CN106059985A - Demodulating device and demodulating method based on vector - Google Patents

Abstract

The invention discloses a demodulating device and a demodulating method based on a vector. The demodulating device based on the vector comprises a configuration unit and a lookup table unit, wherein the configuration unit is used for receiving configuration information of users so as to map digital signals to corresponding vector signals; and the lookup table unit is used for storing the digital signals, the corresponding vector signals and mapping relationships between the digital signals and the corresponding vector signals in a form of a lookup table and is also used for looking up the lookup table according to the input digital signals and outputting the corresponding vector signals. According to the application, by the configuration unit and the lookup table unit, a signal modulation mode is configurable, and the digital signals are mapped into the vector signals, so that phase and amplitude modulation can be simultaneously implemented, and thus, the modulation mode of the demodulating device and the demodulating method which are disclosed by the application can be compatible to any existing modulation modes including rectangular QAM (Quadrature Amplitude Modulation), heart-shaped QAM, PSK (Phase Shift Keying), ASK (Amplitude Shift Keying) and the like.

Description

A vector-based demodulation device and demodulation method

technical field

The invention relates to the field of modulation technology, in particular to a vector-based demodulation device and demodulation method.

Background technique

Demodulation is the process of recovering a message from a modulated signal that carries it. In various information transmission or processing systems, the sending end modulates the carrier wave with the message to be transmitted to generate a signal carrying the message, and the receiving end must recover the transmitted message before it can be used. Demodulation is the inverse process of modulation. The modulation method is different, and the demodulation method is also different. Corresponding to the classification of modulation, demodulation can be divided into sine wave demodulation and pulse wave demodulation. Sine wave demodulation can be further divided into amplitude demodulation, frequency demodulation and phase demodulation. In addition, there are some variants such as single sideband signal demodulation and vestigial sideband signal demodulation. Similarly, pulse wave demodulation can also be divided into pulse amplitude demodulation, pulse phase demodulation, pulse width demodulation and pulse code demodulation. Multiple demodulations are required for multiple modulations. Since the digital baseband signal can only take discrete finite values, the corresponding carrier parameter can only take discrete finite values, and the modulated signal can be regarded as the result of the digital baseband signal controlling the switch to switch the carrier of different parameters. This implementation method is called keying method. Therefore, the above three basic digital modulation methods are usually called ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), and PSK (Phase Shift Keying). On the basis of the basic digital modulation method, QAM (Quadrature Amplitude Modulation) is derived, which is essentially a hybrid modulation of ASK and PSK.

In the prior art, no matter what kind of modulation method is used, the method of mapping from digital signal to modulation symbol is fixed, cannot be programmed, and is not compatible with each other. Correspondingly, the demodulation modes corresponding to the modulation modes cannot be programmed, nor are they compatible with each other. In the existing modulation technology, the relative positions of the constellation points in the constellation diagram are fixed and cannot be programmed, and the constellation points cannot be arbitrarily selected according to actual needs. Correspondingly, in the demodulation technology, the relative positions of the constellation points in the constellation diagram are fixed and cannot be programmed, and the constellation points cannot be arbitrarily selected according to actual needs.

Contents of the invention

Aiming at the defect that various demodulation methods in the prior art are not compatible with each other and cannot be programmed, the present invention provides a vector-based demodulation device and demodulation method.

The technical scheme that the present invention proposes with respect to above-mentioned technical problem is as follows:

On the one hand, a kind of vector-based demodulation device is provided, comprising:

The lookup table unit is used to store the vector signal, the digital signal corresponding to the vector signal and its mapping relationship in the form of a lookup table; and

The comparison unit is used to compare the input vector signal with the vector signal stored in the look-up table unit, and the look-up table unit outputs a corresponding digital signal according to the comparison result of the comparison unit.

Preferably, the vector signal is any vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

Preferably, in the constellation diagram, the vector signals are mutually independent.

Preferably, the look-up table unit is a register.

On the other hand, a vector-based demodulation method is also provided, comprising the following steps:

S1. Store the vector signal, the corresponding digital signal and its mapping relationship in the form of a lookup table; and

S2. Comparing the input vector signal with the vector signal stored in the look-up table unit, and outputting a corresponding digital signal according to the comparison result of the comparison unit.

Preferably, the vector signal is any vector signal in any quadrant of the constellation diagram, and is different in the constellation diagram.

Preferably, in the constellation diagram, the vector signals are mutually independent.

Preferably, said look-up table is stored in a register.

Implementing the embodiment of the present invention has the following beneficial effects: the present application uses the comparison unit and the look-up table unit to make the signal demodulation mode compatible with any existing demodulation mode, including rectangular QAM, cardioid QAM, PSK, and ASK. Moreover, the demodulation method of the present application is based on vector, and can simultaneously have the functions of amplitude modulation and phase modulation.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a typical block diagram of a communication system provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of the demodulation device shown in Fig. 1;

Fig. 3 is a flow chart of the demodulation method provided by the present invention;

4a and 4b are schematic structural diagrams of constellation diagrams provided by an embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Communication Systems

Fig. 1 is a typical block diagram of a communication system provided by an embodiment of the present invention. The communication system 100 includes: a source coding device 102 , a channel coding device 104 , a modulation device 106 , a channel 108 , a demodulation device 110 , a channel decryption device 112 and a source coding device 114 . The source encoder 102 is used to receive the source 151 to be sent. The information source encoding device 102 is configured to encode the information source 151 and generate an information source encoded signal 152 . The channel coding device 104 is configured to perform channel coding on the source coded signal 152 and generate a channel coded signal 153 . The modulation device 106 is used for modulating the coded signal 153 into a signal 154 to be transmitted.

The signal to be transmitted 154 provides a received signal 155 to the receiving end through the channel 108 . The channel 108 includes, but is not limited to, a microwave radio frequency link, satellite channel, fiber optic cable, composite fiber optic cable system, or copper cable. The channel 108 includes a propagation medium that can introduce interference and distortion into the signal to be transmitted 154 such that the received signal 155 differs from the signal 154 to be transmitted. Interference and distortion include, but are not limited to, noise, attenuation, phase shift changes, and the like.

The demodulation device 110 is used for demodulating the received signal 155 into a demodulated signal 156 . The channel decoding device 112 is used for decoding the demodulated signal 156 into a channel decoded signal 157 . The source decoding device 114 is used to further decode the channel decoded signal 157 into a target signal 158 . The target signal 158 is provided to one or more receiver user devices. The one or more receiver user devices include, but are not limited to, personal computers, digital terminal equipment, telephone devices, personal digital assistants, software applications, or any other device that can send or receive data.

demodulator

Fig. 2 is a schematic structural diagram of a demodulation device provided by an embodiment of the present invention. The demodulation device 110 includes: a comparison unit 202 and a lookup table unit 204 . The lookup table unit 204 is used to store the vector signal, the digital signal corresponding to the vector signal and its mapping relationship in the form of a lookup table. Choose to store the vector signal and the mapping relationship in the form of a lookup table, so that the vector signal and the mapping relationship can be changed at will. Because the mappings are stored in tables rather than hard circuits, they can be updated at any time. In the communication system provided by the present invention, before or when the signal source 151 is sent to the target terminal, the digital signal, the vector signal and the mapping relationship stored in the modulating device 106 will be sent to the modulating device 110, so that the modulating device 110 The contents of its lookup table can be automatically updated accordingly. In an embodiment of the present invention, the mapping relationship between the digital signal and the vector signal is one-to-one mapping.

The comparison unit 202 is used to compare the input vector signal 155 with the vector signal 251 stored in the lookup table unit 204 , and the lookup table unit 204 outputs a corresponding digital signal 156 according to the comparison result 252 of the comparison unit 202 .

In an embodiment of the present invention, the lookup table unit 204 can use various data lookup methods to quickly find the vector signal 251 matching the input vector signal 155 to be input into the comparison unit 202 . In this way, the number of comparisons by the comparison unit 202 can be greatly reduced, the working speed can be improved and the power consumption can be reduced. The data search method adopted by the lookup table unit 202 includes: sequential search method, binary search method, binary tree and so on. In an embodiment of the present invention, if there is no completely identical vector signal with the input vector signal 155 in the look-up table unit 204, then select the vector signal with the closest distance to the input quantity signal 155 as the vector signal of the input, and make the distance the closest The digital signal 156 corresponding to the vector signal is used as the output of the lookup table unit 204 .

In one embodiment of the present invention, as shown in Fig. 4a and 4b, the vector signals A1-A8 may be any vector signals in any quadrant of the constellation diagram, and are different in the constellation diagram. As shown in Fig. 4a, the vector signals A1-A8 can be selected from the same quadrant of the constellation diagram. As shown in FIG. 4b, the vector signals A1-A8 can also be selected from different quadrants of the constellation diagram. However, whether they come from the same quadrant or from different quadrants, the vector signals A1-A8 are different in the constellation diagram, so that the mapping relationship between the digital signal and the vector signal can be guaranteed to be one-to-one mapping.

In another embodiment provided by the present invention, as shown in Figs. 4a and 4b, the vector signals A1-A8 may be independent of each other, and there is no dependency between the vector signals. Users can select each vector signal in a targeted manner. It should be understood that the user can individually configure each vector signal according to actual needs so that there is a specific correlation between them. In this way, when compatibility with existing modulation methods is required, the vector signal can be configured to meet the existing modulation methods.

In an embodiment provided by the present invention, the lookup table unit 204 is a register. The input digital signal 153 may be an address signal of a register, and the vector signal 154 corresponding to the digital signal 154 may be stored in the register. When a specific address signal 153 is input, the register 204 automatically outputs the vector signal 154 stored in the address. The corresponding relationship between address signals and vector signals can be configured through the configuration unit 202 .

In this application, the demodulation mode of the signal is compatible with any existing demodulation mode through the comparison unit and the look-up table unit, including rectangular QAM, cardioid QAM, PSK, and ASK. Moreover, the demodulation method of the present application is based on vector, and can simultaneously have the functions of amplitude modulation and phase modulation.

demodulation method

This embodiment provides a vector-based demodulation method, as shown in Figure 3, the vector-based demodulation method can be applied to the demodulation device as described above, the method may include the following steps:

S1. Store the vector signal, the corresponding digital signal and its mapping relationship in the form of a lookup table; and

S2. Comparing the input vector signal with the vector signal stored in the look-up table unit, and outputting a corresponding digital signal according to the comparison result of the comparison unit.

In one embodiment of the present invention, as shown in Fig. 4a and 4b, the vector signals A1-A8 may be any vector signals in any quadrant of the constellation diagram, and are different in the constellation diagram. As shown in Fig. 4a, the vector signals A1-A8 can be selected from the same quadrant of the constellation diagram. As shown in FIG. 4b, the vector signals A1-A8 can also be selected from different quadrants of the constellation diagram. However, whether they come from the same quadrant or from different quadrants, the vector signals A1-A8 are different in the constellation diagram, so that the mapping relationship between the digital signal and the vector signal can be guaranteed to be one-to-one mapping.

In another embodiment provided by the present invention, as shown in Figs. 4a and 4b, the vector signals A1-A8 may be independent of each other, and there is no dependency between the vector signals. Users can select each vector signal in a targeted manner. It should be understood that the user can individually configure each vector signal according to actual needs so that there is a specific correlation between them. In this way, when compatibility with existing modulation methods is required, the vector signal can be configured to meet the existing modulation methods.

In one embodiment provided by the present invention, the lookup table is stored in a register. As shown in Table 1 below, the lookup table 1 includes the input vector signals A1-A8, and the digital signals 000-111 corresponding to the vector signals one-to-one (assuming that the address signal is 3 bits). It should be understood that the number of bits of the address signal is 3 in this embodiment is just an example, and is not used to limit the number of bits of the address signal, and the number of bits of the address signal can be designed to meet any modulation mode as required. As shown in FIG. 2, when a specific vector signal 155 is input, the lookup table unit 204 inputs one or more of the vector signals A1 to A8 in the lookup table into the comparator 202 according to a certain lookup method The signal 155 is compared, and then a corresponding digital signal 156 is output according to the comparison result. For example, when the input vector signal 155 is the same as the vector signal A2 in the lookup table, the comparison unit 202 feeds back the comparison result 252 to the lookup table unit 204, and then the lookup table unit 204 outputs a digital signal 000 corresponding to the vector signal A2. For another example, when the input vector signal 155 is not the same as the vector signals A1-A8 in the look-up table, but the distance to A5 is the shortest, the comparison unit 252 will feed back the comparison result to the look-up table unit 204, and then the look-up table unit 204 outputs Digital signal 110 corresponding to vector signal A5.

Table 1 Lookup table

vector signal Digital signal A1 000 A2 001 A3 011 A4 010 A5 110 A6 111 A7 101 A8 100

In this application, the demodulation mode of the signal is compatible with any existing demodulation mode through the comparison unit and the look-up table unit, including rectangular QAM, cardioid QAM, PSK, and ASK. Moreover, the demodulation method of the present application is based on vector, and can simultaneously have the functions of amplitude modulation and phase modulation.

It should be understood that in the above look-up table 1, the digital signal adopts Gray code to reduce the bit error rate. In other embodiments of the present invention, other binary codes may also be used.

What is disclosed above is only a preferred embodiment of the present invention, and of course it cannot limit the scope of rights of the present invention. Those of ordinary skill in the art can understand all or part of the process for realizing the above embodiments, and according to the rights of the present invention The equivalent changes required still belong to the scope covered by the invention.

Claims (8)

1. A vector-based demodulator, characterized in that, comprising: The lookup table unit is used to store the vector signal, the digital signal corresponding to the vector signal and its mapping relationship in the form of a lookup table; and The comparison unit is used to compare the input vector signal with the vector signal stored in the look-up table unit, and the look-up table unit outputs a corresponding digital signal according to the comparison result of the comparison unit. 2. The vector-based demodulation device according to claim 1, wherein the vector signal is any vector signal in any quadrant in the constellation diagram, and is different in the constellation diagram. 3. The vector-based demodulation device according to claim 2, characterized in that, in the constellation diagram, the vector signals are mutually independent. 4. The demodulation device according to claim 1, wherein the look-up table unit is a register. 5. A demodulation method based on vector, is characterized in that, comprises the following steps: S1. Store the vector signal, the corresponding digital signal and its mapping relationship in the form of a lookup table; and S2. Comparing the input vector signal with the vector signal stored in the look-up table unit, and outputting a corresponding digital signal according to the comparison result of the comparison unit. 6. The vector-based demodulation method according to claim 5, wherein the vector signal is any vector signal in any quadrant in the constellation diagram, and is different in the constellation diagram. 7. The vector-based demodulation method according to claim 6, characterized in that, in the constellation diagram, the vector signals are mutually independent. 8. The vector-based demodulation method according to claim 5, wherein the look-up table is stored in a register.