High-rate differential keying communication method based on hybrid multiple access and orthogonal frequency division multiple access

Abstract

The application discloses a high-speed differential keying communication method based on chaotic multiple access and orthogonal frequency division multiple access, which comprises the following steps: after a to-be-transmitted information sequence is subjected to serial-parallel conversion and spread spectrum mapping processing, the information sequence is subjected to chaotic orthogonal filter processing to obtain corresponding chaotic pseudo-orthogonal signals; the chaotic pseudo-orthogonal signals are subjected to real part sequence and imaginary part sequence summation to obtain chaotic subcarrier transmission signals; after a received signal is recovered, real part signals / imaginary part signals are subjected to matched filtering and correlation filtering, the matched filtering result is subjected to downsampling / mean filtering, threshold decision and classification processing; the correlation filtering result is subjected to downsampling and sorting processing, and then is subjected to symbol decision together with the result after the classification processing to obtain a recovered spread spectrum sequence corresponding to the real part signals; then, the recovered spread spectrum sequence is subjected to reference extraction processing and correlation operation to obtain a recovered bit stream; finally, the recovered bit streams output by all decoding channels are subjected to serial-parallel conversion processing to obtain a recovered information sequence.

Description

Technical Field

[0001] This invention relates to the field of chaotic communication technology, and specifically to a high-speed differential keying communication method based on mixed-distribution multiple access and orthogonal frequency division multiple access. Background Technology

[0002] In current IoT communication systems, multiple access technology, spectrum utilization, and communication speed are several core aspects that have attracted significant attention. With the surge in the number of communication devices and the exponential growth in communication demands, existing communication systems are increasingly struggling to meet the multiple access capabilities, anti-interference capabilities, and communication speeds required by IoT communication. Chaotic systems, characterized by noise-like properties and near-zero impulse autocorrelation and cross-correlation, have been widely applied in communication system research in recent years, with the aim of enhancing the multiple access capabilities, spectrum utilization, and anti-interference performance in complex environments.

[0003] Recent research has proposed a chaotic pseudo-orthogonal shaping filter bank for communication systems. By passing the transmitted signal through the corresponding chaotic pseudo-orthogonal shaping filter, the signal to be transmitted can be modulated. However, the anti-interference capability of this scheme in complex channel environments still needs to be improved. Summary of the Invention

[0004] The purpose of this invention is to provide a high-speed differential keying communication method based on mixed-access multiple access and orthogonal frequency division multiple access, which has high speed, high spectrum utilization and stronger anti-interference capability.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] High-speed differential keying communication methods based on mixed-access multiple access and orthogonal frequency division multiple access include:

[0007] The information sequences A and B to be transmitted are converted into multiple sets of parallel information through serial-to-parallel conversion. The spread spectrum sequences obtained after spreading mapping of the two sets of parallel information in each modulation channel are processed by a set of chaotic orthogonal filters to obtain the corresponding chaotic pseudo-orthogonal signals. The real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals corresponding to the two sets of parallel information are summed respectively, and used as the chaotic subcarrier transmission signals of the modulation channel. After Fourier transform and parallel-to-serial conversion of the chaotic subcarrier transmission signals of all modulation channels, they are modulated into complex transmission signals according to OFDM modulation and transmitted to the wireless channel through the radio frequency antenna.

[0008] The received signal is obtained through radio frequency reception. This signal undergoes Fourier transform and parallel-to-serial conversion to obtain the complex received signal for each decoding channel. Each complex received signal is divided into a real part and an imaginary part. The real part is processed by matched filtering and correlation filtering. The result of matched filtering is then processed by downsampling / mean filtering, threshold decision, and classification to recover the symbol sequence type. The result of correlation filtering is downsampled and sorted, and then combined with the result of classification processing for symbol decision to obtain the recovered spread spectrum sequence corresponding to the real part. The imaginary part undergoes the same processing flow as the real part to obtain the corresponding recovered spread spectrum sequence.

[0009] The recovered spread spectrum sequences corresponding to the real and imaginary parts of the signal are processed by reference extraction and correlation operations to obtain a set of recovered bit streams corresponding to the real and imaginary parts of the signal, respectively.

[0010] The recovered bitstreams output from all decoding channels are subjected to parallel-to-serial conversion to obtain the recovered information sequence. and information sequence

[0011] A high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access includes a transmitter and a receiver;

[0012] The transmitter includes a sequence of information to be transmitted module 1, a serial-to-parallel conversion module 2, a spread spectrum mapping module 3, a chaotic pseudo-orthogonal shaping filter bank module 4, an adder module 5, an inverse Fourier transform parallel-to-serial conversion module 6, and an RF transmission module 7.

[0013] The receiver includes an RF receiving module 8, a Fourier transform / serial-to-parallel conversion module 9, a real part extraction module 10, a matched filter bank module 11, a downsampling / mean filtering module 12, a threshold / classification module 13, a correlation filter bank module 14, a downsampling module 15, a sorting module 16, a symbol decision module 17, a reference extraction module 18, a correlation module 19, a threshold judgment module 20, an imaginary part extraction module 21, and a parallel-to-serial conversion module 22; the receiver has M decoding channels, corresponding to the M modulation channels of the transmitter.

[0014] Furthermore, the information sequence module 1 to be transmitted is used to generate information sequence A to be transmitted and information sequence B to be transmitted;

[0015] The serial-to-parallel conversion module 2 is used to convert the information sequences A and B to be transmitted into multiple sets of parallel information, including 2M sets of A information streams and 2M sets of B information streams.

[0016] The spread spectrum mapping module 3 has two sets in each modulation channel, which are used to receive the two sets of A information stream and B information stream corresponding to the modulation channel and perform spread spectrum mapping processing to obtain the corresponding spread spectrum sequence.

[0017] There are two sets of chaotic pseudo-orthogonal shaping filter banks 4 in each modulation channel. Each set of chaotic pseudo-orthogonal shaping filter banks 4 is used to receive the spread spectrum sequence output by the corresponding spread spectrum mapping module 3 to obtain the corresponding chaotic pseudo-orthogonal signal.

[0018] The adder module 5 is used to sum the real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals output by the two sets of chaotic pseudo-orthogonal shaping filter groups 4 in each modulation channel, and then use them as the chaotic subcarrier transmission signal of that modulation channel.

[0019] The inverse Fourier transform / parallel-to-serial conversion module 6 is used to receive the chaotic subcarrier transmission signals output from all M modulation channels, perform Fourier transform and parallel-to-serial conversion processing, and modulate them into complex transmission signals according to OFDM modulation.

[0020] The radio frequency transmission module 7 is used to transmit the complex transmission signal to the wireless channel via electromagnetic waves.

[0021] Furthermore, the radio frequency receiving module 8 is used to receive complex transmitted signals from the wireless channel and process them to obtain received signals;

[0022] The Fourier transform / serial-to-parallel conversion module 9 is used to perform Fourier transform and parallel-to-serial conversion on the received signal r(t) to obtain M complex received signals;

[0023] The real part extraction module 10 and the imaginary part extraction module 21 are used to extract the real part signal and the imaginary part signal from the complex received signal corresponding to each decoding channel, respectively.

[0024] Each decoding channel has two sets of matched filter bank module 11 and correlation filter bank module 14. One set of matched filter bank module 11 and correlation filter bank module 14 is used to perform matched filtering and correlation filtering on the real part signal, respectively. The matched-filtered signal enters the downsampling / mean filtering module 12 for downsampling and mean filtering, and then passes through the threshold / classification module 13 for threshold decision and classification to recover the symbol sequence type. The correlation-filtered signal enters the downsampling module 15 for downsampling, and then enters the sorting module 16 for sorting. The sorted signal and the classified signal enter the symbol decision module 17 for symbol decision to obtain the recovered spread spectrum sequence corresponding to the real part signal. This recovered spread spectrum sequence is input to the reference extraction module 18 and the correlation module 19, respectively. The reference extraction module 18 is used for reference extraction processing to obtain the recovered bit stream. The correlation module 19 is used to perform correlation operations, and the correlation results are sent to the threshold judgment module 20 for threshold judgment processing to obtain the recovered bitstream. The imaginary part of the signal is processed through the same procedure to recover the bit stream. and the recovered bitstream

[0025] Parallel-to-serial conversion module 22 is used to process the 2M recovered bit streams output from all M decoding channels. 2M recovered bit streams Perform parallel-to-serial conversion to obtain the recovered information sequence. and information sequence

[0026] Furthermore, the formula for the spread spectrum mapping process is:

[0027] S i =[A i A i ·B i ]

[0028] Among them, S i Indicates information flow A i and information flow B i The generated spread spectrum sequence has 1≤i≤2M, where 2M represents the number of information stream groups.

[0029] Furthermore, the expression for the chaotic pseudo-orthogonal shaping filter bank 4 is:

[0030]

[0031] Where t is the time parameter, u i,n (t) is the i-th spreading sequence S i The nth (1≤n≤N) c The chaotic pseudo-orthogonal signal output from the chaotic pseudo-orthogonal shaping filter, s i,n,l It is the i-th (1≤i≤2M) group of spreading sequences S i The nth (1≤n≤N) c The symbol in row l (1≤l≤2L) is f, where f is the symbol frequency and p is the symbol frequency. n It is the nth pseudoorthogonal basis function; N c L represents the number of chaotic pseudo-orthogonal subcarriers, and L represents the spreading coefficient.

[0032] Furthermore, after summing the real and imaginary sequences in adder module 5, the summation is used as the chaotic subcarrier transmission signal for this modulation channel, specifically:

[0033]

[0034] Where 1≤j≤M, U j This represents the j-th chaotic subcarrier transmission signal, whose real and imaginary parts are respectively represented by Re. j (·) and Im j (·) indicates; u 2j-1,nS represents the second j-1th group of spreading sequences. i The chaotic pseudo-orthogonal signal output by the nth chaotic pseudo-orthogonal shaping filter, N c This represents the number of chaotic pseudo-orthogonal subcarriers.

[0035] Furthermore, the matched filter bank in matched filter bank module 11 is as follows:

[0036]

[0037] Where ξ i,n (t) is the real part / imaginary part of the i-th signal R. i (τ) The output signal after passing through the nth matched filter; g n (t) is the time inverse function of the nth pseudoorthogonal basis function in the chaotic pseudoorthogonal shaping filter bank, and τ is the integration variable;

[0038] The correlation filter bank in correlation filter bank module 14 is as follows:

[0039]

[0040] Among them, y i,n (t) The real part of the i-th path / the imaginary part of the signal R i (τ) is the output signal after passing through the nth correlation filter, o n (t) is the nth pseudoorthogonal basis function.

[0041] Furthermore, when the threshold / classification module 13 performs threshold decision and classification processing, it first sets k decision thresholds J. k , 1≤k≤N c +1; then calculate the mean of the sequence obtained after downsampling and mean filtering. With each decision threshold J k The distance between them, and the decision N. c By adding 1 index value of the minimum distance among the distances, the information symbol distribution of the symbol sequence can be recovered, and the recovered symbol sequence type can be obtained.

[0042] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, it implements the high-speed differential keying communication method based on mixed-access multiple access and orthogonal frequency division multiple access.

[0043] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the high-speed differential keying communication method based on mixed-access multiple access and orthogonal frequency division multiple access.

[0044] Compared with the prior art, the present invention has the following technical features:

[0045] 1. The chaotic pseudo-orthogonal shaping filter bank generates pseudo-orthogonal chaotic signals and is used in conjunction with orthogonal frequency division multiple access technology to provide information transmission speed-up capability, while also meeting the stronger multiple access requirements in the future industrial Internet of Things;

[0046] 2. The receivers employing conventional spread spectrum operation and mixed multiple access utilize matched filter banks and orthogonal filter banks respectively, which effectively reduces noise interference and multiple access interference in the communication system and further enhances the anti-interference capability of the communication system. Attached Figure Description

[0047] Figure 1 This is a block diagram of the transmitting end of the system of the present invention;

[0048] Figure 2 This is a block diagram of the receiving end of the system of the present invention;

[0049] Figure 3 The first spread spectrum sequence in S1 is the output signal u after passing through the first chaotic pseudo-orthogonal filter. 1,1 (t);

[0050] Figure 4 The output signal u of the second row of spread spectrum sequence in S1 after passing through the second chaotic pseudo-orthogonal filter is... 1,2 (t);

[0051] Figure 5 The first spread spectrum sequence in S2 is the output signal u after passing through the first chaotic pseudo-orthogonal filter. 2,1 (t);

[0052] Figure 6 The output signal u of the second row of spread spectrum sequence in S2 after passing through the second chaotic pseudo-orthogonal filter is... 2,2 (t);

[0053] Figure 7 It is the real part signal of the first chaotic subcarrier;

[0054] Figure 8 It is the imaginary part signal of the first chaotic subcarrier;

[0055] Figure 9 It is the output signal of the demodulated signal R1(t) after passing through the first matched filter and the downsampling point;

[0056] Figure 10 It is the output signal of the demodulated signal R1(t) after passing through the second matched filter and the downsampling point;

[0057] Figure 11 It is the output signal of the demodulated signal R2(t) after passing through the first matched filter and the downsampling point;

[0058] Figure 12It is the output signal of the demodulated signal R2(t) after passing through the second matched filter and the downsampling point;

[0059] Figure 13 It is the output downsampled sequence of the real demodulated signal R1(t) in the first decoding channel after passing through the correlation filter bank;

[0060] Figure 14 It is the output downsampled sequence of the imaginary demodulated signal R2(t) in the first decoding channel after passing through the correlation filter bank;

[0061] Figure 15 These are the bit error rate simulation results of the present invention and the comparison method. Detailed Implementation

[0062] This invention provides a high-speed differential keying communication method based on mixed-mode multiple access and orthogonal frequency division multiple access. It utilizes chaotic pseudo-orthogonal chaotic signals generated by chaotic pseudo-orthogonal shaping filters, and simultaneously uses orthogonal frequency division multiple access (OFDM) to achieve simultaneous transmission of multiple information streams, which greatly improves the speed and spectrum utilization of spread spectrum communication systems.

[0063] High-speed differential keying communication methods based on mixed-access multiple access and orthogonal frequency division multiple access include:

[0064] The information sequences A and B to be transmitted are converted into multiple sets of parallel information through serial-to-parallel conversion. The spread spectrum sequences obtained after spreading mapping of the two sets of parallel information in each modulation channel are processed by a set of chaotic orthogonal filters to obtain the corresponding chaotic pseudo-orthogonal signals. The real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals corresponding to the two sets of parallel information are summed respectively, and used as the chaotic subcarrier transmission signals of the modulation channel. After Fourier transform and parallel-to-serial conversion of the chaotic subcarrier transmission signals of all modulation channels, they are modulated into complex transmission signals according to OFDM modulation and transmitted to the wireless channel through the radio frequency antenna.

[0065] The received signal is obtained through radio frequency reception. This signal undergoes Fourier transform and parallel-to-serial conversion to obtain the complex received signal for each decoding channel. Each complex received signal is divided into a real part and an imaginary part. The real part is processed by matched filtering and correlation filtering. The result of matched filtering is then processed by downsampling / mean filtering, threshold decision, and classification to recover the symbol sequence type. The result of correlation filtering is downsampled and sorted, and then combined with the result of classification processing for symbol decision to obtain the recovered spread spectrum sequence corresponding to the real part. The imaginary part undergoes the same processing flow as the real part to obtain the corresponding recovered spread spectrum sequence.

[0066] The recovered spread spectrum sequences corresponding to the real and imaginary parts of the signal are processed by reference extraction and correlation operations to obtain a set of recovered bit streams corresponding to the real and imaginary parts of the signal, respectively.

[0067] The recovered bitstreams output from all decoding channels are subjected to parallel-to-serial conversion to obtain the recovered information sequence. and information sequence

[0068] The present invention also provides a high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access, comprising a transmitter and a receiver, wherein:

[0069] Reference Figure 1 The transmitting end includes a sequence of information to be transmitted module 1, a serial-to-parallel conversion module 2, a spread spectrum mapping module 3, a chaotic pseudo-orthogonal shaping filter bank module 4, an adder module 5, an inverse Fourier transform (IFFT) / parallel-to-serial conversion module 6, and an RF transmission module 7.

[0070] The information sequence module 1 to be transmitted is used to generate information sequence A to be transmitted and information sequence B to be transmitted;

[0071] The serial-to-parallel conversion module 2 is used to convert the information sequences A and B to be transmitted into multiple sets of parallel information, including 2M sets of A information streams [A1, A2, ..., A...]. 2M ] and 2M group B information flow [B1,B2,…,B 2M ]; where M represents the number of modulation channels, and each modulation channel corresponds to two sets of information streams A and B;

[0072] The spread spectrum mapping module 3 has two sets in each modulation channel, which are used to receive the two sets of A information streams and B information streams corresponding to that modulation channel and perform spread spectrum mapping processing to obtain the corresponding spread spectrum sequence [S1, S2, ..., S]. M ];by Figure 1 Taking the first modulation channel as an example, the two sets of information streams [A1,B1] and [A2,B2] enter the two spread spectrum mapping modules 3 of the first modulation channel respectively, and obtain the corresponding spread spectrum sequences S1 and S2 respectively.

[0073] There are two sets of chaotic pseudo-orthogonal shaping filter banks 4 in each modulation channel. Each set of chaotic pseudo-orthogonal shaping filter banks 4 is used to receive the spread spectrum sequence output by the corresponding spread spectrum mapping module 3 to obtain the corresponding chaotic pseudo-orthogonal signal.

[0074] The adder module 5 is used to sum the real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals output by the two sets of chaotic pseudo-orthogonal shaping filter groups 4 in each modulation channel, and then use them as the chaotic subcarrier transmission signal of that modulation channel.

[0075] Inverse Fourier transform / parallel-to-serial conversion module 6 is used to receive the chaotic subcarrier transmission signals [U1, U2, ..., U] output from all M modulation channels. MPerform Fourier transform and parallel-to-serial conversion processing, and modulate it into a complex transmission signal T(t) according to OFDM modulation method;

[0076] The radio frequency transmission module 7 is used to transmit the complex transmission signal T(t) to the wireless channel via electromagnetic waves.

[0077] Reference Figure 2 The receiver includes an RF receiving module 8, a Fourier transform (FFT) / serial-to-parallel conversion module 9, a real part extraction module 10, a matched filter bank module 11, a downsampling / mean filtering module 12, a threshold / classification module 13, a correlation filter bank module 14, a downsampling module 15, a sorting module 16, a symbol decision module 17, a reference extraction module 18, a correlation module 19, a threshold judgment module 20, an imaginary part extraction module 21, and a parallel-to-serial conversion module 22; the receiver has M decoding channels, corresponding to the M modulation channels of the transmitter; wherein:

[0078] The radio frequency receiving module 8 is used to receive complex transmitted signals T(t) from the wireless channel and process them to obtain the received signal r(t).

[0079] The Fourier transform / serial-to-parallel conversion module 9 is used to perform Fourier transform and parallel-to-serial conversion on the received signal r(t) to obtain M complex received signals r1(t), r2(t), ..., r M (t);

[0080] The real part extraction module 10 and the imaginary part extraction module 21 are used to extract the real part signal and the imaginary part signal from the complex received signal corresponding to each decoding channel, respectively.

[0081] Each decoding channel has two sets of matched filter bank module 11 and correlation filter bank module 14. One set of matched filter bank module 11 and correlation filter bank module 14 is used to perform matched filtering and correlation filtering on the real part signal, respectively. The matched-filtered signal enters the downsampling / mean filtering module 12 for downsampling and mean filtering, and then passes through the threshold / classification module 13 for threshold decision and classification to recover the symbol sequence type. The correlation-filtered signal enters the downsampling module 15 for downsampling, and then enters the sorting module 16 for sorting to extract subcarriers and determine the recovered symbol order. The sorted signal and the classified signal enter the symbol decision module 17 for symbol decision to obtain the recovered spread spectrum sequence corresponding to the real part signal. This recovered spread spectrum sequence is input to the reference extraction module 18 and the correlation module 19, respectively. The reference extraction module 18 is used for reference extraction to obtain the recovered bit stream. The correlation module 19 is used to perform correlation operations, and the correlation results are sent to the threshold judgment module 20 for threshold judgment processing to obtain the recovered bitstream.

[0082] Another set of matched filter bank module 11 and correlation filter bank module 14 are used to perform matched filtering and correlation filtering on the imaginary part signal, respectively. The matched-filtered signal enters the downsampling / mean filtering module 12 for downsampling and mean filtering, and then passes through the threshold / classification module 13 for threshold decision and classification to recover the type of the spread spectrum sequence. The correlation-filtered signal enters the downsampling module 15 for downsampling, and then enters the sorting module 16 for sorting. The sorted signal and the classified signal enter the symbol decision module 17 for symbol decision to obtain the recovered spread spectrum sequence corresponding to the imaginary part signal. The recovered spread spectrum sequence is input to the reference extraction module 18 and the correlation module 19, respectively, where the reference extraction module 18 is used for reference extraction processing to obtain the recovered bit stream. The correlation module 19 is used to perform correlation operations, and the correlation results are sent to the threshold judgment module 20 for threshold judgment processing to obtain the recovered bitstream.

[0083] Parallel-to-serial conversion module 22 is used to process the 2M recovered bit streams output from all M decoding channels. (1≤i≤2M), 2M recovered bit streams Perform parallel-to-serial conversion to obtain the recovered information sequence. and information sequence

[0084] Example:

[0085] Step 1, System parameter configuration, setting the 4-sampling frequency f of the chaotic pseudo-orthogonal shaping filter bank. s Symbol frequency f, number of chaotic pseudo-orthogonal subcarriers N c The frequency f of the nth chaotic subcarrier n (1≤n≤N c Spreading factor L, symbol period T s =1 / f, OFDM parameter configuration for the number of data subcarriers M.

[0086] In this embodiment, the sampling frequency f is set. s =40MHz, symbol frequency f = 0.625MHz, number of chaotic pseudo-orthogonal subcarriers N c =2, corresponding to subcarrier frequencies f1 = 0.625MHz, f2 = 1.25MHz, spreading factor L = 3, symbol period T s =1 / f=1.6μs, the number of data subcarriers transmitted by OFDM is M=48.

[0087] Step 2, prepare the information sequence to be transmitted A = [A1, A2, ..., A...]. 2M ]Tr The sequence of information to be transmitted is B = [B1, B2, ..., B...]. 2M ] Tr T r As the transpose operator, the two sets of information streams are fed into the serial-to-parallel conversion module 2, resulting in 2M parallel A information streams and 2M B information streams. Each information stream contains binary information +1 or -1, and the transmission information of the i-th information stream is defined as follows:

[0088]

[0089] Where 1≤i≤2M, 1≤n≤N c , L and N c These represent the spreading coefficients and the number of chaotic subcarriers defined in step 1, respectively. i,n,l Represents the i-th information flow A i The nth row of the middle Column information, b i,n Represents the i-th information flow B i The nth piece of information.

[0090] In this embodiment, taking the first modulation channel as an example, i.e., i = 1, 2; since L = 3, N c =2, assuming the transmitted information stream is:

[0091]

[0092] Step 3: Combine 2M A information streams and 2M B information streams and send them to the spread spectrum mapping module 3 in each modulation channel for spread spectrum mapping processing to obtain the spread spectrum sequence S. i (1≤i≤2M), as follows:

[0093]

[0094] For ease of understanding, matrix S in the above formula will be... i Represented as S i =[S i,1 ,S i,2 ,…,S i,l ,…,S i,2L ], 1≤l≤2L, where S i,l For equation (1)S i The l-th column in the data, i.e.:

[0095]

[0096] In this embodiment, the output spreading sequences S1 and S2 of the spreading mapping in the first modulation channel are respectively:

[0097]

[0098] The same applies to other channels.

[0099] Step 4, spread spectrum sequence S i (1≤i≤2M) are fed into the following chaotic pseudo-orthogonal shaping filter bank 4:

[0100]

[0101] Where t is the time parameter, u i,n (t) is the i-th spreading sequence S i The nth (1≤n≤N) c The chaotic pseudo-orthogonal signals output by the chaotic pseudo-orthogonal shaping filters, s i,n,l It is the i-th (1≤i≤2M) group of spreading sequences S i The nth (1≤n≤N) c The symbol in the l-th column (1≤l≤2L) of the row satisfies s i,n,l ∈{±1}, f is the symbol frequency of step 1, p n It is the nth pseudoorthogonal basis function, as follows:

[0102]

[0103] Where β = fln2 and ω n =2πf n f n The frequency of the nth pseudoorthogonal basis function in step 1.

[0104] In this embodiment, in step 1, f = 0.625MHz, f1 = 0.625MHz, and f2 = 1.25MHz are set. Substituting S1 from step 3 into formula (2), we can obtain two channels (N) c =2) Output chaotic pseudo-orthogonal signals.

[0105] Figure 3 The solid line in the middle represents the first chaotic pseudo-orthogonal signal u. 1,1 (t), corresponding to the dashed line as the first row of the spreading sequence of S1 [s 1,1,1 ,s 1,1,2 ,s 1,1,3 ,s 1,1,4 ,s 1,1,5 ,s 1,1,6 ] = [+1,+1,-1,+1,+1,-1]. It can be seen that, since the symbol period T is obtained in step 1... s =1 / f=1.6μs; the duration of the signal corresponding to the 6 spread spectrum sequences here is t∈[0,9.6)μs. Figure 4 The solid line represents the output signal u of the second chaotic pseudo-orthogonal filter. 1,2(t), corresponding to the second row of the spreading sequence S1 as shown by the dashed line [s 1,2,1 ,s 1,2,2 ,s 1,2,3 ,s 1,2,4 ,s 1,2,5 ,s 1,2,6 ] = [+1,-1,-1,-1,+1,+1]. Similarly, the chaotic pseudo-orthogonal signal u of S2 2,1 (t) and u 2,2 (t) and the corresponding spreading sequence [s] 2,1,1 ,s 2,1,2 ,s 2,1,3 ,s 2,1,4 ,s 2,1,5 ,s 2,1,6 ] = [-1,+1,-1,+1,-1,+1] and [s 2,2,1 ,s 2,2,2 ,s 2,2,3 ,s 2,2,4 ,s 2,2,5 ,s 2,2,6 ] = [+1,-1,-1,+1,-1,-1] are respectively as follows Figure 5 and Figure 6 As shown.

[0106] Step 5, spread spectrum sequence S i The chaotic pseudo-orthogonal signals output from the chaotic pseudo-orthogonal shaping filter are summed in adder module 5. The two outputs of each modulation channel are used as the real and imaginary parts of the complex signal, respectively, to obtain the subcarrier signal for that channel.

[0107]

[0108] Where 1≤j≤M, U j This represents the j-th chaotic subcarrier transmission signal, whose real and imaginary parts are respectively represented by Re. j (·) and Im j (·) indicates M subcarriers U j (1≤j≤M) is processed by the inverse Fourier transform / parallel-to-serial conversion module 6, and the transmission signal T(t) is obtained by OFDM multicarrier modulation and then transmitted to the wireless channel through the radio frequency transmission module 7.

[0109] In the embodiment, in the first modulation channel, the signal output by the spread spectrum sequence S1 after passing through the chaotic pseudo-orthogonal shaping filter is u. 1,1 and u 1,2 The signal output from S2 after passing through the chaotic pseudo-orthogonal shaping filter is u. 2,1 and u 2,2 According to equation (4), the first chaotic subcarrier signal can be obtained as follows:

[0110] U1=Re1(u 1,1 +u 1,2 )+Im1(u 2,1 +u 2,2 ),

[0111] like Figure 7 and Figure 8 As shown, where Figure 7 The real part of the first chaotic subcarrier signal, i.e., Re1(u 1,1 +u 1,2 ). Figure 8 The first chaotic subcarrier imaginary part signal, i.e., Im1(u 2,1 +u 2,2 Following the steps above, we can obtain M = 48 chaotic subcarrier signals [U1, U2, ..., U...]. 48 The 48 chaotic subcarrier signals are subjected to inverse Fourier transform and modulated into a complex transmission signal T(t) using OFDM modulation. Since IFFT transform and OFDM transmission are the basic modulation methods in the field of communication, the modulated signal is transmitted to the wireless channel through the radio frequency antenna, which will not be elaborated here.

[0112] Step 6: Signal Acquisition. The receiving end obtains the received signal r(t) = T(t) + w(t) through the RF receiving module 8, where T(t) is the transmitted signal from step 5, and w(t) is the noise signal introduced by the channel. r(t) is then processed by the Fourier transform / serial-to-parallel conversion module 9, and divided into M complex received signals r1(t), r2(t), ..., r M (t). Each complex received signal is sent to the corresponding decoding channel, and the real part signal and the imaginary part signal are separated by the real part extraction module 10 and the imaginary part extraction module 21 to obtain 2M demodulated signals as follows:

[0113]

[0114] In this embodiment, for ease of understanding the modulation process, the influence of noise is ignored, i.e., w(t) = 0. The received signal r(t) undergoes OFDM transmission and Fourier transform to achieve basic OFDM demodulation, which will not be elaborated here.

[0115] Taking the first decoding channel as an example, i.e., j=1, the real part signal and the imaginary part signal can be obtained according to equation (5):

[0116]

[0117] Since the noise is assumed to be zero in the embodiment, the demodulated signals R1(t) and R2(t) are consistent with the transmitting signal, such as... Figure 7 and Figure 8 .

[0118] Step 7: Input the demodulated signal of each decoding channel into the matched filter bank module 11; the matched filter bank is as follows:

[0119]

[0120] Where ξ i,n (t) is the output signal of the i-th real / imaginary signal after passing through the n-th matched filter, R i (t), given in step 6, is the real or imaginary part of the complex received signal. n (t)=p n (-t) is the time inverse function of the nth pseudoorthogonal basis function in equation (3), and τ is the integration variable.

[0121] In this embodiment, taking the real demodulated signal R1(t) (i=1) in the first decoding channel as an example, the demodulated signal R1(t) is input into the matched filter bank of equation (6), where N c =2, corresponding to the output signals ξ of the first and second matched filters. 1,1 (t) and ξ 1,2 (t) respectively as Figure 9 and Figure 10 As shown. Similarly, the output signal ξ of the imaginary demodulated signal R2(t) in the first decoding channel after passing through the matched filter bank can be obtained. 2,1 (t) and ξ 2,2 (t), respectively as Figure 11 and Figure 12 As shown. Following the steps above, the output signals of all filters in the M-channel signal decoding can be obtained, which will not be repeated here.

[0122] Step 8, filter the nth output ξ of the i-th demodulated signal. i,n (t) Input sampling / mean filtering module 12, with sampling interval T s =1 / f downsampling, then the sampling point ξ at the l-th (1≤l≤2L) sampling time. i,n,l for:

[0123] ξ i,n,l =ξ i,n (T s (l-1)+T s / 2), 1≤l≤2L (7)

[0124] Where L is the spreading coefficient defined in step 1.

[0125] The i-th demodulated signal N is calculated according to the following formula. c The mean of the downsampled sequence of the filtered output signal:

[0126]

[0127] in It is the average value of the sampling points at the l-th (1≤l≤2L) sampling time of the i-th demodulated signal.

[0128] In this embodiment, T is set according to step 1. s =1 / f=1.6μs, spreading coefficient L=3, then the real demodulated signal R1(t) and the imaginary demodulated signal R2(t) are respectively the output signals ξ of the matched filter bank. 1,1 (t), ξ 1,2 (t), ξ 2,1 (t), ξ 2,2 The sampling time and downsampling value of (t) are as follows Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown in Table 1.

[0129] Table 1. Downsampling values ​​and corresponding sampling times of the matched filter bank

[0130]

[0131]

[0132] According to equation (8), the mean of the downsampling sequence of the two demodulated signals when i = 1, 2 can be obtained:

[0133]

[0134] The results are shown in Table 2;

[0135] Table 2 shows the mean of the downsampling sequence in the examples.

[0136]

[0137] Step 9: The threshold / classification module 13 sets the decision threshold and restores the symbol sequence type. The decision threshold is as follows:

[0138]

[0139] J k This represents the threshold for the k-th decision.

[0140] Calculate the mean of the downsampled sequence The distance to each decision threshold is as follows:

[0141]

[0142] And ruled that N c +1 index value of the minimum distance among the distances, as follows:

[0143]

[0144] Where I i,l Let be the index value of the l-th sampling time in the i-th demodulated signal, min{·} is the minimum value operator, and arg{·} is the index value operator.

[0145] The information symbol distribution of the recovered symbol sequence is as follows:

[0146]

[0147] in and These represent the number of "+1" and "-1" information items at the l-th sampling time in the i-th demodulated signal, respectively, indicating that the recovered symbol sequence type is:

[0148]

[0149] Where T r This is the transpose operator.

[0150] In this embodiment, according to the parameters set in step 1, the decision threshold can be obtained by formula (9):

[0151] [J1,J2,J3]=[1,0,-1],

[0152] The mean of the downsampled sequence can be calculated according to formula (10). The distances to each threshold are shown in Table 3.

[0153] Table 3 shows the mean of the downsampling sequence in the examples. Distance to each threshold and index of the minimum value

[0154]

[0155]

[0156] The mean of the downsampled sequence at the l-th sampling time is calculated according to equation (11). The index value (i.e., k value) corresponding to the minimum value among all thresholds, taking i=1, l=1 as an example, at this time... The distances to [J1,J2,J3]=[1,0,-1] are respectively [d 1,l,1 ,d 1,l,2 ,d 1,l,3 If ] = [0.09, 0.91, 1.91], then the minimum distance d 1,l,1 =0.09 corresponds to the index value k=1, that is, I 1,1 =1. Following the above process, the index values ​​for other sampling times can be obtained, as shown in Table 3.

[0157] The information symbol distribution of the recovered spread spectrum sequence is as follows:

[0158]

[0159] The recovered spread spectrum sequence type is:

[0160]

[0161] The information quantity distribution of the spread spectrum sequence recovered at other times was obtained by the same method, as shown in Table 3.

[0162] Step 10: Input the real / imaginary part of the signal from each decoding channel into the correlation filter bank module 14, where the output of the nth filter is:

[0163]

[0164] Where R i (t) represents the real / imaginary part of the i-th signal, τ is the integration variable, and o n (t) is the nth pseudoorthogonal basis function, as follows:

[0165]

[0166] The parameter settings are the same as in equation (3).

[0167] The filter output signal is input to the downsampling module 15 at a sampling interval T. s =1 / f downsampling, then the sampling point y at time l (1≤l≤2L) i,n,l for:

[0168] y i,n,l =y i,n (T s (l-1)+T s / 2), 1≤l≤2L; (16) L is the spreading factor.

[0169] In this embodiment, taking the real demodulated signal R1(t) (i=1) in the first decoding channel as an example, the demodulated signal R1(t) is input into the correlation filter bank of equation (15) and sampled by equation (16), with a sampling interval T. s =1 / f=1.6μs, the resulting downsampling sequence is as follows Figure 13 As shown, where N c =2, L=3. Similarly, the sequence of the imaginary demodulated signal R2(t) in the first decoding channel after passing through the correlation filter bank and downsampling is as follows: Figure 14 As shown in Table 4, the sampling time and sampled values ​​are as follows.

[0170] Table 4. Downsampling values ​​and corresponding sampling times of the relevant filter bank

[0171]

[0172] Step 11: Enter the sorting module 16 to determine the order of the recovered spread spectrum sequence, sort the outputs of the relevant filters by downsampling, and sort the i-th downsampled sequence Y. i,l =[y i,1,l ,y i,2,l ,…y i,n,l ,…,y i,Nc,l Sort by size, the sorting index is defined as Ind i =[m1,m2,…,m Nc ],satisfy

[0173] In the embodiment, when i=1, l=1, the downsampling sequence Y 1,1 =[y 1,1,1 ,y 1,2,1 If [2.40, 6.43] are arranged in ascending order, then the index values ​​m1 = 2 and m2 = 1, satisfying y 1,2,1 >y 1,1,1 Following the above procedure, the sorting index values ​​for other sequences and sampling times were obtained, as shown in Table 5.

[0174] Table 5. Sorting Index of Downsampled Values ​​of Correlated Filter Banks

[0175]

[0176] Step 12, the symbol decision module 17 jointly recovers the spread spectrum sequence type and the spread spectrum sequence order; the spread spectrum sequence at time l of the M-channel decoding channel is recovered according to the following formula:

[0177]

[0178] Where 1≤i≤2M, 1≤l≤2L, the spread spectrum sequence to be recovered subscript The order of the recovered spread spectrum sequence determined in step 11, equation (13), The type of recovery spread spectrum sequence determined in step 9 (17).

[0179] Following the above procedure, all spread spectrum sequences of channel M can be recovered.

[0180] In the embodiment, assuming i = 1, l = 1, using equations (13) and (17), and combining with Tables 3 and 5, it can be seen that:

[0181]

[0182] Similarly, the decoding spread spectrum sequences for other sequences and sampling times can be obtained, as shown in Table 6.

[0183] Table 6 shows the joint recovery spread spectrum sequence in the embodiments.

[0184]

[0185] According to Table 6, the recovered spread spectrum sequence in the first decoding channel can be summarized as follows:

[0186]

[0187] The recovered spread spectrum sequence is compared with the transmitter spread spectrum sequences S1 and S2 in step 3. They are completely identical, and the recovered spread spectrum sequence is correct.

[0188] Step 13, Information Flow and Decode; the information for one of the channels is the reference sequence.

[0189] The M-channel recovered spread spectrum sequence is input into the reference extraction module 18 and the correlation module 19, and the relevant operations are performed according to the following formula:

[0190]

[0191] Information flow In After threshold judgment by threshold judgment module 20, the result is decoded as follows:

[0192]

[0193] Information Flow Decoded as:

[0194]

[0195] Decode all M-channel information streams according to the above process. and The parallel-to-serial conversion of the decoded information stream is performed according to the following formula:

[0196]

[0197] This concludes the entire decoding process.

[0198] In this embodiment, the first spreading sequence in the first modulation channel... Perform the relevant operations according to formula (18):

[0199]

[0200] Z 2,1 =-3

[0201] Z 2,2 =3

[0202] The relevant value Z 1,1 Z 1,2 Z 2,1 Z 2,2 By inputting equation (19), we can obtain:

[0203]

[0204] According to equation (20), we can obtain:

[0205]

[0206] contrast The transmission information streams A1, A2, B1, and B2 set in step 2 are exactly the same. Decode all M information streams according to the above process. and By inputting the parallel-to-serial converter, we can obtain:

[0207]

[0208] Contains 96 sub-bit streams and 96 sub-bit streams The decoding process has ended.

[0209] Experimental verification:

[0210] Simulations compared the performance of the proposed scheme with that of a traditional chaotic spread spectrum scheme, namely the differential chaotic keying (DCSK) scheme. The simulation was conducted with the sampling frequency f of the proposed scheme set to... s =40MHz, initial frequency f = 0.625MHz, and the number of chaotic pseudo-orthogonal subcarriers are N c =2,3,4, corresponding to subcarrier frequencies f1=0.625MHz, f2=1.25MHz, f3=1.875MHz, f4=2.5MHz, and the number of OFDM subcarriers M=48. The spreading gain L=15 for this invention and DCSK. Simulation results are as follows. Figure 15 As shown, the solid, dashed, and dotted lines within the black boxes represent the bitstream B of the present invention at N... c Error rate curves for 2, 3, and 4 are shown. The solid black circle, dashed line, and dotted line represent the bit stream A of the present invention at N. c Error rate curves for 2, 3, and 4. The contrasting scheme DCSK is represented by a solid black line.

[0211] As can be seen, the bit error rate (BER) of bit stream B in this invention is much lower than that of bit stream A and DCSK due to the use of spread spectrum communication. Bit stream A's BER is significantly lower than DCSK's at low signal-to-noise ratios (SNR). At high SNRs, as the number of pseudo-orthogonal subcarriers increases, the multiple access interference between different subcarriers gradually increases, leading to performance degradation and a BER similar to DCSK. However, the increase in the number of pseudo-orthogonal subcarriers means a rapid increase in the communication rate of this invention, achieving a higher communication rate than the comparative DCSK scheme.

[0212] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A high-speed differential keying communication method based on mixed-access multiple access and orthogonal frequency division multiple access, characterized in that, include: The information sequences A and B to be transmitted are converted into multiple sets of parallel information through serial-to-parallel conversion. The spread spectrum sequences obtained by spreading the two sets of parallel information of each modulation channel through spread spectrum mapping are processed by a set of chaotic orthogonal filters to obtain the corresponding chaotic pseudo-orthogonal signals. The real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals corresponding to the two sets of parallel information are summed and used as the chaotic subcarrier transmission signals of the modulation channel. After Fourier transform and parallel-to-serial conversion of the chaotic subcarrier transmission signals of all modulation channels, they are modulated into complex transmission signals according to OFDM modulation and transmitted to the wireless channel through the radio frequency antenna. The received signal is obtained through radio frequency reception. The received signal is then processed by Fourier transform and parallel-to-serial conversion to obtain the complex received signal corresponding to each decoding channel. Each complex received signal is divided into a real part signal and an imaginary part signal. The real part signal is processed by matched filtering and correlation filtering. The result of matched filtering is processed by downsampling and mean filtering, threshold decision and classification to recover the symbol sequence type. The results of correlation filtering are downsampled and sorted, and then combined with the results of classification processing for symbol determination to obtain the reconstructed spread spectrum sequence corresponding to the real part signal; the imaginary part signal is processed in the same way as the real part signal to obtain the corresponding reconstructed spread spectrum sequence. The recovered spread spectrum sequences corresponding to the real and imaginary parts of the signal are processed by reference extraction and related operations to obtain a set of recovered bit streams corresponding to the real and imaginary parts of the signal, respectively. The recovered bitstreams output from all decoding channels are subjected to parallel-to-serial conversion to obtain the recovered information sequence. and information sequence .

2. A high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access, characterized in that, Includes the transmitter and receiver; The transmitter includes a sequence of information to be transmitted module (1), a serial-to-parallel conversion module (2), a spread spectrum mapping module (3), a chaotic pseudo-orthogonal shaping filter bank module (4), an adder module (5), an inverse Fourier transform parallel-to-serial conversion module (6), and an RF transmission module (7). The receiver includes an RF receiving module (8), a Fourier transform / serial-to-parallel conversion module (9), a real part extraction module (10), a matched filter bank module (11), a downsampling / mean filtering module (12), a threshold / classification module (13), a correlation filter bank module (14), a downsampling module (15), a sorting module (16), a symbol decision module (17), a reference extraction module (18), a correlation module (19), a threshold judgment module (20), an imaginary part extraction module (21), and a parallel-to-serial conversion module (22); the receiver's decoding channels include... M The road, and the launch terminal M Corresponding to the modulation channel; The information sequence module (1) is used to generate information sequence A and information sequence B to be transmitted; The serial-to-parallel conversion module (2) is used to convert the information sequences A and B to be transmitted into multiple sets of parallel information, including 2 M Group A information flow and 2 M Group B information flow; The spread spectrum mapping module (3) has two sets in each modulation channel, which are used to receive the two sets of A information stream and B information stream corresponding to the modulation channel and perform spread spectrum mapping processing to obtain the corresponding spread spectrum sequence. There are two sets of chaotic pseudo-orthogonal shaping filter banks (4) in each modulation channel. Each set of chaotic pseudo-orthogonal shaping filter banks (4) is used to receive the spread spectrum sequence output by the corresponding spread spectrum mapping module (3) to obtain the corresponding chaotic pseudo-orthogonal signal. The adder module (5) is used to sum the real part sequence and the imaginary part sequence of the chaotic pseudo-orthogonal signals output by the two sets of chaotic pseudo-orthogonal shaping filter groups (4) in each modulation channel, and then use them as the chaotic subcarrier transmission signal of the modulation channel. The inverse Fourier transform / parallel-to-serial conversion module (6) is used to receive all M The chaotic subcarrier transmission signal output from the modulation channel is subjected to Fourier transform and parallel-to-serial conversion processing, and then modulated into a complex transmission signal according to OFDM modulation. The radio frequency transmission module (7) is used to transmit the complex transmission signal to the wireless channel via electromagnetic waves; The radio frequency receiving module (8) is used to receive complex transmission signals from the wireless channel and process them to obtain the received signal; The Fourier transform / serial-to-parallel conversion module (9) is used to process the received signal. r ( t Perform Fourier transform and parallel-to-serial conversion to obtain M Complex signal reception path; The real part extraction module (10) and the imaginary part extraction module (21) are used to extract the real part signal and the imaginary part signal from the complex received signal corresponding to each decoding channel, respectively. Two sets of matched filter bank modules (11) and correlation filter bank modules (14) are set in each decoding channel. One set of matched filter bank modules (11) and correlation filter bank modules (14) is used to perform matched filtering and correlation filtering on the real part signal, respectively. The signal after matched filtering enters the downsampling / mean filtering module (12) for downsampling and mean filtering, and then passes through the threshold / classification module (13) for threshold decision and classification to recover the symbol sequence type. The signal after correlation filtering enters the downsampling module (15) for downsampling, and then enters the sorting module (16) for sorting. The sorted signal and the classified signal enter the symbol decision module (17) for symbol decision to obtain the recovered spread spectrum sequence corresponding to the real part signal. The recovered spread spectrum sequence is input to the reference extraction module (18) and the correlation module (19), respectively. The reference extraction module (18) is used for reference extraction to obtain the recovered bit stream. ; The correlation module (19) is used to perform correlation operations. The correlation results are sent to the threshold judgment module (20) for threshold judgment processing to obtain the recovered bit stream. The imaginary part of the signal is processed through the same procedure to recover the bit stream. and the recovered bitstream ; The parallel-to-serial conversion module (22) is used to convert all M 2-way decoding channel output M A recovered bitstream 2 M A recovered bitstream Perform parallel-to-serial conversion to obtain the recovered information sequence. and information sequence .

3. The high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access according to claim 2, characterized in that, The formula for the spread spectrum mapping process is: in, Represents information flow and information flow The generated spread spectrum sequence, , Indicates the number of groups in the information flow.

4. The high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access according to claim 2, characterized in that, The expression for the chaotic pseudo-orthogonal shaping filter bank (4) is: in t It is a time parameter. It is the first i Group spread spectrum sequence S i The Middle n (1≤ n ≤ N c The chaotic pseudo-orthogonal signals output by the chaotic pseudo-orthogonal shaping filters. It is the first i (1≤ i ≤2 M Group S spread spectrum sequence i The Middle n (1≤ n ≤ N c ) line number l (1≤ l ≤2 L ) column symbols, f It is the symbol frequency. p n It is the first n One pseudo-orthogonal basis function; N c This represents the number of chaotic pseudo-orthogonal subcarriers. L This represents the spreading factor.

5. The high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access according to claim 2, characterized in that, After summing the real and imaginary sequences in the adder module (5), the result is used as the chaotic subcarrier transmission signal for the modulation channel, specifically: Where 1≤ j ≤ M , Indicates the first j A chaotic subcarrier transmission signal, the real and imaginary parts of which are respectively composed of... and express; Indicates the first Group spread spectrum sequence S i The Middle n The chaotic pseudo-orthogonal signal output by a chaotic pseudo-orthogonal shaping filter. N c This represents the number of chaotic pseudo-orthogonal subcarriers.

6. The high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access according to claim 2, characterized in that, The matched filter bank in the matched filter bank module (11) is as follows: in It is the first i Real part signal / Imaginary part signal After the first n The output signal of a matched filter; g n ( t ) is the first in the chaotic pseudo-orthogonal shaping filter bank n The time inverse function of a pseudoorthogonal basis function τ For integration variables; The correlation filter bank in the correlation filter bank module (14) is as follows: in, No. i Real part signal / Imaginary part signal After the first n The output signal of each correlation filter o n ( t ) is the first n A pseudo-orthogonal basis function.

7. The high-speed differential keying communication system based on mixed-access multiple access and orthogonal frequency division multiple access according to claim 2, characterized in that, When the threshold / classification module (13) performs threshold decision and classification processing, it first sets... k Each decision threshold J k , Then calculate the mean of the sequence obtained after downsampling and mean filtering. With each decision threshold J k The distance between them, and the judgment. N c The index value of the minimum distance among the + 1 distances is used to recover the information symbol distribution of the symbol sequence and obtain the recovered symbol sequence type.

8. A terminal device, comprising a processor, a memory, and a computer program stored in the memory; characterized in that, When the processor executes the computer program, it implements the high-speed differential keying communication method based on mixed-access and orthogonal frequency-division multiple access as described in claim 1.

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