponding to the PRACH, the number of time slots occupied by the PRACH within a subframe, the number of PRACH opportunities within a time slot, and the duration of the PRACH opportunity. The terminal device as described in any one of claims 50-52 is characterized in that the frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap, including: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different. The terminal device as described in any one of claims 50-53, characterized in that the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the multiple preamble formats is different, or The mapping relationship between different PRACH resources and downlink reference signals is the same among the multiple PRACH resources corresponding to the various preamble formats. The terminal device as described in claim 54, wherein the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping relationship is determined based on one or more of the following parameters: The number of SSBs associated with a PRACH event; The number of contention-based preambles corresponding to each SSB at each valid PRACH time. The terminal device as described in any one of claims 45-55 is characterized in that different preamble formats among the multiple preamble formats correspond to a first measurement threshold, and the first measurement threshold is used to determine whether the terminal device performs PRACH retransmission. The terminal device as described in claim 56 is characterized in that the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device. The terminal device as described in any one of claims 45-57, characterized in that the terminal device further comprises: A processing unit is configured to determine a first preamble format from the plurality of preamble formats. The terminal device as claimed in claim 58, wherein the first preamble format is used for a competition-based RACH process. The terminal device as described in any one of claims 45-57, wherein the receiving unit is configured to: The network device receives second information, which is used to indicate a first preamble format from among the multiple preamble formats. The terminal device as described in claim 60, wherein the second information is dynamic indication information or semi-static configuration information. The terminal device as described in claim 60 or 61, wherein the first preamble format is used for a non-contested RACH process. The terminal device as described in any one of claims 58-62, wherein the first preamble format is selected from the plurality of preamble formats based on a first measurement result of the downlink signal. The terminal device as described in claim 63 is characterized in that the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, and the other beams are beams other than the first beam among the plurality of beams. The terminal device as described in claim 63 or 64 is characterized in that each of the multiple preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format. The terminal device as described in claim 65 is characterized in that the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information. The terminal device as described in any one of claims 63-66, wherein the first measurement result is used to determine the preamble format used in the first RACH process; or The first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process. A network device, characterized in that it comprises: The sending unit is used to send first information to the terminal device, wherein the first information is used to configure multiple preamble formats for the first cell. The network device as described in claim 68, wherein the plurality of preamble formats satisfies one or more of the following: The different preamble formats have different preamble sequence lengths. The different preamble formats correspond to different subcarrier spacings; The different guard interval GT lengths correspond to different guard formats among the various guard formats; The different preamble formats have different cyclic prefix (CP) lengths; The different number of repetitions of the leader sequence correspond to different leader formats among the various leader formats. The network device as described in claim 68 or 69 is characterized in that the configuration indexes of the Physical Random Access Channel (PRACH) corresponding to the various preamble formats are different. The network device as described in any one of claims 68-70 is characterized in that the multiple preamble formats correspond to different regional ranges within the first cell, wherein the distance between the different regional ranges within the first cell and the network device is different. The network device as described in any one of claims 68-71, wherein the first information is carried in system information or Radio Resource Control (RRC) signaling. The network device as described in any one of claims 68-72 is characterized in that the PRACH resources corresponding to different preamble formats among the multiple preamble formats do not overlap. The network device as described in claim 73 is characterized in that the time-domain resources and/or frequency-domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap. The network device as described in claim 73 or 74, characterized in that the non-overlapping temporal resources of the PRACH corresponding to different preamble formats among the multiple preamble formats include: one or more of the following parameters being different for the different preamble formats among the multiple preamble formats: The PRACH period, the radio frame offset corresponding to the PRACH, the subframe number within the radio frame corresponding to the PRACH, the start symbol within the subframe corresponding to the PRACH, the number of time slots occupied by the PRACH within a subframe, the number of PRACH opportunities within a time slot, and the duration of the PRACH opportunity. The network device as described in any one of claims 73-75 is characterized in that the frequency domain resources of PRACH corresponding to different preamble formats among the multiple preamble formats do not overlap, including: the starting frequency domain position and/or the number of PRACH timings in the frequency domain corresponding to different preamble formats among the multiple preamble formats are different. The network device as described in any one of claims 73-76, characterized in that the mapping relationship between different PRACH resources and downlink reference signals among the multiple PRACH resources corresponding to the various preamble formats is different, or The mapping relationship between different PRACH resources and downlink reference signals is the same among the multiple PRACH resources corresponding to the various preamble formats. The network device of claim 77, wherein the downlink reference signal includes a synchronization signal/physical broadcast channel block (SSB), and the mapping relationship is determined based on one or more of the following parameters: The number of SSBs associated with a PRACH event; The number of contention-based preambles corresponding to each SSB at each valid PRACH time. The network device as described in any one of claims 68-78 is characterized in that different preamble formats among the multiple preamble formats correspond to a first measurement threshold, and the first measurement threshold is used to determine whether the terminal device performs PRACH retransmission. The network device as described in claim 79, wherein the first measurement threshold corresponding to different preamble formats among the multiple preamble formats is configured by the network device. The network device as described in any one of claims 68-80, wherein the sending unit is further configured to send second information to the terminal device, the second information being used to indicate a first preamble format from among the plurality of preamble formats. The network device as described in claim 81, wherein the second information is dynamic indication information or semi-static configuration information. The network device as described in claim 81 or 82, wherein the first preamble format is used for a non-contested RACH process. The network device as described in any one of claims 81-83, wherein the first preamble format is selected from the plurality of preamble formats based on a first measurement result of the downlink signal. The network device as described in claim 84, wherein the beam corresponding to the first measurement result belongs to the first beam among a plurality of beams, the first measurement result is higher than the measurement results corresponding to other beams among the plurality of beams, and the other beams are beams other than the first beam among the plurality of beams. The network device as described in claim 84 or 85, wherein each of the multiple preamble formats corresponds to a measurement result interval, and the first measurement result belongs to the measurement result interval corresponding to the first preamble format. The network device as described in claim 86, wherein the measurement result intervals corresponding to different preamble formats among the multiple preamble formats are configured based on the first information. The network device as described in any one of claims 84-87, wherein the first measurement result is used to determine the preamble format used in the first RACH process; or The first measurement result is used to determine the preamble format used in the first PRACH transmission during the first RACH process. A terminal device, characterized in that it includes a transceiver, a memory, and a processor, wherein the memory is used to store a program, the processor is used to call the program in the memory, and control the transceiver to receive or send signals, so that the terminal device performs the method as described in any one of claims 1-23. A network device, characterized in that it includes a transceiver, a memory, and a processor, wherein the memory is used to store a program, the processor is used to invoke the program in the memory, and to control the transceiver to receive or transmit signals, so that the network device performs the method as described in any one of claims 24-44. An apparatus, characterized in that it includes a processor for calling a program from a memory to cause the apparatus to perform the method as described in any one of claims 1-44. A chip, characterized in that it includes a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 1-44. A computer-readable storage medium, characterized in that it stores a program thereon, the program causing a computer to perform the method as described in any one of claims 1-44. A computer program product, characterized in that it includes a program that causes a computer to perform the method as described in any one of claims 1-44. A computer program, characterized in that the computer program causes a computer to perform the method as described in any one of claims 1-44.