CN115720129A - A method and system for information transmission of polarization-coded continuous phase modulation - Google Patents

Abstract

The invention discloses an information transmission method and system for polar coding continuous phase modulation. The method includes: performing cyclic redundancy check coding and polar coding on information streams; interleaving and mapping code words obtained by coding; The CPM signal obtained by performing continuous phase modulation on the mapped symbols is sent into the channel for transmission. The invention combines the CPM modulation technology with the Polar code encoding and decoding technology to ensure a relatively high code error performance of the system and at the same time ensure a low complexity of the receiving end, and can be used in underwater environments where the communication environment is relatively harsh.

Description

A method and system for information transmission of polarization-coded continuous phase modulation

technical field

The present invention relates to the field of communication technology, in particular to an information transmission method and system of polar coding continuous phase modulation.

Background technique

Polar codes are based on a digital signal processing technology called channel polarization, which introduces correlation through channel segmentation and merging. When the number of channels participating in channel polarization is large enough, the reliability of the obtained channel will be polarized. And the more the number of channels, the more obvious the channel polarization, so the coding structure can be optimized. Polar codes have been proven to achieve channel capacity when the code length is sufficiently large. In actual transmission, the channel code length is limited, so the maximum achievable rate will be lost.

The most basic decoding scheme of polar codes is the SC algorithm. In theory, when the code length is sufficiently long, the channel capacity can be achieved, but in practice, the error performance of polar codes cannot achieve the desired effect. Since the decoding algorithm of the polar code can be regarded as a process of path search on the polar code tree, the system performance can be effectively improved by introducing breadth-first traversal to improve the path search algorithm, that is, the serial cancellation list (SCL) algorithm. After that, an optimized algorithm is derived, the decoding scheme of the concatenated cyclic redundancy check and polar code (CRC-Polar), that is, CA-SCL, by optimizing the structure of the CRC-Polar code The communication performance can be further improved while keeping the complexity unchanged.

Based on the channel polarization phenomenon, it is necessary to allocate channel settings and freeze bits according to the reliability of each polarized channel. Generally, the methods for calculating channel reliability include traditional density evolution (DE) and Gaussian approximation scheme (GA). Compared with the former , the Gaussian approximation scheme has less complexity and a smaller performance gap.

The CPM modulation involved in this system belongs to constant envelope modulation, and the power amplifier at the sending end can work stably in the nonlinear amplification region, avoiding nonlinear distortion and achieving higher power efficiency. The traditional CPM modulation has high complexity at the receiving end. Using Laurent decomposition to match and demodulate the principal component of the received signal can greatly reduce the complexity of the system while ensuring that the system performance is almost unchanged. Assuming an M-ary CPM signal, its debugging index is h, the memory length is L, and the pulse integral waveform q(t) selects the integral of cosine pulse or Gaussian pulse, then the corresponding Laurent decomposition formula is as follows:

Among them, Q=2 ^L-1 , P=log ₂ M, g _K (t) is the component waveform obtained by Laurent decomposition, that is, the PAM signal, K is the serial number of the component waveform, a _K,n is the Kth The coefficient corresponding to the component waveform is a function of the information sequence {α _n }, which is generally called a pseudosymbol in the literature. It should be noted that the component waveform is a real number waveform, and the corresponding pseudosymbol is a complex number.

Because Laurent decomposition decomposes the original CPM signal into N kinds of component pulses, and these component pulses are different in duration and amplitude, which also leads to extremely uneven energy distribution of these pulses. According to statistics, when the modulation order M or the memory length L is small, the energy of the M-1 pulses before the energy accounts for more than 90% of the total energy, which also means that the PAM signal with larger energy can be used to approximate The CPM signal in the scheme further simplifies the processing of the signal by the receiver.

In the case of equal probability of prior information, according to the maximum likelihood criterion, when the correlation measure between the received signal and the decision signal at the receiving end is the largest, the information sequence corresponding to the decision signal is the desired one. Through Laurent decomposition, the different kinds of Laurent pulses of the CPM signal are received and matched with the received signal, x _K,n =∫r(t)g _K (t-nT)dt, x _K,n is the output response after matching, and the After it is combined with the dummy symbol, the branch metric is obtained, and a trellis structure (trellis structure) of the CPM signal is formed, and the BCJR algorithm is used for demodulation. Thus, the complexity of the demodulation algorithm is related to the number of states of the trellis structure. When the CPM modulation index is h=q/p (p, q is a coprime integer), if all the Laurent pulses of the CPM signal are matched, the number of states is pM ^L-1 , which is the optimal demodulation , the increase in the number of states leads to an exponential increase in complexity. When only the first M-1 pulses are matched, the number of states is only p, and the complexity is very low, but the demodulation accuracy will decrease, resulting in a decrease in subsequent bit error performance.

There are many coding and modulation related schemes related to linear modulation, but there are few coding and modulation schemes that take nonlinear modulation as an entry point. Traditional nonlinear coding and modulation schemes mostly use RS codes, and convolutional codes are serially concatenated to improve bit error performance. At present, there are some cases where LDPC codes, turbo codes and other coding methods are combined with nonlinear modulation.

To sum up, the disadvantages of the current technology are: traditional RS codes, convolutional codes and other coding schemes combined with nonlinear coding have poor bit error performance, while LDPC codes, turbo codes and other methods are more complicated at the decoding end; in addition, the traditional The complexity of the detector at the CPM receiving end is relatively high. Although there have been ideas for demodulation using the decomposition of CPM signals, these solutions are either only for binary CPM, or only use the first M-1 order principal components for matching. When the modulation index and memory length increase, only using the M-1 order principal component may lead to a decrease in bit error performance due to insufficient energy proportion, and lacks a more flexible pulse matching mechanism.

Contents of the invention

In view of this, the purpose of the present invention is to propose an information transmission method and system of polar coding continuous phase modulation, through the combination of CPM modulation technology and Polar code coding and decoding technology, it can ensure a higher bit error performance of the system while ensuring a higher The complexity of the receiving end is low, and it can be used in underwater environments where the communication environment is relatively harsh.

Based on the above purpose, the present invention provides an information transmission method of polar coding continuous phase modulation, including:

Carry out cyclic redundancy check coding and polarization coding on the information flow;

Perform bit interleaving and binary-to-multiary mapping on the encoded codeword;

The CPM signal obtained by performing continuous phase modulation on the mapped symbols is sent into the channel for transmission.

Further, the method also includes:

After receiving the CPM signal transmitted through the channel, the log-MAP algorithm is used to demodulate the CPM signal;

After the soft information obtained by demodulation is deinterleaved, the serial cancellation list assisted by the cyclic redundancy check is used for decoding.

The present invention also provides an information transmission system for polar coding continuous phase modulation, including:

CRC cascaded polar code encoder, used to perform cyclic redundancy check coding and polar coding on the information stream;

A bit interleaver, which is used to bit-interleave the encoded codeword and map from binary to multi-ary;

The continuous phase modulator is configured to send the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission.

Further, the system also includes:

The continuous phase demodulator is used to demodulate the CPM signal transmitted through the channel by using the log-MAP algorithm;

A deinterleaver, used for deinterleaving soft information obtained by demodulation;

The decoder is used to decode the deinterleaved soft information by using a serial cancellation list assisted by a cyclic redundancy check.

The present invention also provides a signal sending end, including:

CRC cascaded polar code encoder, used to perform cyclic redundancy check coding and polar coding on the information stream;

A bit interleaver, which is used to bit-interleave the encoded codeword and map from binary to multi-ary;

The continuous phase modulator is configured to send the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission.

The present invention also provides a signal receiving end, including:

The continuous phase demodulator is used to demodulate the CPM signal transmitted through the channel by using the log-MAP algorithm;

A deinterleaver, used for deinterleaving soft information obtained by demodulation;

The decoder is used to decode the deinterleaved soft information by using a serial cancellation list assisted by a cyclic redundancy check.

In the technical solution of the present invention, the information flow is subjected to cyclic redundancy check encoding and polar encoding; the code words obtained by encoding are interleaved and mapped; the CPM signal obtained by performing continuous phase modulation on the mapped symbols is sent into the channel for transmission . The present invention uses CRC (Cyclic Redundancy Check) to cascade with Polar codes, which can effectively improve the performance of Polar codes under short codes. Compared with LDPC and Turbo codes, polar codes have lower encoding and decoding complexity and higher reliability. In this way, the high bit error performance of the system is guaranteed while the complexity of the receiving end is low, and it can be used in the underwater environment where the communication environment is relatively harsh.

表达式AGA-2以及似然比迭代算法求出每个子信道的对数似然比；由于AGA-2近似表达式在码长较长时不会产生很大的性能损失，复杂度也比密度进化法低得多，且反函数更易求得，因此，可以简化信道可靠性估计的计算。Further, in the technical solution of the present invention, when estimating the polar channel reliability in the polar encoding process, the optimized Gaussian approximation algorithm is used

The expression AGA-2 and the likelihood ratio iterative algorithm calculate the logarithmic likelihood ratio of each sub-channel; since the approximate expression of AGA-2 does not produce a large performance loss when the code length is long, the complexity is also higher than the density The evolution method is much lower, and the inverse function is easier to obtain, so the calculation of channel reliability estimation can be simplified.

Further, in the technical solution of the present invention, the accuracy parameter D of continuous phase modulation can be determined according to the different matching pulse energy proportions corresponding to different accuracy parameters D under the condition that the modulation order, modulation index, memory length L, and pulse waveform are determined, Select the minimum value of D corresponding to the proportion of matching pulse energy higher than the set threshold value as the final precision parameter D of continuous phase modulation; thus, when the modulation order M or the memory length L is large When compared with the fixed precision parameter D value in the traditional continuous phase modulation technology, it can avoid the bit error performance degradation caused by the insufficient proportion of pulse energy when only using the principal component pulse matching (D=1), and can also avoid the use of High complexity for all component pulses to be matched (D=L).

Description of drawings

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

FIG. 1 is a schematic structural diagram of an information transmission system for polar coding continuous phase modulation provided by an embodiment of the present invention;

FIG. 2 is a flow chart of an information transmission method for polar coding continuous phase modulation provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a subchannel log likelihood ratio expectation simulation result using a Gaussian approximation algorithm provided by an embodiment of the present invention;

4 is a schematic diagram of the internal structure of the Laurent matched filter bank provided by the embodiment of the present invention;

Figure 5a is a schematic diagram of the state transition of the trellis structure provided by the embodiment of the present invention;

FIG. 5b is a schematic diagram of a state transition grid diagram of a trellis structure provided by an embodiment of the present invention;

6 is a flow chart of a method for detecting a CPM signal using a log-MAP algorithm provided by an embodiment of the present invention;

FIG. 7 is a flowchart of a decoding method of a CA-SCL algorithm provided by an embodiment of the present invention;

Fig. 8 is a schematic diagram of experiment and simulation provided by the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention shall have the usual meanings understood by those skilled in the art to which the present disclosure belongs. "First", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Comprising" or "comprising" and similar words mean that the elements or items appearing before the word include the elements or items listed after the word and their equivalents, without excluding other elements or items. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right" and so on are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

The present invention provides an information transmission method of polar coding continuous phase modulation. The method performs cyclic redundancy check coding and polar coding on the information flow; interleaves and maps the code words obtained by coding; and performs mapping on the mapped symbols. A CPM (Continue Phase Modulation, continuous phase modulation) signal obtained by continuous phase modulation is sent into a channel for transmission. The present invention uses CRC (Cyclic Redundancy Check) to cascade with Polar codes, which can effectively improve the performance of Polar codes under short codes. Compared with LDPC and Turbo codes, polar codes have lower encoding and decoding complexity and higher reliability. In this way, the high bit error performance of the system is guaranteed while the complexity of the receiving end is low, and it can be used in the underwater environment where the communication environment is relatively harsh.

Moreover, the technical solution of the present invention combines CPM modulation technology with Polar (polarization) coding and decoding technology; CPM modulation makes the system have the characteristics of constant envelope, low out-of-band leakage, and high channel utilization. For the signal receiving end, The complexity of the receiving end of this solution is related to the precision parameters defined in the present invention. In practical applications, a trade-off can be made between the bit error performance and the complexity of the receiving end according to requirements.

The technical solutions of the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

An information transmission system for polar coding continuous phase modulation provided by an embodiment of the present invention has a structure as shown in FIG. 1 , including: a signal transmitting end 101 and a signal receiving end 102;

Wherein, the signal transmitting end 101 includes: CRC concatenated polar code encoder 111, bit interleaver 112, continuous phase modulator 113;

The signal receiving end 102 includes: a continuous phase demodulator 121 , a deinterleaver 122 , and a decoder 123 .

Based on the above-mentioned information transmission system of polar coding continuous phase modulation, an information transmission method of polar coding continuous phase modulation provided by an embodiment of the present invention, the process flow is shown in Figure 2, including the following steps:

Step S201: Perform cyclic redundancy check coding and polar coding on the information flow.

In this step, in the CRC concatenated polar code encoder 111 of the signal transmitting end 101, the information stream is subjected to cyclic redundancy check encoding and polar encoding: the input information stream is grouped into a sequence consisting of k information bits , the information sequence is subjected to cyclic redundancy check (CRC) encoding, after adding m CRC check bits, the code length is K (K=k+m), and finally the code is passed through the code rate R=K/N A polar code encoder to obtain a polar code with a code length of N.

表达式AGA-2以及似然比迭代算法求出每个子信道的对数似然比，也可以进一步得到N个子信道的巴氏参数，对数似然比或者巴氏参数就在一定程度上体现了极化信道的可靠性，即根据每个子信道的对数似然比可以估计子信道的可靠性；进而进行比特混合：根据信道的可靠性对信道进行排序，将可靠性高的K个子信道设置为信息传输比特，剩下的则设置为冻结比特，将信息序列填充到信息传输比特上，形成待传输的信息序列

之后，构造生成矩阵，即生成N×N矩阵G_N＝B_NF_N。其中B_N是比特倒序置换矩阵，完成比特反序操作，

表示矩阵

进行log₂N次Kronecker积的结果，即进行log₂ N次

递归操作；最终根据生成矩阵将待传输的信息序列

映射为信道编码比特

即

The specific process of polar coding includes: polar channel reliability estimation, bit mixing, and construction of generator matrix. Specifically, the Gaussian approximation algorithm can be used to estimate the reliability of the polarized channel; the Gaussian approximation algorithm is the most widely used and the closest to reality, and has less computational complexity than the density evolution method: according to the set channel model and Initialize the signal-to-noise ratio of the modulation scheme, calculate the channel likelihood value according to the signal-to-noise ratio, and use the optimized Gaussian approximation algorithm

The expression AGA-2 and the likelihood ratio iterative algorithm can calculate the log-likelihood ratio of each sub-channel, and can further obtain the Bhatia parameters of N sub-channels. The reliability of the polarized channel is ensured, that is, the reliability of the subchannel can be estimated according to the logarithmic likelihood ratio of each subchannel; and then the bit mixing is performed: the channels are sorted according to the reliability of the channel, and the K subchannels with high reliability Set it as the information transmission bit, and set the rest as frozen bits, and fill the information sequence into the information transmission bit to form the information sequence to be transmitted

Afterwards, a generator matrix is constructed, that is, an N×N matrix G _N =B _N F _N is generated. Among them, B _N is the bit reverse order permutation matrix, which completes the bit reverse order operation,

representation matrix

The result of performing log ₂ N Kronecker products, that is, performing log ₂ N times

Recursive operation; finally, according to the generation matrix, the sequence of information to be transmitted

mapped to channel coded bits

Right now

Among them, the most critical part is the part of the reliability estimation of the polarized channel. The Gaussian approximation construction scheme adopted in this scheme is introduced below:

假设信道端的对数似然比为

在N长极化码的信道极化过程中，会从信道侧(每一个比特视为一个子信道)N个长度为1的极化信道极化成为1个长度为N的极化信道，那么对于高斯近似每个子信道的对数似然比的期望可以用如下递归公式1和公式2计算：Assuming that the probability density function of the log-likelihood ratio of received symbols through channel demodulation satisfies symmetry, and for binary codewords, the channel is further approximated as a binary additive white Gaussian noise channel, and the log-likelihood ratio obtained by bit soft demodulation ( LLR) probability density function can be represented by a Gaussian distribution with mean m and variance 2m. At this time, the equivalent signal-to-noise ratio (SNR) is

Suppose the log-likelihood ratio at the channel end is

In the channel polarization process of N-length polar codes, N polarized channels with a length of 1 are polarized from the channel side (each bit is regarded as a sub-channel) to a polarized channel with a length of N, then The expectation of the log-likelihood ratio of each subchannel for the Gaussian approximation can be calculated using the following recursive Equation 1 and Equation 2:

表示在信道极化过程中，长度为n的极化码中第i个极化信道的对数似然比，

表示信道假设的对数似然比，可以视为长度为1的极化信道的对数似然比。in,

Indicates the log-likelihood ratio of the i-th polarized channel in a polar code of length n during the channel polarization process,

Indicates the log-likelihood ratio of the channel hypothesis, which can be regarded as the log-likelihood ratio of a polarized channel with length 1.

表达式较为复杂，本方案采用优化的

近似表达式(AGA-2)来近似表示：Since the function in Equation 1

The expression is more complicated, this scheme adopts the optimized

Approximate expressions (AGA-2) to approximate:

The approximate expression of AGA-2 will not cause a great performance loss when the code length is long, and the complexity is much lower than that of the density evolution method, and the inverse function is easier to obtain. By recursively calculating the mean value of each polarization channel, when selecting the information bit, it can be sorted in descending order according to the expectation of the log likelihood ratio, and the first k sub-channel indexes are taken as the information bit.

近似表达式选取AGA-2近似表示，则使用高斯近似算法的对数似然比期望仿真结果如图3所示。由此可得以下结论：Example: select N=1024, the code rate is 1/2,

AGA-2 approximate expression is selected for the approximate expression, then the logarithmic likelihood ratio expectation simulation results using the Gaussian approximation algorithm are shown in Figure 3. From this we can draw the following conclusions:

(1) When the channel index is small, the expected value of the corresponding channel log-likelihood ratio is small, and vice versa;

(2) When the channel index is at an intermediate value, the expected value of the corresponding channel log-likelihood ratio shows a stepwise upward trend;

(3) When selecting information bits, they can be sorted in descending order according to the expectation of the log likelihood ratio, and the first k sub-channel indices are taken as information bits.

Step S202: Perform bit interleaving and binary-to-multiary mapping on the encoded codeword.

In this step, the bit interleaver 112 in the signal transmitting end 101 performs bit interleaving and binary-to-multiary mapping on the encoded codeword;

其中a_i∈{-M+1,-M+3,……，M-3，M-1}，N_M是映射后符号长度

N为极化码编码码长，在多进制符号前后分别添加L个符号，多进制发送序列可以表示为

其中，前L个符号均为-M+1，可使得初始状态从零状态开始；同理，后L个符号可使得初始状态以零状态结束。More preferably, for the implementation of the follow-up BCJR algorithm, the bit interleaver 112 in this step can also set the codeword structure as follows: carry out bit interleaving and multi-ary mapping on the encoded binary bits, so that the obtained multi-ary symbols are

where a _i ∈{-M+1,-M+3,..., M-3, M-1}, N _M is the length of the symbol after mapping

N is the code length of the polar code, and L symbols are added before and after the multi-ary symbols, and the multi-ary sending sequence can be expressed as

Among them, the first L symbols are all -M+1, which can make the initial state start from the zero state; similarly, the last L symbols can make the initial state end with the zero state.

Step S203: Send the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission.

In this step, the continuous phase modulator 113 in the signal transmitting end 101 sends the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission;

In the nth symbol period, the phase state of the CPM can be expressed as the following formula 3:

In formula 3, α is the above-mentioned multi-ary symbol sequence, h is the modulation index, the positive integer L is the memory length, T is the symbol period, that is, the duration of a multi-ary symbol of CPM; q(t) is the pulse integral function , is the integral of the pulse shaping function g _cpm (t), and the waveform of g _cpm (t) is generally selected as square wave pulse, raised cosine pulse, and Gaussian pulse.

Corresponding to the sending end, the present invention adopts CRC-Polar and CPM joint decoding and demodulation at the receiving end, which greatly reduces the complexity of the receiving end and improves the bit error performance of the receiving end. First, the log-MAP (log Maximum a posteriori) algorithm is used to demodulate the CPM signal, and the soft information obtained by demodulation is transferred to the CRC-Polar decoding module, and the cyclic redundancy is adopted at the decoding end Check-assisted serial cancellation list (CA-SCL) decoding algorithm performs decoding, as described in steps S204 and S206 below.

Step S204: After receiving the CPM signal transmitted through the channel, the log-MAP algorithm is used to demodulate the CPM signal.

In this step, after the continuous phase demodulator 121 in the receiving end 102 of the signal receives the CPM signal transmitted through the channel, the log-MAP algorithm is used to demodulate the CPM signal; the continuous phase demodulator 121 includes a matched filter Group and trellis structures.

Specifically, firstly, based on the modulation parameters of the CPM signal, a trellis structure and a filter bank for demodulation at the receiving end are constructed. Before receiving the signal, the pre-initialization and post-measurement are pre-initialized, assuming that the prior information of the input signal is equal, and then the received CPM signal is decomposed into the superposition of several PAM signals by the matched filter bank; the symbol of the detected PAM signal is passed through the trellis structure It is transformed into a branch metric, and the likelihood value of the symbol is finally merged and calculated through iterative front and back metrics. Finally, the likelihood value of the multi-ary symbol needs to be converted into the likelihood ratio of binary bits, and finally the likelihood ratio of binary bits as calculated soft information.

In the specific details of the CPM demodulation scheme involved in the present invention, the log-MAP algorithm and Laurent decomposition are used to demodulate the CPM signal.

As shown in Figure 4, the multi-ary Laurent Decomposition (Laurent Decomposition)-based matched filter bank at the receiving end based on the CPM parameters is referred to as the Laurent matched filter bank. The matched filter bank uses the Laurent decomposition principle of the CPM signal, which can Decompose the CPM signal into the superposition of several PAM (Pulse Amplitude Modulation, pulse amplitude modulation) signals (pulse signals), although theoretically the greater the memory length of the pulse, the number of decomposed PAM signals also increases exponentially, but the large CPM Part of the energy is only concentrated in a small part of the signal. Accordingly, the filter bank only includes pulses whose signal duration is longer than L-D. Compared with the traditional CPM demodulation method, this will reduce the number of matched filters.

Before demodulation, the trellis structure of the receiving end can be constructed according to the CPM parameters. The following introduces the construction method of the trellis structure and state variables of the receiving end:

其中，

表示状态对应i时刻的估计符号

的倾斜状态表示，

代表状态对应的累计相位

符号上的尖角号表示倾斜状态，倾斜符号与原符号的关系为

mod表示取余操作，p表示CPM调制因子的分母(调质因子h＝q/p，q与p是一对互质的整数)。D代表本发明定义的精度参数(1≤D≤L)。一个时刻的状态个数共有pM^D-1个。Suppose the state variable of the CPM demodulator at the nth moment is defined as

in,

Indicates the estimated symbol corresponding to the state at time i

The tilt state of

Represents the cumulative phase corresponding to the state

The sharp angle on the symbol indicates the tilted state, and the relationship between the tilted symbol and the original symbol is

mod represents the remainder operation, and p represents the denominator of the CPM modulation factor (modulation factor h=q/p, q and p are a pair of relatively prime integers). D represents the precision parameter (1≤D≤L) defined in the present invention. There are a total of pM ^D-1 states at a time.

(或者表示为

来表示，I(s_n,s_n+1)表示表示由n时刻状态s_n转至状态s_n+1的输入符号，对应着估计的n时刻估计符号

如此可以构建接收端trellis结构的状态转移关系。参见图5a，以有限状态机的形式描述了接收端trellis结构的状态变量的状态转移方式。举例：如图5b所示，M＝4，D＝1时，状态转移格图表示。The state variable transfer process can use the state transfer recursion formula:

(or expressed as

to represent, I(s _n ,s _n+1 ) represents the input symbol representing the transition from state s _n to state s _n+1 at time n, corresponding to the estimated symbol at time n

In this way, the state transition relationship of the trellis structure at the receiving end can be constructed. Referring to Fig. 5a, the state transition mode of the state variables of the trellis structure at the receiving end is described in the form of a finite state machine. Example: As shown in Figure 5b, when M=4 and D=1, the state transition lattice diagram shows.

The value range of the precision parameter D is an integer between 1 and the memory length L (including 1 and L), which means that the filter bank at the receiving end selects all Laurent pulses with a duration greater than L-D for receiving matching, which reflects the receiver's ability to CPM The accuracy of the signal approximation and the corresponding state variable of the demodulation terminal will also change with the change of D.

As a preferred embodiment, the precision parameter D in the technical solution of the present invention can be selected according to the energy proportion of the matching pulse in the filter bank:

When the modulation order, modulation index, memory length L, and pulse waveform of the CPM signal are determined, D is sequentially taken as an integer value from 1 to L, and the corresponding matching pulse energy ratio is calculated in turn;

Select the matching pulse energy proportion higher than the set energy proportion threshold value, and then use the minimum value among the values of D corresponding to the selected matching pulse energy proportion as the finally determined precision parameter D;

Wherein, the proportion of matched pulse energy specifically refers to the ratio of the energy of matched pulses in the Laurent matched filter bank to the energy of all Laurent pulses.

According to experience, the energy ratio threshold can be set to 98.70%; for example: as shown in Table 1 below, it shows that when the modulation order M=4, the modulation index h is 1/4, and the waveform of the shaped pulse function is raised cosine (RC ), under different memory lengths L (the numbers in the brackets on the right side of L in the table represent the number of all pulses), when selecting different precision parameters D (the numbers in the brackets on the right side of D in the table represent the number of pulses whose duration is longer than L-D , that is, the number of pulses corresponding to the filter bank) The proportion of energy in the filter bank:

Table 1

D=1(3) D=2(12) D=3(48) D=4(192) D=5(768) D=6(3072) L=1(3) 1 L=2(12) 99.96% 1 L=3(48) 98.66% 99.99% 1 L=4(192) 94.12% 99.93% 100.00% 1 L=5(768) 86.80% 99.30% 99.99% 100.00% 1 L=6(3072) 78.01% 97.33% 99.90% 99.99% 100.00% 1

According to the selection rules of the precision parameters mentioned in the present invention, in the above example, when the memory length L=1 (pulse total number is 3), the precision parameter should be selected as D=1 (the corresponding matched filter bank pulse number is 3); When the length is L=2 (the total number of pulses is 12), the precision parameter is selected as D=1 (the corresponding matched filter bank pulse number is 3); when the memory length is L=3 (the total number of pulses is 48), the precision parameter is selected as D=2 (the number of pulses corresponding to the matched filter group is 12); when the memory length is L=4 (the total number of pulses is 192), the precision parameter is selected as D=2 (the number of pulses corresponding to the matched filter group is 12); the memory length When L=5 (the total number of pulses is 768), the precision parameter is selected as D=2 (the corresponding matched filter bank pulse number is 12); when the memory length is L=6 (the total number of pulses is 3072), the precision parameter is selected as D =3 (the number of pulses corresponding to the matched filter bank is 48).

In summary, the accuracy parameter D of continuous phase modulation can be determined according to the modulation parameters of the continuous phase modulation and the set energy threshold; when the modulation order M or the memory length L is large, compared with the traditional continuous phase modulation The precision parameter D in the technology is a fixed value, which can avoid the bit error performance degradation caused by the insufficient proportion of pulse energy by only using the main component pulse matching (D=1), and can also avoid using all component pulses for matching (D=L) The high complexity of , the complexity here is mainly reflected in the number of states of the receiving end state variable s _n and the number of matching pulses in the corresponding matched filter bank.

Since the first and last states of the CPM are known and the state transfer is known, then the continuous phase demodulator 121 of this step adopts the log-MAP algorithm to detect the specific flow of the CPM signal, as shown in Figure 6, including the following sub-steps:

Sub-step S601: initialization;

In this sub-step, the forward metric A and the backward metric B of the state variables of the trellis structure are initialized: because L symbols are added before and after the multi-ary symbols in step S202, the first and last states are zero states, that is, s=[ 0,0,……0]), so the initial forward metric A ₀ (s ₀ =[0,0,……,0])=0, A ₀ (s ₀ ≠[0,0, ...,0])=-∞, the backward metric B _end (s _end =[0,0,...,0])=0 at the end of initialization, B _end (s _end ≠[0,0,... ,0])=-∞.

Sub-step S602: Calculating the branch metric, that is, the likelihood value of the state transition;

Specifically, the MAP algorithm obtains the probability of the corresponding estimated symbol through the transition probability of the state. Since the baseband signal is randomly generated, the probability is equal. Then for the M system, the prior probability of the input symbol of the trellis structure is equal to is p(α _i )=1/M, then the posterior probability of estimated symbol at n time is equal to the likelihood value of state transition, that is:

Γ _n (s _n ,s _n+1 )=logp(r _n (t)|s _n ,I(s _n ,s _n+1 )) (Formula 4)

也可以说是状态转移的条件；p(r_n(t)|s_n,I(s_n,s_n+1))，表示已知状态转移(从n时刻状态s_n到n+1时刻的状态s_n+1)的过程下，接收到的观测符号r_n(t)的概率。In Formula 4, Γ _n (s _n ,s _n+1 ) represents the branch metric expression at time n, corresponding to the transition probability from state s _n at time n to state s n+1 at time _n+1 ; I(s _n ,s _n+1 ) represents the input symbol from state s _n to state s _n+1 at time n, corresponding to the estimated input symbol

It can also be said to be the condition of state transition; p(r _n (t)|s _n ,I(s _n ,s _n+1 )), which means the known state transition (from state s _n at time n to time n+1 In the process of state s _n+1 ), the probability of received observation symbol r _n (t).

的相关值为

其中r(t)为接收序列，

序列为估计序列

时的CPM信号，(·)^*表示取共轭操作，

表示取实部操作。将s(t)的Laurent分解近似表示式

带入上述相关值

表达式，可以进一步推导得到n时刻基于Luarent脉冲的相关值，它正比于示n时刻分支度量表达式Γ_n(s_n,s_n+1)，即：Since maximizing the log-likelihood function is equivalent to maximizing the correlation value, that is, for the estimated sequence

The relevant value of

where r(t) is the receiving sequence,

sequence is estimated sequence

When the CPM signal, (·) ^* means to take the conjugate operation,

Indicates the operation of taking the real part. Approximate Expression of Laurent Decomposition of s(t)

Bring in the relevant values above

The expression can be further derived to obtain the correlation value based on Luarent pulse at time n, which is proportional to the branch metric expression Γ _n (s _n ,s _n+1 ) shown at time n, namely:

In formula 5, a _K,n is the pseudo symbol of the Kth Laurent pulse at time n, which corresponds to the state transition (s _n ,s _n+1 ); {x _K,n } is the CPM signal received by the receiving end r(t) is the result of the Kth real pulse in the matched filter bank, x _K,n = ∫r(t)g _K (t-nT)dt, N _D is the number of matched filters in the filter bank , that is, the number of Laurent's pulses whose duration is longer than LD, N _D =(2 ^D-1 ) ^P (2 ^P -1), P=log ₂ M. Since the Laurent pulses are all real pulses, it is not necessary to take the conjugate.

For the pseudo-symbol a _K,n of the K-th pulse of the Laurent matched filter bank at time n, for a pulse whose duration is longer than LD, its corresponding pseudo-symbol can be obtained by the following formulas 6 and 7:

为第l(0≤l≤P-1)个的二进制CPM信号的Laurent分解对应的第n个时刻的第k个伪符号；根据多进制Laurent分解算法，多进制的Laurent脉冲集合{g_K(t)}分为Q^P组(Q＝2^L-1)，为方便起见，构建映射关系(j,m)→K，即第j组(0≤j≤Q^P-1)的第m个脉冲对应着第K个多进制Laurent脉冲，{d_j,l}表示第j(0≤j≤Q^P-1)组多进制脉冲对应的第l(0≤l≤P-1)个二进制Luarent脉冲的序号；

表示第j(0≤j≤Q^P-1)组的第m个脉冲

均可通过多进制Luarent分解算法求得；{γ_n,l}表示第n个符号周期内第l(0≤l≤P-1)个二进制CPM信号的对应的估计符号，它与多进制CPM信号的估计符号之间的换算关系为

{β_k,i}为整数k进行二进制展开后的序列，根据公式

求得，i表示整数k进行二进制展开后的数位序号。Among them, a _{K, n} represents the pseudo-symbol of the K pulse of the Laurent matched filter bank in the n symbol period, P=log ₂ M, M, D are respectively the modulation order and precision parameters of the CPM signal, and an M step The CPM modulation signal of system can be regarded as the result of multiplication of P binary CPM signals (correspondingly, a multi-ary system Laurent pulse is the result of multiplication of P binary system CPM signal Laurent pulses; a pseudo-system Laurent pulse corresponding to The sign is the result of multiplying the pseudo-signs for P binary CPM signals);

is the kth pseudo-symbol at the nth moment corresponding to the Laurent decomposition of the l (0≤l≤P-1) binary CPM signal; according to the multi-ary Laurent decomposition algorithm, the multi-ary Laurent pulse set {g _K (t)} is divided into Q ^P group (Q=2 ^L-1 ). For convenience, the mapping relationship (j,m)→K is constructed, that is, the first group j (0≤j≤Q ^P -1) The m pulse corresponds to the Kth multi-ary system Laurent pulse, and {d _j,l } represents the lth (0≤l≤P-1) group of multi-ary system pulses corresponding to the jth (0≤j≤Q ^P -1) group ) the serial number of a binary Luarent pulse;

Indicates the mth pulse of the jth (0≤j≤Q ^P -1) group

Both can be obtained by the multi-ary Luarent decomposition algorithm; {γ _n,l } represents the corresponding estimated symbol of the l (0≤l≤P-1) binary CPM signal in the n-th symbol period, which is related to the multi-ary The conversion relationship between the estimated symbols of the CPM signal is

{β _k,i } is the binary expanded sequence of integer k, according to the formula

Obtained, i represents the digit serial number of the integer k after binary expansion.

Sub-step S603: based on the iteratively calculated forward metric, backward metric and branch metric (posterior probability of pseudo-symbol), finally combine and calculate the likelihood value of the multi-ary symbol;

Specifically, the forward metric A _n (s _n ) is iteratively calculated according to the following formula 8:

且max^*操作能够通过迭代使用雅各比公式ln(e^x+e^y)＝max(x,y)+ln(1+e^-|x-y|)进行计算；Ξ(s)表示与状态后向连接的状态，Ξ^-1(s)表示与状态前向连接的状态。In formula 8,

And the max ^* operation can be calculated by iteratively using the Jacobian formula ln(e ^x +e ^y )=max(x,y)+ln(1+e ^-|xy| ); Ξ(s) represents the backward The state of the connection, Ξ ^-1 (s) represents the state that is forward connected with the state.

Iteratively calculate the backward metric B _n (s _n ) according to the following formula 9:

According to the following formula 10, the logarithmic likelihood value of the multi-ary symbol is obtained:

When the bit error performance is acceptable, the max ^* (·) operation in the log-MAP algorithm can be replaced by the max(·) operation, which can greatly reduce the computational complexity, that is, the Max-Log-MAP algorithm.

Sub-step S604: Convert the likelihood probability of the multi-ary symbol into a binary bit likelihood ratio to obtain demodulated soft information;

对应的二进制比特序列为

根据多进制下符号的似然值

计算对应的二进制符号序列二进制比特的对数似然比，得到二进制估计符号序列作为解调的软信息，如公式11所示：Specifically, let the multi-ary (oblique) notation

The corresponding binary bit sequence is

According to the likelihood value of the symbol under the multi-ary system

Calculate the log likelihood ratio of the binary bits of the corresponding binary symbol sequence, and obtain the binary estimated symbol sequence as the demodulated soft information, as shown in formula 11:

In particular, when the modulation order is 2, the corresponding log likelihood ratio is

Step S205: Deinterleaving the soft information obtained by using the log-MAP algorithm and Laurent decomposition;

i＝1,2,……N，N为极化码码长。In this step, the deinterleaver 122 in the receiving end 102 of the signal deinterleaves the soft information obtained by using the log-MAP algorithm and Laurent decomposition to obtain the LLR values of the binary bit streams of all received sequences, that is, the soft information of the received sequences

i=1,2,...N, N is the code length of the polar code.

The present invention deinterleaves the soft information obtained by using the log-MAP algorithm and Laurent decomposition as the input of the decoding end of the CRC-Polar code. At the decoding end, a cyclic redundancy check-assisted serial cancellation list (CA-SCL, CRC-AidedSCL) is used as a decoding algorithm. The decoding process of the CA-SCL algorithm is as described in step S206.

Step S206: The deinterleaved soft information is decoded by a cyclic redundancy check-assisted serial cancellation list (CA-SCL) algorithm, and a restored information stream is obtained after removing cyclic redundancy check bits.

In this step, the decoder 123 in the receiving end 102 of the signal decodes the deinterleaved soft information using a serial cancellation list assisted by a cyclic redundancy check: according to the binary bit sequence in the soft information, determine The values of elements in the serial cancellation list; after obtaining the list of candidate paths in the serial cancellation list based on the SCL algorithm, perform CRC checks on the candidate paths in descending order of path metrics to obtain decoding results.

Specifically, according to the log likelihood ratio of the binary bit sequence obtained in the above steps, it is subjected to SCL decoding whose maximum candidate path number (list size) is L _list , and the decoding process is as shown in Figure 7, including the following steps :

Step S701: initialization;

In this step, first define L ⁽ⁱ⁾ as the set of candidate paths corresponding to the i-th layer of the SCL decoding tree, write an empty sequence into the initial serial offset list, that is, initialize L ⁽⁰⁾ = {φ}, and Initialize its corresponding path metric to 0;

Step S702: Path expansion: according to the binary estimated symbol sequence in the soft information, determine the candidate paths in the serial cancellation list;

通过添加元素v_i＝0或1进行路径扩展后得到的所有候选路径记录在表L⁽ⁱ⁾中；其中，{v_i}v_i∈{0,1}对应着步骤S604中得到的软信息中的二进制估计符号序列

具体地，若

则对应v_i＝0；若

则对应v_i＝1；

表示从v₁到v_i-1的序列；Specifically, after the i-th layer, all candidate paths in the serial cancellation list L ^(i-1 )

All candidate paths obtained after path extension by adding element v _i =0 or 1 are recorded in table L ⁽ⁱ⁾ ; among them, {v _i }v _i ∈{0,1} corresponds to the soft information obtained in step S604 Binary estimated sign sequence in

Specifically, if

Then corresponding to v _i =0; if

Then corresponding to v _i =1;

Represents the sequence from v ₁ to v _i-1 ;

根据SCL算法利用接收序列的软信息

计算并记录列表中所有

的路径度量值

表示从SCL算法译码码树根节点到当前第i层的某个路径

的路径度量值，对应着已知接收序列为

下，估计序列为

时的后验概率的对数。Record all the candidate paths obtained in the table

Using the soft information of the received sequence according to the SCL algorithm

Calculate and record all the

The path metric of

Indicates a path from the root node of the SCL algorithm decoding tree to the current i-th layer

The path metric value of , corresponding to the known received sequence as

Next, the estimated sequence is

The logarithm of the posterior probability when .

Step S703: path competition;

Specifically, if the number of candidate paths in the serial cancellation list L ⁽ⁱ⁾ is less than or equal to the set number L _list , then keep all candidate paths; otherwise keep the L _list candidate paths with the maximum path metric value, and start from L ^{(i )} to delete the rest of the candidate paths.

Step S704: Determine whether to terminate the judgment; specifically, if the path does not extend to a leaf node, that is, if i<N, then add 1 to i and then skip to step S702; if i≥N, terminate the judgment and execute step S705. Wherein, N is the code length of the polar code.

Step S705: Obtain the candidate path with the largest path metric value in the list L ^(N) .

Specifically, obtain the candidate path with the largest path metric value in the list L ^(N) as the decoding output; the candidate path with the largest path metric value in L ^(N) is

More preferably, decoding assistance can also be performed through the cyclic redundancy check in the following step S706:

Step S706: After obtaining the list of candidate paths through the SCL algorithm, perform CRC checks on the candidate paths in the list L ^(N) according to the order of the path metrics from large to small, and use the decoding sequences corresponding to the candidate paths that pass the CRC check as decoding result;

Specifically, the CRC check is performed on the decoding sequence corresponding to the candidate path according to the order of the path metrics from large to small;

For the candidate path currently undergoing CRC check, if the obtained check bits are all 0, then the candidate path is the correct decoding path, and the corresponding decoding bit sequence is output to complete the decoding;

If the obtained check bits are not all 0, the check fails; select the candidate path with the largest next path metric in the candidate path list to perform CRC check until the check bits are all 0, and output the corresponding decoding bit sequence;

If the verification results of all acquired candidate paths are incorrect, output the decoding sequence corresponding to the candidate path with the largest path metric value in the list as the decoding result; at this time, the decoding output results of CA-SCL and SCL are the same.

The present invention has carried out multiple implementation experiments and simulations, and the results are described in detail below:

The simulation parameters are shown in Table 2 below:

Table 2

CPM parameters configuration modulation index 0.5 modulation order 2 oversampling rate 4 normalized band 0.3 data rate 1kHz channel AWGN, the signal-to-noise ratio is SNR(dB)

Referring to Figure 8, under the AWGN channel, when the code length is 512 and the code rate is 0.5, the simulation results show that the bit error performance is significantly improved compared with the traditional RS code. When the memory length L=1 and the block error rate When it is 10 ^-4 , the technical solution of the present invention has a performance gain of 2.6dB compared with the RS code by using the polar code.

In the technical solution of the present invention, the information flow is subjected to cyclic redundancy check encoding and polar encoding; the code words obtained by encoding are interleaved and mapped; the CPM signal obtained by performing continuous phase modulation on the mapped symbols is sent into the channel for transmission .

The computer-readable medium in this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be realized by any method or technology. Information may be computer readable instructions, data structures, modules of a program, 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 technology, Compact Disc Read-Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical storage, Magnetic tape cartridge, tape magnetic disk storage or other magnetic storage device or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is exemplary only, and is not intended to imply that the scope of the present disclosure (including claims) is limited to these examples; under the idea of the present invention, the above embodiments or Combinations between technical features in different embodiments are also possible, steps may be carried out in any order, and there are many other variations of the different aspects of the invention as described above, which are not presented in detail for the sake of brevity.

In addition, well-known power/ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures, for simplicity of illustration and discussion, and so as not to obscure the present invention. . Furthermore, devices may be shown in block diagram form in order to avoid obscuring the invention, and this also takes into account the fact that details regarding the implementation of these block diagram devices are highly dependent on the platform on which the invention is to be implemented (i.e. , these details should be well within the understanding of those skilled in the art). Where specific details (eg, circuits) have been set forth to describe example embodiments of the invention, it will be apparent to those skilled in the art that other embodiments may be implemented without or with variations from these specific details. Implement the present invention down. Accordingly, these descriptions should be regarded as illustrative rather than restrictive.

Although the invention has been described in conjunction with specific embodiments of the invention, many alternatives, modifications and variations of those embodiments will be apparent to those of ordinary skill in the art from the foregoing description. For example, other memory architectures such as dynamic RAM (DRAM) may use the discussed embodiments.

Embodiments of the present invention are intended to embrace all such alterations, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent replacements, improvements, etc. within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (11)

1. A method for information transmission of polarization-coded continuous phase modulation, characterized in that it comprises: Carry out cyclic redundancy check coding and polarization coding on the information flow; Perform bit interleaving and binary-to-multiary mapping on the encoded codeword; The CPM signal obtained by performing continuous phase modulation on the mapped symbols is sent into the channel for transmission. 2. The method according to claim 1, further comprising: After receiving the continuous phase modulation CPM signal transmitted through the channel, the log-MAP algorithm is used to demodulate the CPM signal; After the soft information obtained by demodulation is deinterleaved, the serial cancellation list assisted by the cyclic redundancy check is used for decoding. 3. The method according to claim 1, wherein the polar channel reliability estimation in the polar encoding process specifically adopts a Gaussian approximation algorithm, specifically comprising: The expectation of the log-likelihood ratio of each subchannel is calculated according to the following formula 1:

in,

Indicates the log-likelihood ratio of the i-th polarized channel in a polar code of length n during the channel polarization process,

Indicates the log-likelihood ratio of the channel hypothesis, which can be regarded as the log-likelihood ratio of a polarized channel with length 1; The following approximate expression AGA-2 is used to approximate the above formula

The reliability of the subchannels is estimated from the computed log-likelihood ratios of the subchannels. 4. The method according to claim 3, wherein, after receiving the CPM signal transmitted through the channel, the log-MAP algorithm is used to demodulate the CPM signal, specifically comprising: Based on the Lauren matched filter bank, the received CPM signal is decomposed into the superposition of several PAM pulses; Determine the input symbol of the trellis structure according to the pseudo-sign of the PAM pulse, and then calculate the posterior probability of the pseudo-symbol based on the state transition mode of the state variable of the trellis structure; calculating a log-likelihood value of the input symbol according to the forward metric, the backward metric, and the posterior probability of the pseudo-symbol of the iterated state variable; The log likelihood value of the input symbol is converted into a binary bit likelihood ratio to obtain demodulated soft information. 5. The method according to claim 4, wherein the pseudo-symbol is calculated according to the following formulas 6 and 7:

Wherein, a _{K, n} represent the false symbol of the K pulse of the Laurent matched filter bank in the n symbol period, P=log ₂ M, M, D are respectively the modulation order of the CPM signal, the precision parameter;

is the k-th pseudo-symbol at the n-th moment corresponding to the Laurent decomposition of the l-th binary CPM signal; {d _j,l } represents the sequence number of the l-th binary Luarent pulse corresponding to the j-th group of multi-ary pulses;

Indicates the delay of the l-th binary Laurent pulse corresponding to the m-th pulse of the j-th group;

Both can be obtained by multi-ary Luarent decomposition algorithm; {γ _n,l } represents the estimated symbol of the lth binary CPM signal in the nth symbol period. 6. The method according to claim 5, wherein D is determined according to the following method: When the modulation order, modulation index, memory length L, and pulse waveform of the CPM signal are determined, D is sequentially taken as an integer value from 1 to L, and the corresponding matching pulse energy ratio is calculated in turn; Select the proportion of matching pulse energy higher than the set threshold value, and then use the minimum value among the values of D corresponding to the selected matching pulse energy proportion as the finally determined precision parameter D; Wherein, the proportion of matched pulse energy specifically refers to the ratio of the energy of matched pulses in the Laurent matched filter bank to the energy of all Laurent pulses. 7. The method according to claim 4, characterized in that, after the soft information obtained by demodulation is deinterleaved, decoding is performed using a cyclic redundancy check-assisted serial offset list, specifically comprising: determining a candidate path in the serial cancellation list according to the binary estimated symbol sequence in the soft information; After the candidate path list in the serial cancellation list is obtained based on the SCL algorithm, a CRC check is performed on the candidate paths in descending order of path metrics to obtain a decoding result. 8. An information transmission system for polarization-encoded continuous phase modulation, characterized in that it comprises: CRC cascaded polar code encoder, used to perform cyclic redundancy check coding and polar coding on the information stream; A bit interleaver, which is used to bit-interleave the encoded codeword and map from binary to multi-ary; The continuous phase modulator is configured to send the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission. 9. The system according to claim 8, further comprising: The continuous phase demodulator is used to demodulate the CPM signal transmitted through the channel by using the log-MAP algorithm; A deinterleaver, used for deinterleaving soft information obtained by demodulation; The decoder is used to decode the deinterleaved soft information by using a serial cancellation list assisted by a cyclic redundancy check. 10. A signal sending end, characterized in that, comprising: CRC cascaded polar code encoder, used to perform cyclic redundancy check coding and polar coding on the information stream; A bit interleaver, which is used to bit-interleave the encoded codeword and map from binary to multi-ary; The continuous phase modulator is configured to send the CPM signal obtained by performing continuous phase modulation on the mapped symbols into the channel for transmission. 11. A signal receiving end, characterized in that, comprising: The continuous phase demodulator is used to demodulate the CPM signal transmitted through the channel by using the log-MAP algorithm; A deinterleaver, used for deinterleaving soft information obtained by demodulation; The decoder is used to decode the deinterleaved soft information by using a serial cancellation list assisted by a cyclic redundancy check.

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