Multistage polarization coding communication method based on M-ary DCSK modulation

Abstract

The invention provides a multilevel polarization coding communication method based on M-ary DCSK modulation, and the method comprises the steps: carrying out the bit segmentation of an original information bit stream, and obtaining a plurality of sub-bit streams; performing multi-stage polarization coding on each sub-bit stream to generate a corresponding polarization code word, and configuring different polarization code rates for the sub-bit streams with different reliability; correspondingly mapping the polar code words with different code rates to bits with different reliability in the modulation symbol sequence through polar segmentation mapping to form the modulation symbol sequence; and finally, performing M-ary DCSK modulation on the sequence to generate a chaotic signal so as to realize multi-stage polarization coding communication. According to the multi-stage polarization coding communication method based on M-ary DCSK modulation provided by the invention, the multi-stage polarization coding and the M-ary DCSK modulation technology are deeply combined, and the bit error rate performance is optimized on the premise of maintaining the original anti-multipath fading capability and spectrum efficiency.

Description

A multi-level polarization coding communication method based on M-ary DCSK modulation Technical Field

[0001] This invention belongs to the field of wireless communication technology, specifically relating to a multi-level polarization coding communication method based on M-ary DCSK modulation. Background Technology

[0002] In the field of wireless communication technology, especially in complex channel environments such as low signal-to-noise ratio and multipath fading, chaotic modulation techniques have attracted widespread attention due to their excellent security and anti-interference capabilities. M-ary DCSK (Multivariate Differential Chaotic Shift Keying), as one such modulation technique, effectively avoids the dependence on channel estimation in traditional coherent demodulation through a non-coherent detection mechanism, demonstrating good robustness. However, within each modulation symbol, due to the characteristics of constellation mapping, the noise immunity and reliability of different bits vary significantly. Applying a uniform coding protection strategy to all bits leads to an overabundance of coding resources for high-reliability bits, while the most vulnerable low-reliability bits are not adequately protected. This becomes a key bottleneck restricting the improvement of bit error rate performance, particularly prominent under harsh channel conditions, easily generating a difficult-to-improve bit error rate layering effect. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a multi-level polar coding communication method based on M-ary DCSK modulation to solve the aforementioned problems. This method deeply integrates multi-level polar coding with M-ary DCSK modulation technology, optimizing bit error rate performance while maintaining the original multipath fading resistance and spectral efficiency.

[0004] To address the aforementioned technical problems, this invention provides a multi-level polar coding communication method based on M-ary DCSK modulation, comprising the following steps: acquiring an original information bitstream; performing bit segmentation on the original information bitstream to obtain several sub-bitstreams; performing multi-level polar coding on each of the sub-bitstreams to obtain several corresponding polar codewords; wherein, based on the bit reliability corresponding to the several sub-bitstreams, configuring different polar code rates for each of the several sub-bitstreams; performing polar segmentation mapping on the several polar codewords to obtain a modulation symbol sequence; wherein, based on the polar code rate corresponding to the several polar codewords, mapping the several polar codewords to bits with different reliability in the modulation symbol sequence; and performing M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to realize multi-level polar coding communication.

[0005] In the above scheme, based on the bit reliability corresponding to multiple sub-bit streams obtained from bit segmentation, different polar code rates are configured for each sub-bit stream. Then, polar segmentation mapping maps the polar codewords with different rates to bits with different reliability in the modulation symbol sequence, achieving differentiated and unequal protection for bits with different reliability. This ensures that the allocation of coding resources matches the actual channel capacity characteristics, thereby optimizing bit error rate performance while maintaining the original multipath fading resistance and spectral efficiency. Under harsh channel conditions such as low signal-to-noise ratio and strong interference, the above scheme can effectively overcome the bit error rate plateau effect, obtain considerable coding gain, improve communication reliability, and provide an effective solution for robust high-speed wireless data transmission in complex environments.

[0006] Further, the step of bit segmentation based on the original information bitstream to obtain several sub-bitstreams includes: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

[0007] In the above scheme, the number of bits corresponding to each modulation symbol is obtained based on the M-ary DCSK modulation order, and the original information bitstream is bit-segmented accordingly to obtain several sub-bitstreams corresponding to the number of bits. This scheme provides an accurate input basis for subsequent multi-level polarization coding and polar segmentation mapping, ensuring that sub-bitstreams with different reliability can be identified and fed into the corresponding coding and mapping processes. The scheme can accurately match the capacity differences of each bit within a symbol, laying the necessary foundation for implementing differentiated coding protection strategies, thereby optimizing anti-interference performance and transmission reliability while maintaining spectral efficiency.

[0008] Furthermore, the step of performing multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codes, wherein different polar code rates are configured for several sub-bit streams with different reliability; includes: obtaining several corresponding reliability values ​​based on several sub-bit streams; configuring polar code rates for several sub-bit streams based on several reliability values ​​corresponding to several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on several multi-level sub-bit streams to obtain several corresponding polar code codes.

[0009] In the above scheme, a reliability value is obtained based on several sub-bit streams, and a polar code rate positively correlated with the reliability value is configured for each sub-bit stream accordingly, resulting in several multi-level sub-bit streams. Polar coding is then performed to obtain the corresponding polar codewords. This scheme achieves differentiated coding protection for bits with different reliability levels, ensuring precise matching of coding resources with the actual needs of each sub-bit stream. Therefore, while maintaining spectral efficiency, it effectively enhances anti-interference capability and transmission reliability, especially achieving superior bit error rate performance under adverse channel conditions.

[0010] Furthermore, the step of obtaining several reliability values ​​based on several sub-bit streams includes: presetting a communication link simulation model corresponding to the M-ary DCSK modulation; inputting several sub-bit streams into the communication link simulation model so that the communication link simulation model performs Monte Carlo simulation based on several sub-bit streams to obtain several bit error rates corresponding to several sub-bit streams; and determining several reliability values ​​based on several bit error rates corresponding to several sub-bit streams.

[0011] In the above scheme, a communication link simulation model corresponding to M-ary DCSK modulation is preset, and each sub-bit stream is input into this model for Monte Carlo simulation to obtain its corresponding bit error rate, thereby determining the reliability value of each sub-bit stream. This scheme can accurately evaluate the actual fault tolerance capability of each bit under specific modulation and channel conditions, ensuring that the obtained reliability value truly reflects its vulnerability. This provides an objective and reliable basis for subsequent differentiated configuration of polarization code rates, thus ensuring a precise match between the coding protection strength and the actual needs of each bit. This optimizes the allocation of error correction resources and effectively improves transmission robustness under complex channel conditions.

[0012] It should be noted that during the Monte Carlo simulation, the code rate of each polar code level can be set to 1. Through a large number of simulations, the number of bit errors in each sub-channel is counted, and the reliability of each sub-channel is ranked accordingly. Finally, the sub-channel with the highest reliability is selected for transmitting information bits, while the remaining sub-channels transmit frozen bits.

[0013] Further, the step of performing polar segmentation mapping based on several polar codewords to obtain a modulation symbol sequence includes: mapping several polar codewords with different polar code rates to bits with different reliability in the modulation symbol sequence; obtaining several corresponding polar code rates based on several polar codewords; mapping several polar codewords to several bits in a preset polar segmentation constellation diagram based on the several polar code rates corresponding to several polar codewords to obtain several modulation symbols; wherein the reliability of the mapped bits is negatively correlated with the polar code rate of the polar codeword; and obtaining the modulation symbol sequence based on the several modulation symbols.

[0014] In the above scheme, the polar code rate of each polar codeword is obtained, and based on the negative correlation between code rate and bit reliability, polar codewords with different code rates are mapped to bits with different reliability in a preset polar segmentation constellation diagram, thereby obtaining the modulation symbol and the modulation symbol sequence. This scheme achieves a precise match between the coding protection strength and the inherent fault tolerance capability of each bit within the modulation symbol, allowing low-rate codewords with high protection strength to carry high-reliability bits, and high-rate codewords to be adapted to low-reliability bits, thus optimizing the coding resource allocation and enhancing the overall robustness of symbol transmission. Therefore, while maintaining spectral efficiency, the reliability of symbol decision-making under adverse channel conditions is improved, providing a better input foundation for subsequent demodulation and decoding.

[0015] It should be noted that the preset polar segmentation constellation diagram adopts a polar segmentation mapping scheme, such as an 8PSK polar segmentation constellation diagram, to maximize the reliability gap between each bit, so that the bit with the lowest reliability corresponds to the bit with the weakest reliability in the constellation diagram, and the bit with the highest reliability corresponds to the bit with the strongest reliability, thereby providing the optimal mapping basis for multi-level polar coding.

[0016] Further, the step of performing M-ary DCSK modulation based on the modulation symbol sequence to obtain a chaotic signal for multi-level polarization coded communication includes: a preset chaotic reference signal; performing a Hilbert transform based on the chaotic reference signal to obtain an auxiliary chaotic signal; converting each modulation symbol in the modulation symbol sequence into a two-dimensional coordinate corresponding to the modulation symbol based on a preset constellation diagram mapping rule; and performing a weighted combination based on the two-dimensional coordinates corresponding to several modulation symbols, the chaotic reference signal, and the auxiliary chaotic signal to obtain the chaotic signal.

[0017] In the above scheme, an auxiliary chaotic signal is obtained by pre-setting a chaotic reference signal and performing a Hilbert transform. The modulation symbol sequence is then converted into two-dimensional coordinates based on a pre-set constellation diagram mapping rule. These coordinates are then weighted and combined with the chaotic reference signal and the auxiliary chaotic signal to ultimately generate a chaotic signal carrying multi-level coding information. This scheme accurately converts the modulation symbol sequence generated by the aforementioned polarization coding and polar segmentation mapping into a physical layer signal, thus fully preserving the reliability differentiation protection achieved in the coding and mapping stages. This scheme fully utilizes the transmission characteristics of chaotic signals and works closely with the front-end processing, thereby effectively improving the robustness and transmission reliability of communication in complex wireless environments.

[0018] It should be noted that the weighted combination specifically refers to the following: for the w-th modulation symbol, the corresponding chaotic signal is composed of the chaotic reference signal transmitted in the first half of the cycle and the information signal formed by linearly combining the chaotic reference signal and the auxiliary chaotic signal after Hilbert transformation based on the two-dimensional coordinates (as, bs) corresponding to the symbol in the second half of the cycle, where s is the symbol index in the constellation diagram.

[0019] This invention also provides a receiving decoding method based on M-ary DCSK modulation. This method is applied to a multi-level polarization coded communication method based on M-ary DCSK modulation as described in this invention, and includes the following steps: acquiring the chaotic signal; performing M-ary DCSK demodulation on the chaotic signal to obtain a symbol receiving sequence; performing soft demodulation on the symbol receiving sequence to obtain several bit log-likelihood ratios; and performing pole-by-pole polarization decoding on the several bit log-likelihood ratios and the chaotic signal to obtain a target information bit stream.

[0020] In the above scheme, the chaotic signal is acquired, and a symbol reception sequence is obtained by M-ary DCSK demodulation based on the signal; then, soft demodulation is performed based on the symbol reception sequence to obtain several bit log-likelihood ratios; based on these bit log-likelihood ratios and the chaotic signal, pole-by-pole polarization decoding is performed to obtain the target information bitstream. This scheme provides accurate soft information input for decoding and fully utilizes a multi-level coding structure. By using feedback from the previous stage decoding results to assist the subsequent stage decoding, the decoding accuracy and efficiency are significantly improved. This effectively combats multipath fading and noise interference, reliably recovering the original information bitstream under harsh channel conditions such as low signal-to-noise ratio, achieving the design goals of differentiated protection and high-performance transmission.

[0021] It should be noted that, in the aforementioned soft demodulation process, the log-likelihood ratio of the i-th bit of the w-th symbol is... Based on the known demodulation results of the first i-1 bits, the probability can be calculated using the posterior probability formula, specifically: in , For symbols The coordinates of the constellation point.

[0022] The stepwise polarization decoding can be a multi-level iterative decoding process: first, the first level of polarization decoding is performed using the log-likelihood ratio of the most reliable bit among all symbols to obtain the estimated value of the information bits at this level; then, this estimated value is re-encoded and used to assist in calculating the log-likelihood ratio of the next level of bits, and the second level of decoding is performed; and so on, until the last level of decoding is completed, and finally the estimated value of all information bits is obtained.

[0023] This invention also provides a multi-level polar coding communication system based on M-ary DCSK modulation, comprising: an information acquisition module for acquiring an original information bit stream; a multi-level polar coding module for performing bit segmentation based on the original information bit stream to obtain several sub-bit streams; performing multi-level polar coding on each of the several sub-bit streams to obtain several corresponding polar codewords; wherein different polar code rates are configured for the several sub-bit streams with different reliability; a polar segmentation mapping module for performing polar segmentation mapping on the several polar codewords to obtain a modulation symbol sequence; wherein the several polar codewords with different polar code rates are mapped to bits with different reliability in the modulation symbol sequence; and a signal modulation module for performing M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to realize multi-level polar coding communication.

[0024] In the above scheme, the information acquisition module acquires the original information bitstream; the multi-level polar coding module performs bit segmentation based on the original information bitstream to obtain several sub-bitstreams, and configures different polar code rates for each sub-bitstream, performing polar coding to obtain the corresponding polar code codewords; the polar segmentation mapping module maps each polar code codeword to bits with different reliability in the modulation symbol sequence; and the signal modulation module performs M-ary DCSK modulation based on the modulation symbol sequence to obtain a chaotic signal. The modules have clear division of labor and work collaboratively, ensuring the performance consistency of the link from bit to signal processing, thereby achieving a stable and effective improvement in transmission reliability under complex channel conditions at the system level.

[0025] Furthermore, the multi-level polarization coding module performs bit segmentation based on the original information bitstream to obtain several sub-bitstreams; including: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

[0026] In the above scheme, the number of bits corresponding to each modulation symbol is obtained based on the M-ary DCSK modulation order, and the original information bitstream is bit-segmented accordingly to obtain several sub-bitstreams corresponding to the number of bits. This scheme provides an accurate input basis for subsequent multi-level polarization coding and polar segmentation mapping, ensuring that sub-bitstreams with different reliability can be identified and fed into the corresponding coding and mapping processes. The scheme can accurately match the capacity differences of each bit within a symbol, laying the necessary foundation for implementing differentiated coding protection strategies, thereby optimizing anti-interference performance and transmission reliability while maintaining spectral efficiency.

[0027] Furthermore, the multi-level polar coding module is used to perform multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codewords, wherein different polar code rates are configured for several sub-bit streams with different reliability; including: obtaining several reliability values ​​based on several sub-bit streams; configuring polar code rates for several sub-bit streams based on several reliability values ​​corresponding to several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on several multi-level sub-bit streams to obtain several corresponding polar code codewords.

[0028] In the above scheme, a reliability value is obtained based on several sub-bit streams, and a polar code rate positively correlated with the reliability value is configured for each sub-bit stream accordingly, resulting in several multi-level sub-bit streams. Polar coding is then performed to obtain the corresponding polar codewords. This scheme achieves differentiated coding protection for bits with different reliability levels, ensuring precise matching of coding resources with the actual needs of each sub-bit stream. Therefore, while maintaining spectral efficiency, it effectively enhances anti-interference capability and transmission reliability, especially achieving superior bit error rate performance under adverse channel conditions.

[0029] It should be noted that the reliability value is obtained based on the Monte Carlo construction method. By performing a large number of simulations on each sub-bit stream in a preset communication link model, the bit error rate is statistically analyzed to quantify its reliability, thereby providing a basis for the differentiated configuration of polar code rate. Attached Figure Description

[0030] Figure 1 is a schematic flowchart of a multi-level polarization coding communication method based on M-ary DCSK modulation according to an embodiment of the present invention; Figure 2 is a schematic flowchart of a receiving and decoding method based on M-ary DCSK modulation according to an embodiment of the present invention; Figure 3 is a schematic diagram of a multi-level polarization coding communication system architecture based on M-ary DCSK modulation according to an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please refer to Figure 1. This embodiment provides a multi-level polar coding communication method based on M-ary DCSK modulation, including the following steps: Step S1: Obtain the original information bit stream; Step S2: Perform bit segmentation based on the original information bit stream to obtain several sub-bit streams; Step S3: Perform multi-level polar coding on the several sub-bit streams to obtain several corresponding polar code codes; wherein, based on the bit reliability corresponding to the several sub-bit streams, different polar code rates are configured for the several sub-bit streams; Step S4: Perform polar segmentation mapping on the several polar code codes to obtain a modulation symbol sequence; wherein, based on the polar code rate corresponding to the several polar code codes, the several polar code codes are mapped to bits with different reliability in the modulation symbol sequence; Step S5: Perform M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to realize multi-level polar coding communication.

[0033] In this embodiment, based on the bit reliability corresponding to multiple sub-bit streams obtained from bit segmentation, different polar code rates are configured for each sub-bit stream. Then, polar segmentation mapping maps the polar codewords with different rates to bits with different reliability in the modulation symbol sequence, achieving differentiated and unequal protection for bits with different reliability. This ensures that the allocation of coding resources matches the actual channel capacity characteristics, thereby optimizing bit error rate performance while maintaining the original multipath fading resistance and spectral efficiency. Under harsh channel conditions such as low signal-to-noise ratio and strong interference, this embodiment can effectively overcome the bit error rate plateau effect, obtain considerable coding gain, improve communication reliability, and provide an effective solution for robust high-speed wireless data transmission in complex environments.

[0034] Further, the step of bit segmentation based on the original information bitstream to obtain several sub-bitstreams includes: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

[0035] In this embodiment, the number of bits corresponding to each modulation symbol is obtained based on the M-ary DCSK modulation order, and the original information bitstream is bit-segmented accordingly to obtain several sub-bitstreams corresponding to the number of bits. This embodiment provides an accurate input basis for subsequent multi-level polarization coding and polar segmentation mapping, ensuring that sub-bitstreams with different reliability can be identified and sent to the corresponding coding and mapping processes. This embodiment can accurately match the capacity differences of each bit within a symbol, laying the necessary foundation for implementing differentiated coding protection strategies, thereby optimizing anti-interference performance and transmission reliability while maintaining spectral efficiency.

[0036] Furthermore, the step of performing multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codes, wherein different polar code rates are configured for several sub-bit streams with different reliability; includes: obtaining several corresponding reliability values ​​based on several sub-bit streams; configuring polar code rates for several sub-bit streams based on several reliability values ​​corresponding to several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on several multi-level sub-bit streams to obtain several corresponding polar code codes.

[0037] In this embodiment, reliability values ​​are obtained based on several sub-bit streams, and polar code rates positively correlated with these reliability values ​​are configured accordingly, resulting in several multi-level sub-bit streams. Polar coding is then performed to obtain the corresponding polar codewords. This embodiment achieves differentiated coding protection for bits with different reliability levels, ensuring precise matching of coding resources with the actual needs of each sub-bit stream. Therefore, while maintaining spectral efficiency, it effectively enhances anti-interference capability and transmission reliability, especially achieving superior error performance under adverse channel conditions.

[0038] Furthermore, the step of obtaining several reliability values ​​based on several sub-bit streams includes: presetting a communication link simulation model corresponding to the M-ary DCSK modulation; inputting several sub-bit streams into the communication link simulation model so that the communication link simulation model performs Monte Carlo simulation based on several sub-bit streams to obtain several bit error rates corresponding to several sub-bit streams; and determining several reliability values ​​based on several bit error rates corresponding to several sub-bit streams.

[0039] In this embodiment, a communication link simulation model corresponding to M-ary DCSK modulation is preset, and each sub-bit stream is input into this model for Monte Carlo simulation to obtain its corresponding bit error rate, thereby determining the reliability value of each sub-bit stream. This embodiment can accurately evaluate the actual fault tolerance capability of each bit under specific modulation and channel conditions, ensuring that the obtained reliability value truly reflects its vulnerability. This provides an objective and reliable basis for subsequent differentiated configuration of polar code rates, thereby ensuring that the coding protection strength is precisely matched with the actual needs of each bit. This optimizes the allocation of error correction resources and effectively improves transmission robustness under complex channel conditions.

[0040] Further, the step of performing polar segmentation mapping based on several polar codewords to obtain a modulation symbol sequence includes: mapping several polar codewords with different polar code rates to bits with different reliability in the modulation symbol sequence; obtaining several corresponding polar code rates based on several polar codewords; mapping several polar codewords to several bits in a preset polar segmentation constellation diagram based on the several polar code rates corresponding to several polar codewords to obtain several modulation symbols; wherein the reliability of the mapped bits is negatively correlated with the polar code rate of the polar codeword; and obtaining the modulation symbol sequence based on the several modulation symbols.

[0041] In this embodiment, by obtaining the polar code rate of each polar codeword and based on the negative correlation between code rate and bit reliability, polar codewords with different code rates are mapped to bits with different reliability in a preset polar segmentation constellation diagram, thereby obtaining modulation symbols and modulation symbol sequences. This embodiment achieves a precise match between the coding protection strength and the inherent fault tolerance capability of each bit within the modulation symbol, allowing low-rate codewords with high protection strength to carry high-reliability bits, and high-rate codewords to be adapted to low-reliability bits, thereby optimizing coding resource allocation and enhancing the overall robustness of symbol transmission. Thus, while maintaining spectral efficiency, the reliability of symbol decision-making under adverse channel conditions is improved, providing a better input foundation for subsequent demodulation and decoding.

[0042] Further, the step of performing M-ary DCSK modulation based on the modulation symbol sequence to obtain a chaotic signal for multi-level polarization coded communication includes: a preset chaotic reference signal; performing a Hilbert transform based on the chaotic reference signal to obtain an auxiliary chaotic signal; converting each modulation symbol in the modulation symbol sequence into a two-dimensional coordinate corresponding to the modulation symbol based on a preset constellation diagram mapping rule; and performing a weighted combination based on the two-dimensional coordinates corresponding to several modulation symbols, the chaotic reference signal, and the auxiliary chaotic signal to obtain the chaotic signal.

[0043] In this embodiment, an auxiliary chaotic signal is obtained by pre-setting a chaotic reference signal and performing a Hilbert transform. The modulation symbol sequence is then converted into two-dimensional coordinates based on a pre-set constellation diagram mapping rule. These coordinates are then weighted and combined with the chaotic reference signal and the auxiliary chaotic signal to ultimately generate a chaotic signal carrying multi-level coding information. This embodiment accurately converts the modulation symbol sequence generated by the aforementioned polarization coding and polar segmentation mapping into a physical layer signal, thus fully preserving the reliability differentiation protection achieved in the coding and mapping stages. This embodiment fully utilizes the transmission characteristics of chaotic signals and works closely with the front-end processing, thereby effectively improving the robustness and transmission reliability of communication in complex wireless environments.

[0044] In one embodiment, a multi-level polarization coding communication method based on M-ary DCSK modulation is provided, executed at the transmitting end, and specifically includes the following steps: First, the original information bit stream is acquired. The original information bit stream is then bit-divided to obtain v sub-bit streams, denoted as vi. Among them, the i-th sub-bit stream The length is That is, including 1 bit.

[0045] Subsequently, regarding the aforementioned Each sub-bit stream undergoes multi-level polar coding. For each level of polar coding, sub-channel selection is required. Specifically, for a polar code of length n, sub-channels are selected from n sub-channels. The most reliable sub-channel is used to transmit the i-th sub-bit stream. Information bits, the rest Each subchannel is used to transmit frozen bits (usually fixed at bit 0). Therefore, the number of information bits transmitted at each level... That is, the information bit length of this level, and the total information bit length satisfies .

[0046] It should be noted that the selection of the sub-channels mentioned above is achieved through the Monte Carlo construction method. The principle is as follows: the code rate of the polar code to be constructed is temporarily set to 1 (i.e., assuming all sub-channels are used to transmit information bits), and through numerous Monte Carlo simulations (typically more than 10⁶ simulations), the number of bit errors for each sub-channel is counted. The reliability of each sub-channel is evaluated and ranked based on the number of bit errors, and finally, the sub-channel is selected. The most reliable sub-channel is selected as the channel for actually transmitting information bits. Through this process, Each sub-bit stream is generated through channel construction. Each of the original encoded sequences corresponding to its selected sub-channel is denoted as . .

[0047] Next, the aforementioned Original encoded sequence Each input is fed into its respective polar encoder for encoding, generating... Individual polarization codewords The polar coding process can be represented as: in, This is the generator matrix of the polar code. , , express The nth order Kronecker product, This is a bit-reversal permutation matrix.

[0048] Then, regarding the above The polar codewords are subjected to polar segmentation mapping to obtain the modulation symbol sequence.

[0049] In this embodiment, it is assumed that the modulation order of M-ary DCSK is Each modulation symbol carries a length of The bit sequence is given. The reliability of each bit in this bit sequence is different, and their reliability order is denoted as follows (arranged from highest to lowest reliability): .

[0050] It should be noted that in multi-level polarization coding design, the lower the code rate (i.e., The smaller the polar code size, the stronger its error correction protection capability and the higher its reliability. In this embodiment, the design makes the number of stages... With the number of bits per symbol Equal (i.e.) ), and the code rates of each polar code satisfy: That is, the first level has the lowest bit rate and the highest reliability, and the bit rate of subsequent levels increases in turn, while the reliability decreases in turn.

[0051] Based on the above design, polar segmentation mapping is performed: the most reliable first-level polar codeword is used. All bits are mapped to the most reliable M-ary DCSK symbol. Position; The second-level polarization codeword All bits are mapped to the second most reliable symbol. Position; and so on, the first Level polarization codeword All bits are mapped to the least reliable symbol in each symbol. (Right now Position. Finally, a sequence containing L modulation symbols is generated.

[0052] Finally, M-ary DCSK modulation is performed based on the modulation symbol sequence to obtain a chaotic signal. Specifically, a chaotic reference signal of length β is preset. For the chaotic reference signal Perform a Hilbert transform to obtain an auxiliary chaotic signal. For the first in the modulation symbol sequence Each symbol, based on its m bits (composed of the mapping bits of each level of polar code codeword at that position), is converted into a two-dimensional coordinate according to a preset constellation mapping rule (such as Gray code mapping). Subsequently, by weighted combination of the chaotic reference signal and the auxiliary chaotic signal obtained through Hilbert transform, the final transmitted chaotic signal is generated, thus completing the communication process.

[0053] This embodiment employs Monte Carlo construction to precisely select sub-channels and implements a collaborative design of multi-level polarization coding and polar segmentation mapping. It precisely matches codewords of different reliability to the corresponding bits in the M-ary DCSK symbol, achieving differentiated unequal protection. This embodiment optimizes coding resource allocation, ensuring that high-protection-strength codes are used for the most vulnerable bit positions. This significantly improves bit error rate performance while maintaining the ability to resist multipath fading and spectral efficiency in chaotic modulation. Especially under harsh channel conditions with low signal-to-noise ratio or strong interference, it effectively reduces the bit error rate plateau effect and enhances communication reliability.

[0054] Please refer to Figure 2. This embodiment also provides a receiving decoding method based on M-ary DCSK modulation. This embodiment is applied to a multi-level polarization coded communication method based on M-ary DCSK modulation as described above, and includes the following steps: Step S1: Obtain the chaotic signal; Step S2: Demodulate the chaotic signal using M-ary DCSK to obtain a symbol receiving sequence; Step S3: Perform soft demodulation based on the symbol receiving sequence to obtain several bit log-likelihood ratios; Step S4: Perform pole-by-pole polarization decoding based on the several bit log-likelihood ratios and the chaotic signal to obtain the target information bit stream.

[0055] In this embodiment, the chaotic signal is acquired, and a symbol reception sequence is obtained by M-ary DCSK demodulation based on the signal. Then, soft demodulation is performed on the symbol reception sequence to obtain several bit-log-likelihood ratios. Based on these bit-log-likelihood ratios and the chaotic signal, pole-by-pole polarization decoding is performed to obtain the target information bitstream. This embodiment provides accurate soft information input for decoding and fully utilizes a multi-level coding structure. Feedback from the previous stage decoding results assists the subsequent stage decoding, significantly improving decoding accuracy and efficiency. This effectively combats multipath fading and noise interference, reliably recovering the original information bitstream under harsh channel conditions such as low signal-to-noise ratio, achieving the design goals of differentiated protection and high-performance transmission.

[0056] In one embodiment, a receiving decoding method based on M-ary DCSK modulation is provided, applied to a multi-level polarization coded communication method based on M-ary DCSK modulation as described above. This embodiment is executed at the receiving end and specifically includes the following steps: First, acquiring the chaotic signal transmitted via the channel. In a Rayleigh multipath fading channel environment, the receiving end receives the first... The signal corresponding to each symbol It can be represented as: in, Indicates the number of paths. and They represent the first The channel fading coefficient and delay of the path, and For Rayleigh distributed random variables (when and At this time, the channel simplifies to an additive white Gaussian noise channel. This indicates that the mean is zero and the variance is... Channel noise. For ease of analysis, it is typically assumed that the channel fading coefficient is constant within a transmission slot and that each path is independent. Simultaneously, it is assumed that the maximum multipath delay is much smaller than the symbol duration. (Right now At this point, the interference between symbols can be ignored.

[0057] Next, M-ary DCSK demodulation is performed based on the received chaotic signal to obtain the symbol reception sequence. Specifically, the demodulator delays... The received signal (corresponding to the reference signal length) is compared with the reference signal component after passing through the channel. and its Hilbert transform signal components Perform relevant calculations to obtain two decision variables. and , respectively represented as: in, for The Hilbert transform. The coordinate pairs of the demodulated output. That is, the estimated constellation points that constitute the w-th symbol. .

[0058] Then, soft demodulation is performed based on the received symbol sequence to obtain the log-likelihood ratio (LLR) of each bit. For M-ary DCSK modulation, each symbol carries m bits ( Let the symbol set be... The nth symbol The corresponding constellation coordinates are Given the received signal r (corresponding to the decision variable) Under the condition that the i-th bit in the w-th symbol is... The LLR is calculated as follows: The LLR of the first bit is: Known before After the decision result (or assumed value) of the nth bit, the nth bit... The LLR of 1 bit is: in, Indicates the preceding -1 bit conforms to the given value A subset of symbols.

[0059] The above posterior probability Under the Gaussian noise assumption, it can be calculated as follows: in, Represents the square of the Euclidean distance. This represents the equivalent noise variance.

[0060] It should be noted that the above LLR calculation process provides reliability soft information for each bit of soft demodulation, laying a crucial foundation for subsequent polarization decoding.

[0061] Finally, based on the bit log-likelihood ratio (LLR), pole-by-pole polarization decoding is performed to obtain the target information bit stream. This process corresponds to the multi-level polarization coding and polar segmentation mapping at the transmitting end, and the specific steps are as follows: First, using the LLR sequence (denoted as LLR1) of the first bit of all symbols (i.e., the bit of the first-level polarization codeword mapped by the transmitting end), it is input into a polarization code decoder (e.g., continuous elimination SC decoding or list SCL decoding) to obtain the estimated value of the first-level information bits. Then, The code is re-encoded using the same polarization coding parameters as the transmitter to obtain an estimate of the first-level polarization codeword. .

[0062] Subsequently, the estimated value of the decoded and re-encoded codeword from the previous stage is used to assist in calculating the LLR of the next stage. Specifically, when calculating the LLR of the second stage (corresponding to the second bit of the symbol mapped at the transmitter), the value of the first bit is fixed at... Substituting the corresponding bit values ​​into the conditional LLR calculation formula above, we obtain the second-level LLR sequence LLR2. Then, we feed LLR2 into a polar code decoder to obtain the estimated second-level information bits. And re-encoded to obtain This process continues in this manner, utilizing all estimated codewords from the first i-1 levels. This is used to assist in calculating the LLR sequence LLRi of the i-th level, and then decode it to obtain... This continues until all v-level (v=m) decoding is completed.

[0063] Next, the estimated information bits obtained from each stage of decoding are... The bits are merged according to the order before the transmitter segmentation to obtain the final recovered target information bit stream.

[0064] It should be noted that this embodiment fully utilizes the structural features of multi-level coding and forward auxiliary information. By feeding back the decoding results from the preceding stage, the uncertainty of decided bits is eliminated when calculating the subsequent LLR, thereby significantly improving the accuracy of the subsequent decoding input and achieving a step-by-step improvement and overall optimization of decoding performance. This embodiment effectively combats multipath fading and noise interference, and can reliably recover the original information under harsh channel conditions such as low signal-to-noise ratio, fully realizing the performance gains intended by the differentiated protection design at the transmitter.

[0065] Referring to Figure 3, this embodiment also provides a multi-level polar coding communication system based on M-ary DCSK modulation, including: an information acquisition module for acquiring an original information bit stream; a multi-level polar coding module for performing bit segmentation based on the original information bit stream to obtain several sub-bit streams; performing multi-level polar coding on the several sub-bit streams to obtain several corresponding polar code codes; wherein, different polar code rates are configured for the several sub-bit streams with different reliability; a polar segmentation mapping module for performing polar segmentation mapping on the several polar code codes to obtain a modulation symbol sequence; wherein, the several polar code codes with different polar code rates are mapped to bits with different reliability in the modulation symbol sequence; and a signal modulation module for performing M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to realize multi-level polar coding communication.

[0066] In this embodiment, the information acquisition module acquires the original information bitstream; the multi-level polar coding module performs bit segmentation based on the original information bitstream to obtain several sub-bitstreams, and configures different polar code rates for each sub-bitstream, performing polar coding to obtain corresponding polar codewords; the polar segmentation mapping module maps each polar codeword to bits with different reliability in the modulation symbol sequence; and the signal modulation module performs M-ary DCSK modulation based on the modulation symbol sequence to obtain a chaotic signal. The clear division of labor and collaborative work among these modules ensures the performance consistency of the link from bit to signal processing, thereby achieving a stable and effective improvement in transmission reliability under complex channel conditions at the system level.

[0067] Furthermore, the multi-level polarization coding module performs bit segmentation based on the original information bitstream to obtain several sub-bitstreams; including: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

[0068] In this embodiment, the number of bits corresponding to each modulation symbol is obtained based on the M-ary DCSK modulation order, and the original information bitstream is bit-segmented accordingly to obtain several sub-bitstreams corresponding to the number of bits. This embodiment provides an accurate input basis for subsequent multi-level polarization coding and polar segmentation mapping, ensuring that sub-bitstreams with different reliability can be identified and sent to the corresponding coding and mapping processes. This embodiment can accurately match the capacity differences of each bit within a symbol, laying the necessary foundation for implementing differentiated coding protection strategies, thereby optimizing anti-interference performance and transmission reliability while maintaining spectral efficiency.

[0069] Furthermore, the multi-level polar coding module is used to perform multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codewords, wherein different polar code rates are configured for several sub-bit streams with different reliability; including: obtaining several reliability values ​​based on several sub-bit streams; configuring polar code rates for several sub-bit streams based on several reliability values ​​corresponding to several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on several multi-level sub-bit streams to obtain several corresponding polar code codewords.

[0070] In this embodiment, reliability values ​​are obtained based on several sub-bit streams, and polar code rates positively correlated with these reliability values ​​are configured accordingly, resulting in several multi-level sub-bit streams. Polar coding is then performed to obtain the corresponding polar codewords. This embodiment achieves differentiated coding protection for bits with different reliability levels, ensuring precise matching of coding resources with the actual needs of each sub-bit stream. Therefore, while maintaining spectral efficiency, it effectively enhances anti-interference capability and transmission reliability, especially achieving superior error performance under adverse channel conditions.

[0071] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A multi-level polarization coding communication method based on M-ary DCSK modulation, characterized in that, Includes the following steps: The process involves: acquiring the original information bitstream; performing bit segmentation on the original information bitstream to obtain several sub-bitstreams; performing multi-level polar coding on each of the sub-bitstreams to obtain several corresponding polar codewords; configuring different polar code rates for the sub-bitstreams with different reliability; performing polar segmentation mapping on the several polar codewords to obtain a modulation symbol sequence; mapping the several polar codewords with different polar code rates to bits with different reliability in the modulation symbol sequence; and performing M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to achieve multi-level polar coded communication.

2. The multi-level polarization coding communication method based on M-ary DCSK modulation according to claim 1, characterized in that, The step of bit segmentation based on the original information bitstream to obtain several sub-bitstreams includes: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

3. The multi-level polarization coding communication method based on M-ary DCSK modulation according to claim 1, characterized in that, The step involves performing multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codes, wherein different polar code rates are configured for the several sub-bit streams with different reliability. This includes: obtaining several reliability values ​​corresponding to the several sub-bit streams; configuring polar code rates for the several sub-bit streams based on the several reliability values ​​corresponding to the several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on the several multi-level sub-bit streams to obtain several corresponding polar code codes.

4. The multi-level polarization coding communication method based on M-ary DCSK modulation according to claim 3, characterized in that, The step of obtaining several reliability values ​​based on several sub-bit streams includes: pre-setting a communication link simulation model corresponding to the M-ary DCSK modulation; inputting several sub-bit streams into the communication link simulation model so that the communication link simulation model performs Monte Carlo simulation based on several sub-bit streams to obtain several bit error rates corresponding to several sub-bit streams; and determining several reliability values ​​based on several bit error rates corresponding to several sub-bit streams.

5. The multi-level polarization coding communication method based on M-ary DCSK modulation according to claim 1, characterized in that, The step involves performing polar segmentation mapping based on several polar codewords to obtain a modulation symbol sequence. Specifically, this includes mapping several polar codewords with different polar code rates to bits with different reliability in the modulation symbol sequence. This includes: obtaining several corresponding polar code rates based on several polar codewords; mapping several polar codewords to several bits in a preset polar segmentation constellation diagram based on the several polar code rates corresponding to the several polar codewords to obtain several modulation symbols; wherein the reliability of the mapped bits is negatively correlated with the polar code rate of the polar codeword; and obtaining the modulation symbol sequence based on the several modulation symbols.

6. The multi-level polarization coding communication method based on M-ary DCSK modulation according to claim 1, characterized in that, The process of performing M-ary DCSK modulation based on the modulation symbol sequence to obtain a chaotic signal for multi-level polarization coded communication includes: a preset chaotic reference signal; performing a Hilbert transform based on the chaotic reference signal to obtain an auxiliary chaotic signal; converting each modulation symbol in the modulation symbol sequence into a two-dimensional coordinate corresponding to the modulation symbol based on a preset constellation diagram mapping rule; and performing a weighted combination based on the two-dimensional coordinates corresponding to several modulation symbols, the chaotic reference signal, and the auxiliary chaotic signal to obtain the chaotic signal.

7. A receiving decoding method based on M-ary DCSK modulation, characterized in that, This method is applied to a multi-level polarization coding communication method based on M-ary DCSK modulation as described in claim 1, comprising the following steps: acquiring the chaotic signal; performing M-ary DCSK demodulation on the chaotic signal to obtain a symbol reception sequence; performing soft demodulation on the symbol reception sequence to obtain several bit log-likelihood ratios; and performing pole-by-pole polarization decoding on the several bit log-likelihood ratios and the chaotic signal to obtain a target information bit stream.

8. A multi-level polar coding communication system based on M-ary DCSK modulation, characterized in that, include: The information acquisition module is used to acquire the raw information bit stream; A multi-level polar coding module is used to perform bit segmentation based on the original information bitstream to obtain several sub-bitstreams; and to perform multi-level polar coding on each of the sub-bitstreams to obtain several corresponding polar codewords; wherein different polar code rates are configured for the several sub-bitstreams with different reliability; a polar segmentation mapping module is used to perform polar segmentation mapping on the several polar codewords to obtain a modulation symbol sequence; wherein the several polar codewords with different polar code rates are mapped to bits with different reliability in the modulation symbol sequence; a signal modulation module is used to perform M-ary DCSK modulation on the modulation symbol sequence to obtain a chaotic signal to realize multi-level polar coded communication.

9. A multi-level polarization coded communication system based on M-ary DCSK modulation according to claim 8, characterized in that, The multi-level polarization coding module performs bit segmentation based on the original information bitstream to obtain several sub-bitstreams; including: obtaining the M-ary DCSK modulation order; obtaining the number of bits corresponding to each modulation symbol based on the M-ary DCSK modulation order; and performing bit segmentation based on the number of bits corresponding to each modulation symbol and the original information bitstream to obtain several sub-bitstreams corresponding to the number of bits.

10. A multi-level polarization coded communication system based on M-ary DCSK modulation according to claim 8, characterized in that, The multi-level polar coding module is used to perform multi-level polar coding on several sub-bit streams to obtain several corresponding polar code codewords, wherein different polar code rates are configured for the several sub-bit streams with different reliability; including: obtaining several reliability values ​​based on several sub-bit streams; configuring polar code rates for several sub-bit streams based on the several reliability values ​​corresponding to several sub-bit streams to obtain several multi-level sub-bit streams; wherein the configured polar code rate is positively correlated with the reliability value of the sub-bit stream; and performing polar coding on several multi-level sub-bit streams to obtain several corresponding polar code codewords.

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