WO2018019110A1 - Ovxdm system-based method, device, and system for equalized decoding - Google Patents

Abstract

An OvXDM system-based method, device, and system for equalized decoding, where equalization and decoding processes are combined, an optimal decoding path is selected by means of calculating in a corresponding domain the measures of a received signal and of a channel-processed multiplexing waveform, and the decoding path is outputted as the final decoding. Solved is the problem in the prior art in which the equalization and decoding processes are calculated independently, the equalization process is complex, and the degree of complexity is high. Thus implemented is the goal of system performance being increased when equalized decoding is employed and thereby greatly reducing the complexity of calculation.

Description

Equalization decoding method, device and system based on OvXDM system Technical field

The present application relates to the field of communications, and in particular, to an equalization decoding method, apparatus, and system based on an OvXDM system.

Background technique

The modulation and demodulation technology based on Overlapped X Division Multiplexing (OvXDM) includes various implementation schemes, such as modulation and demodulation based on Overlapped Time Division Multiplexing (OvTDM), based on overlapping frequency division multiplexing. (OvFDM: Overlapped Frequency Division Multiplexing) modulation and demodulation technology, OvCDM (Overlapped Code Division Multiplexing) modulation and demodulation technology, and overlapped space division multiplexing (OvSDM: Overlapped Space Division Multiplexing) modulation Demodulation technology, modulation and demodulation technology based on Overlapped Time Hybrid Multiplexing (OvHDM).

It should be noted that, in the OvXDM mentioned in the present application, X represents an arbitrary domain, such as time T, space S, frequency F, code division C, mixed H, and the like.

TDM (Time Division Multiplexing) is a technique for sharing a plurality of signal symbols occupying a narrow time duration in a digital communication for a wide time duration. As shown in FIG. 1, it is a schematic diagram of a conventional time division multiplexing technique.

The time durations of each multiplexed signal symbol in Figure 1 (referred to as the slot width in engineering) are T1, T2, T3, T4, ..., respectively, which are generally required to occupy the same time slot width in engineering. ΔT is the minimum guard slot, and the actual guard slot width should be a bit more. ΔT should be greater than the transition time width of the demultiplexed gate used plus the maximum amount of time jitter of the system. This is the most common time division multiplexing technique. Most of the existing multi-channel digital broadcasting systems and multi-channel digital communication systems use this technology.

The most important feature of this technology when applied to digital communication is that the multiplexed signal symbols are completely isolated from each other in time, and there is never mutual interference. There is no restriction on the multiplexed signal symbols, and the symbols of the respective signals. The duration (slot width) can have different widths, and can also be applied to different communication systems, as long as their time slots do not overlap each other, and thus are most widely used. But with this multiplexing, multiplexing itself has no effect on improving the spectral efficiency of the system.

Therefore, the conventional view is that adjacent channels do not overlap in the time domain to avoid interference between adjacent channels, but this technique restricts the improvement of spectral efficiency. The prior art time division multiplexing technology has the view that the channels do not need to be isolated from each other, and can have strong mutual overlap. As shown in FIG. 2, the prior art regards the overlap between channels as a new one. Coding the constraint relationship and according to the constraint The corresponding modulation and demodulation techniques are proposed, so it is called Overlapped Time Division Multiplexing (OvTDM), which increases the spectral efficiency proportionally to the number of overlaps K.

Referring to FIG. 3, the OvXDM system includes a signal transmitter A01 and a receiver A02.

The transmitter A01 includes an OvXDM system modulation device 101 and a transmitting device 102. The OvXDM system modulation device 101 is configured to generate a complex modulation envelope waveform carrying an input signal sequence; the transmitting device 102 is configured to transmit the complex modulation envelope waveform to the receiver A02.

The receiver A02 includes a receiving device 201 and a sequence detecting device 202. The receiving device 201 is configured to receive a complex modulation envelope waveform transmitted by the transmitting device 102. The sequence detecting device 202 is configured to perform time series data sequence detection on the received complex modulation envelope waveform for decision output.

Typically, receiver A02 also includes pre-processing means 203 disposed between receiving means 201 and sequence detecting means 202 for assisting in the formation of a sequence of synchronous received digital signals within each frame.

In the transmitter A01, the input digital signal sequence is formed by the OvXDM system modulation device 101 to form a plurality of transmission signals whose symbols overlap each other in the time domain, and the transmission device 102 transmits the transmission signal to the receiver A02. The receiving device 201 of the receiver A02 receives the signal transmitted by the transmitting device 102, and forms a digital signal suitable for the sequence detecting device 202 to detect and receive through the pre-processing device 203. The sequence detecting device 202 performs the data sequence detection in the time domain of the received signal, thereby outputting judgment.

Referring to FIG. 4, the OvXDM system modulation apparatus 101 (OvTDM modulation apparatus) includes a waveform generation module 301, a shift module 302, a multiplication module 303, and a superposition module 304.

The waveform generation module 301 is configured to generate an initial envelope waveform of the waveform smoothing in the time domain according to the design parameters.

The shifting module 302 is configured to shift the initial envelope waveform by a predetermined shift interval in the time domain according to the number of overlapping multiplexing to obtain a shift envelope waveform of each fixed interval.

Modulation module 305 is operative to convert the input digital signal sequence into a sequence of signal symbols represented by positive and negative signs.

The multiplication module 303 is configured to multiply the sequence of signal symbols by the shifted envelope waveforms of each fixed interval after the offset to obtain respective modulation envelope waveforms.

The superposition module 304 is configured to superimpose each modulation envelope waveform in the time domain to obtain a complex modulation envelope waveform carrying the input signal sequence.

Please refer to FIG. 5, which is a block diagram of the pre-processing apparatus 203 of the receiver A02.

The pre-processing device 203 includes a synchronizer 501, a channel estimator 502, and a digitizer 503. The synchronizer 501 forms symbol time synchronization in the receiver for the received signal; the channel estimator 502 then estimates the channel parameters; the digitizer 503 digitizes the received signal in each frame to form a suitable sequence detecting device. The sequence detects the received digital signal sequence.

Please refer to FIG. 6, which is a block diagram of the sequence detecting device 202 of the receiver A02.

The sequence detecting means 202 includes an analyzing unit memory 601, a comparator 602 and a plurality of reserved path memories 603 and an Euclidean distance memory 604 or a weighted Euclidean distance memory (not shown). In the detection process, the analysis unit memory 601 makes a complex convolutional coding model and a trellis diagram of the OvXDM system, and lists all states of the OvXDM system, and stores them; and the comparator 602 according to the trellis diagram in the analysis unit memory 601, The path of the minimum Euclidean distance or the weighted minimum Euclidean distance of the received digital signal is searched; and the reserved path memory 603 and the Euclidean distance memory 604 or the weighted Euclidean distance memory are used to store the reserved path output by the comparator 602 and the Distance or weighted Euclidean distance. Among them, the reserved path memory 603 and the Euclidean distance memory 604 or the weighted Euclidean distance memory need to be prepared for each of the stable states. The length of the reserved path memory 603 may preferably be 4K to 5K. The Euclidean distance memory 604 or the weighted Euclidean distance memory preferably stores only relative distances.

At present, when the OvXDM receiving end processes signals, most of them process the channel equalization and decoding process independently. Since the equalization process is not only related to the channel parameters, but also related to the data frame length, the computational complexity is high, and the system performance is high. Lower.

Summary of the invention

The present invention provides an equalization decoding method, apparatus and system based on the OvXDM system, which solves the problem that the equalization and decoding processes are independently calculated in the prior art, and the equalization process is complicated and has high complexity.

According to the first aspect of the present application, the present application provides an equalization decoding method based on an OvXDM system, including:

Calculating the fading multiplexing waveform;

The received signal and the fading multiplexed waveform are simultaneously used as the input end of the decoding, and the measure of the received signal and the fading multiplexed waveform is calculated in the corresponding domain; the measure d is:

Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

Selecting the path corresponding to the minimum value of the received signal and the fading multiplexed waveform as the optimal decoding path path;

A final sequence of input symbols is obtained from the optimal decoding path.

Further, the fading multiplexing waveform is calculated using the following formula:

h"=h×h'

Where h" is the fading multiplexing waveform, h' is the channel fading coefficient, and h is the multiplexed waveform coefficient.

According to the second aspect of the present application, the present application further provides an equalization decoding method based on an OvXDM system, including:

Calculate multipath multiplexed waveforms;

The received signal and the multipath multiplexed waveform are simultaneously used as the input end of the decoding, and the measurement of the received signal and the multipath multiplexed waveform is calculated in the corresponding domain;

Selecting an optimal decoding path based on the received signal and the measure of the multipath multiplexed waveform;

A final sequence of input symbols is obtained from the optimal decoding path.

Further, the calculation of the multipath multiplexed waveform uses the following formula:

Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.

In an embodiment, the step of synchronizing the received signal is further included before the received signal is used as the input of the decoding.

According to the third aspect of the present application, the present application provides an equalization decoding apparatus based on an OvXDM system, including:

a fading multiplexing waveform calculation module for calculating a fading multiplexing waveform;

a measurement calculation module, configured to simultaneously use the received signal and the fading multiplexed waveform as an input end of the decoding, and calculate a measure of the received signal and the fading multiplexed waveform in the corresponding domain;

An optimal path selection module for selecting an optimal decoding path based on the received signal and the measure of the fading multiplexed waveform;

And a decoding output module, configured to obtain a final input symbol sequence according to the optimal decoding path.

Further, when the fading multiplexing waveform calculation module is used to calculate the fading multiplexing waveform, the following formula is adopted:

h"=h×h'

Where h" is the fading multiplexing waveform, h' is the channel fading coefficient, and h is the multiplexed waveform coefficient.

According to the fourth aspect of the present application, the present application further provides an equalization decoding apparatus based on an OvXDM system, including:

Multipath multiplexed waveform calculation module for calculating multipath multiplexed waveforms;

The measurement calculation module is configured to simultaneously calculate the received signal and the multipath multiplexed waveform in the corresponding domain by using the received signal and the multipath multiplexed waveform as the input end of the decoding; the measure d is:

Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

An optimal path selection module, configured to select, according to the received signal and the path corresponding to the minimum value of the multipath multiplexed waveform, an optimal decoding path;

And a decoding output module, configured to obtain a final input symbol sequence according to the optimal decoding path.

Further, when the multipath multiplexed waveform calculation module is used to calculate a multipath multiplexed waveform, the following formula is adopted:

Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.

According to a fifth aspect of the present application, the present application provides a communication system based on an OvXDM system, including a transmitter and a receiver;

The transmitter includes:

a modulating device for generating a complex modulation envelope waveform carrying an output signal sequence;

a transmitting device, configured to transmit the complex modulation envelope waveform to a receiver;

The receiver includes:

Receiving means for receiving a complex modulation envelope waveform transmitted by the transmitting device;

The equalization decoding apparatus based on the OvXDM system according to any of the above.

Specifically, the communication system is applicable to the OvXDM system, and the OvXDM system is an OvTDM system, an OvFDM system, an OvCDM system, an OvSDM system, or an OvHDM system.

The OvXDM system-based equalization decoding method, device and system provide a combination of equalization and decoding processes, and select an optimal decoding path by calculating a received signal and a channel-processed multiplexed waveform. This decoding path is used as the final decoding output. The invention solves the problem that the equalization and decoding processes are independently calculated in the prior art, and the equalization process is complicated and has high complexity. Therefore, after the equalization decoding is adopted, the computational complexity is greatly reduced, and the system performance is improved.

DRAWINGS

1 is a schematic diagram of a conventional time division multiplexing technique;

2 is a schematic diagram of the principle of the OvTDM system;

3 is a schematic structural view of an OvTDM system;

4 is a schematic structural view of a modulation device of an OvTDM system;

5 is a schematic structural diagram of a receiver preprocessing apparatus;

6 is a schematic structural diagram of a receiver sequence detecting device;

Figure 7 is an OvTDM equivalent convolutional coding model;

8 is a schematic flow chart of a modulation step in a decoding method based on overlapping multiplexing;

9 is a schematic diagram of the principle of K-way waveform multiplexing;

10 is a schematic diagram showing the principle of a symbol superposition process of a K-path waveform;

FIG. 11 is a schematic flowchart diagram of an equalization decoding method based on an OvTDM system according to an embodiment of the present application;

12 is a schematic block diagram of an equalization decoding apparatus based on an OvTDM system according to an embodiment of the present application;

FIG. 13 is a schematic flowchart of an equalization decoding method based on an OvTDM system according to another embodiment of the present application;

14 is a schematic block diagram of an equalization decoding apparatus based on an OvTDM system in another embodiment of the present application;

FIG. 15 is a schematic structural diagram of a communication system based on an OvTDM system according to an embodiment of the present application.

detailed description

The decoding method provided by the present invention is applicable to an OvXDM (Overlapped X Division Multiplexing) system, such as a modulation and demodulation technique based on Overlapped Time Division Multiplexing (OvTDM), based on overlapping frequency division multiplexing (OvFDM: Overlapped Frequency Division Multiplexing), modulation and demodulation based on Overlapped Code Division Multiplexing (OvSDM), and Overlapped Space Division Multiplexing (OvSDM) Modulation and demodulation technology based on Overlapped Time Hybrid Multiplexing (OvHDM).

The decoding method of the present invention is similar in different OvXDM decoding methods. The following only uses the OvTDM system as an explanation. Those skilled in the art can make adaptive adjustments according to the correspondence between overlapping multiplexing systems, so as to enable translation. The code method works in other systems.

First, a brief description of the OvTDM system, including the sender and receiver.

(1) A brief description of the OvTDM sender process is as follows:

The OvTDM transmitting end convolutionally encodes the input symbol sequence x and the multiplexed waveform h to form a coded transmission waveform.

The transmitted waveform is transmitted through the antenna, and the signal is transmitted through the channel to the receiving end.

The coding model of the transmitting end is shown in Fig. 7. The input symbol sequence x is convoluted according to the model and the multiplexed waveform h to obtain a transmission symbol sequence y, thereby realizing mutual displacement overlap between symbols, shifting the volume. The product process can be expressed as:

Where N is the length of the data frame, K is the number of times of overlap multiplexing, and the length of the data after the overlap coding is N+K-1, and ΔT is the shift interval.

Referring to Figure 8, the modulation step in the OvTDM system includes the following sub-steps:

Step 2.1: Generate an initial envelope waveform h(t) in the time domain based on the design parameters.

When generating the initial envelope waveform, the user can input the design parameters to achieve flexible configuration according to system performance indicators in the actual system.

In some embodiments, when the sidelobe attenuation of the initial envelope waveform has been determined, the design parameters include the window length L of the initial envelope waveform, such as when the initial envelope waveform is a Bartlett envelope waveform.

In some embodiments, the design parameters include the window length L of the initial envelope waveform and the sidelobe attenuation r, such as when the initial envelope waveform is a Chebyshev envelope waveform.

Of course, when the initial envelope waveform is in other forms, the design parameters can be determined according to the characteristics of the corresponding initial envelope waveform.

Step 2.2: The initial envelope waveform is shifted in the time domain according to the predetermined shift interval according to the number of overlap multiplexing K to obtain the shift envelope waveform h(t-i*ΔT) of each fixed interval.

Wherein, the shift interval is a time interval ΔT, and the time interval ΔT is: ΔT=L/K. At this time, the symbol width of the signal is ΔT.

In addition, it is also necessary to ensure that ΔT is not less than the reciprocal of the system sampling rate.

The value of i is related to the input symbol length N, and i takes an integer from 0 to N-1. For example, when N=8, i takes an integer from 0 to 7.

Step 2.3: Convert the input signal digital sequence into a sequence of signal symbols represented by positive and negative signs.

Specifically, 0 in the input digital signal sequence is converted to +A, 1 is converted to -A, and A is a non-zero arbitrary number to obtain a sequence of positive and negative symbols. For example, when A is 1, the input {0, 1} bit sequence is converted into a {+1, -1} symbol sequence by BPSK (Binary Phase Shift Keying) modulation.

Step 2.4: Convert the converted signal symbol sequence x _i (in the present embodiment, x _i ={+1 +1 -1 -1 -1 +1 -1 +1}) and the fixed-interval shift envelope waveform h (ti*ΔT) is multiplied to obtain each modulation envelope waveform x _i h(ti*ΔT).

Step 2.5: superimposing each modulation envelope waveform x _i h(ti*ΔT) in a corresponding domain (time domain in this embodiment) to obtain a complex modulation envelope waveform carrying the input signal sequence, that is, transmitting signal.

The signal sent can be expressed as follows:

Step 2.6: The obtained complex modulation envelope waveform is transmitted as a transmission signal.

Therefore, in this embodiment, when A is 1, the superimposed output symbol (output signal symbol sequence) is: s(t)={+1 +2 +1 -1 -3 -1 -1 + 1}.

Please refer to FIG. 9 , which is a schematic diagram of the principle of K-way waveform multiplexing, which has a parallelogram shape. Each row represents a waveform to be transmitted x _i h(ti*ΔT) obtained by multiplying a symbol x _i to be transmitted with an envelope waveform h (ti*ΔT) at a corresponding time. a ₀ to a _k-1 represent coefficient values of each part obtained by K-segmentation of each window function waveform (envelope waveform), specifically, coefficients regarding amplitude values.

Since the input digital signal sequence is converted into a sequence of positive and negative symbols, 0,1 in the input digital signal sequence is converted to ±A, and A is a non-zero arbitrary number to obtain a sequence of positive and negative symbols. For example, when A takes a value of 1, the input {0, 1} bit sequence is BPSK-modulated into a sequence of {+1, -1} symbols to obtain a sequence of positive and negative symbols. Therefore, FIG. 9 is a schematic diagram showing the principle of the symbol superposition process of the K-way waveform. In the superimposition process of FIG. 10, the first three digits on the left side of the first row represent the first input symbol +1, the third digit on the left side of the second row represents the second input symbol +1, and the third digit on the left of the third row represents the third input. Symbol-1, the middle 3 digits of the 1st line represent the 4th input symbol -1, the middle 3 digits of the 2nd row represent the 5th input symbol -1, and the 3rd row of the 3rd row represents the 6th input symbol + 1. The third number on the right side of the first line indicates the seventh input symbol -1, and the third number on the right side of the second line indicates the eighth input symbol +1. Therefore, after the three waveforms are superimposed, the resulting output symbol is {+1 +2 +1 -1 -3 -1 -1 +1}.

Of course, if the length of the input symbol is other values, it can be superimposed in the manner shown in FIG. 9 and FIG. 10 to obtain an output symbol.

(2) A brief description of the OvTDM receiver process is as follows:

Since the actual channel generally has a certain fading or multipath condition, the signal received by the receiving end is actually the signal transmitted by the transmitting end after channel fading or multipath transmission.

Where h' denotes channel fading or multipath parameters.

The processing of the receiving end basically includes the following three parts:

Signal synchronization

After receiving the signal y', the receiving end needs to perform synchronization processing on the signal, including timing synchronization, carrier synchronization, and the like.

b. Channel equalization

After the synchronization is completed, channel estimation and equalization processing are performed. The role of channel estimation is mainly to estimate the channel parameter h'. The role of equalization is mainly to eliminate h' from the received signal y' to obtain the true sender signal. No. y.

When the channel environment is relatively simple, the signal passes through the channel transmission and only passes through the fading or only the single-path channel exists. The h' can be understood as the fading coefficient and the received signal.

It can be equivalent to y'=h'×y, and the method of calculating y by equalization processing is y=y'/h', the computational complexity is related to the length N of the data frame, and a large number of division operations are required. In engineering design, it is generally necessary to avoid division operations, because in hardware implementation, division operations consume more resources and clocks.

If the channel environment is complex, that is, there is a multipath condition, then the multipath factor h' and the transmitted signal are convolutional relationships, that is,

The method of equalization processing y is a deconvolution operation, and the deconvolution operation is more complicated. The computational complexity is not only related to the number of multipaths, but also related to the length N of the data frame. The complexity of the equalization will vary with the number of multipaths. The growth of the index has increased exponentially.

c. decoding

The OvTDM decoding process decodes the equalized signal y and the multiplexed waveform h, selects the optimal decoding path by calculating the equalized signal and the measure of the ideal superimposed signal, and finally obtains the input symbol sequence x, and the decoding process ends. There are many decoding methods. The more common method is Viterbi decoding, and the algorithm complexity is 2 ^K. Generally, the to-be-decoded signal and the multiplexed waveform of the decoding input are both signals of a specified domain. For example, when the system is OvTDM, the specified domain is the time domain; when the system is OvFDM, the designated domain is the frequency domain, that is, The decoded signal is converted into a frequency domain signal by Fourier transform, and the multiplexed waveform is a frequency domain waveform.

The present application proposes an equalization decoding method suitable for the OvTDM system, combining the equalization and decoding processes, and selecting the best decoding path by calculating the received signal and the measured waveform of the multiplexed waveform after channel processing. The decoding path is used as the final decoded output. The invention solves the problem that the equalization and decoding processes are independently calculated in the prior art, and the equalization process is complicated and has high complexity. Therefore, after the equalization decoding is adopted, the computational complexity is greatly reduced, and the system performance is improved.

The present application will be further described in detail below with reference to the accompanying drawings.

In the equalization decoding method based on the OvXDM system provided by the present application, the equalization process and the decoding process are combined, and the decoding process simultaneously utilizes the received signal y' and the channel parameter h', aiming at reducing system complexity. For the two channel environments, the equalization decoding process is divided into two types. See Embodiment 1 and Embodiment 2 below.

Embodiment 1

When the channel environment of the OvTDM receiving end is simple, and only the fading or single-path channel exists, the channel parameter h' is understood as the fading coefficient, and the received signal is the convolved process of the attenuated multiplexed waveform h" and the input symbol x, and the fading coefficient h' is the attenuation of the multiplexed waveform h, and the received signal can be equivalent to

among them

It can be equivalent to h"=h×h', indicating the multiplexed waveform after attenuation.

Referring to FIG. 11, an equalization decoding method based on the OvTDM system provided in this embodiment includes the following steps:

Step 3.1: Calculate the fading multiplexing waveform h".

In this embodiment, the fading multiplexing waveform is calculated by the following formula:

h"=h×h'

Where h" is the fading multiplexing waveform, h' is the channel fading coefficient, and h is the multiplexed waveform coefficient.

In the calculation process of step 3.1, only the multiplication operation is included, and the computational complexity is only related to the number of overlapping multiplexing K.

Step 3.2: The received signal y' and the attenuated fading multiplexed waveform h" are simultaneously used as decoding inputs, and the measure of the received signal y' and the fading multiplexed waveform h" is calculated in the corresponding domain.

Step 3.3: Select the best decoding path according to the measure of the received signal y' and the fading multiplexed waveform h". The path with the smallest measure is selected as the best decoding path.

Step 3.4: The final input symbol sequence x is obtained according to the selected optimal decoding path, and the decoding process ends.

It should be noted that the measure in this application represents the distance between two signals, which is defined as:

Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

When p=2, it is the Euclidean distance. The Euclidean distance is the true distance between the two signals. It can truly reflect the distance between the actual signal and the ideal signal. In this patent, the Euclidean distance is defined as

In this embodiment, a more common Viterbi decoding method can be used in calculating the final input symbol sequence x, and the algorithm complexity is ^2K . Of course, other feasible decoding methods in the prior art can also be employed.

Specifically, the method provided in this embodiment further includes the step of performing synchronization processing on the received signal, including timing synchronization, carrier synchronization, and the like, before the received signal is used as the input end of the decoding.

The equalization decoding method based on the OvTDM system provided in this embodiment simplifies the original complex division operation into a simple multiplication operation, and the computational complexity is only related to the number of overlapping multiplexing times K, which greatly reduces the complexity of the system.

Embodiment 2

When the channel environment of the OvTDM receiving end is simple, when there is only a fading or single-path channel, the channel parameter h' is understood as a fading coefficient, and the received signal is a convolved process of the attenuated multiplexed waveform h" and the input symbol x, and the fading coefficient h' is the attenuation of the multiplexed waveform h, and the received signal can be equivalent to

among them

It can be equivalent to h"=h×h', indicating the multiplexed waveform after attenuation.

Referring to FIG. 12, based on the equalization decoding method provided in the first embodiment, the embodiment provides an equalization decoding device based on the OvTDM system, including a fading multiplexing waveform calculation module 701, a measurement calculation module 702, and an optimal solution. Path selection module 703 and decoding output module 704.

The fading multiplexing waveform calculation module 701 is for calculating the fading multiplexing waveform h".

In this embodiment, the fading multiplexing waveform is calculated by the following formula:

h"=h×h'

Where h" is the fading multiplexing waveform, h' is the channel fading coefficient, and h is the multiplexed waveform coefficient.

In the above calculation process, only the multiplication operation is included, and the computational complexity is only related to the number of overlapping multiplexes K.

The measurement calculation module 702 is configured to simultaneously calculate the received signal y' and the fading multiplexed waveform h" in the corresponding domain by using the received signal y' and the attenuated fading multiplexed waveform h" as the input ends of the decoding.

The optimal path selection module 703 is configured to select an optimal decoding path based on the measure of the received signal y' and the fading multiplexed waveform h".

The decoding output module 704 is configured to obtain a final input symbol sequence x according to the selected optimal decoding path, and the decoding process ends.

It should be noted that the measure in this application represents the distance between two signals, which is defined as:

When p=2, it is the Euclidean distance. The Euclidean distance is the true distance between the two signals. It can truly reflect the distance between the actual signal and the ideal signal. In this patent, the Euclidean distance is defined as

In this embodiment, a more common Viterbi decoding method can be used in calculating the final input symbol sequence x, and the algorithm complexity is ^2K . Of course, other feasible decoding methods in the prior art can also be employed.

Specifically, the apparatus provided in this embodiment further includes a synchronization processing module 700 for performing synchronization processing on the received signal before the received signal is used as the input end of the decoding, and the synchronization processing includes timing synchronization, carrier synchronization, and the like.

The equalization decoding device based on the OvTDM system provided in this embodiment simplifies the original complex division operation into a simple multiplication operation, and the computational complexity is only related to the number of overlapping multiplexing times K, which greatly reduces the complexity of the system.

Embodiment 3

When the channel environment is relatively complex and there is a multipath channel, the received signal is transmitted by the transmission signal y ₀ through multiple channels, and the transmitted signal and the multipath factor are convoluted, expressed as

among them

h′′ ₀ can be understood as a multiplexed waveform after the multiplexed waveform h ₀ is convolved by the multipath h′ ₀ , and the received signal is a convolution process of h′′ ₀ and the input symbol x.

Referring to FIG. 13, an equalization decoding method based on the OvTDM system provided in this embodiment includes the following steps:

Step 4.1: Calculate the multipath multiplexed waveform h _"0.

In this embodiment, the multipath multiplexed waveform is calculated by the following formula:

Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.

In step 4.1, a new multiplexed waveform h" _{0 is} obtained by a convolution operation whose computational complexity is only related to the number of multipaths.

Step 4.2: received signal h _'0, and "h ₀ simultaneously receive signals coded as an input, the corresponding region is calculated through convolution of the multi-path multipath multiplexed waveform h' ₀ and multipath multiplexed waveform h" The measure of ₀ .

"Measure ₀ selects the best decoding path based on the received signal h _'0 and multipath multiplexed waveform h smallest measure as the best decoding path route: step 4.3.

Step 4.4: The final input symbol sequence x is obtained according to the selected optimal decoding path, and the decoding process ends.

It should be noted that the measure in this application represents the distance between two signals, which is defined as:

Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

When p=2, it is the Euclidean distance. The Euclidean distance is the true distance between the two signals. It can truly reflect the distance between the actual signal and the ideal signal. In this patent, the Euclidean distance is defined as

In this embodiment, a more common Viterbi decoding method can be used in calculating the final input symbol sequence x, and the algorithm complexity is ^2K . Of course, other feasible decoding methods in the prior art can also be employed.

Specifically, the method provided in this embodiment further includes the step of performing synchronization processing on the received signal, including timing synchronization, carrier synchronization, and the like, before the received signal is used as the input end of the decoding.

In the prior art equalization method, the complexity is not only related to the number of multipaths, but also related to the length of the data frame, and the complexity of the equalization increases exponentially as the number of multipaths increases. The equalization decoding method based on the OvTDM system provided in this embodiment, the complexity in the equalization decoding process is only related to the number of multipaths. Greatly reduce the complexity of the system.

Embodiment 4

When the channel environment is complex and there is a multipath channel, the received signal is transmitted by the transmission signal y over multiple channels, and the transmitted signal and the multipath factor are convoluted, expressed as

among them

h′′ ₀ can be understood as a multiplexed waveform after the multiplexed waveform h ₀ is convolved by the multipath h′ ₀ , and the received signal is a convolution process of h′′ ₀ and the input symbol x.

Referring to FIG. 14 , based on the equalization decoding method provided in the foregoing embodiment 3, the embodiment provides an equalization decoding device based on the OvTDM system, including a multipath multiplexed waveform calculation module 801, a metric calculation module 802, and the most The best path selection module 803 and the decoding output module 804.

The multipath multiplexed waveform calculation module 801 is configured to calculate the multipath multiplexed waveform h" ₀ .

In this embodiment, the multipath multiplexed waveform is calculated by the following formula:

Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.

In the above calculation process, a new multiplexed waveform h" _{0 is} obtained by a convolution operation, and its computational complexity is only related to the number of multipaths.

Measurement module 802 for calculating the reception signal h _'0, and after many multipath after convolution diameter multiplexed waveform h _"0 at the same time as the coded input, the received signal is calculated in the domain corresponding to h' ₀ multipath multiplexed and The measure of waveform h" ₀ .

Best path selection module 803 for selecting the best measure ₀ the decoding paths based on the received signal h _'0 and H multipath multiplexed waveforms. "

The decoding output module 804 is configured to obtain a final input symbol sequence x according to the selected optimal decoding path, and the decoding process ends.

It should be noted that the measure in this application represents the distance between two signals, which is defined as:

When p=2, it is the Euclidean distance. The Euclidean distance is the true distance between the two signals. It can truly reflect the distance between the actual signal and the ideal signal. In this patent, the Euclidean distance is defined as

In this embodiment, a more common Viterbi decoding method can be used in calculating the final input symbol sequence x, and the algorithm complexity is ^2K . Of course, other feasible decoding methods in the prior art can also be employed.

Specifically, the apparatus provided in this embodiment further includes a synchronization processing module 800 for performing synchronization processing on the received signal before using the received signal as the input end of the decoding. Synchronization processing includes timing synchronization, carrier synchronization, and the like.

In the prior art equalization method, the complexity is not only related to the number of multipaths, but also related to the length of the data frame, and the complexity of the equalization increases exponentially as the number of multipaths increases. The equalization decoding apparatus based on the OvTDM system provided in this embodiment has a complexity in the equalization decoding process only related to the number of multipaths, which greatly reduces the complexity of the system.

Embodiment 5

Referring to FIG. 15, the embodiment provides a communication system based on an OvTDM system, including a transmitter B01 and a receiver B02.

Transmitter B01 includes modulation device 901 and transmitting device 902.

Modulation device 901 is operative to generate a complex modulation envelope waveform carrying an output signal sequence.

Transmitting device 902 is configured to transmit the complex modulation envelope waveform to the receiver.

For the working principle of the transmitter B01, please refer to the above modulation method, which will not be described here.

The receiver B02 includes a receiving device 903 and a demodulating device 904.

The receiving device 903 is configured to receive a complex modulation envelope waveform transmitted by the transmitting device 902.

The decoding device 904 adopts any equalization decoding device based on the OvTDM system provided in the second embodiment or the fourth embodiment. For the working principle of the decoding device 904, please refer to the foregoing Embodiment 2 and Embodiment 4, and details are not described herein.

It should be noted that the equalization decoding method, device and system based on the OvTDM system provided by the embodiments of the present application can be applied to mobile communication, satellite communication, microwave line-of-sight communication, scatter communication, atmospheric optical communication, infrared communication, and underwater acoustic communication. In wireless communication systems, it can be applied to both large-capacity wireless transmissions and small-capacity lightweight radio systems.

It can be understood by those skilled in the art that all or part of the steps of the various methods in the foregoing embodiments may be implemented by a program to control related hardware. The program may be stored in a computer readable storage medium, and the storage medium may include: a read only memory. Random access memory, disk or optical disk, etc.

The above content is a further detailed description of the present application in conjunction with the specific embodiments, and the specific implementation of the present application is not limited to the description. For those skilled in the art to which the present invention pertains, several simple deductions or substitutions can be made without departing from the inventive concept.

Claims (11)

1. An equalization decoding method based on OvXDM system, characterized in that it comprises:

   Calculating the fading multiplexing waveform;

   The received signal and the fading multiplexed waveform are simultaneously used as the input end of the decoding, and the measure of the received signal and the fading multiplexed waveform is calculated in the corresponding domain; the measure d is:

   

   Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

   Selecting a path corresponding to the minimum value of the received signal and the fading multiplexed waveform as the optimal decoding path;

   A final sequence of input symbols is obtained from the optimal decoding path.
2. The method of claim 1 wherein the fading multiplexing waveform is calculated using the following formula:

   h′′=h×h’

   Where h′′ is a fading multiplexing waveform, h′ is a channel fading coefficient, and h is a multiplexed waveform coefficient.
3. The method of claim 1 or 2, further comprising the step of synchronizing the received signal prior to using the received signal as the input of the decoding.
4. An equalization decoding method based on OvXDM system, characterized in that it comprises:

   Calculate multipath multiplexed waveforms;

   The received signal and the multipath multiplexed waveform are simultaneously used as the input end of the decoding, and the measurement of the received signal and the multipath multiplexed waveform is calculated in the corresponding domain;

   Selecting an optimal decoding path based on the received signal and the measure of the multipath multiplexed waveform;

   A final sequence of input symbols is obtained from the optimal decoding path.
5. The method of claim 4 wherein the multipath multiplexed waveform is calculated using the following formula:

   

   Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.
6. The method of claim 4 or 5, further comprising the step of synchronizing the received signal prior to using the received signal as the input of the decoding.
7. An equalization decoding device based on an OvXDM system, comprising:

   a fading multiplexing waveform calculation module for calculating a fading multiplexing waveform;

   a measurement calculation module, configured to simultaneously use the received signal and the fading multiplexed waveform as an input end of the decoding, and calculate a measure of the received signal and the fading multiplexed waveform in the corresponding domain;

   An optimal path selection module for selecting the best translation based on the received signal and the measure of the fading multiplexed waveform Code path

   And a decoding output module, configured to obtain a final input symbol sequence according to the optimal decoding path.
8. The apparatus according to claim 7, wherein when the fading multiplexing waveform calculation module is configured to calculate the fading multiplexing waveform, the following formula is used:

   h′′=h×h’

   Where h′′ is a fading multiplexing waveform, h′ is a channel fading coefficient, and h is a multiplexed waveform coefficient.
9. An equalization decoding device based on an OvXDM system, comprising:

   Multipath multiplexed waveform calculation module for calculating multipath multiplexed waveforms;

   The measurement calculation module is configured to simultaneously calculate the received signal and the multipath multiplexed waveform in the corresponding domain by using the received signal and the multipath multiplexed waveform as the input end of the decoding; the measure d is:

   

   Where x _i is the ith transmitted symbol, y _i is the ith received symbol, and p is the dimension;

   An optimal path selection module, configured to select, according to the received signal and the path corresponding to the minimum value of the multipath multiplexed waveform, an optimal decoding path;

   And a decoding output module, configured to obtain a final input symbol sequence according to the optimal decoding path.
10. The apparatus according to claim 9, wherein when the multipath multiplexed waveform calculation module is used to calculate the multipath multiplexed waveform, the following formula is adopted:

    

    Where h′′ ₀ is a multipath multiplexed waveform, h′ ₀ is a multipath factor, and h ₀ is a multiplexed waveform coefficient.
11. A communication system based on an OvXDM system, comprising: a transmitter and a receiver;

    The transmitter includes:

    a modulating device for generating a complex modulation envelope waveform carrying an output signal sequence;

    a transmitting device, configured to transmit the complex modulation envelope waveform to a receiver;

    The receiver includes:

    Receiving means for receiving a complex modulation envelope waveform transmitted by the transmitting device;

    And an equalization decoding apparatus based on the OvXDM system according to any one of claims 6-10.

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