Iterative reception method of polar coded continuous phase modulation signals and related devices

Abstract

The present disclosure provides an iterative receiving method of a polar coded continuous phase modulation signal and a related device. The method comprises: receiving, by a demodulator, a continuous phase modulation signal from a channel, and determining an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; performing, by the demodulator, an operation on the initial accuracy parameter to obtain a target accuracy parameter; performing, by the demodulator, a recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary code word probability, and obtaining an estimated information stream at a receiving end based on the multi-ary code word probability and converting the estimated information stream into a decoder prior information stream; performing, by a decoder, a decoding process on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performing a decoding process on the candidate code word sequence based on a belief propagation decoding algorithm, and judging whether the decoding process meets a preset termination condition, and outputting a source information bit or a target information stream at the receiving end according to a result of the judgment.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of signal processing, and particularly relates to an iterative receiving method of polar coded continuous phase modulation signal and related equipment. BACKGROUND

[0002] Continuous phase modulation is a constant envelope modulation mode, has higher spectrum efficiency, and performs excellently in bandwidth limited environment, and is often used in mobile communication, satellite communication, underwater communication and the like. Continuous phase modulation is a phase continuous modulation scheme, which gives it a nonlinear characteristic, which also leads to a relatively complex receiving end. In addition, in recent years, some turbo codes, low density parity check codes (LDPC codes) concatenated continuous phase modulation systems have also been proposed, which improve the performance of the system. However, there is still a technical problem of a relatively complex receiving end.

[0003] Therefore, how to simplify the complexity of the receiving end without affecting the error code performance has become a problem to be solved. SUMMARY

[0004] Therefore, the purpose of the present disclosure is to provide an iterative receiving method of polar coded continuous phase modulation signal and related equipment to solve or partially solve the above technical problems.

[0005] To achieve the above purpose, a first aspect of the present disclosure provides an iterative receiving method of polar coded continuous phase modulation signal, which is applied to an iterative receiving system of polar coded continuous phase modulation signal, the system comprising a demodulator and a decoder; the method comprising:

[0006] The demodulator receives a continuous phase modulation signal from a channel, and determines an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; wherein the continuous phase modulation signal is obtained by encoding and modulating the source information bits of the transmitting end;

[0007] The demodulator performs operation processing on the initial accuracy parameter to obtain a target accuracy parameter;

[0008] The demodulator performs recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary code word probability, obtains an estimated information stream of the receiving end based on the multi-ary code word probability, converts the estimated information stream of the receiving end into a priori information stream of the decoder and sends it to the decoder;

[0009] The decoder decodes the decoder priori information stream based on a serial cancellation list decoding algorithm to obtain a candidate codeword sequence, decodes the candidate codeword sequence based on a belief propagation decoding algorithm, judges whether the decoding process meets a preset termination condition to obtain a judgment result, and outputs source information bits of the receiving end or a target information stream according to the judgment result.

[0010] Based on the same inventive concept, a second aspect of the present disclosure provides an iterative receiving system of a polar coded continuous phase modulation signal, the system comprising a demodulator and a decoder.

[0011] The demodulator is configured to receive a continuous phase modulation signal from a channel, and determine an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; wherein the continuous phase modulation signal is obtained by encoding and modulating source information bits of a sending end based on the source information bits of the sending end.

[0012] The demodulator is configured to perform operation processing on the initial accuracy parameter to obtain a target accuracy parameter.

[0013] The demodulator is configured to perform recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary codeword probability, and obtain an estimated information stream of the receiving end based on the multi-ary codeword probability, convert the estimated information stream of the receiving end into a decoder priori information stream and send the decoder priori information stream to the decoder.

[0014] The decoder decodes the decoder priori information stream based on a serial cancellation list decoding algorithm to obtain a candidate codeword sequence, decodes the candidate codeword sequence based on a belief propagation decoding algorithm, judges whether the decoding process meets a preset termination condition to obtain a judgment result, and outputs source information bits of the receiving end or a target information stream according to the judgment result.

[0015] Based on the same inventive concept, a third aspect of the present disclosure provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method described above when executing the computer program.

[0016] Based on the same inventive concept, a fourth aspect of the present disclosure provides a non-transitory computer readable storage medium, which stores computer instructions for causing a computer to execute the method described above.

[0017] It can be seen from the above that the iterative receiving method of a polar coded continuous phase modulation signal and a related device provided by the present disclosure, the demodulator performs operation processing on the initial precision parameter to obtain a target precision parameter, and by controlling the precision parameter, the complexity of the receiving end can be simplified under the condition of ensuring that the error code performance is not affected. The demodulator performs recursive operation on the forward metric and the backward metric based on the target precision parameter to obtain a multi-ary code word probability, so that the iterative algorithm in the logarithmic domain adopted by the demodulation algorithm can avoid data overflow and maintain numerical stability under the condition of ensuring that the error code performance is not affected. The demodulator performs recursive operation on the forward metric and the backward metric based on the target precision parameter to obtain a multi-ary code word probability, and obtains an estimated information stream of the receiving end based on the multi-ary code word probability, converts the estimated information stream of the receiving end into a decoder prior information stream and sends it to the decoder. The decoder performs decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performs decoding processing on the candidate code word sequence based on a belief propagation decoding algorithm, and judges whether the decoding processing meets a preset termination condition to obtain a judgment result, and outputs a source information bit or a target information stream of the receiving end according to the judgment result. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present disclosure or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description are only embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0019] Figure 1 Flow chart of the iterative receiving method of a polar coded continuous phase modulation signal of an embodiment of the present disclosure;

[0020] Figure 2A Flow chart of the signal processing method based on polar coding and continuous phase modulation of an embodiment of the present disclosure;

[0021] Figure 2B Schematic diagram of a finite state machine of an embodiment of the present disclosure;

[0022] Figure 2C Algorithm flow chart of determining a target precision parameter of an embodiment of the present disclosure;

[0023] Figure 2D Flow chart of receiving end iterative demodulation and decoding of an embodiment of the present disclosure;

[0024] Figure 2E Algorithm flow chart of a decoder of an embodiment of the present disclosure;

[0025] Figure 2F a schematic diagram of simulation results of an embodiment of the present disclosure;

[0026] Figure 3 a structural schematic diagram of an iterative receiving system of a polar coded continuous phase modulation signal of an embodiment of the present disclosure;

[0027] Figure 4 a structural schematic diagram of an electronic device of an embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and drawings.

[0029] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood as the general meaning understood by those skilled in the art to which the present disclosure belongs. The terms "first", "second" and the like used in the embodiments of the present disclosure do not represent any order, number or importance, but are only used to distinguish different components. The terms "include", "contain" and the like mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and the like do not mean physical or mechanical connection, but can include electrical connection, whether direct or indirect. The terms "up", "down", "left", "right" and the like only represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0030] The terms involved in the present disclosure are explained as follows:

[0031] CRC data check: Cyclic Redundancy Check (CRC) is a kind of channel coding technology that generates a short fixed number of check codes according to network data packets or computer files and other data, mainly used to detect or check possible errors after data transmission or saving. It uses the principle of division and remainder to detect errors.

[0032] CPM: Continue Phase Modulation (CPM) is a phase modulation technology, which has the characteristics of continuous phase, excellent spectral characteristics, and higher frequency band utilization rate compared with phase shift keying modulation. Continuous phase modulation is a constant envelope modulation method, which has high spectral efficiency and performs well in bandwidth limited environment, and is commonly used in mobile communication, satellite communication, underwater communication and other environments.

[0033] SISO: In the field of channel coding, soft-input soft-output (SISO) is also called soft-in soft-out, where "soft" means soft decision, that is, constantly iterating according to the existing information to make the most likely decision.

[0034] SCL algorithm: The serial cancellation list decoding algorithm is an improved algorithm of the serial cancellation algorithm (SC). By increasing the most likely candidate path after each layer path search, the path metric minimum code word sequence is selected as the estimated code word sequence output by the decoder during final decoding.

[0035] BP algorithm: The back propagation decoding algorithm (BackPropagation, BP) is a decoding algorithm that uses factor graph to propagate soft information, and is a SISO decoding algorithm.

[0036] LLR: Log Likelihood Ratio (LLR) is commonly used for soft decoding in communication. By judging the possibility of sending which modulation signal from the received signal, the greater the possibility, the more reliable the result of the decision.

[0037] The complex baseband equivalent signal of the CPM signal can be expressed as: Where T represents the symbol period, E s represents the average symbol energy, j is the imaginary unit, θ(t, α) is the CPM real-time phase, and θ0 is the initial phase. Wherein the code word α in the code word sequence α belongs to the multi-ary alphabet The real-time phase can be expressed as: Where t ∈ [n, n+1]T, is the modulation index of CPM modulation, and p and q are two coprime integers. q(t) is the integral function of the shaping pulse, and the shaping pulse can be a rectangular pulse or a raised cosine pulse, or the integral of a Gaussian pulse. The length of these shaping pulses is L cpm Also known as the memory length of CPM.

[0038] CPM is a phase continuous modulation scheme, which gives it nonlinear characteristics, which also leads to its receiving end relatively complex, to solve this problem, some simplified detection scheme is proposed, Rimoldi decomposition (Rimoldi Decomposition) and Laurent decomposition (Laurent Decomposition, referred to as LD) is two of the decomposition method. Rimoldi decomposition more in the signal representation level provides a state-based mathematical representation, while Laurent decomposition more from the waveform level of the signal at the same time the waveform is decomposed into a number of pulse amplitude modulation (Pulse Amplitude Modulation, referred to as PAM) pulse superposition. CPM signal modulation can be regarded as a band memory continuous phase encoder (Continuous Phase Encoder, referred to as CPE) and memoryless modulator (Memoryless Modulator, referred to as MM) cascade, CPE can be regarded as a convolution structure, which makes the correlation between the previous and the next symbol, and this correlation between the previous and the next symbol has advantages and disadvantages, the disadvantage is the complexity of the demodulation end, and the advantage is higher spectral efficiency and certain coding gain.

[0039] Assume a M-ary CPM signal, memory length L cpm , pulse integral waveform selection cosine pulse or Gaussian pulse integral, then its corresponding Laurent decomposition formula is as follows:

[0040]

[0041] Among them, P = log2M, {g k (t) is a set of component waveforms obtained by multinary Laurent decomposition, that is, a set of PAM signals, a k,n is the coefficient corresponding to the kth component waveform at time n.

[0042] Because of the high complexity of the receiver detector, some scholars design a simplified demodulation scheme for the Laurent decomposition of the signal, but most of these schemes only use M-1 order main component, that is, the principle pulse approximate (Principle Pulse Approximate, referred to as PPA) When the CPM memory length increases, the PPA performance will decrease sharply. This performance loss comes from the bias of the prior condition (the energy of the sub-pulse other than the main pulse has become negligible with the increase of the modulation order, the memory length), the error code performance of this scheme using the approximate signal at the receiving end to match the original signal can be estimated by the following formula,

[0043]

[0044] where E b is the bit energy of the signal, N0is the noise power spectral density, W(x min ) is the minimum modified distance d'(i,j) corresponding to the difference sequence x min = a i -a j Hamming distance, R is the span of the observed codeword sequence. The minimum modified distance d'(i,j) is obtained by traversing all difference sequences from the following formula.

[0045]

[0046] When the approximate signal used by the receiving end is equivalent to the original signal (optimal receiver), that is , the modified distance obtained at this time is called the minimum Euclidean distance d opt of the optimized receiver.

[0047] In recent years, some scholars have found that after CPM is cascaded with channel coding technology (such as convolutional code, turbo code, etc.), the receiving end can obtain additional performance gain through the soft information iteration between the CPM detector and the decoder, that is, serially concatenated CPM (SCCPM). Early schemes used convolutional codes and CPM systems to improve system performance through soft in and soft out (SISO) iteration. Later, some turbo codes and LDPC coding cascaded CPM systems were also proposed, which effectively improved the error performance under low signal-to-noise ratio conditions.

[0048] Polar code has been selected for 5G NR control channel, which is a theoretically Shannon limited encoding method with better block error rate (BLER) performance in short code length. Arikan introduced the Successive Cancellation (SC) decoding algorithm, on the basis of which, a cyclic redundancy check (CRC) auxiliary SC list decoding algorithm, namely CA-SCL, greatly improves the decoding performance, but these decoding methods ultimately output hard decision codewords as output, and cannot be used for turbo receiver iterative update of log likelihood ratio (LLR). The error back propagation decoding algorithm (Belief propagation, BP) and soft cancellation (Soft Cancellation, SCAN) decoding algorithm and its improved algorithm can output soft information, but there is a certain performance loss compared with CA-SCL.

[0049] As described above, how to simplify the complexity of the receiving end under the condition of guaranteeing not affecting the error code performance has become an important research problem.

[0050] Based on the above description, as Figure 1 The iterative receiving method of the polar coded continuous phase modulation signal provided in the embodiment is applied to an iterative receiving system of the polar coded continuous phase modulation signal, and the system comprises a demodulator and a decoder. The method comprises the following steps.

[0051] In step 101, the demodulator receives the continuous phase modulation signal sent by the channel, and determines the initial accuracy parameter, the forward metric and the backward metric of the continuous phase modulation signal. The continuous phase modulation signal is obtained by encoding and modulating the source information bits of the sending end.

[0052] In specific implementation, the iterative receiving system of the polar coded continuous phase modulation signal comprises a sending end and a receiving end. The sending end comprises an encoder and a modulator, and the receiving end comprises a demodulator and a decoder. For example, the encoder is a polar code encoder, and the modulator is a continuous phase modulator.

[0053] As Figure 2A shown, Figure 2A is a flowchart of the signal processing method based on polar coding and continuous phase modulation according to the embodiment of the disclosure. Figure 2AThe overall flow of the transmission method of the polar coded continuous phase modulation of the embodiment is illustrated. At the sending end: the source generates the sending end source information bits, the sending end source information bits are CRC concatenated polar code encoded to obtain binary code words, the polar code encoder adopts a Gaussian approximation algorithm as a channel reliability estimation scheme; the binary code words are mapped through interleaving to obtain multi-ary code words as the input of the continuous phase modulator, the continuous phase modulator modulates and processes the multi-ary code words to generate the waveform signal of the continuous phase modulation signal. The continuous phase modulation signal is transmitted through the channel and is assumed to be interfered by Gaussian white noise. At the receiving end: the estimated sequence is obtained through mutual iteration of the simplified CPM demodulator and the polar code decoder, the receiver adopts a simplified receiver scheme based on the Laurent decomposition (i.e. Laurent decomposition method) and the LogMAP algorithm (i.e. log maximum a posteriori probability decoding algorithm), the complexity of the receiving end is simplified by controlling the precision parameter under the condition of ensuring the optimal error performance. The polar code decoder (i.e. polar code decoder) adopts the combination of the SCL algorithm and the BP algorithm, and outputs the target information stream through the reverse LLR of the re-encoding. If the early stopping condition is triggered or the maximum iteration number is reached, the most likely binary code word is directly outputted, and the estimated sequence is transmitted to the signal sink.

[0054] In step 102, the demodulator performs operation processing on the initial precision parameter to obtain a target precision parameter.

[0055] In implementation, the demodulator performs operation processing on the initial precision parameter to obtain a target precision parameter.

[0056] The demodulator performs traversal processing on the pulses with the pulse duration greater than or equal to the pulse duration threshold, and adds the pulses with the pulse duration equal to the pulse duration threshold to a target pulse set. The demodulator performs operation processing on the continuous phase modulation signal in the target pulse set to obtain a minimum modified Euclidean distance, and determines an error performance estimation value based on the minimum modified Euclidean distance.

[0057] The demodulator determines a target precision parameter based on at least one of the current precision parameter, the minimum modified Euclidean distance, and the error performance estimation value.

[0058] In step 103, the demodulator performs recursive operation on the forward metric and the backward metric based on the target precision parameter to obtain a multi-ary code word probability, obtains an estimated information stream of the receiving end based on the multi-ary code word probability, converts the estimated information stream of the receiving end into a decoder prior information stream, and sends the decoder prior information stream to the decoder.

[0059] In implementation, the demodulator determines a state transition relationship of the receiving end based on the target accuracy parameter, and initializes the state transition relationship of the receiving end to obtain an initial forward metric at a starting time and an initial backward metric at an ending time. The demodulator performs operation processing based on the state transition relationship of the receiving end and the continuous phase modulation signal to obtain branch metrics.

[0060] The demodulator performs recursive operation processing based on the initial forward metric and the branch metrics to obtain target forward metrics at all times, and performs recursive operation processing based on the initial backward metric and the branch metrics to obtain target backward metrics at all times.

[0061] The demodulator performs operation processing on the target forward metrics, the target backward metrics, and the branch metrics to obtain the multi-ary code word probability.

[0062] In step 104, the decoder performs decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performs decoding processing on the candidate code word sequence based on a belief propagation decoding algorithm, judges whether the decoding processing satisfies a preset termination condition to obtain a judgment result, and outputs source information bits or target information stream of the receiving end according to the judgment result.

[0063] In implementation, the decoder performs decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm (i.e., a polar decoding algorithm) to obtain a candidate code word sequence.

[0064] The decoding processing is performed on the candidate code word sequence based on a belief propagation decoding algorithm, and whether the decoding processing satisfies a preset termination condition is judged to obtain a judgment result, and source information bits or target information stream of the receiving end is output according to the judgment result.

[0065] Through the above embodiment, the demodulator performs operation processing on the initial precision parameter to obtain a target precision parameter, and through control of the precision parameter, the complexity of the receiving end can be simplified under the condition of ensuring that the error code performance is not affected. The demodulator performs recursive operation on the forward metric and the backward metric based on the target precision parameter to obtain a multi-ary code word probability, so that the log domain iterative algorithm of the demodulation algorithm can avoid data overflow and maintain numerical stability under the condition of ensuring that the error code performance is not affected. The demodulator performs recursive operation on the forward metric and the backward metric based on the target precision parameter to obtain a multi-ary code word probability, obtains an estimated information stream of the receiving end based on the multi-ary code word probability, converts the estimated information stream of the receiving end into a decoder prior information stream and sends the decoder prior information stream to the decoder. The decoder performs decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performs decoding processing on the candidate code word sequence based on a belief propagation decoding algorithm, and judges whether the decoding processing meets a preset termination condition to obtain a judgment result, and outputs a source information bit or a target information stream of the receiving end according to the judgment result.

[0066] Before step 101, further comprising:

[0067] Step 10A, the encoder of the sending end first performs encoding processing on the target information stream to obtain a binary code word.

[0068] In specific implementation, the input target information stream is a binary source information stream, and the binary source information stream is grouped into a sequence composed of k information bits The information sequence is encoded by using a cyclic redundancy check (CRC), in which r CRC check bits are added to form a sequence with a code length of K=k+r. The reliability of a polarization channel is estimated by using a Gaussian approximation algorithm, the most reliable K sub-channels are selected from N (generally, the code length N is selected as a power of 2) polarization sub-channels to transmit information bits, and the remaining N-K sub-channels transmit frozen bits (defaulted to 0). The code word sequence is filled according to the information bit positions to form a transmission message sequence Then multiplied by a polarization encoding matrix, that is to obtain an encoding code word that is, a binary code word. Wherein G N =B N F N , B N is a bit inversion matrix, is the result of n=log2 N times Kronecker product of a basic polarization matrix .

[0069] Step 10B, the sending end performs interleaving mapping processing on the binary code word to obtain a multi-ary code word.

[0070] In implementation, the interleaver performs interleaving processing on the binary codeword, the essence of interleaving is to disrupt the order of the binary codeword, and the purpose is to resist possible burst and continuous noise interference, in addition, interleaving and deinterleaving can fully exchange soft information in the soft information iteration process at the receiving end, and avoid deep inter-code interference.

[0071] The mapper performs mapping processing on the binary codeword to obtain a multi-codeword, and the mapping from binary to M-codeword adopts natural mapping, and here, the concept of tilt state is introduced for the convenience of subsequent algorithm description, that is, The tilt state of x (x e x) is represented, and |x| represents the number of elements of the set x (note that the binary codeword of 01 bit itself is the tilt state, and it does not need to be converted, and in this embodiment, the codeword that needs to be converted to the tilt state is a bipolar codeword such as a bipolar codeword in ±1 state).

[0072] Let the codeword sequence of a group of binary codewords to be mapped be l e {0, 1,..., P-1}, i e {0, 1,..., N M -1}, N M = log2 M, then the multi-codeword after mapping of the codeword sequence of this group of binary codewords is: The corresponding tilt state is

[0073] Taking M = 4 as an example, the mapping relationship is shown in Table 1.

[0074] Table 1

[0075]

[0076] Step 10C, the modulator of the sending end performs modulation processing on the multi-codeword to obtain a continuous phase modulation signal.

[0077] In implementation, the mapped multi-codeword is input into the CPM modulator, and the CPM modulator performs modulation processing on the multi-codeword to obtain a continuous phase modulation signal, and the complex baseband equivalent signal of the continuous phase modulation signal can be represented as:

[0078] Where T represents a symbol period, E s represents an average symbol energy, j is an imaginary unit, θ(t, a) is a CPM real-time phase, and θ0 is an initial phase. Wherein the codeword a in the codeword sequence a of the input multi-codeword belongs to the multi-codeword alphabet The real-time phase can be represented by , wherein t e [n, n+1]T, is the modulation index of CPM modulation, p, q are two coprime integers. q(t) is the integral of the rectangular pulse or the raised cosine pulse, or the Gaussian pulse, and the length of these pulses is L cpm Also called the memory length of CPM. The modulated continuous phase modulation signal is sent into the channel for transmission, and it is assumed that the channel noise power spectral density is N0.

[0079] The process of demodulation and decoding of the received continuous phase modulation signal at the receiving end is as follows: the soft-in soft-out simplified CPM demodulator and the soft-in soft-out polar code decoder at the receiving end exchange soft information, output through multiple iterations, and take the CRC check as the early stopping condition of iteration, and finally output the most likely estimated code word sequence. The receiving end is composed of a soft-in soft-out (SISO) simplified CPM demodulator and a soft-in soft-out (SISO) polar code decoder. The simplified CPM demodulator combines the advantages of the Laurent pulse resolution scheme, and constructs the receiving end grid state by extracting the main pulse component to achieve the purpose of simplifying the receiving end; the polar code decoder combines the SCL decoding algorithm and the BP decoding algorithm, and takes the CRC check as the early stopping condition of iteration, which can terminate the iteration in advance to avoid unnecessary operation and greatly improve the operation efficiency when the channel condition is good.

[0080] wherein the simplified SISO demodulation end, the demodulation end first constructs the receiving end trellis structure according to the CPM parameters. For modulation order M, memory length L cpm , modulation factor h=p / q (p, q are coprime integers), and precision parameter D (1≤D≤L), the transition relationship of the receiving end trellis structure can be represented by a set of state variables mod represents the modulo operation, and the number of states at one time is pM D-1 Here, the inclined state is used in state description to avoid classification discussion of the number of state variables when p is odd or even, and the inclined state is convenient for modulo operation. The state transition process of the receiving end under the trellis structure can be represented by the finite state machine shown in Figure 2B

[0081] For the description of subsequent algorithms, the following definitions are defined: the state transition s'→s occurs in the n symbol period t∈[n,n+1]T, s' is called the predecessor state of state s, s is called the successor state of state s', and u(s',s)=α n is the corresponding code word under the current state transition, Ξ(s') represents the set of successor states of state s', and Ξ -1 (s) represents the set of predecessor states of state s.

[0082] At this time, it is equivalent to that the receiving end uses N​D =(2 D-1 ) P (2 P -1) The original signal at the transmitter is coherently demodulated using LD pulses, and the approximate signal can be written as:

[0083]

[0084] Among them, {g k (t)} represents the set of component waveforms obtained from Laurent decomposition, i.e., the set of PAM signals, a k,n The coefficients corresponding to the k-th component waveform at time n can be mathematically derived to be state variables. The function.

[0085] When D=1, the receiver is equivalent to the PPA algorithm, which has the fewest state types and the simplest receiver structure, but the demodulation accuracy is low. When D=L... cpm At the same time, the accuracy is the highest, which can achieve the best demodulation effect, but the complexity is also the highest. In order to balance the advantages and disadvantages between demodulation effect and complexity, the optimal target accuracy parameter D that meets the conditions is selected by using a target accuracy parameter determination algorithm.

[0086] In some embodiments, step 102 includes:

[0087] The demodulator performs the following process:

[0088] like Figure 2C As shown, Figure 2C This is a flowchart of the algorithm for determining the target accuracy parameters according to an embodiment of the present disclosure.

[0089] Step 1021: Perform calculations based on the initial precision parameters to obtain the current precision parameters, and determine the number of target pulses whose pulse duration is greater than or equal to a preset pulse duration threshold based on the current precision parameters.

[0090] In practice, the demodulator's inputs include: channel signal-to-noise ratio E. b / N0, the minimum corrected Euclidean distance and the preset optimal distance satisfy the preset minimum threshold condition δ, and the lower limit of bit error rate p. min The minimum threshold condition δ is set to 0.1 by default, and the lower limit of the bit error rate p... min The default value is 10. -2 The demodulator output includes the target accuracy parameter D.

[0091] The demodulator undergoes initialization, setting the initial precision parameter to zero (D0 = 0), the number of selected LD pulses k = 0, and the selected LD pulse set to be empty.

[0092] The current precision parameter D1 is obtained through calculation based on the initial precision parameter, and the number of target pulses with a pulse duration greater than or equal to a preset pulse duration threshold is determined based on the current precision parameter. For example, the preset pulse duration threshold is L. cpm -D1 determines the duration of the LD pulse, identifying pulses with a duration greater than or equal to L within the current precision parameter D1. cpm The number of pulses in the LD pulse duration of -D1, i.e.

[0093] Step 1022: Iterate through the pulses whose pulse duration is greater than or equal to the pulse duration threshold, and add the pulses whose pulse duration is equal to the pulse duration threshold to the target pulse set.

[0094] In specific implementation, pulses with a duration greater than or equal to the pulse duration threshold are traversed, and each pulse with a duration of L is processed. cpm The LD pulse of -D1+1 is added to the pulse set G, and the pulse count is updated by setting the pulse count k = k+1; this continues until k ≥ N. D1 The iteration ends when the time is right.

[0095] Step 1023: Perform calculations on the continuous phase modulation signals in the target pulse set to obtain the minimum corrected Euclidean distance, and determine the bit error rate performance estimate based on the minimum corrected Euclidean distance.

[0096] In practice, when using the signal in the current pulse set G to approximate a continuous phase modulated signal... Calculate the minimum corrected Euclidean distance d under the current accuracy parameter D1. min ,

[0097]

[0098] Among them, E b This represents the bit energy of a continuous phase modulated signal.

[0099] Calculate the bit error rate performance estimate p under the current minimum corrected Euclidean distance. e ,

[0100]

[0101] Among them, W(χ) min The minimum corrected distance d is . min The corresponding difference sequence χ min =α i -α j The Hamming distance, R is the span of the observed codeword sequence.

[0102] Step 1024: Determine the target accuracy parameter based on at least one of the current accuracy parameter, the minimum corrected Euclidean distance, and the bit error rate performance estimate.

[0103] In practice, if at least one of the current accuracy parameter, minimum corrected Euclidean distance, and bit error rate performance estimate meets the corresponding preset condition, the current accuracy parameter D1 is directly returned and used as the target accuracy parameter D; if none of the above conditions are met, the current accuracy parameter D1 is incremented by 1 and the process jumps to step 1021.

[0104] The above scheme simplifies the complexity of the receiver by controlling the accuracy parameters by determining the target accuracy parameters, while ensuring a better estimate of bit error rate performance.

[0105] In some embodiments, step 1024 includes:

[0106] The demodulator performs the following process:

[0107] Step 1024A: Determine at least one of the current accuracy parameter, the minimum corrected Euclidean distance, and the bit error rate performance estimate.

[0108] Step 1024B: In response to determining that the current precision parameter is equal to the memory length of the continuous phase modulation signal, the current precision parameter is used as the target precision parameter.

[0109] And / or; step 1024C, in response to determining that the minimum corrected Euclidean distance and the preset optimal distance satisfy a preset minimum threshold condition, the current accuracy parameter is used as the target accuracy parameter.

[0110] And / or; Step 1024D, in response to determining that the bit error rate estimate is less than a preset lower limit of bit error rate; the current precision parameter is used as the target precision parameter.

[0111] In practical implementation, condition one: the current precision parameter is equal to the memory length of the continuous phase modulation signal, i.e., D1 = L. cpm Condition 2: The minimum corrected Euclidean distance and the preset optimal distance satisfy a preset minimum threshold condition, i.e. Condition 3: The estimated bit error rate is less than the preset lower limit of bit error rate, i.e., p e <p min .

[0112] If condition one, condition two, or condition three is met, the current precision parameter D1 is returned directly and used as the target precision parameter D; if none of the above conditions are met, the process jumps to step 1021.

[0113] The above scheme determines the target precision parameter based on at least one of the current precision parameter, the minimum corrected Euclidean distance, and the bit error rate performance estimate, making the determined target precision parameter more accurate and ensuring demodulation effect while simplifying the receiver.

[0114] In some embodiments, step 103 includes:

[0115] The demodulator performs the following process:

[0116] Step 1031: Determine the receiver state transition relationship based on the target accuracy parameter, and initialize the receiver state transition relationship to obtain the initial forward metric at the start time and the initial backward metric at the end time.

[0117] In practical implementation, the hyperparameter settings of the demodulator include: the target precision parameter D, and the receiver trellis structure, pulse set, and pseudo-symbol set information under the target precision parameter D. The receiver trellis structure includes the set of valid state transition pairs T(u(s',s)), and the input multi-level codewords corresponding to the state transitions. The valid predecessor and successor sets of a state.

[0118] The demodulator's inputs include the received signal r(t) and prior symbol information P(u(s',s)); the demodulator's outputs include the probability of the multi-level codeword.

[0119] Based on the target accuracy parameters, the receiver state transition relationship is determined and initialized to obtain the initial forward metric at the start time and the initial backward metric at the end time.

[0120] Step 1032: Perform calculations based on the receiver state transition relationship and the continuous phase modulation signal to obtain the branch metric.

[0121] In specific implementation, the demodulator initializes the initial forward metric and the backward metric. Assuming the initial and final states are known, the initial forward metric A0(s0) = 0 and A0(s...) = 0 at the start time. i = -∞, the initial backward metric B at the end time. end (s0)=0、B end (s i ) = -∞.

[0122] The branch metric is obtained by performing calculations on the target accuracy parameters.

[0123]

[0124] in, For branching measure, xk,n It is the result of the received signal r(t) passing through the k-th real pulse in the matched filter bank, x k,n =∫r(t)g k (t-nT)dt,g k (t) is the selected duration greater than L. cpm -D's kth LD pulse.

[0125] Step 1033: Perform recursive calculations based on the initial forward metric and the branch metric to obtain the target forward metric at all times.

[0126] In practice, the preceding states of the input are traversed, and the initial forward metric is recursively processed based on the branch metric to obtain the target forward metric at all times.

[0127]

[0128] Among them, A n+1 (s) is the forward metric of the target at time n+1 with state s. Thus, based on the above recursive formula, the forward metric of the target at all times can be obtained, that is, the forward metric of the target from the initial time n=0 to the end time n=end.

[0129] Step 1034: Perform recursive calculations based on the initial backward metric and the branch metric to obtain the target backward metric at all times.

[0130] In practice, the successor states of the input are traversed, and the initial backward metric is recursively calculated based on the branch metric to obtain the target backward metric at all times.

[0131]

[0132] Among them, B n (s') is the target backward metric at time n with state s'. Thus, based on the above recursive formula, the target backward metric at all times can be obtained, that is, the target backward metric from the end time n = end to the initial time n = 0.

[0133] Step 1035: Perform calculations on the target forward metric, the target backward metric, and the branch metric to obtain the multi-base codeword probability.

[0134] In practice, the set of all possible state transitions under all transition symbols is traversed to obtain the probabilities of multi-base codewords.

[0135]

[0136] Where T(u(s',s)) is the transfer symbol. The set of all possible valid state transitions under the given conditions. If the error rate performance is acceptable, the max function in the log-MAP algorithm can be optimized. * The (·) operation is replaced with the max(·) operation, which can greatly reduce the computational complexity.

[0137] The above scheme makes the probabilities of multi-base codewords obtained through recursive processing more accurate, and greatly reduces the complexity of the algorithm and the amount of computation.

[0138] In some embodiments, prior to step 104, the method further includes:

[0139] like Figure 2D As shown, Figure 2D This is a flowchart of the iterative demodulation and decoding process at the receiving end in an embodiment of this disclosure.

[0140] Step 104A: The demodulator acquires the decoder prior information stream and sets the initial number of iterations.

[0141] In practical implementation, the hyperparameter settings of the demodulator include: target accuracy parameter D, and SCL algorithm list length F. The inputs of the demodulator include: received signal r(t), maximum number of iterations I, and maximum soft information value LLR. Max The demodulator's output includes: the most likely decoded sequence.

[0142] The initial iteration count is set to iter = 0, and the demodulator inputs the prior information stream to the decoder.

[0143] Step 104B: The demodulator performs calculations on the prior information stream of the decoder to obtain multi-ary symbol probabilities, performs deinterleaving and clipping processing on the multi-ary symbol probabilities to obtain the prior information stream of the target decoder, and sends the prior information stream of the target decoder to the decoder.

[0144] In practice, the demodulator will input the decoder's prior information stream. This is converted into prior multi-level symbolic information P(u(s',s)). The inputs to the SISO demodulator include the received signal r(t) and the prior multi-level symbolic information P(u(s',s)); the outputs of the SISO demodulator include the probability of the multi-level codeword.

[0145] The SISO demodulator converts the probability of multi-base codewords. Log-likelihood ratio converted to binary The soft information output by the receiver is processed through calculation. Subtract the receiver's prior information Probability of obtaining multi-base symbols The probabilities of multi-ary symbols are reduced through deinterleaving. Restoring the order. The probability of multi-base symbols after restoration is limited. The absolute value is greater than LLR Max Amplitude limiting is performed to obtain the prior information stream of the target decoder. The prior information stream of the target decoder is then input into the decoder.

[0146] Step 104C: The decoder performs calculations on the target decoder prior information stream to obtain multi-ary symbol probabilities, performs interleaving and clipping processing on the multi-ary symbol probabilities to obtain the decoder prior information stream, and sends the decoder prior information stream to the demodulator for the demodulator to process the decoder prior information stream and update the initial iteration number to obtain the target iteration number.

[0147] In practice, the input to the decoder includes: the target decoder prior information stream. The decoder output includes: target information stream When the SISO decoder decodes, if the CRC check condition (early stop condition) is met and the maximum number of iterations is reached, it can output the codeword that has passed the check or the most likely codeword (the decoding sequence with the smallest path metric).

[0148] The decoder processes the target information stream output by the receiver through calculations. Subtract the prior information stream of the target decoder Probability of obtaining multi-base symbols Interleaving processes are used to determine the probabilities of multi-ary symbols. Shuffle the order. Calculate the probability of shuffled multi-base symbols. The absolute value is greater than LLR Max Amplification is performed to obtain the decoder's prior information stream. Then input the decoder prior information stream into the decoder and return to step 104B.

[0149] The demodulator processes the prior information stream of the decoder and updates the initial iteration number to obtain the target iteration number, which is iter' = iter + 1.

[0150] In some embodiments, step 104 includes:

[0151] The decoder performs the following process:

[0152] like Figure 2E As shown, Figure 2E This is a flowchart of the decoder algorithm in an embodiment of this disclosure.

[0153] Step 1041: Based on the string cancellation list decoding algorithm, decode the prior information stream of the decoder to obtain a candidate codeword sequence, and calculate the path metric of the candidate path corresponding to the candidate codeword sequence.

[0154] In practice, the input to the decoder includes the decoder's prior information stream. The decoder output includes the target information stream.

[0155] The decoder receives the prior information stream from the decoder. Given a list length F, it performs SCL decoding on the obtained demodulated soft information. During the execution of the SCL decoding algorithm, it can be recursively calculated according to the polar code factor graph.

[0156] L i,j =f(L i+1,j ,L i+1,j+2i )

[0157]

[0158] The initial condition for recursion is: n=log2 N, j∈{0,1,2,N-1}. f(x,y)≈sign(x)sign(y)*min(|x|,|y|), g(x,y,u)=(-1) u x+y, For L i,j Estimated codewords under hard decision. The SCL algorithm calculates the path metric for each generated candidate path, retaining the soft information on the decoding factor graph for the path with the smallest metric. Assume the soft information matrix corresponding to the recorded minimum path metric is L. SCL

[0159] Step 1042: Sort the candidate codeword sequences in ascending order according to the path metric, perform cyclic redundancy checks on the candidate codeword sequences in sequence, and judge the check bits of the cyclic redundancy checks to obtain the check code judgment result.

[0160] In practice, the SCL algorithm is used to obtain F candidate codeword sequences and their corresponding path metrics. Each path split involves sorting the path metrics, recording the soft information corresponding to the smallest path metric, and then sorting the candidate paths in ascending order of path metric to obtain a sorted set of codeword sequences. Perform CRC check: Perform CRC check on these decoded sequences in sequence.

[0161] Step 1043: In response to determining that all check bits in the check code judgment result are zero, the check passes and the decoder outputs the candidate codeword sequence as the source information bits of the receiver.

[0162] In practice, when all check bits in the checksum determination result are zero, the selected path is determined to be the correct decoding path. The decoding path corresponding to all check bits being zero is taken as the target decoding path, and the corresponding decoded bit sequence is output. Decoding complete (stop early).

[0163] Step 1044: In response to determining that at least one of the check bits in the check code judgment result is not zero, the candidate codeword sequence is decoded based on the belief propagation decoding algorithm to obtain the target information stream, and the current iteration number is judged to obtain the iteration number judgment result. Based on the iteration number judgment result, the source information bits or the target information stream of the receiving end are output.

[0164] In specific implementation, if at least one of the check bits in the check code judgment result is not zero, all candidate codewords fail the check. The candidate codeword sequence is decoded using a belief propagation decoding algorithm to obtain the target information stream, and the current iteration number is judged to obtain the iteration number judgment result. Based on the iteration number judgment result, the source information bits or the target information stream of the receiving end are output.

[0165] If the current iteration number equals the iteration number threshold, select the path metric to obtain the decoding sequence corresponding to the most likely candidate path. Output the source information bits from the receiving end. The most likely candidate path is the path with the smallest path metric. If the current iteration count is less than the iteration count threshold, output the target information stream.

[0166] In some embodiments, step 1044 includes:

[0167] The decoder performs the following process:

[0168] Step 1044A: In response to determining that the iteration count judgment result is that the current iteration count is equal to the iteration count threshold, the source information bits of the receiving end are output; wherein, the source information bits of the receiving end are the candidate codeword sequence corresponding to the path with the smallest path metric.

[0169] In practice, if the current iteration number equals the iteration number threshold, the path metric is selected to obtain the decoding sequence corresponding to the most likely candidate path. Output the source information bits from the receiving end. The most likely candidate path is the one with the smallest path metric.

[0170] If we obtain the decoding sequence corresponding to the most likely (smallest path metric) candidate path based on the path metric, and then recode it to obtain the recoded codeword sequence... Right now

[0171] Step 1044B: In response to determining that the iteration count judgment result is that the current iteration count is less than the iteration count threshold, the target information stream is output.

[0172] In practice, BP decoding is performed using the recorded soft information matrix. The soft information on the decoding factor graph with the smallest path metric is used to replace the leftward propagation result of BP decoding. Once BP decoding is complete, it can be recursively calculated according to the polar code factor diagram.

[0173]

[0174]

[0175] Where the initial condition is

[0176] Take the last layer (nth layer) of soft information sequence from the BP decoding, compare it one by one with the result after recoding, and after completing the soft information inversion, obtain the soft information output by the decoder.

[0177]

[0178] Where sign is the sign function.

[0179] The above scheme uses iterative computation to make the target information stream obtained from the decoding process more accurate, which can effectively reduce the bit error rate. When all the check bits in the check code judgment result are zero, the codeword sequence that has passed the check is directly output to complete the decoding. By setting an early stop condition, decoding is completed when the above condition is met, avoiding the problem of large computational load and reducing resource waste.

[0180] This invention has undergone multiple implementation experiments and simulations, and the results are described in detail below:

[0181] The simulation parameters are shown in Table 2 below:

[0182] Table 2

[0183] CPM parameters Configuration Modulation index 0.5 Modulation order 2 Over-sampling rate 16 Waveform 1 RC Data rate 1 kHz Channel AWGN, signal-to-noise ratio SNR (dB)

[0184] like Figure 2F As shown, Figure 2FThis is a schematic diagram illustrating the simulation results of an embodiment of this disclosure. Under a weighted white Gaussian noise (AWGN) channel, with a code length of 1024, a code rate of 0.5, an SCL algorithm list length of 8, and a CRC length of 16, the simulation results show that, compared to the CA-SCL algorithm without iteration, the proposed iterative decoding scheme achieves a performance improvement of approximately 1.2 dB when the number of iterations reaches 6.

[0185] Through the above embodiments, this invention provides a simplified CPM signal receiver. By controlling precision parameters, the complexity of the receiver is simplified while ensuring superior bit error rate performance. Applying the MAP algorithm to the number domain ensures bit error rate performance while avoiding data overflow and maintaining numerical stability. Polar codes are inherently good codes that reach the Shannon limit, and their use as channel coding significantly increases system stability. Furthermore, by designing a soft-in, soft-out polar code decoder, the soft information exchange between the demodulator and decoder can be maximized to achieve greater performance gains. Using CRC checksum as an early stopping condition for iteration avoids unnecessary iterations that waste computational resources. This system is applicable not only to various binary CPM signals, including common MSK and GMSK signals, but also to multi-level CPM signals and their different memory lengths.

[0186] It should be noted that the method of this disclosure embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this disclosure embodiment, and the multiple devices will interact with each other to complete the method described.

[0187] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0188] Based on the same inventive concept, corresponding to any of the above embodiments, this disclosure also provides an iterative receiving system for polarization-coded continuous phase modulation signals.

[0189] refer to Figure 3The iterative receiving system for polarization-coded continuous phase modulation signals includes a demodulator and a decoder.

[0190] The demodulator 301 is configured to receive a continuous phase modulation signal from the channel channel and determine the initial precision parameters, forward metric, and backward metric of the continuous phase modulation signal; wherein the continuous phase modulation signal is obtained by the transmitter through encoding and modulation processing based on the transmitter source information bits;

[0191] The demodulator 301 is configured to perform calculations on the initial accuracy parameters to obtain the target accuracy parameters;

[0192] The demodulator 301 is configured to perform recursive operations on the forward metric and the backward metric based on the target precision parameter to obtain multi-level codeword probabilities, obtain the estimated information stream of the receiving end based on the multi-level codeword probabilities, convert the estimated information stream of the receiving end into a decoder prior information stream and send it to the decoder 302.

[0193] The decoder 302 is configured to decode the prior information stream of the decoder based on the serial cancellation list decoding algorithm to obtain a candidate codeword sequence, decode the candidate codeword sequence based on the belief propagation decoding algorithm, and determine whether the decoding process meets a preset termination condition to obtain a judgment result, and output the source information bits or target information stream of the receiving end according to the judgment result.

[0194] In some embodiments, the demodulator 301 is further configured to: perform calculations based on the initial precision parameters to obtain current precision parameters, and determine the number of target pulses whose pulse duration is greater than or equal to a preset pulse duration threshold according to the current precision parameters; perform traversal processing on the pulses whose pulse duration is greater than or equal to the pulse duration threshold, and add the pulses whose pulse duration is equal to the pulse duration threshold to the target pulse set; perform calculations on the continuous phase modulation signals in the target pulse set to obtain the minimum corrected Euclidean distance, and determine the bit error rate performance estimate based on the minimum corrected Euclidean distance; and determine the target precision parameters based on at least one of the current precision parameters, the minimum corrected Euclidean distance, and the bit error rate performance estimate.

[0195] In some embodiments, the demodulator 301 is further configured to: perform a judgment process on at least one of the current accuracy parameter, the minimum corrected Euclidean distance, and the bit error rate performance estimate; in response to determining that the current accuracy parameter is equal to the memory length of the continuous phase modulation signal, use the current accuracy parameter as the target accuracy parameter; and / or; in response to determining that the minimum corrected Euclidean distance satisfies a preset minimum threshold condition between the minimum corrected Euclidean distance and a preset optimal distance, use the current accuracy parameter as the target accuracy parameter; and / or; in response to determining that the bit error rate performance estimate is less than a preset lower bit error rate limit, use the current accuracy parameter as the target accuracy parameter.

[0196] In some embodiments, the demodulator 301 is further configured to: determine the receiver state transition relationship based on the target precision parameter, and initialize the receiver state transition relationship to obtain an initial forward metric at the start time and an initial backward metric at the end time; perform calculations based on the receiver state transition relationship and the continuous phase modulation signal to obtain a branch metric; perform recursive calculations based on the initial forward metric and the branch metric to obtain the target forward metric at all times; perform recursive calculations based on the initial backward metric and the branch metric to obtain the target backward metric at all times; and perform calculations on the target forward metric, the target backward metric, and the branch metric to obtain the multi-level codeword probability.

[0197] In some embodiments, the demodulator 301 is further configured to: acquire a decoder prior information stream and set an initial number of iterations; perform computational processing on the decoder prior information stream to obtain multi-ary symbol probabilities; perform deinterleaving and amplitude limiting processing on the multi-ary symbol probabilities to obtain a target decoder prior information stream; and send the target decoder prior information stream to the decoder.

[0198] In some embodiments, the decoder 302 is further configured to: decode the prior information stream of the decoder based on the string cancellation list decoding algorithm to obtain a candidate codeword sequence, and calculate the path metric of the candidate path corresponding to the candidate codeword sequence; sort the candidate codeword sequence in ascending order according to the path metric, perform cyclic redundancy check on the candidate codeword sequence in sequence, and judge the check bits of the cyclic redundancy check to obtain a check code judgment result; in response to determining that all check bits in the check code judgment result are zero, the check passes, and the decoder outputs the candidate codeword sequence as the source information bits of the receiver; in response to determining that at least one check bit in the check code judgment result is not zero, decode the candidate codeword sequence based on the belief propagation decoding algorithm to obtain a target information stream, judge the current iteration number to obtain an iteration number judgment result, and output the source information bits or the target information stream of the receiver based on the iteration number judgment result.

[0199] In some embodiments, the decoder 302 is further configured to: output source information bits of the receiving end in response to determining that the iteration count judgment result is that the current iteration count is equal to the iteration count threshold; wherein the source information bits of the receiving end are candidate codeword sequences corresponding to the path with the smallest path metric; and output the target information stream in response to determining that the iteration count judgment result is that the current iteration count is less than the iteration count threshold.

[0200] For ease of description, the above apparatus is described in terms of its functions, divided into various modules. Of course, in implementing this disclosure, the functions of each module can be implemented in one or more software and / or hardware.

[0201] The apparatus of the above embodiments is used to implement the iterative reception method of the corresponding polarization-coded continuous phase modulation signal in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0202] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the iterative reception method of polarization-coded continuous phase modulation signal described in any of the above embodiments.

[0203] Figure 4This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0204] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0205] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0206] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0207] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB (Universal Serial Bus), network cable, etc.) or wireless means (such as mobile network, WIFI (Wireless Fidelity), Bluetooth, etc.).

[0208] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0209] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0210] The electronic devices described above are used to implement the iterative reception method for the corresponding polarization-coded continuous phase modulation signal in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0211] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this disclosure also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the iterative reception method of polarized coded continuous phase modulation signals as described in any of the above embodiments.

[0212] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0213] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute the iterative reception method of polarized coded continuous phase modulated signal as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0214] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.

[0215] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this disclosure, the provided drawings may or may not show well-known power / ground connections to integrated circuit (IC) chips and other components. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this disclosure, and this also takes into account the fact that the details of implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this disclosure will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuitry) have been set forth to describe exemplary embodiments of this disclosure, it will be apparent to those skilled in the art that the embodiments of this disclosure may be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0216] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0217] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An iterative reception method of a polar coded continuous phase modulation signal, characterized by, The method is applied to an iterative receiving system of a polar coded continuous phase modulation signal, and the system comprises a demodulator and a decoder. The demodulator receives a continuous phase modulation signal from a channel, and determines an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; wherein the continuous phase modulation signal is obtained by encoding and modulating a source information bit at a sending end; The demodulator performs operation processing on the initial accuracy parameter to obtain a target accuracy parameter; The demodulator performs recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary code word probability, and converts an estimated information stream of a receiving end into a decoder prior information stream and sends the decoder prior information stream to the decoder; The decoder performs decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain a candidate code word sequence, performs decoding processing on the candidate code word sequence based on a belief propagation decoding algorithm, and judges whether the decoding processing meets a preset termination condition to obtain a judgment result, and outputs a source information bit or a target information stream of the receiving end according to the judgment result; The demodulator performs operation processing on the initial accuracy parameter to obtain a target accuracy parameter, comprising: The demodulator performs the following process: Based on the initial accuracy parameter, a current accuracy parameter is obtained by operation processing, and a target pulse number with a pulse duration greater than or equal to a preset pulse duration threshold is determined according to the current accuracy parameter; Pulses with the pulse duration greater than or equal to the pulse duration threshold are traversed, and a pulse with the pulse duration equal to the pulse duration threshold is added to a target pulse set; The continuous phase modulation signal in the target pulse set is processed to obtain a minimum modified Euclidean distance, and a bit error performance estimate value is determined based on the minimum modified Euclidean distance; A target accuracy parameter is determined based on at least one of the current accuracy parameter, the minimum modified Euclidean distance and the bit error performance estimate value; The target accuracy parameter is determined based on at least one of the current accuracy parameter, the minimum modified Euclidean distance and the bit error performance estimate value, comprising: The demodulator performs the following process: At least one of the current accuracy parameter, the minimum modified Euclidean distance and the bit error performance estimate value is judged; In response to determining that the current accuracy parameter is equal to a memory length of the continuous phase modulation signal, the current accuracy parameter is taken as the target accuracy parameter; and / or; In response to determining that the minimum modified Euclidean distance meets a preset minimum threshold condition with a preset optimal distance, the current accuracy parameter is taken as the target accuracy parameter; and / or; In response to determining that the bit error performance estimate value is less than a preset bit error rate lower limit, the current accuracy parameter is taken as the target accuracy parameter; The demodulator, based on the target precision parameter, recursively calculates the forward and backward metrics to obtain multi-base codeword probabilities, including: The demodulator performs the following process: The receiver state transition relationship is determined based on the target accuracy parameters, and the receiver state transition relationship is initialized to obtain the initial forward metric at the start time and the initial backward metric at the end time. The branch metric is obtained by performing calculations based on the state transition relationship of the receiving end and the continuous phase modulation signal. Recursive calculations are performed based on the initial forward metric and the branch metric to obtain the target forward metric at all times; Recursive calculations are performed based on the initial backward metric and the branch metric to obtain the target backward metric at all times. The target forward metric, the target backward metric, and the branch metric are processed to obtain the multi-base codeword probability; The decoder decodes the prior information stream of the decoder based on the serial cancellation list decoding algorithm to obtain a candidate codeword sequence, decodes the candidate codeword sequence based on the belief propagation decoding algorithm, and judges whether the decoding process meets a preset termination condition to obtain a judgment result. Based on the judgment result, it outputs the source information bits or target information stream of the receiving end, including: The decoder performs the following process: The prior information stream of the decoder is decoded based on the aforementioned string cancellation list decoding algorithm to obtain a candidate codeword sequence, and the path metric of the candidate path corresponding to the candidate codeword sequence is calculated. The candidate codeword sequences are sorted in ascending order according to the path metric. Cyclic redundancy checks are performed on the candidate codeword sequences in sequence, and the check bits of the cyclic redundancy checks are judged to obtain the check code judgment result. In response to determining that all check bits in the check code judgment result are zero, the check passes and the decoder outputs the candidate codeword sequence as the source information bits of the receiving end; In response to determining that at least one of the check bits in the check code judgment result is not zero, the candidate codeword sequence is decoded based on the belief propagation decoding algorithm to obtain the target information stream, and the current iteration number is judged to obtain the iteration number judgment result. Based on the iteration number judgment result, the source information bits or the target information stream of the receiving end are output.

2. The method of claim 1, wherein, Before the decoder decodes the prior information stream to obtain a candidate codeword sequence based on the serial cancellation list decoding algorithm, decodes the candidate codeword sequence based on the belief propagation decoding algorithm, and determines whether the decoding process meets a preset termination condition to obtain a judgment result, and outputs the source information bits or target information stream of the receiving end according to the judgment result, the following steps are further included: The demodulator acquires the decoder's prior information stream and sets the initial number of iterations; The demodulator performs operation processing on the decoder prior information stream to obtain a multi-ary symbol probability, performs de-interleaving processing and amplitude limiting processing on the multi-ary symbol probability to obtain a target decoder prior information stream, and sends the target decoder prior information stream to the decoder.

3. The method of claim 1, wherein, The outputting the source information bits of the receiving end or the target information stream based on the iteration number judgment result comprises: The decoder performs the following process: In response to determining that the iteration number judgment result is that the current iteration number is equal to the iteration number threshold, the source information bits of the receiving end are outputted; wherein the source information bits of the receiving end are candidate codeword sequences corresponding to a path with the minimum path metric; In response to determining that the iteration number judgment result is that the current iteration number is less than the iteration number threshold, the target information stream is outputted.

4. An iterative reception system of a polar coded continuous phase modulation signal, characterized by The system comprises a demodulator and a decoder; The demodulator is configured to receive a continuous phase modulation signal sent by a channel, and determine an initial accuracy parameter, a forward metric and a backward metric of the continuous phase modulation signal; wherein the continuous phase modulation signal is obtained by encoding and modulating a source information bit of a sending end; The demodulator is configured to perform operation processing on the initial accuracy parameter to obtain a target accuracy parameter; The demodulator is configured to perform recursive operation on the forward metric and the backward metric based on the target accuracy parameter to obtain a multi-ary codeword probability, and obtain an estimated information stream of a receiving end based on the multi-ary codeword probability, convert the estimated information stream of the receiving end into a decoder prior information stream and send the decoder prior information stream to the decoder; The decoder is configured to perform decoding processing on the decoder prior information stream based on a serial cancellation list decoding algorithm to obtain candidate codeword sequences, perform decoding processing on the candidate codeword sequences based on a belief propagation decoding algorithm, judge whether the decoding processing meets a preset termination condition to obtain a judgment result, and output the source information bits of the receiving end or the target information stream according to the judgment result; The demodulator is further configured to: perform operation processing on the initial accuracy parameter to obtain a current accuracy parameter, and determine a target pulse number of pulses with a pulse duration greater than or equal to a preset pulse duration threshold based on the current accuracy parameter; perform traversal processing on the pulses with the pulse duration greater than or equal to the pulse duration threshold, and add a pulse with the pulse duration equal to the pulse duration threshold to a target pulse set; perform operation processing on the continuous phase modulation signal in the target pulse set to obtain a minimum modified Euclidean distance, and determine an error performance estimation value based on the minimum modified Euclidean distance; determine a target accuracy parameter based on at least one of the current accuracy parameter, the minimum modified Euclidean distance and the error performance estimation value; The demodulator is further configured to: perform judgment processing on at least one of the current accuracy parameter, the minimum modified Euclidean distance and the error performance estimation value; in response to determining that the current precision parameter is equal to the memory length of the continuous phase modulation signal, taking the current precision parameter as the target precision parameter; and / or; in response to determining that the minimum correction Euclidean distance and a preset optimal distance satisfy a preset minimum threshold condition, taking the current precision parameter as the target precision parameter; and / or; in response to determining that the error code performance estimation value is less than a preset bit error rate lower limit, taking the current precision parameter as the target precision parameter; The demodulator is further configured to: determine a receiver state transition relationship based on the target precision parameter, and initialize the receiver state transition relationship to obtain an initial forward metric at a starting time and an initial backward metric at an ending time; perform operation processing based on the receiver state transition relationship and the continuous phase modulation signal to obtain branch metrics; perform recursive operation processing based on the initial forward metric and the branch metrics to obtain target forward metrics at all times; perform recursive operation processing based on the initial backward metric and the branch metrics to obtain target backward metrics at all times; perform operation processing on the target forward metrics, the target backward metrics, and the branch metrics to obtain the multi-ary code word probability; The decoder is further configured to: perform decoding processing on the decoder a priori information stream based on the serial cancellation list decoding algorithm to obtain a candidate code word sequence, and calculate path metrics of candidate paths corresponding to the candidate code word sequence; perform sorting processing on the candidate code word sequence in order from small to large according to the path metrics, perform cyclic redundancy check on the candidate code word sequence in turn, and perform judgment processing on check bits of the cyclic redundancy check to obtain a check code judgment result; in response to determining that all check bits in the check code judgment result are zero, the check passes, and the decoder outputs the candidate code word sequence as source information bits of a receiver; in response to determining that at least one check bit in the check code judgment result is not zero, performing decoding processing on the candidate code word sequence based on a belief propagation decoding algorithm to obtain a target information stream, and performing judgment on a current iteration number to obtain an iteration number judgment result, and outputting source information bits or the target information stream of the receiver based on the iteration number judgment result.

5. An electronic device, comprising: The non-transitory computer readable storage medium stores computer instructions for causing a computer to execute the method of any one of claims 1 to 3.

6. A non-transitory computer-readable storage medium, comprising, The non-transitory computer readable storage medium stores computer instructions for causing a computer to execute the method of any one of claims 1 to 3.

Images