High-order modulation signal group delay distortion compensation method and device based on sub-band decomposition

Abstract

The embodiment of the invention provides a high-order modulation signal group delay distortion compensation method and device based on sub-band decomposition, and the method comprises the steps: obtaining a received signal, extracting a target guide code, and calculating a signal-to-noise ratio estimation value; determining a signal sub-band decomposition number and a compensation filter length based on a predetermined signal decomposition parameter and a signal-to-noise ratio estimation value; decomposing the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands; calculating a filter compensation coefficient of each signal sub-band based on the compensation filter length, and performing group delay compensation on each signal sub-band based on the compensation coefficient; according to the embodiment of the invention, fine compensation of different frequency components is carried out on group delay through sub-band decomposition, channel frequency response in the sub-bands is flatter, requirements for estimation errors and the length of a filter are reduced, and therefore the performance bottleneck of a global equalizer is avoided.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of wireless communication technologies, and particularly to a method and apparatus for compensating group delay distortion of high-order modulation signals based on sub-band decomposition. Background Art

[0002] In order to solve the contradiction between the information transmission volume and the limited bandwidth, various modern modulation and demodulation technologies are pursuing reliable high-speed data transmission. QAM (Quadrature Amplitude Modulation) is a composite modulation method that simultaneously performs digital modulation on the amplitude and phase of a carrier, and has advantages such as high spectral efficiency and anti-noise performance. For a multi-level M-QAM signal, one symbol carries log2M bits of information. The larger the modulation order M, the greater the information carrying capacity and the higher the spectral efficiency. Therefore, high-order QAM (such as 256QAM) can more effectively improve the spectral efficiency and has been widely applied in fields such as digital microwave communication systems, cable television networks, and satellite communications. However, as the modulation order increases, the constellation distribution of the signal will become denser and denser, resulting in high-order QAM signals being very sensitive to noise interference and channel distortion. In specific applications, we have found that QAM signals are greatly affected by channel distortion, especially group delay distortion. How to improve the demodulation accuracy and demodulation efficiency of high-order QAM under group delay distortion channels has become a difficult problem for high-order QAM. Summary of the Invention

[0003] In view of this, the embodiments of this specification provide a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition. One or more embodiments of this specification simultaneously relate to an apparatus for compensating group delay distortion of high-order modulation signals based on sub-band decomposition, a computing device, a computer-readable storage medium, and a computer program to solve the technical defects existing in the prior art.

[0004] According to the first aspect of the embodiments of this specification, a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition is provided, including: Obtain the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value according to the target pilot code, where the received signal is a signal with a single symbol rate after timing synchronization processing, and the received signal is a digital signal; Based on the pre-determined signal decomposition parameters and the signal-to-noise ratio estimation value, determine the signal sub-band decomposition number and the compensation filter length, where both the signal sub-band decomposition number and the compensation filter length are ≥ 4; Decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands; Calculate the filter compensation coefficients of each signal sub-band based on the compensation filter length, and perform group delay compensation on each signal sub-band based on the compensation coefficients; Generate a target signal based on the compensated signal subbands.

[0005] In some alternative embodiments, calculating a signal-to-noise ratio (SNR) estimate value based on a target pilot code in a received signal includes: Obtain an original pilot code, and calculate the SNR estimate value according to the original pilot code and the target pilot code.

[0006] In some alternative embodiments, the steps of determining signal decomposition parameters include: Form at least two SNR intervals based on at least one preset threshold value; Establish an inverse correlation relationship between the SNR intervals and the signal decomposition parameters, where a high SNR interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband decomposition number M is constrained such that M = 2 i and M ≥ 4, where i is a natural number, and the compensation filter length L is constrained such that L = 2j and L ≥ 4, where j is a natural number; Determine a lower limit value of the signal subband decomposition number according to the ratio relationship between a preset subbandwidth and the total bandwidth of the received signal, and determine the lower limit value as the signal subband decomposition number corresponding to the highest SNR interval.

[0007] In some alternative embodiments, calculating a filter compensation coefficient for each signal subband based on the compensation filter length includes: Obtain an original pilot code; Based on the signal subband decomposition number M, decompose the original pilot code into M first subcodes of equal length, and decompose the target pilot code into M second subcodes of equal length, where the subcode length of the first subcode or the second subcode is N, and N is a natural number; Construct a received signal matrix Y for the kth second subcode k , Y k has N + 1 - L rows k , Y k has L columns k , where L k represents the compensation filter length of the kth signal subband, and the first row of Y k is the signal values of L consecutive second subcodes, the nth row is the signal values of L consecutive second subcodes obtained by shifting the first row n - 1 times, the left boundary of the first row is y k [0], and the right boundary of the (N + 1 - L) k th row is y k [N - 1], or, when the right boundary of the first row is y k [0], the left boundary of the (N + 1 - L) k th row is y k [N - 1], or, when the left boundary of the first row is y kWhen it is [N - 1], the right boundary of the (N + 1 - L)-th k row is y k [0], or the right boundary of the first row is y k When it is [N - 1], the right boundary of the (N + 1 - L)-th k row is y k [0], k, n are natural numbers, k ∈ [1, M], n ∈ [0, N - L k ; Construct the desired response vector S of the k-th signal subband k , where the desired response vector is, in the original pilot code, the transposed vector of the vector composed of the signal values with a length of N + 1 - L corresponding to the first column of the received signal matrix Y k ; k Combine the received signal matrix Y k and the desired response vector S k , and calculate the filter compensation coefficients of the k-th signal subband, where the filter compensation coefficients are composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to the coefficient at the corresponding position of the filter.

[0008] In some alternative embodiments, combining the received signal matrix Y k and the desired response vector S k , calculating the filter compensation coefficients of the k-th signal subband includes: According to a preset first calculation formula, combine the received signal matrix Y k and the desired response vector S k , and calculate the filter compensation coefficients of the k-th signal subband, where the first calculation formula includes:

[0009] where W k represents the filter compensation coefficients, represents the conjugate transpose of Y k ;

[0010] In some alternative embodiments, the method for compensating the group delay distortion of high-order modulation signals based on subband decomposition further includes: Performing post-equalization processing on the target signal to dynamically track the group delay change of the target signal for dynamic compensation.

[0011] In some alternative embodiments, after determining the number of signal subband decompositions and the length of the compensation filter corresponding to the received signal, it includes: Obtain the original pilot code and calculate the average group delay of the target pilot code with respect to the original pilot code; Obtain the subband group delays of each signal subband and calculate the group delay differences between the subband group delays and the average group delay; ​When the group delay difference is greater than a preset offset threshold, if the sub-band group delay is greater than the average group delay, increase the compensation filter length of the corresponding signal sub-band based on a preset first step value; If the sub-band group delay is less than the average group delay, decrease the compensation filter length of the corresponding signal sub-band based on a preset second step value; wherein, the updated compensation filter length L is constrained to L = 2j and L ≥ 4, where j is a natural number; When the group delay difference is not greater than the preset offset threshold, do not update the compensation filter length of each signal sub-band.

[0012] In some alternative embodiments, the method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition further includes: Analyze the target signal to determine the frame synchronization result; If the frame synchronization result indicates maintaining lock, it means the target signal meets the requirements; If the frame synchronization result indicates maintaining unlock, re-execute the steps of acquiring the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value according to the target pilot code.

[0013] According to the second aspect of the embodiments of this specification, there is provided a device for compensating group delay distortion of high-order modulation signals based on sub-band decomposition, including: An acquisition module, configured to acquire the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value according to the target pilot code, wherein the received signal is a single-symbol-rate signal that has undergone timing synchronization processing, and the received signal is a digital signal; A determination module, configured to determine the number of signal sub-band decompositions and the compensation filter length based on pre-determined signal decomposition parameters and the signal-to-noise ratio estimation value, wherein both the number of signal sub-band decompositions and the compensation filter length are ≥ 4; A decomposition module, configured to decompose the received signal based on the number of signal sub-band decompositions to obtain at least four signal sub-bands; A compensation module, configured to calculate the filter compensation coefficients of each signal sub-band based on the compensation filter length, and perform group delay compensation on each signal sub-band based on the compensation coefficients; A generation module, configured to generate a target signal based on each compensated signal sub-band.

[0014] In some alternative embodiments, calculating the signal-to-noise ratio estimation value according to the target pilot code in the received signal includes: Acquire the original pilot code, and calculate the signal-to-noise ratio estimation value according to the original pilot code and the target pilot code.

[0015] In some alternative embodiments, the steps of determining the signal decomposition parameters include: Form at least two signal-to-noise ratio intervals based on at least one preset threshold value; Establish an inverse correlation relationship between the signal-to-noise ratio interval and the signal decomposition parameters. Among them, the high signal-to-noise ratio interval corresponds to a low number of signal subband decompositions and a low length of the compensation filter. The number of signal subband decompositions M is constrained to M = 2 i and M ≥ 4, where i is a natural number, and the length of the compensation filter L is constrained to L = 2j and L ≥ 4, where j is a natural number; According to the ratio relationship between the preset subbandwidth and the total bandwidth of the received signal, determine the lower limit value of the number of signal subband decompositions, and determine the lower limit value as the number of signal subband decompositions corresponding to the highest signal-to-noise ratio interval.

[0016] In some alternative embodiments, calculating the filter compensation coefficients of each signal subband based on the length of the compensation filter includes: Obtain the original pilot code; Based on the number of signal subband decompositions M, decompose the original pilot code into M first subcodes of equal length, and decompose the target pilot code into M second subcodes of equal length. Among them, the subcode length of the first subcode or the second subcode is N, and N is a natural number; Construct the received signal matrix Y of the kth second subcode k , Y k The number of rows of is N + 1 - L k , Y k The number of columns of is L k , where L k Represents the length of the compensation filter of the kth signal subband, and the first row of Y k Is the signal value of L consecutive second subcodes, and the nth row is the signal value of L consecutive second subcodes obtained by shifting the first row n - 1 times. The left boundary of the first row is y k [0], when the right boundary of the (N + 1 - L)th k Row is y k [N - 1], or when the right boundary of the first row is y k [0], the left boundary of the (N + 1 - L)th k Row is y k [N - 1], or when the left boundary of the first row is y k [N - 1], the right boundary of the (N + 1 - L)th k Row is y k [0], or when the right boundary of the first row is y k [N - 1], the left boundary of the (N + 1 - L)th k Row is y k [0], k, n are natural numbers, k ∈ [1, M], n ∈ [0, N - L k ; Construct the desired response vector S of the kth signal subband k , and the desired response vector is in the original pilot code, corresponding to the received signal matrix Yk The length corresponding to the first column of k The signal values of form the transposed vector of the vector; Combined with the received signal matrix Y k and the desired response vector S k , calculate the filter compensation coefficient of the k-th signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to the coefficient at a corresponding position of the filter.

[0017] In some alternative embodiments, combined with the received signal matrix Y k and the desired response vector S k , calculating the filter compensation coefficient of the k-th signal subband includes: According to a preset first calculation formula, combined with the received signal matrix Y k and the desired response vector S k , calculate the filter compensation coefficient of the k-th signal subband, where the first calculation formula includes:

[0018] where, W k represents the filter compensation coefficient, represents the conjugate transpose of Y k .

[0019] In some alternative embodiments, the method for compensating the group delay distortion of high-order modulation signals based on subband decomposition further includes: Perform post-equalization processing on the target signal, and dynamically track the group delay change of the target signal to perform dynamic compensation.

[0020] In some alternative embodiments, after determining the number of subband decompositions and the length of the compensation filter corresponding to the received signal, it includes: Obtain the original pilot code, and calculate the average group delay of the target pilot code with respect to the original pilot code; Obtain the subband group delay of each signal subband, and calculate the group delay difference between each subband group delay and the average group delay; In the case where the group delay difference is greater than a preset offset threshold, if the subband group delay is greater than the average group delay, increase the length of the compensation filter of the corresponding signal subband based on a preset first step value; If the subband group delay is less than the average group delay, reduce the length of the compensation filter of the corresponding signal subband based on a preset second step value; where the updated compensation filter length L is constrained to L = 2j and L ≥ 4, and j is a natural number; In the case where the group delay difference is not greater than the preset offset threshold, do not update the length of the compensation filter of each signal subband.

[0021] In some alternative embodiments, the method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition further includes: Analyze the target signal to determine the frame synchronization result; If the frame synchronization result indicates maintaining lock, it means the target signal meets the requirements; If the frame synchronization result indicates maintaining unlock, re-execute the steps of acquiring the received signal, extracting the target pilot code, and calculating the signal-to-noise ratio estimation value according to the target pilot code.

[0022] According to the third aspect of the embodiments of this specification, a computing device is provided, including: A memory and a processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition are implemented.

[0023] According to the fourth aspect of the embodiments of this specification, a computer-readable storage medium is provided, which stores computer-executable instructions. When the instructions are executed by a processor, the steps of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition are implemented.

[0024] According to the fifth aspect of the embodiments of this specification, a computer program is provided. When the computer program is executed on a computer, the computer is made to execute the steps of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0025] In at least one of the embodiments of this specification, group delay is finely compensated for different frequency components through sub-band decomposition. The channel frequency response within the sub-band is flatter, and the requirements for estimation error and filter length are reduced, thus breaking through the performance bottleneck of the global equalizer. Description of the Drawings

[0026] Figure 1a is a comparison diagram of the influence of 0 ns group delay distortion in the prior art provided by some embodiments of this specification on the 16QAM and 256QAM signal constellations; Figure 1b is a comparison diagram of the influence of 0.1 ns group delay distortion in the prior art provided by some embodiments of this specification on the 16QAM and 256QAM signal constellations; Figure 1c is a comparison diagram of the influence of 0.5 ns group delay distortion in the prior art provided by some embodiments of this specification on the 16QAM and 256QAM signal constellations; Figure 2It is a flowchart of some embodiments of a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 3a It is a constellation diagram of a 256QAM signal with a group delay of 1 ns before sub-band decomposition in a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 3b It is a constellation diagram of a 256QAM signal with a group delay of 1 ns after sub-band decomposition in a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 4a It is a constellation diagram of a 256QAM signal with a group delay of 1 ns before compensation in a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 4b It is a constellation diagram of a 256QAM signal with a group delay of 1 ns after compensation in a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 5 It is a comparison diagram of bit error rates of group delay distortion before and after compensation in a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 6 It is a schematic diagram of a simple structure of a device for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification; Figure 7 It is a block diagram of the structure of a computing device provided by some embodiments of this specification. Detailed implementation manners

[0027] In the following description, many specific details are set forth in order to provide a thorough understanding of this specification. However, this specification can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of this specification. Therefore, this specification is not limited by the specific implementations disclosed below.

[0028] The terms used in one or more embodiments of this specification are for the purpose of describing specific embodiments only and are not intended to limit one or more embodiments of this specification. The singular forms "a" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and encompasses any and all possible combinations of one or more of the associated listed items. The modifications of "one" and "multiple" mentioned in this disclosure are illustrative rather than restrictive. Those skilled in the art should understand that, unless clearly specified otherwise in the context, it should be understood as "one or more".

[0029] It should be understood that although the terms first, second, etc. may be used in one or more embodiments of this specification to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of one or more embodiments of this specification, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0030] First, the noun terms related to one or more embodiments of this specification are explained: DFT: Discrete Fourier Transform, based on the discrete Fourier transform.

[0031] ‌DD-LMS: Decision Directed-Least Mean Square, the decision-directed least mean square algorithm.

[0032] OFDM: Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing. ‌

[0033] FBMC‌: Filter Bank Multi-Carrier, filter bank multi-carrier.

[0034] The channel group delay characteristic causes distortion to the modulated signal, mainly manifested as the divergence of the constellation diagram and the offset from the theoretical points. As Figure 1a 、 Figure 1b and Figure 1cThe simulation results (where the abscissa "in-phase" in the figure represents in-phase and the ordinate "quadrature" represents quadrature, and the same representation is used hereinafter without further elaboration) show the impact of group delay distortion on the constellation diagram of high-order QAM signals. The simulation signals use 16QAM / 256QAM modulation respectively, the symbol rate is 750Msps, and there is no noise interference. It can be seen that the distribution of high-order QAM signals in the complex plane is denser, and the Euclidean distance between constellation points is closer. Even a very small position distortion may cause crosstalk between symbols, increasing the bit error rate. Therefore, 256QAM is more sensitive to group delay distortion. As the group delay increases, the distortion rate of high-order QAM signals also gradually increases.

[0035] Group delay is a transmission characteristic index of a linear system. Since digital signals are usually composed of multiple spectral components, the phase-frequency characteristic of the transmission system is usually described by the concept of group delay. If, after the transmitted signal passes through the transmission system, multiple spectral components of the signal have the same group delay, then the sum of these spectral components is the same as the transmitted signal, except that there is a group delay in signal transmission. This situation indicates that the phase-frequency characteristic of the system is flat and there is no group delay distortion. However, in actual high-speed data transmission communication systems, the phase-frequency characteristic of the system is not flat and often distorted. The group delays generated by each spectral component of the signal after passing through the system are different, and the sum of the spectral components is distorted. Such a situation is called group delay distortion. At this time, the superposition of multiple signal spectra at the output is different from the original signal, often resulting in serious inter-symbol interference and an increase in the bit error performance of the system.

[0036] Currently, the common methods for compensating group delay distortion of high-order QAM signals in the industry are mainly divided into the following categories: (1) Predistortion technology, which introduces a memory polynomial at the transmitter to jointly compensate for the channel group delay and the nonlinearity of the power amplifier. Its disadvantage is that it is difficult to ensure the requirements of high-order QAM in terms of modeling accuracy, and its dynamic tracking ability is insufficient. (2) Blind equalization algorithm, which adaptively corrects channel distortion in the time domain. For high-order QAM signals, a relatively high filter length is usually required. However, as the filter length increases, the convergence speed of the equalization coefficient increases significantly, and the steady-state error of the equalization filter increases significantly. These all lead to the performance bottleneck of the global filter for compensating group delay.

[0037] In view of the above situation, the embodiments of this specification provide a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0038] See Figure 2 , Figure 2 shows a flowchart of a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification, which specifically includes the following steps.

[0039] Step 201: Obtain the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value according to the target pilot code.

[0040] In some embodiments, the execution subject (such as a preset computing device) of the high-order modulation signal group delay distortion compensation method based on subband decomposition can be connected to the target device through a wired connection method or a wireless connection method. Then, obtain the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value according to the target pilot code. Among them, the received signal is a signal with a single symbol rate that has been subjected to timing synchronization processing, and the received signal is a digital signal. The above wireless connection methods can include but are not limited to 3G / 4G / 5G / 6G connections, WiFi connections, Bluetooth connections, WiMAX connections, Zigbee connections, UWB (ultrawideband) connections, and other currently known or future-developed wireless connection methods.

[0041] The high-order modulation signal can refer to a digital modulation signal using high-order constellation mapping (such as 64QAM, 128QAM, 256QAM, 1024QAM, etc.), and more bit information is carried by each symbol to achieve high spectral efficiency transmission. The minimum limits of the corresponding high-order modulation signals in different application environments may be different. For example, the high-order modulation signal corresponding to this application can be specified as a high-order constellation mapping of at least 256QAM, but no specific limitation is made thereto.

[0042] The received signal can refer to a set of digital signals that have undergone timing synchronization and symbol alignment processing. This signal can maintain the time-domain integrity of the baseband signal, avoid redundant calculations introduced by oversampling, and provide a standardized input for subband decomposition. The single symbol rate can refer to the processing method in which only one valid sampling point is retained in each symbol period after the received signal has been synchronized. This rate is strictly matched with the symbol period designed by the system to ensure the energy conservation of the time-domain signal during the subband decomposition process and avoid spectral aliasing distortion. In some examples, the received signal can be the output signal of one of the steps or components of a multi-carrier communication system such as OFDM or FBMC.

[0043] The target pilot code can refer to a known reference signal sequence extracted by the receiving end from the received signal, which is used for channel characteristic analysis and distortion parameter calculation. Its structure is consistent with the original pilot code preset by the transmitting end, and the group delay distortion characteristics of the channel are accurately estimated by comparing the differences between the received / transmitted pilot codes.

[0044] The signal-to-noise ratio estimation value can refer to a channel quality quantization index calculated through the cross-correlation operation between the target pilot code and the original pilot code, combined with the minimum mean square error criterion. This value characterizes the signal purity in the current channel environment and is used to dynamically adjust the parameter configuration of the subband decomposition and compensation strategy.

[0045] In some alternative implementation manners, calculating a signal-to-noise ratio (SNR) estimation value based on a target pilot code in a received signal includes: obtaining an original pilot code, and calculating the SNR estimation value according to a preset second calculation formula, the original pilot code, and the target pilot code, where the second calculation formula includes:

[0046] where SNR represents the SNR estimation value, Ls represents the length of the original pilot code or the target pilot code (the lengths of the two are equal), Re represents the real part, x(n) represents the data at the n-th position in the original pilot code, y(n) represents the data at the n-th position in the target pilot code, and n is a natural number. The original pilot code corresponds to the target pilot code. The original pilot code may refer to a known reference signal sequence pre-generated at a sending end, having a fixed coding structure and time-frequency distribution characteristics, and serving as a reference for signal distortion compensation.

[0047] Step 202: Determine a signal sub-band decomposition number and a compensation filter length based on pre-determined signal decomposition parameters and the SNR estimation value, where both the signal sub-band decomposition number and the compensation filter length are ≥ 4.

[0048] In some embodiments, the signal decomposition parameters may refer to core control parameters dynamically configured in channel compensation processing. These parameters include the sub-band decomposition number (M) and the compensation filter length. The numerical ranges of the sub-band decomposition number (M) and the compensation filter length are jointly determined by the real-time SNR estimation value and a preset threshold. The signal sub-band decomposition number may refer to the number of sub-bands of a signal in divided narrow bands. This parameter is negatively correlated with the degree of channel distortion. In a high SNR environment, a smaller number of sub-bands is selected (such as M = 4), and in a low SNR or strong interference scenario, a larger decomposition number is enabled (such as M = 16). The compensation filter length may refer to the number of taps of an equalization filter in each sub-band, determining the fineness of time-domain compensation. It should be noted that both M and L should be ≥ 4; otherwise, the basic calculation requirements are not met. As M increases, the calculation accuracy is higher, but the calculation delay and resource consumption increase synchronously. For the value of L, within a target range segment, as its value increases, its fitting ability also increases, but when the value of L is too large, the calculation effect starts to decline. Therefore, more restrictions need to be imposed on the value of L.

[0049] In some alternative implementation manners, the steps of determining the signal decomposition parameters include: First step, form at least two SNR intervals based on at least one preset threshold value.

[0050] The threshold value can refer to a preset signal-to-noise ratio (SNR) critical value used to divide the interval levels of channel quality. When the SNR is high, the noise ratio is small, and fewer subbands can be divided, and a smaller filter coefficient length can be used to reduce resource occupancy. When the SNR is low, the noise ratio is high, and more subbands need to be divided, and a larger filter coefficient length is used to improve the compensation effect. In particular, in view of the differences in group delay characteristics of different frequency bands, such as the group delay in the high-frequency band may change more violently, the strategy of the number of subbands and the filter length can be further adjusted to dynamically allocate the compensation resources of different frequency bands: longer filters can be allocated to high-frequency and highly distorted subbands, and shorter filters can be allocated to low-frequency and low-distortion subbands.

[0051] As a specific example, the threshold values can be Th1, Th2, Th3, and Th4. Then the SNR can be set as follows.

[0052]

[0053] In the second step, an inverse correlation relationship between the SNR interval and the signal decomposition parameters is established, where the high SNR interval corresponds to a low signal subband decomposition number and a low compensation filter length. The signal subband decomposition number M is constrained to M = 2 i and M ≥ 4, where i is a natural number, and the compensation filter length L is constrained to L = 2j and L ≥ 4, where j is a natural number.

[0054] In the third step, according to the ratio relationship between the preset subband width and the total bandwidth of the received signal, the lower limit value of the signal subband decomposition number is determined, and the lower limit value is determined as the signal subband decomposition number corresponding to the highest SNR interval.

[0055] The preset subband width can refer to the preset single-subband spectrum span. For example, if the total bandwidth is set to 10 (the unit is not limited) and the preset subband width is 2, and their quotient is 5, then the decomposition number must be greater than 5. On the premise of satisfying the constraint condition of the signal subband decomposition number M in the second step, the lower limit value of the signal subband decomposition number can be determined to be 8. That is, the signal subband decomposition number corresponding to the highest SNR interval is 8.

[0056] In some embodiments, after determining the signal subband decomposition number and the compensation filter length corresponding to the received signal, it includes: In the first step, the original pilot code is obtained, and the average group delay of the target pilot code with respect to the original pilot code is calculated. By comparing the group delay characteristics of the original pilot code and the received pilot code, a global benchmark of the overall channel distortion is obtained, so as to objectively reflect the comprehensive distortion degree of the signal transmission path, provide a unified reference standard for subsequent subband-level compensation, and avoid local overcompensation or undercompensation problems.

[0057] Step 2: Obtain the sub-band group delay of each signal sub-band, and calculate the group delay difference between each sub-band group delay and the average group delay. Measure the group delay independently for each sub-band, and calculate its deviation from the overall average. This process accurately identifies the distribution characteristics of frequency-domain distortion, locates the high-distortion sub-bands with significant group delay fluctuations, and provides data support for dynamic resource allocation.

[0058] Step 3: When the group delay difference is greater than the preset offset threshold, if the sub-band group delay is greater than the average group delay, increase the length of the compensation filter for the corresponding signal sub-band based on the preset first step value. The offset threshold can refer to the preset tolerance boundary value of group delay fluctuation, which is used to determine whether to adjust the length of the compensation filter for a specific sub-band. This threshold is comprehensively determined based on the channel characteristics and modulation order, and is essentially a critical determination criterion for group delay differences. When the deviation between the sub-band group delay and the overall average exceeds this threshold, an adaptive adjustment mechanism for the filter length is triggered to ensure the balance between compensation accuracy and resource consumption. For sub-bands with group delay significantly higher than the average, automatically increase the length of the compensation filter. Thereby strengthening the correction ability for severely distorted sub-bands, enhancing the depth of phase linearization processing by increasing the filter order, and effectively suppressing the high-frequency group delay components in broadband signals.

[0059] Step 4: If the sub-band group delay is less than the average group delay, reduce the length of the compensation filter for the corresponding signal sub-band based on the preset second step value. Among them, the updated compensation filter length L is constrained to L = 2^j and L ≥ 4, where j is a natural number. For sub-bands with group delay lower than the average, dynamically reduce the filter length. This mechanism avoids excessive consumption of computing resources in low-distortion sub-bands, while maintaining the binary constraint of the filter structure (such as the length taking an integer power of two), ensuring the regularity and operation efficiency of hardware implementation.

[0060] Step 5: When the group delay difference is not greater than the preset offset threshold, do not update the length of the compensation filter for each signal sub-band. When the group delay fluctuation of the sub-band is within the threshold range, maintain the existing filter configuration to reduce the frequency of unnecessary parameter updates, reduce the dynamic load of real-time computing, and improve the operating stability of the system in a steady-state channel environment.

[0061] The foregoing hierarchical compensation mechanism is particularly applicable to high-order modulation scenarios such as satellite communication and millimeter-wave backhaul. It can not only cope with the non-uniform distortion of broadband channels but also adapt to the resource constraints of hardware platforms, providing a reliable solution for the engineering deployment of high spectral efficiency technologies.

[0062] Step 203: Decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands.

[0063] In some embodiments, to improve efficiency and reduce operation complexity, a DFT filter bank based on polyphase decomposition can be selected as the analysis filter bank to divide the symbol bandwidth R of the 256QAM channel s equally into M (M is the number of signal sub-band decompositions) sub-bands, and the bandwidth of each sub-band is R s / M. The principle of the DFT filter bank is to shift a low-pass filter (prototype filter) with a bandwidth of R s / M to M evenly distributed frequency points through DFT modulation, thereby forming a filter bank composed of M filters with a bandwidth of Rs / M. Then, the filter bank is used for filtering in parallel with a lower computational complexity through the form of polyphase filtering to decompose M sub-band signals. Since the bandwidth of each sub-band signal becomes 1 / M of the global bandwidth, the group delay distortion of the sub-band is significantly reduced compared to the global distortion. An independent filter with a smaller number of points can be used to compensate the group delay distortion of each sub-band and achieve good results, breaking through the performance bottleneck of the global filter.

[0064] Using a DFT modulation filter bank with a polyphase filtering structure, the filter coefficients of each sub-channel are independently calculated at a small cost, and the group delay of each sub-channel is compensated. The overall scheme naturally supports parallel processing by CPU, GPU, and FPGA, greatly improving the speed of group delay distortion compensation.

[0065] Step 204: Calculate the filter compensation coefficients of each signal sub-band based on the compensation filter length, and perform group delay compensation on each signal sub-band based on the compensation coefficients.

[0066] In some embodiments, the filter compensation coefficient may refer to an array in the compensation filter for correcting signal distortion. The compensation coefficient includes L data, that is, the length of the compensation filter is L.

[0067] In some alternative implementation manners, calculating the filter compensation coefficients of each signal sub-band based on the compensation filter length includes: The first step is to obtain the original pilot code.

[0068] The second step is to decompose the original pilot code into M first sub-codes with equal lengths and decompose the target pilot code into M second sub-codes with equal lengths based on the number of signal sub-band decompositions M, where the sub-code length of the first sub-code or the second sub-code is N, and N is a natural number.

[0069] The third step is to construct the received signal matrix Y of the k-th second sub-code k , Y k has N + 1 - L rows k , Y k has L columns k , where L kDenote the compensation filter length of the k-th signal sub-band, Y k The first row of k is the signal values of L consecutive second sub-codes. The n-th row is the signal values of L consecutive second sub-codes obtained by shifting the first row by n - 1 times. The left boundary of the first row is y k When at [0], the right boundary of the (N + 1 - L)-th k row is y k [N - 1], or when the right boundary of the first row is y k [0], the left boundary of the (N + 1 - L)-th k row is y k [N - 1], or when the left boundary of the first row is y k [N - 1], the right boundary of the (N + 1 - L)-th k row is y k [0], or when the right boundary of the first row is y k [N - 1], the left boundary of the (N + 1 - L)-th k row is y k [0], where k and n are natural numbers, k ∈ [1, M], n ∈ [0, N - L k .

[0070] As a specific example, Yk can be as follows: .

[0071] Fourth step, construct the desired response vector S of the k-th signal sub-band k , and the desired response vector is the transposed vector of the vector composed of the signal values with a length of N + 1 - L corresponding to the first column of the received signal matrix Y k in the original pilot code. k

[0072] As a specific example, S k can be as follows: .

[0073] Fifth step, combine the received signal matrix Y k and the desired response vector S k , and calculate the filter compensation coefficients of the k-th signal sub-band, where the filter compensation coefficients are composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to the coefficient at a corresponding position of the filter.

[0074] In some alternative implementation manners, combining the received signal matrix Y k and the desired response vector S k , calculating the filter compensation coefficients of the k-th signal sub-band includes: according to a preset first calculation formula, combining the received signal matrix Y k and the desired response vector S k ​, calculate the filter compensation coefficient of the k-th signal sub-band, where the first calculation formula includes:

[0075] where, W k represents the filter compensation coefficient, represents the conjugate transpose of Y k .

[0076] The above calculation formula is a calculation formula constructed based on the least squares Gaussian reconstructor. By designing the sub-band compensation filter coefficients, it specifically solves the group delay distortion characteristics of each sub-band and improves the group delay distortion compensation performance.

[0077] Step 205: Generate a target signal based on each compensated signal sub-band.

[0078] In some embodiments, the compensated sub-band signals after compensating the group delay can be sub-band synthesized through a synthesis filter bank to restore the complete global QAM modulated signal. A DFT filter bank based on polyphase filtering can be used as the synthesis filter bank; if the prototype filter of the DFT filter bank satisfies the perfect reconstruction condition, the synthesis filter bank can completely reconstruct the original global signal from the M sub-band signals in the form of polyphase filtering with a relatively low computational complexity. In this way, the re-synthesized full-bandwidth signal has compensated most of the group delay distortion, leaving only a very small amount of residual group delay. Refer to 3a and Figure 3b , to evaluate the effect of this sub-band compensation of group delay, we conducted a simulation analysis. The signal uses 256QAM modulation, the symbol rate is 750Msps, and the channel has a linear group delay of 1ns. It can be seen that the signal before sub-band decomposition (refer to Figure 3a ) is significantly affected by the global group delay, and the signal after sub-band synthesis (refer to Figure 3b ) only has a small amount of residual group delay left.

[0079] The beneficial effects of at least one of the embodiments in this specification include: through sub-band decomposition, fine compensation of group delay for different frequency components, the channel frequency response within the sub-band is flatter, the requirements for estimation error and filter length are reduced, thus avoiding the performance bottleneck of the global equalizer.

[0080] In some embodiments, the method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition further includes: performing post-equalization processing on the target signal to dynamically track the change of the group delay of the target signal to perform dynamic compensation.

[0081] The commonly used DD-LMS adaptive equalizer in signal processing has the advantages of simple implementation, low algorithm complexity, and small convergence steady-state error. However, it cannot converge when the constellation diagram diverges severely and cannot be directly used to compensate for the global group delay distortion of high-order QAM signals. After being processed by the method for compensating group delay distortion of high-order modulation signals based on subband decomposition provided in the embodiments of this specification, due to the residual group delay, the constellation diagram only diverges to a small extent. Therefore, the DD-LMS adaptive equalizer can be used for post-equalization processing. Thus, it can adaptively track the change of the residual group delay and compensate for the inter-symbol interference caused by time-varying group delay distortion. As an example, please refer to Figure 4a and Figure 4b . Before compensating for the group delay distortion (refer to Figure 4a ), the constellation diagram of the 256QAM demodulated signal diverges significantly, and the inter-symbol interference is severe, resulting in the deterioration of the demodulation bit error rate. After being processed by the method for compensating group delay distortion of high-order modulation signals based on subband decomposition provided in the embodiments of this specification (refer to Figure 4b ), the constellation diagram of the signal returns to near the theoretical position, and the degree of aggregation of the constellation diagram meets the expectation. Therefore, the inter-symbol interference is greatly reduced, and the demodulation performance is improved.

[0082] As Figure 5 shown, in a specific embodiment, in order to evaluate the bit error rate performance of the embodiments of this specification, a simulation analysis is performed. The signal uses 256QAM modulation, the symbol rate is 750Msps, and the channel has a linear group delay of 1ns. Through Monte Carlo simulation, the comparison between the relationship curve of the bit error rate (BER in the figure) and the signal-to-noise ratio (EbN0 in the figure) of signal demodulation using this method and without using this method and the theoretical value is obtained. It can be seen that if the group delay distortion is not compensated, the bit error rate deteriorates severely and it is almost impossible to demodulate; after being compensated by the present invention, the bit error rate is significantly reduced and approaches the theoretical value, and the greater the signal-to-noise ratio, the better the compensation effect.

[0083] In some embodiments, the method for compensating group delay distortion of high-order modulation signals based on subband decomposition further includes: parsing the target signal to determine the frame synchronization result; if the frame synchronization result indicates that the lock is maintained, it means that the target signal meets the requirements (at this time, there is no need to repeat the operations of obtaining the received signal and extracting the target pilot code and calculating the signal-to-noise ratio estimation value according to the target pilot code). If the frame synchronization result indicates that the lock is lost, the steps of obtaining the received signal and extracting the target pilot code and calculating the signal-to-noise ratio estimation value according to the target pilot code are re-executed.

[0084] When parsing the target signal, it can be after the processing of the demodulation module. Frame synchronization lock can refer to the state in a communication system where the receiving end continuously tracks the frame structure of the sending end to ensure that the start and end positions of the data frames are accurately aligned and stably maintained. The adaptive control mechanism for frame synchronization state monitoring realizes the dynamic collaborative optimization of the compensation strategy and communication quality. When the channel condition is stable, the calculation overhead is reduced by freezing parameter updates to avoid resource waste caused by repeated compensation; while when the frame is unlocked due to channel deterioration, the signal re-capture and parameter reset processes are automatically triggered to ensure that the system quickly resumes effective communication. This closed-loop control logic significantly improves the tracking ability for time-varying channels, maintaining both the long-term stability of the compensation accuracy and avoiding the risk of continuous miscompensation caused by sudden interference. Combining sub-band decomposition and dynamic filter adjustment techniques, the system can still ensure the integrity and demodulation reliability of high-order modulation signals in the low-power mode, especially suitable for wireless transmission scenarios such as satellite communication and mobile backhaul that require both energy efficiency and anti-interference performance.

[0085] Corresponding to the above method embodiments, this specification also provides embodiments of a device for compensating group delay distortion of high-order modulation signals based on sub-band decomposition. Figure 6 The structural schematic diagram of a device for compensating group delay distortion of high-order modulation signals based on sub-band decomposition provided by some embodiments of this specification is shown. As Figure 6 shown, the device includes: An acquisition module 601, configured to acquire the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value according to the target pilot code, where the received signal is a single-symbol rate signal that has undergone timing synchronization processing, and the received signal is a digital signal.

[0086] A determination module 602, configured to determine the number of signal sub-band decompositions and the length of the compensation filter based on the pre-determined signal decomposition parameters and the signal-to-noise ratio estimation value, where both the number of signal sub-band decompositions and the length of the compensation filter are ≥ 4.

[0087] A decomposition module 603, configured to decompose the received signal based on the number of signal sub-band decompositions to obtain at least four signal sub-bands.

[0088] A compensation module 604, configured to calculate the filter compensation coefficients of each signal sub-band based on the length of the compensation filter, and perform group delay compensation on each signal sub-band based on the compensation coefficients.

[0089] A generation module 605, configured to generate the target signal based on each compensated signal sub-band.

[0090] In some alternative embodiments, calculating the signal-to-noise ratio estimation value based on the target pilot code in the received signal includes: Acquiring the original pilot code, and calculating the signal-to-noise ratio estimation value according to the original pilot code and the target pilot code.

[0091] In some alternative embodiments, the step of determining the signal decomposition parameters includes: forming at least two signal-to-noise ratio intervals based on at least one preset threshold value; establishing an inverse correlation relationship between the signal-to-noise ratio intervals and the signal decomposition parameters, wherein a high signal-to-noise ratio interval corresponds to a low signal sub-band decomposition number and a low compensation filter length, the signal sub-band decomposition number M is constrained to M = 2 i and M ≥ 4, i is a natural number, the compensation filter length L is constrained to L = 2j and L ≥ 4, j is a natural number; determining a lower limit value of the signal sub-band decomposition number according to the ratio relationship between the preset sub-bandwidth and the total bandwidth of the received signal, and determining the lower limit value as the signal sub-band decomposition number corresponding to the highest signal-to-noise ratio interval.

[0092] In some alternative embodiments, calculating the filter compensation coefficient of each signal sub-band based on the compensation filter length includes: obtaining the original pilot code; based on the signal sub-band decomposition number M, decomposing the original pilot code into M first sub-codes with equal lengths, and decomposing the target pilot code into M second sub-codes with equal lengths, wherein the sub-code length of the first sub-code or the second sub-code is N, N is a natural number; constructing the received signal matrix Y of the k-th second sub-code k , Y k has N + 1 - L rows k , Y k has L columns k , wherein, L k represents the compensation filter length of the k-th signal sub-band, the first row of Y k is the signal values of L consecutive second sub-codes, the n-th row is the signal values of L consecutive second sub-codes obtained by shifting the first row n - 1 times, the left boundary of the first row is y k [0], when the right boundary of the N + 1 - L k th row is y k [N - 1], or, when the right boundary of the first row is y k [0], the left boundary of the N + 1 - L k th row is y k [N - 1], or, when the left boundary of the first row is y k [N - 1], the right boundary of the N + 1 - L k th row is y k [0], or, when the right boundary of the first row is y k [N - 1], the left boundary of the N + 1 - L k th row is y k [0], k, n are natural numbers, k ∈ [1, M], n ∈ [0, N - Lk ; Construct the desired response vector S of the k-th signal sub-band k , where the desired response vector is the vector formed by the signal values of length N + 1 - L corresponding to the first column of the received signal matrix Y k in the original pilot code, and take the transpose vector; k Combine the received signal matrix Y k and the desired response vector S k , and calculate the filter compensation coefficients of the k-th signal sub-band. Among them, the filter compensation coefficients are composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to the coefficient at the corresponding position of the filter.

[0093] In some alternative embodiments, combining the received signal matrix Y k and the desired response vector S k , calculating the filter compensation coefficients of the k-th signal sub-band includes: According to a preset first calculation formula, combine the received signal matrix Y k and the desired response vector S k , and calculate the filter compensation coefficients of the k-th signal sub-band. Among them, the first calculation formula includes:

[0094] where W k represents the filter compensation coefficient, represents the conjugate transpose of Y k .

[0095] In some alternative embodiments, the method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition further includes: Perform post-equalization processing on the target signal to dynamically track the group delay change of the target signal for dynamic compensation.

[0096] In some alternative embodiments, after determining the number of signal sub-band decompositions and the length of the compensation filter corresponding to the received signal, it includes: Obtain the original pilot code and calculate the average group delay of the target pilot code with respect to the original pilot code; Obtain the sub-band group delays of each signal sub-band and calculate the group delay differences between the sub-band group delays and the average group delay; In the case where the group delay difference is greater than a preset offset threshold, if the sub-band group delay is greater than the average group delay, increase the length of the compensation filter of the corresponding signal sub-band based on a preset first step value; If the sub-band group delay is less than the average group delay, decrease the length of the compensation filter of the corresponding signal sub-band based on a preset second step value; among them, the updated compensation filter length L is constrained to L = 2j and L ≥ 4, where j is a natural number;​ When the group delay difference is not greater than a preset offset threshold, the compensation filter lengths of the respective signal sub-bands are not updated.

[0097] In some alternative embodiments, the method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition further includes: Analyze the target signal to determine the frame synchronization result; If the frame synchronization result indicates maintaining lock, it means the target signal meets the requirements; If the frame synchronization result indicates maintaining unlock, re-execute the steps of obtaining the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value according to the target pilot code.

[0098] The above is a schematic solution of an apparatus for compensating group delay distortion of high-order modulation signals based on sub-band decomposition according to an embodiment of the present disclosure. It should be noted that the technical solution of the apparatus for compensating group delay distortion of high-order modulation signals based on sub-band decomposition belongs to the same concept as the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition. For the details not described in the technical solution of the apparatus for compensating group delay distortion of high-order modulation signals based on sub-band decomposition, reference can be made to the description of the technical solution of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0099] Figure 7 FIG. shows a block diagram of a computing device 700 according to some embodiments of the present specification. The components of the computing device 700 include, but are not limited to, a memory 701 and a processor 702. The processor 702 is connected to the memory 701 through a bus 703, and a database 705 is used to store data.

[0100] The computing device 700 also includes an access device 704 that enables the computing device 700 to communicate via one or more networks 706. Examples of such networks include the Public Switched Telephone Network (PSTN), Local Area Network (LAN), Wide Area Network (WAN), Personal Area Network (PAN), or a combination of communication networks such as the Internet. The access device 704 may include one or more of any type of wired or wireless network interface (e.g., network interface controller (NIC)), such as an IEEE 802.11 Wireless Local Area Network (WLAN) wireless interface, Worldwide Interoperability for Microwave Access (Wi-MAX) interface, Ethernet interface, Universal Serial Bus (USB) interface, cellular network interface, Bluetooth interface, Near Field Communication (NFC).

[0101] In one embodiment of the present specification, the above components of the computing device 700 and Figure 7 other components not shown therein may also be connected to each other, for example, via a bus. It should be understood that Figure 7 the block diagram of the computing device shown is for illustrative purposes only and is not a limitation on the scope of the present specification. Those skilled in the art may add or replace other components as needed.

[0102] The computing device 700 can be any type of stationary or mobile computing device, including mobile computers or mobile computing devices (e.g., tablet computers, personal digital assistants, laptop computers, notebook computers, netbooks, etc.), mobile phones (e.g., smartphones), wearable computing devices (e.g., smartwatches, smart glasses, etc.) or other types of mobile devices, or stationary computing devices such as desktop computers or personal computers (PCs). The computing device 700 can also be a mobile or stationary server.

[0103] Among them, the processor 702 is used to execute the following computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition are implemented. The above is a schematic solution of a computing device according to this embodiment. It should be noted that the technical solution of this computing device and the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition belong to the same concept. For the details not described in detail in the technical solution of the computing device, reference can be made to the description of the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition.

[0104] An embodiment of this specification also provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, the steps of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition are implemented.

[0105] The above is a schematic solution of a computer-readable storage medium according to this embodiment. It should be noted that the technical solution of this storage medium and the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition belong to the same concept. For the details not described in detail in the technical solution of the storage medium, reference can be made to the description of the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition.

[0106] An embodiment of this specification also provides a computer program. When the computer program is executed on a computer, the computer is made to execute the steps of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition.

[0107] The above is a schematic solution of a computer program according to this embodiment. It should be noted that the technical solution of this computer program and the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition belong to the same concept. For the details not described in detail in the technical solution of the computer program, reference can be made to the description of the technical solution of the above-mentioned method for compensating the group delay distortion of high-order modulation signals based on sub-band decomposition.

[0108] The above describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain implementations, multitasking and parallel processing are also possible or may be advantageous.

[0109] Computer instructions include computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms, etc. A computer-readable medium can include: any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a removable hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice within the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0110] It should be noted that for the foregoing method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the embodiments of this specification are not limited by the described action sequence, because according to the embodiments of this specification, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential for the embodiments of this specification.

[0111] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0112] The preferred embodiments of this specification disclosed above are only used to help explain this specification. The alternative embodiments do not elaborate on all details and do not limit the invention to only the specific implementation manners. Obviously, many modifications and changes can be made according to the content of the embodiments of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the embodiments of this specification, so that those skilled in the art can well understand and utilize this specification. This specification is only limited by the claims and their full scope and equivalents.

Claims

1. A method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition, characterized in that, Including: Obtain the received signal and extract the target pilot code, and calculate the signal-to-noise ratio (SNR) estimation value according to the target pilot code, where the received signal is a single-symbol-rate signal that has undergone timing synchronization processing, and the received signal is a digital signal; Based on the pre-determined signal decomposition parameters and the SNR estimation value, determine the signal sub-band decomposition number and the compensation filter length, where both the signal sub-band decomposition number and the compensation filter length are ≥ 4; Decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands; Calculate the filter compensation coefficients of each signal sub-band based on the compensation filter length, and perform group delay compensation on each signal sub-band based on the compensation coefficients; Generate a target signal based on each compensated signal sub-band.

2. The method according to claim 1, characterized in that Calculating the SNR estimation value based on the target pilot code in the received signal includes: Obtain the original pilot code, and calculate the SNR estimation value according to the original pilot code and the target pilot code.

3. The method according to claim 1, characterized in that, The steps for determining the signal decomposition parameters include: Form at least two SNR intervals based on at least one preset threshold value; Establish an inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameters, where a high signal-to-noise ratio interval corresponds to a low number of signal sub-band decompositions and a low length of the compensation filter, and the number of signal sub-band decompositions M is constrained to M = 2 i and M ≥ 4, where i is a natural number, and the length of the compensation filter L is constrained to L = 2j and L ≥ 4, where j is a natural number; According to the ratio relationship between the preset sub-bandwidth and the total bandwidth of the received signal, determine the lower limit value of the signal sub-band decomposition number, and determine the lower limit value as the signal sub-band decomposition number corresponding to the highest SNR interval.

4. The method according to claim 1, wherein Calculating the filter compensation coefficients of each signal sub-band based on the compensation filter length includes: Obtain the original pilot code; Based on the signal sub-band decomposition number M, decompose the original pilot code into M first sub-codes of equal length, and decompose the target pilot code into M second sub-codes of equal length, where the sub-code length of the first sub-code or the second sub-code is N, and N is a natural number; Construct the received signal matrix Y of the k-th second sub-code k , Y k has N + 1 - L rows k , Y k has L columns k , where L k represents the length of the compensation filter of the k-th signal sub-band, the first row of Y k is the signal values of L consecutive second sub-codes, the n-th row is the signal values of L consecutive second sub-codes obtained by shifting the first row by n - 1 times, the left boundary of the first row is y k [0], when the right boundary of the (N + 1 - L)-th k row is y k [N - 1], or when the right boundary of the first row is y k [0], the left boundary of the (N + 1 - L)-th k row is y k [N - 1], or when the left boundary of the first row is y k [N - 1], the right boundary of the (N + 1 - L)-th k row is y k [0], or when the right boundary of the first row is y k [N - 1], the left boundary of the (N + 1 - L)-th k row is y k [0], k and n are natural numbers, k ∈ [1, M], n ∈ [0, N - L k ; Construct the desired response vector S for the k-th signal subband k , where the desired response vector is the transposed vector formed by the signal values of length N + 1 - L corresponding to the first column of the received signal matrix Y k in the original pilot code k . Combined with the received signal matrix Y k and the desired response vector S k , calculate the filter compensation coefficient of the k-th signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to the coefficient at a corresponding position of the filter.

5. The method according to claim 4, wherein Combined with the received signal matrix Y k and the desired response vector S k , calculating the filter compensation coefficient of the k-th signal sub-band, including: According to a preset first calculation formula, in combination with the received signal matrix Y k and the desired response vector S k , calculate the filter compensation coefficient of the k-th signal sub-band, where the first calculation formula includes: Among them, W k represents the filter compensation coefficient, represents Y k which is the conjugate transpose of 6. The method according to claim 1, characterized in that The method further includes: Perform post-equalization processing on the target signal, and dynamically track the group delay change of the target signal to perform dynamic compensation.

7. The method according to any one of claims 1 to 6, characterized in that After determining the signal sub-band decomposition number and the compensation filter length corresponding to the received signal, it includes: Obtain the original pilot code, and calculate the average group delay of the target pilot code with respect to the original pilot code; Obtain the sub-band group delay of each signal sub-band, and calculate the group delay difference between each sub-band group delay and the average group delay; In the case where the group delay difference is greater than the preset offset threshold, if the sub-band group delay is greater than the average group delay, increase the compensation filter length of the corresponding signal sub-band based on the preset first step value; If the sub-band group delay is less than the average group delay, decrease the compensation filter length of the corresponding signal sub-band based on the preset second step value; where the updated compensation filter length L is constrained to L = 2j and L ≥ 4, and j is a natural number; In the case where the group delay difference is not greater than the preset offset threshold, do not update the compensation filter length of each signal sub-band.

8. The method according to any one of claims 1 to 6, characterized in that It also includes: Parse the target signal to determine the frame synchronization result; If the frame synchronization result indicates maintaining lock, it means the target signal meets the requirements; If the frame synchronization result indicates maintaining unlock, re-execute the steps of obtaining the received signal and extracting the target pilot code, and calculating the SNR estimation value according to the target pilot code.

9. A high-order modulation signal group delay distortion compensation device based on sub-band decomposition, characterized in that, Including: An acquisition module, configured to acquire a received signal and extract a target pilot code, and calculate a signal-to-noise ratio estimation value according to the target pilot code, wherein the received signal is a single-symbol rate signal that has undergone timing synchronization processing, and the received signal is a digital signal; A determination module, configured to determine a signal subband decomposition number and a compensation filter length based on pre-determined signal decomposition parameters and the signal-to-noise ratio estimation value, wherein both the signal subband decomposition number and the compensation filter length are ≥4; A decomposition module, configured to decompose the received signal based on the signal subband decomposition number to obtain at least four signal subbands; A compensation module, configured to calculate a filter compensation coefficient for each signal subband based on the compensation filter length, and perform group delay compensation on each signal subband based on the compensation coefficient; A generation module, configured to generate a target signal based on each compensated signal subband.

10. A computing device, characterized in that, Comprising: A memory and a processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the method for compensating group delay distortion of a high-order modulation signal based on subband decomposition according to any one of claims 1 to 8 are implemented.

Images