Method and device for compensating group delay distortion of high-order modulation signals based on sub-band decomposition

Abstract

Embodiments of the present specification provide a method and apparatus for compensating for group delay distortion of high-order modulated signals based on subband decomposition, wherein the method for compensating for group delay distortion of high-order modulated signals based on subband decomposition includes: obtaining a received signal and extracting a target pilot code, and calculating a signal-to-noise ratio estimate; determining the number of signal subband decompositions and the length of a compensation filter based on predetermined signal decomposition parameters and a signal-to-noise ratio estimate; decomposing the received signal based on the number of signal subband decompositions to obtain at least four signal subbands; calculating a filter compensation coefficient for each signal subband based on the compensation filter length, and performing group delay compensation on each signal subband based on the compensation coefficient; and generating a target signal based on each compensated signal subband. Embodiments of the present specification perform fine compensation for different frequency components of group delay through subband decomposition, resulting in a flatter channel frequency response within the subband and reduced requirements for estimation error and filter length, thereby avoiding the performance bottleneck of the global equalizer.

Description

Technical Field

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

[0002] To address the conflict between information transmission capacity and limited bandwidth, various modern modulation and demodulation technologies are pursuing reliable, high-speed data transmission. Quadrature Amplitude Modulation (QAM) is a composite modulation scheme that simultaneously digitally modulates the carrier amplitude and phase, offering advantages such as high spectrum efficiency and noise immunity. In a multi-level M-QAM signal, each symbol carries bits of information. A higher modulation order, M, increases the information carried and the spectrum efficiency. Therefore, higher-order QAM (such as 256QAM) can more effectively improve spectrum efficiency and has found widespread application in digital microwave communication systems, cable television networks, and satellite communications. However, as the modulation order increases, the signal constellation becomes increasingly dense, making high-order QAM signals highly sensitive to noise and channel distortion. In specific applications, we have found that QAM signals are significantly affected by channel distortion, particularly group delay distortion. Improving the demodulation accuracy and efficiency of high-order QAM in channels with group delay distortion has become a challenging problem for high-order QAM. Summary of the Invention

[0003] In light of this, embodiments of this specification provide a method for compensating group delay distortion of high-order modulated signals based on subband decomposition. One or more embodiments of this specification also provide an apparatus for compensating group delay distortion of high-order modulated signals based on subband decomposition, a computing device, a computer-readable storage medium, and a computer program to address technical deficiencies in the prior art.

[0004] According to a first aspect of an embodiment of this specification, a method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition is provided, comprising:

[0005] Acquiring a received signal and extracting a target pilot code, and calculating a signal-to-noise ratio estimation value based on the target pilot code, wherein the received signal is a single symbol rate signal that has been subjected to timing synchronization processing, and the received signal is a digital signal;

[0006] Determining the number of signal subband decompositions and the length of the compensation filter based on predetermined signal decomposition parameters and a signal-to-noise ratio estimate, wherein the number of signal subband decompositions and the length of the compensation filter are both ≥ 4;

[0007] Decomposing the received signal based on the signal subband decomposition number to obtain at least four signal subbands;

[0008] Calculating a filter compensation coefficient for each signal subband based on the compensation filter length, and performing group delay compensation on each signal subband based on the compensation coefficient;

[0009] A target signal is generated based on the compensated signal subbands.

[0010] In some optional embodiments, calculating a signal-to-noise ratio estimate based on a target pilot code in a received signal includes:

[0011] Obtain the original guidance code, and calculate the signal-to-noise ratio estimation value based on the original guidance code and the target guidance code.

[0012] In some optional embodiments, the step of determining the signal decomposition parameter includes:

[0013] forming at least two signal-to-noise ratio intervals based on at least one preset threshold value;

[0014] The inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameter is established, where the high signal-to-noise ratio interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband 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 be L = 2j and L ≥ 4, j is a natural number;

[0015] The lower limit of the number of signal subband decompositions is determined according to the ratio of the preset subband bandwidth to the total bandwidth of the received signal, and the lower limit is determined as the number of signal subband decompositions corresponding to the highest signal-to-noise ratio interval.

[0016] In some optional embodiments, calculating the filter compensation coefficient of each signal subband based on the compensation filter length includes:

[0017] Get the original guidance code;

[0018] Based on the signal subband decomposition number M, the original pilot code is decomposed into M first subcodes of equal length, and the target pilot code is decomposed into M second subcodes of equal length, wherein the subcode length of the first subcode or the second subcode is N, where N is a natural number;

[0019] Construct the received signal matrix Y of the kth second subcode k , Y k The number of rows is N+1-L k , Y k The number of columns is L k , where L k represents the compensation filter length of the kth signal subband, Y k The first line is the signal value of L consecutive second subcodes, the nth line is the signal value of L consecutive second subcodes shifted n-1 times by the first line, and the left boundary of the first line is y k[0], the N+1-L k The right edge of the row is y k [N-1], or, the right edge of the first row is y k [0], the N+1-L k The left edge of the row is y k [N-1], or the left edge of the first row is y k [N-1], N+1-L k The right edge of the row is y k [0], or, the right edge of the first row is y k [N-1], N+1-L k The left edge of the row is y k [0], k, n are natural numbers, k∈[1, M], n∈[0, NL k ];

[0020] Construct the expected response vector S of the kth signal subband k , the expected response vector is the original pilot code, and the received signal matrix Y k The length of the first column is N+1-L k The signal value of constitutes the transpose vector of the vector;

[0021] Combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to a coefficient of a corresponding position of the filter.

[0022] In some optional embodiments, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, including:

[0023] According to the preset first calculation formula, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the first calculation formula includes:

[0024]

[0025] Among them, W k represents the filter compensation coefficient, Indicates Y k The conjugate transpose of .

[0026] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0027] Post-equalization processing is performed on the target signal, and the group delay change of the target signal is dynamically tracked to perform dynamic compensation.

[0028] In some optional embodiments, after determining the number of signal subband decompositions and the compensation filter length corresponding to the received signal, the method further includes:

[0029] Obtaining an original pilot code and calculating an average group delay of the target pilot code relative to the original pilot code;

[0030] Obtaining the subband group delay of each signal subband, and calculating the group delay difference between each subband group delay and the average group delay;

[0031] When the group delay difference is greater than a preset offset threshold, if the subband group delay is greater than the average group delay, increasing the compensation filter length of the corresponding signal subband based on a preset first step value;

[0032] If the subband group delay is less than the average group delay, reducing the compensation filter length of the corresponding signal subband based on a preset second step value; wherein the updated compensation filter length L is constrained to be L=2j and L≥4, where j is a natural number;

[0033] When the group delay difference is not greater than the preset offset threshold, the compensation filter length of each signal subband is not updated.

[0034] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0035] Analyze the target signal and determine the frame synchronization result;

[0036] If the frame synchronization result indicates that the lock is maintained, it means that the target signal meets the requirements;

[0037] If the frame synchronization result indicates that the lock is still lost, the steps of acquiring the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value based on the target pilot code are re-executed.

[0038] According to a second aspect of the embodiments of this specification, a device for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition is provided, comprising:

[0039] an acquisition module configured to acquire a received signal and extract a target pilot code, and calculate a signal-to-noise ratio estimation value based on the target pilot code, wherein the received signal is a single symbol rate signal that has been subjected to timing synchronization processing, and the received signal is a digital signal;

[0040] a determination module configured to determine the number of signal subband decompositions and the length of the compensation filter based on a predetermined signal decomposition parameter and a signal-to-noise ratio estimation value, wherein the number of signal subband decompositions and the length of the compensation filter are both ≥ 4;

[0041] a decomposition module configured to decompose the received signal based on the signal subband decomposition number to obtain at least four signal subbands;

[0042] a compensation module configured to calculate a filter compensation coefficient for each signal subband based on a compensation filter length, and perform group delay compensation on each signal subband based on the compensation coefficient;

[0043] The generating module is configured to generate a target signal based on the compensated signal sub-bands.

[0044] In some optional embodiments, calculating a signal-to-noise ratio estimate based on a target pilot code in a received signal includes:

[0045] Obtain the original guidance code, and calculate the signal-to-noise ratio estimation value based on the original guidance code and the target guidance code.

[0046] In some optional embodiments, the step of determining the signal decomposition parameter includes:

[0047] forming at least two signal-to-noise ratio intervals based on at least one preset threshold value;

[0048] The inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameter is established, where the high signal-to-noise ratio interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband 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 be L = 2j and L ≥ 4, j is a natural number;

[0049] The lower limit of the number of signal subband decompositions is determined according to the ratio of the preset subband bandwidth to the total bandwidth of the received signal, and the lower limit is determined as the number of signal subband decompositions corresponding to the highest signal-to-noise ratio interval.

[0050] In some optional embodiments, calculating the filter compensation coefficient of each signal subband based on the compensation filter length includes:

[0051] Get the original guidance code;

[0052] Based on the signal subband decomposition number M, the original pilot code is decomposed into M first subcodes of equal length, and the target pilot code is decomposed into M second subcodes of equal length, wherein the subcode length of the first subcode or the second subcode is N, where N is a natural number;

[0053] Construct the received signal matrix Y of the kth second subcode k , Y k The number of rows is N+1-L k , Y k The number of columns is L k , where L krepresents the compensation filter length of the kth signal subband, Y k The first line is the signal value of L consecutive second subcodes, the nth line is the signal value of L consecutive second subcodes shifted n-1 times by the first line, and the left boundary of the first line is y k [0], the N+1-L k The right edge of the row is y k [N-1], or, the right edge of the first row is y k [0], the N+1-L k The left edge of the row is y k [N-1], or the left edge of the first row is y k [N-1], N+1-L k The right edge of the row is y k [0], or, the right edge of the first row is y k [N-1], N+1-L k The left edge of the row is y k [0], k, n are natural numbers, k∈[1, M], n∈[0, NL k ];

[0054] Construct the expected response vector S of the kth signal subband k , the expected response vector is the original pilot code, and the received signal matrix Y k The length of the first column is N+1-L k The signal value of constitutes the transpose vector of the vector;

[0055] Combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to a coefficient of a corresponding position of the filter.

[0056] In some optional embodiments, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, including:

[0057] According to the preset first calculation formula, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the first calculation formula includes:

[0058]

[0059] Among them, W k represents the filter compensation coefficient, Indicates Yk The conjugate transpose of .

[0060] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0061] Post-equalization processing is performed on the target signal, and the group delay change of the target signal is dynamically tracked to perform dynamic compensation.

[0062] In some optional embodiments, after determining the number of signal subband decompositions and the compensation filter length corresponding to the received signal, the method further includes:

[0063] Obtaining an original pilot code and calculating an average group delay of the target pilot code relative to the original pilot code;

[0064] Obtaining the subband group delay of each signal subband, and calculating the group delay difference between each subband group delay and the average group delay;

[0065] When the group delay difference is greater than a preset offset threshold, if the subband group delay is greater than the average group delay, increasing the compensation filter length of the corresponding signal subband based on a preset first step value;

[0066] If the subband group delay is less than the average group delay, reducing the compensation filter length of the corresponding signal subband based on a preset second step value; wherein the updated compensation filter length L is constrained to be L=2j and L≥4, where j is a natural number;

[0067] When the group delay difference is not greater than the preset offset threshold, the compensation filter length of each signal subband is not updated.

[0068] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0069] Analyze the target signal and determine the frame synchronization result;

[0070] If the frame synchronization result indicates that the lock is maintained, it means that the target signal meets the requirements;

[0071] If the frame synchronization result indicates that the lock is still lost, the steps of acquiring the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value based on the target pilot code are re-executed.

[0072] According to a third aspect of an embodiment of this specification, a computing device is provided, including:

[0073] memory and processor;

[0074] 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 high-order modulation signal group delay distortion compensation method based on sub-band decomposition are realized.

[0075] According to a 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 high-order modulation signal group delay distortion compensation method based on sub-band decomposition are implemented.

[0076] According to a fifth aspect of the embodiments of this specification, a computer program is provided, wherein when the computer program is executed in a computer, the computer is caused to execute the steps of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0077] At least one embodiment of the embodiments in this specification performs fine compensation for different frequency components of group delay through sub-band decomposition, making the channel frequency response within the sub-band flatter and reducing the requirements for estimation error and filter length, thereby breaking through the performance bottleneck of the global equalizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1a This is a comparison diagram of the impact of 0ns group delay distortion on 16QAM and 256QAM signal constellations in the prior art provided by some embodiments of this specification;

[0079] Figure 1b This is a comparison diagram of the impact of 0.1ns group delay distortion on 16QAM and 256QAM signal constellations in the prior art provided by some embodiments of this specification;

[0080] Figure 1c This is a comparison diagram of the impact of 0.5ns group delay distortion on 16QAM and 256QAM signal constellations in the prior art provided by some embodiments of this specification;

[0081] Figure 2 This is a flowchart of some embodiments of a method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition provided by some embodiments of this specification;

[0082] Figure 3a 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 a high-order modulation signal based on sub-band decomposition provided in some embodiments of this specification;

[0083] Figure 3b 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 a high-order modulation signal based on sub-band decomposition provided in some embodiments of this specification;

[0084] Figure 4a A constellation diagram of a 256QAM signal with a group delay of 1 ns before compensation, according to a method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition provided in some embodiments of this specification;

[0085] Figure 4b A constellation diagram of a 256QAM signal with a group delay of 1 ns after compensation according to a method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition provided in some embodiments of this specification;

[0086] Figure 5 This is a comparison diagram of the bit error rates of group delay distortion before and after compensation for a high-order modulation signal group delay distortion compensation method based on sub-band decomposition provided by some embodiments of this specification;

[0087] Figure 6 This is a simplified structural diagram of a high-order modulation signal group delay distortion compensation device based on sub-band decomposition provided by some embodiments of this specification;

[0088] Figure 7 This is a structural block diagram of a computing device provided in some embodiments of this specification. DETAILED DESCRIPTION

[0089] The following description sets forth many specific details to facilitate a thorough understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the scope of this specification. Therefore, this specification is not limited to the specific implementations disclosed below.

[0090] 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 of "a" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items. The modifications of "one" and "a plurality" mentioned in this disclosure are illustrative and not restrictive, and those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more".

[0091] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish the same type of information 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 "at the time of" or "when" or "in response to determining".

[0092] First, the terms used in one or more embodiments of this specification are explained:

[0093] DFT: Discrete Fourier Transform, based on discrete Fourier transform.

[0094] ‌DD-LMS:Decision Directed-Least Mean Square, decision-directed least mean square algorithm.

[0095] OFDM: Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing.

[0096] FBMC‌: Filter Bank Multi-Carrier, filter bank multi-carrier.

[0097] The channel group delay characteristic causes distortion to the modulated signal, which is mainly manifested as the divergence of the constellation diagram and the deviation from the theoretical point. Figure 1a 、 Figure 1b and Figure 1c (The horizontal axis "in-phase" in the figure represents in-phase, and the vertical axis "quadrature" represents quadrature. These notations are used interchangeably and are not further elaborated.) Simulation results demonstrate the impact of group delay distortion on the constellation diagram of a high-order QAM signal. The simulated signals use 16QAM and 256QAM modulation, a symbol rate of 750Msps, and no noise interference. High-order QAM signals are denser in the complex plane, with closer Euclidean distances between constellation points. Even small positional distortions can cause crosstalk between symbols, increasing the bit error rate. Therefore, 256QAM is highly sensitive to group delay distortion. As group delay increases, the distortion rate of high-order QAM signals also increases.

[0098] Group delay is a transmission characteristic metric for linear systems. Since digital signals are typically composed of multiple spectral components, the phase-frequency characteristics of a transmission system are often described using the concept of group delay. If, after a transmitted signal passes through a transmission system, the multiple spectral components comprising the signal have the same group delay, then the sum of these spectral components is the same as the transmitted signal, with only the group delay of the signal transmission occurring. This indicates that the system's phase-frequency characteristic is flat, with no group delay distortion. However, in actual high-speed data transmission and communication systems, the system's phase-frequency characteristic is not flat and often exhibits distortion. The spectral components of the signal experience different group delays after passing through the system, causing the sum of the spectral components to be distorted. This is called group delay distortion. The resulting superposition of the multiple output signal spectra differs from the original signal, often resulting in severe intersymbol interference and increased system bit error performance.

[0099] The commonly used methods for compensating group delay distortion of high-order QAM signals in the industry are mainly divided into the following categories: (1) Pre-distortion technology, which introduces memory polynomials at the transmitter to jointly compensate for channel group delay and power amplifier nonlinearity. Its disadvantage is that the modeling accuracy cannot meet the requirements of high-order QAM, and the dynamic tracking capability is insufficient. (2) Blind equalization algorithm, which adaptively corrects channel distortion in the time domain. For high-order QAM signals, a longer 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, which leads to a performance bottleneck in the global filter compensation of group delay.

[0100] In view of the above situation, an embodiment of this specification provides a method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0101] See also Figure 2 , Figure 2 A flowchart of a method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition according to some embodiments of this specification is shown, which specifically includes the following steps.

[0102] Step 201: Acquire the received signal and extract the target pilot code, and calculate the signal-to-noise ratio estimation value based on the target pilot code.

[0103] In some embodiments, an entity executing the method for compensating group delay distortion of high-order modulated signals based on subband decomposition (e.g., a pre-defined computing device) can connect to a target device via a wired or wireless connection. The entity then acquires a received signal, extracts a target pilot code, and calculates a signal-to-noise ratio estimate based on the target pilot code. The received signal is a single symbol rate signal that has undergone timing synchronization processing and is a digital signal. The wireless connection method may include, but is 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.

[0104] A high-order modulated signal may refer to a digitally modulated signal using a high-order constellation mapping (such as 64QAM, 128QAM, 256QAM, 1024QAM, etc.), which carries more bits of information per symbol to achieve high spectral efficiency transmission. The minimum requirements for high-order modulated signals may vary in different application environments. For example, the high-order modulated signal corresponding to this application may be specified as a high-order constellation mapping of at least 256QAM, but this is not a specific limitation.

[0105] The received signal may refer to a set of digital signals that have undergone timing synchronization and symbol alignment. This signal can maintain the time domain integrity of the baseband signal, avoid redundant calculations introduced by oversampling, and provide standardized input for subband decomposition. Single symbol rate may refer to a processing method in which only one valid sampling point is retained per symbol period after the received signal has been synchronized. This rate strictly matches the symbol period designed for the system, ensuring energy conservation of the time domain signal during the subband decomposition process and avoiding spectral aliasing distortion. In some examples, the received signal may be the output signal of a step or component in a multi-carrier communication system such as OFDM or FBMC.

[0106] The target pilot code refers to a known reference signal sequence extracted from the received signal by the receiver, used for channel characteristic analysis and distortion parameter calculation. Its structure is identical to the original pilot code preset by the transmitter. By comparing the differences between the received and transmitted pilot codes, the channel group delay and distortion characteristics can be accurately estimated.

[0107] The signal-to-noise ratio estimate is a quantitative indicator of channel quality calculated by cross-correlating the target and original pilot codes and applying the minimum mean square error criterion. This value represents the signal purity in the current channel environment and is used to dynamically adjust the parameters of the subband decomposition and compensation strategies.

[0108] In some optional implementations, calculating a signal-to-noise ratio estimate based on a target pilot code in a received signal includes obtaining an original pilot code and calculating a signal-to-noise ratio estimate based on a preset second calculation formula and the original pilot code and the target pilot code, wherein the second calculation formula includes:

[0109]

[0110] Where SNR represents the estimated signal-to-noise ratio, Ls represents the length of the original or target pilot code (they are equal), Re represents the real part, x(n) represents the data at the nth position in the original pilot code, y(n) represents the data at the nth 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 can refer to a known reference signal sequence pre-generated by the transmitter. It has a fixed coding structure and time-frequency distribution characteristics and serves as a reference for signal distortion compensation.

[0111] Step 202: Based on predetermined signal decomposition parameters and a signal-to-noise ratio estimation value, determine the number of signal subband decompositions and the length of the compensation filter, wherein both the number of signal subband decompositions and the length of the compensation filter are ≥4.

[0112] In some embodiments, signal decomposition parameters may refer to core control parameters dynamically configured during channel compensation. These parameters include the subband decomposition number (M) and the compensation filter length. The numerical range of the subband decomposition number (M) and the compensation filter length are determined by a combination of the real-time signal-to-noise ratio estimate and a preset threshold. The signal subband decomposition number ("Signal subband decomposition number") may refer to the number of subbands in the narrowband into which the signal is divided. This parameter is negatively correlated with the degree of channel distortion. A smaller number of subbands (e.g., M = 4) is used in high SNR environments, while a larger number (e.g., M = 16) is used in low SNR or strong interference scenarios. The compensation filter length ("Compensation filter length") may refer to the number of equalization filter taps in each subband and determines the precision of time-domain compensation. It is important to note that both M and L must be ≥ 4; otherwise, basic computational requirements will not be met. Increasing M increases computational accuracy, but computational latency and resource consumption also increase. The L value should be within the target range. As its value increases, the fitting capability also increases. However, when the L value is too large, the computational performance begins to decline, so further restrictions on the L value are necessary.

[0113] In some optional implementations, the step of determining the signal decomposition parameter includes:

[0114] In the first step, at least two signal-to-noise ratio intervals are formed based on at least one preset threshold value.

[0115] The threshold value can refer to a preset signal-to-noise ratio (SNR) critical value, which is used to divide the channel quality into interval levels. When the signal-to-noise ratio is high, the noise ratio is low, fewer sub-bands can be divided, and a smaller filter coefficient length can be used to reduce resource usage. When the signal-to-noise ratio is low, the noise ratio is high, more sub-bands need to be divided, and a larger filter coefficient length needs to be used to improve the compensation effect. In particular, in view of the differences in group delay characteristics of different frequency bands, such as the fact that the group delay in high-frequency bands may vary more dramatically, the strategy of the number of sub-bands and filter length can be further adjusted to dynamically allocate compensation resources for different frequency bands: for high-frequency, high-distortion sub-bands, longer and larger filters can be allocated, and for low-frequency, low-distortion sub-bands, shorter and smaller filters can be allocated.

[0116] As a specific example, the threshold values ​​may be Th1, Th2, Th3, and Th4. Then the signal-to-noise ratio SNR may be set as follows.

[0117]

[0118] The second step is to establish an inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameters, where the high signal-to-noise ratio interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband decomposition number M is constrained to M=2 i And M≥4, i is a natural number, and the compensation filter length L is constrained to be L=2j and L≥4, j is a natural number.

[0119] The third step is to determine the lower limit of the signal subband decomposition number according to the ratio of the preset subband bandwidth to the total bandwidth of the received signal, and determine the lower limit as the signal subband decomposition number corresponding to the highest signal-to-noise ratio interval.

[0120] The preset subbandwidth can refer to the pre-set span of a single subband spectrum. For example, if the total bandwidth is set to 10 (units are not limited), the preset subbandwidth is set to 2, and the quotient is 5, then the decomposition number must be greater than 5. Assuming the constraint of the signal subband decomposition number M in step 2 is met, the lower limit of the signal subband decomposition number can be determined to be 8. This means that the signal subband decomposition number corresponding to the highest signal-to-noise ratio interval is 8.

[0121] In some embodiments, after determining the number of signal subband decompositions and the compensation filter length corresponding to the received signal, the method includes:

[0122] The first step is to obtain the original pilot code and calculate the average group delay of the target pilot code relative to the original pilot code. By comparing the group delay characteristics of the original and received pilot codes, a global benchmark for overall channel distortion is obtained. This objectively reflects the comprehensive distortion level of the signal transmission path, providing a unified reference standard for subsequent subband-level compensation and avoiding local over-compensation or under-compensation.

[0123] The second step is to obtain the subband group delay for each signal subband and calculate the difference between each subband's group delay and the average group delay. The group delay is measured independently for each subband, and its deviation from the overall average is calculated. This process accurately identifies the distribution characteristics of frequency domain distortion and locates high-distortion subbands with significant group delay fluctuations, providing data support for dynamic resource allocation.

[0124] In the third step, when the group delay difference is greater than the preset offset threshold, if the subband group delay is greater than the average group delay, the compensation filter length of the corresponding signal subband is increased based on the preset first step value. The offset threshold can refer to a pre-set group delay fluctuation tolerance boundary value, which is used to determine whether the compensation filter length of a specific subband needs to be adjusted. This threshold is determined based on a combination of channel characteristics and modulation order, and is essentially a critical judgment standard for group delay differences. When the deviation of the subband group delay from the overall average value exceeds this threshold, the adaptive adjustment mechanism of the filter length is triggered to ensure a balance between compensation accuracy and resource consumption. For subbands whose group delay is significantly higher than the average value, the compensation filter length is automatically increased. This strengthens the correction capability for severely distorted subbands, enhances the depth of phase linearization processing by increasing the filter order, and effectively suppresses high-frequency group delay components in broadband signals.

[0125] In the fourth step, if the subband group delay is less than the average group delay, the compensation filter length of the corresponding signal subband is reduced based on a preset second step value. The updated compensation filter length L is constrained to be L = 2j and L ≥ 4, where j is a natural number. For subbands with group delays below the average, the filter length is dynamically reduced. This mechanism avoids excessive computational resources in low-distortion subbands while maintaining binary constraints on the filter structure (e.g., length is an integer power of two), ensuring regularity and computational efficiency in hardware implementation.

[0126] In the fifth step, if the group delay difference is no greater than the preset offset threshold, the compensation filter length for each signal subband is not updated. When the subband group delay fluctuation is within the threshold, the existing filter configuration is maintained to reduce the frequency of unnecessary parameter updates, reduce the dynamic load of real-time calculations, and improve system stability in steady-state channel environments.

[0127] The aforementioned hierarchical compensation mechanism is particularly suitable for high-order modulation scenarios such as satellite communications 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 the hardware platform, providing a reliable solution for the engineering deployment of high-spectrum-efficiency technologies.

[0128] Step 203: Decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands.

[0129] In some embodiments, in order to improve efficiency and reduce operation complexity, a DFT filter bank based on polyphase decomposition can be selected as the analysis filter bank, and the symbol bandwidth R of the 256QAM channel can be set to s It is divided into M (M is the number of signal subband decomposition) subbands, and the bandwidth of each subband is R s / M. The principle of DFT filter bank is to convert the bandwidth to R s A low-pass filter (prototype filter) with a bandwidth of Rs / M is shifted to M evenly distributed frequency points through DFT modulation, forming a filter bank consisting of M filters with a bandwidth of Rs / M. This filter bank is then used in parallel through polyphase filtering with low computational complexity to decompose M subband signals. Because the bandwidth of each subband signal is reduced to 1 / M of the global bandwidth, the group delay distortion of the subband is significantly reduced relative to the global distortion. This group delay distortion can be compensated for in each subband using independent filters with fewer points, achieving excellent results and breaking through the performance bottleneck of the global filter.

[0130] By utilizing a DFT-modulated filter bank with a polyphase filtering structure, the filter coefficients of each subchannel are independently calculated at a relatively low cost, and the group delay of each subchannel is compensated. The overall solution naturally supports parallel processing by CPU, GPU, and FPGA, significantly improving the speed of group delay distortion compensation.

[0131] Step 204: Calculate the filter compensation coefficient 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 coefficient.

[0132] In some embodiments, the filter compensation coefficients may refer to an array of L data in the compensation filter for correcting signal distortion. The compensation coefficients include L data, meaning the compensation filter length is L.

[0133] In some optional implementations, calculating the filter compensation coefficient for each signal subband based on the compensation filter length includes:

[0134] The first step is to obtain the original guidance code.

[0135] In the second step, based on the signal subband decomposition number M, the original pilot code is decomposed into M first subcodes of equal length, and the target pilot code is decomposed 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.

[0136] The third step is to construct the received signal matrix Y of the kth second subcode k , Y k The number of rows is N+1-L k , Y k The number of columns is L k , where L krepresents the compensation filter length of the kth signal subband, Y k The first line is the signal value of L consecutive second subcodes, the nth line is the signal value of L consecutive second subcodes shifted n-1 times by the first line, and the left boundary of the first line is y k [0], the N+1-L k The right edge of the row is y k [N-1], or, the right edge of the first row is y k [0], the N+1-L k The left edge of the row is y k [N-1], or the left edge of the first row is y k [N-1], N+1-L k The right edge of the row is y k [0], or, the right edge of the first row is y k [N-1], N+1-L k The left edge of the row is y k [0], k, n are natural numbers, k∈[1, M], n∈[0, NL k ].

[0137] As a specific example, Yk can be as follows:

[0138] .

[0139] The fourth step is to construct the expected response vector S of the kth signal subband k , the expected response vector is the original pilot code, and the received signal matrix Y k The length of the first column is N+1-L k The signal values ​​of form the transpose vector of the vector.

[0140] As a specific example, S k It can be as follows:

[0141] .

[0142] Step 5: Combine the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to a coefficient of a corresponding position of the filter.

[0143] In some optional implementations, the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, including: according to the preset first calculation formula, combined with the received signal matrix Yk and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the first calculation formula includes:

[0144]

[0145] Among them, W k represents the filter compensation coefficient, Indicates Y k The conjugate transpose of .

[0146] The above calculation formula is based on the least squares Gaussian reconstruction formula. By designing the sub-band compensation filter coefficients, the group delay distortion characteristics of each sub-band are specifically solved, thereby improving the group delay distortion compensation performance.

[0147] Step 205: Generate a target signal based on the compensated signal sub-bands.

[0148] In some embodiments, the sub-band signals after group delay compensation can be synthesized by a synthesis filter bank to restore the complete global QAM modulated signal. A DFT filter bank based on polyphase filtering can be used as a synthesis filter bank; if the prototype filter of the DFT filter bank meets the complete 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 low amount of computation. In this way, the re-synthesized full-bandwidth signal has compensated for most of the group delay distortion, leaving only a very small amount of residual group delay. See 3a and Figure 3b In order to evaluate the effect of compensating group delay in this sub-band, we conducted a simulation analysis. The signal adopts 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 a small amount of residual group delay remains.

[0149] The beneficial effects of one of the embodiments of this specification include at least: fine compensation of different frequency components of group delay through sub-band decomposition, flatter channel frequency response within the sub-band, and reduced requirements for estimation error and filter length, thereby avoiding the performance bottleneck of the global equalizer.

[0150] In some embodiments, the high-order modulation signal group delay distortion compensation method based on sub-band decomposition further includes: performing post-equalization processing on the target signal, and dynamically tracking the group delay variation of the target signal to perform dynamic compensation.

[0151] The DD-LMS adaptive equalizer commonly used 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 high-order modulated signal group delay distortion compensation method based on sub-band decomposition provided in the embodiment of this specification, since the constellation diagram caused by the residual group delay has only a small degree of divergence, the DD-LMS adaptive equalizer can be used for post-equalization processing. In this way, the residual group delay changes can be adaptively tracked to compensate for the inter-symbol interference caused by the time-varying group delay distortion. As an example, please refer to Figure 4a and Figure 4b Before compensating for group delay distortion (refer to Figure 4a ), the constellation diagram of the 256QAM demodulated signal diverges significantly, and the inter-symbol interference is serious, resulting in a deterioration of the demodulation bit error rate. After being processed by the high-order modulation signal group delay distortion compensation method based on sub-band decomposition provided by the embodiment of this specification (reference Figure 4b ), the signal constellation is restored to near the theoretical position, and the degree of constellation aggregation is in line with expectations, thus significantly reducing inter-symbol interference and improving demodulation performance.

[0152] like Figure 5 As shown, in a specific embodiment, a simulation analysis was performed to evaluate the bit error rate performance of the embodiments of this specification. The signal was modulated using 256QAM, the symbol rate was 750Msps, and the channel had a linear group delay of 1ns. Through Monte Carlo simulation, the relationship curves of the bit error rate (refer to the BER in the figure) and the signal-to-noise ratio (refer to the EbN0 in the figure) for signal demodulation using this method and not using this method were obtained and compared with the theoretical values. It can be seen that if the group delay distortion is not compensated, the bit error rate will deteriorate severely and demodulation will be almost impossible; after compensation using the present invention, the bit error rate is significantly reduced, approaching the theoretical value, and the larger the signal-to-noise ratio, the better the compensation effect.

[0153] In some embodiments, the method for compensating group delay distortion of a high-order modulated signal based on subband decomposition further includes: parsing a target signal and determining a frame synchronization result; if the frame synchronization result indicates that the target signal is locked, then the target signal meets the requirements (in this case, there is no need to repeat the aforementioned steps of acquiring the received signal, extracting the target pilot code, and calculating the signal-to-noise ratio estimate based on the target pilot code). If the frame synchronization result indicates that the target signal is locked, then the steps of acquiring the received signal, extracting the target pilot code, and calculating the signal-to-noise ratio estimate based on the target pilot code are repeated.

[0154] When parsing the target signal, this can be done after the demodulation module's processing. Frame synchronization lock refers to a state in a communication system where the receiver continuously tracks the transmitter's frame structure to ensure that the start and end positions of the data frame are precisely aligned and maintained stably. The adaptive control mechanism for frame synchronization status monitoring enables dynamic, coordinated optimization of compensation strategies and communication quality. When channel conditions are stable, parameter updates are frozen to reduce computational overhead and avoid resource waste caused by repeated compensation. When channel deterioration causes frame lock loss, signal recapture and parameter reset processes are automatically triggered to ensure the system quickly resumes effective communication. This closed-loop control logic significantly improves the ability to track time-varying channels, maintaining long-term stability of compensation accuracy while avoiding the risk of persistent miscompensation caused by sudden interference. Combined with subband decomposition and dynamic filter adjustment technology, the system can ensure the integrity and demodulation reliability of high-order modulated signals even in low-power mode. This makes it particularly suitable for wireless transmission scenarios such as satellite communications and mobile backhaul, where both energy efficiency and interference immunity are crucial.

[0155] Corresponding to the above method embodiment, this specification also provides an embodiment of a high-order modulation signal group delay distortion compensation device based on sub-band decomposition, Figure 6 FIG. 1 shows a schematic diagram of a high-order modulation signal group delay distortion compensation device based on sub-band decomposition provided by some embodiments of this specification. Figure 6 As shown, the device includes:

[0156] The acquisition module 601 is configured to acquire a received signal and extract a target pilot code, and calculate a signal-to-noise ratio estimation value based on the target pilot code, wherein the received signal is a single symbol rate signal that has been subjected to timing synchronization processing, and the received signal is a digital signal.

[0157] The determination module 602 is configured to determine the number of signal subband decompositions and the length of the compensation filter based on predetermined signal decomposition parameters and a signal-to-noise ratio estimation value, wherein the number of signal subband decompositions and the length of the compensation filter are both ≥4.

[0158] The decomposition module 603 is configured to decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands.

[0159] The compensation module 604 is configured to calculate a filter compensation coefficient for each signal sub-band based on the compensation filter length, and perform group delay compensation on each signal sub-band based on the compensation coefficient.

[0160] The generating module 605 is configured to generate a target signal based on the compensated signal sub-bands.

[0161] In some optional embodiments, calculating a signal-to-noise ratio estimate based on a target pilot code in a received signal includes:

[0162] Obtain the original guidance code, and calculate the signal-to-noise ratio estimation value based on the original guidance code and the target guidance code.

[0163] In some optional embodiments, the step of determining the signal decomposition parameter includes:

[0164] forming at least two signal-to-noise ratio intervals based on at least one preset threshold value;

[0165] The inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameter is established, where the high signal-to-noise ratio interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband 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 be L = 2j and L ≥ 4, j is a natural number;

[0166] The lower limit of the number of signal subband decompositions is determined according to the ratio of the preset subband bandwidth to the total bandwidth of the received signal, and the lower limit is determined as the number of signal subband decompositions corresponding to the highest signal-to-noise ratio interval.

[0167] In some optional embodiments, calculating the filter compensation coefficient of each signal subband based on the compensation filter length includes:

[0168] Get the original guidance code;

[0169] Based on the signal subband decomposition number M, the original pilot code is decomposed into M first subcodes of equal length, and the target pilot code is decomposed into M second subcodes of equal length, wherein the subcode length of the first subcode or the second subcode is N, where N is a natural number;

[0170] Construct the received signal matrix Y of the kth second subcode k , Y k The number of rows is N+1-L k , Y k The number of columns is L k , where L k represents the compensation filter length of the kth signal subband, Y k The first line is the signal value of L consecutive second subcodes, the nth line is the signal value of L consecutive second subcodes shifted n-1 times by the first line, and the left boundary of the first line is y k [0], the N+1-L k The right edge of the row is y k [N-1], or, the right edge of the first row is y k [0], the N+1-L k The left edge of the row is y k [N-1], or the left edge of the first row is y k [N-1], N+1-L k The right edge of the row is yk [0], or, the right edge of the first row is y k [N-1], N+1-L k The left edge of the row is y k [0], k, n are natural numbers, k∈[1, M], n∈[0, NL k ];

[0171] Construct the expected response vector S of the kth signal subband k , the expected response vector is the original pilot code, and the received signal matrix Y k The length of the first column is N+1-L k The signal value of constitutes the transpose vector of the vector;

[0172] Combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to a coefficient of a corresponding position of the filter.

[0173] In some optional embodiments, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, including:

[0174] According to the preset first calculation formula, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, where the first calculation formula includes:

[0175]

[0176] Among them, W k represents the filter compensation coefficient, Indicates Y k The conjugate transpose of .

[0177] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0178] Post-equalization processing is performed on the target signal, and the group delay change of the target signal is dynamically tracked to perform dynamic compensation.

[0179] In some optional embodiments, after determining the number of signal subband decompositions and the compensation filter length corresponding to the received signal, the method further includes:

[0180] Obtaining an original pilot code and calculating an average group delay of the target pilot code relative to the original pilot code;

[0181] Obtaining the subband group delay of each signal subband, and calculating the group delay difference between each subband group delay and the average group delay;

[0182] When the group delay difference is greater than a preset offset threshold, if the subband group delay is greater than the average group delay, increasing the compensation filter length of the corresponding signal subband based on a preset first step value;

[0183] If the subband group delay is less than the average group delay, reducing the compensation filter length of the corresponding signal subband based on a preset second step value; wherein the updated compensation filter length L is constrained to be L=2j and L≥4, where j is a natural number;

[0184] When the group delay difference is not greater than the preset offset threshold, the compensation filter length of each signal subband is not updated.

[0185] In some optional embodiments, the method for compensating group delay distortion of a high-order modulation signal based on sub-band decomposition further includes:

[0186] Analyze the target signal and determine the frame synchronization result;

[0187] If the frame synchronization result indicates that the lock is maintained, it means that the target signal meets the requirements;

[0188] If the frame synchronization result indicates that the lock is still lost, the steps of acquiring the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value based on the target pilot code are re-executed.

[0189] The above is a schematic scheme of a high-order modulated signal group delay distortion compensation device based on subband decomposition according to this embodiment. It should be noted that the technical scheme of the high-order modulated signal group delay distortion compensation device based on subband decomposition and the technical scheme of the high-order modulated signal group delay distortion compensation method based on subband decomposition are based on the same concept. For details not described in detail in the technical scheme of the high-order modulated signal group delay distortion compensation device based on subband decomposition, please refer to the description of the technical scheme of the high-order modulated signal group delay distortion compensation method based on subband decomposition.

[0190] Figure 7 7 shows a block diagram of a computing device 700 according to some embodiments of the present disclosure. 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 via a bus 703, and a database 705 is used to store data.

[0191] Computing device 700 also includes an access device 704 that enables computing device 700 to communicate via one or more networks 706. Examples of such networks include a public switched telephone network (PSTN), a local area network (LAN), a wide area network (WAN), a personal area network (PAN), or a combination of communication networks such as the Internet. Access device 704 may include one or more of any type of network interface (e.g., a network interface card (NIC)) whether wired or wireless, such as an IEEE 802.11 wireless local area network (WLAN) wireless interface, a Worldwide Interoperability for Microwave Access (Wi-MAX) interface, an Ethernet interface, a universal serial bus (USB) interface, a cellular network interface, a Bluetooth interface, or a near field communication (NFC) interface.

[0192] In one embodiment of the present specification, the above components of the computing device 700 and Figure 7 Other components not shown in the figure may also be connected to each other, for example, via a bus. Figure 7 The computing device structure block diagram shown is for illustrative purposes only and is not intended to limit the scope of this specification. Those skilled in the art may add or replace other components as needed.

[0193] Computing device 700 can be any type of stationary or mobile computing device, including a mobile computer or mobile computing device (e.g., a tablet computer, personal digital assistant, laptop computer, notebook computer, netbook computer, etc.), a mobile phone (e.g., a smartphone), a wearable computing device (e.g., a smartwatch, smart glasses, etc.), or other types of mobile devices, or a stationary computing device such as a desktop computer or personal computer (PC). Computing device 700 can also be a mobile or stationary server.

[0194] Processor 702 is configured to execute the following computer-executable instructions, which, when executed by the processor, implement the steps of the above-mentioned method for compensating for group delay distortion of high-order modulated signals based on subband decomposition. The above is a schematic scheme of a computing device of this embodiment. It should be noted that the technical scheme of the computing device and the technical scheme of the above-mentioned method for compensating for group delay distortion of high-order modulated signals based on subband decomposition are based on the same concept. For details not described in detail in the technical scheme of the computing device, please refer to the description of the technical scheme of the above-mentioned method for compensating for group delay distortion of high-order modulated signals based on subband decomposition.

[0195] An embodiment of the present specification further provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the above-mentioned method for compensating high-order modulation signal group delay distortion based on subband decomposition.

[0196] The above is an illustrative embodiment of a computer-readable storage medium according to this embodiment. It should be noted that the technical solution of this storage medium shares the same concept as the technical solution of the method for compensating for group delay distortion of high-order modulated signals based on subband decomposition. For details not described in detail in the technical solution of the storage medium, please refer to the description of the technical solution of the method for compensating for group delay distortion of high-order modulated signals based on subband decomposition.

[0197] An embodiment of the present specification further provides a computer program, wherein when the computer program is executed in a computer, the computer is instructed to execute the steps of the above-mentioned method for compensating group delay distortion of high-order modulation signals based on sub-band decomposition.

[0198] The above is an illustrative solution of a computer program according to this embodiment. It should be noted that the technical solution of this computer program shares the same concept as the technical solution of the method for compensating group delay distortion of high-order modulated signals based on subband decomposition. For details not described in detail in the technical solution of the computer program, please refer to the description of the technical solution of the method for compensating group delay distortion of high-order modulated signals based on subband decomposition.

[0199] The foregoing description of this specification describes specific embodiments. 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 an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0200] Computer instructions include computer program code, which may be in source code, object code, executable files, or some intermediate form. Computer-readable media may include any entity or device capable of carrying computer program code, recording media, USB flash drives, removable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunications signals, and software distribution media. It should be noted that the content of computer-readable media may be expanded or reduced based on the requirements of legislation and patent practice within a jurisdiction. For example, in some jurisdictions, based on legislation and patent practice, computer-readable media does not include electric carrier signals or telecommunications signals.

[0201] It should be noted that for the aforementioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of this specification are not limited by the order of the actions described, because according to the embodiments of this specification, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of this specification.

[0202] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0203] The preferred embodiments disclosed above are intended only to help illustrate this specification. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to specific embodiments. Obviously, many modifications and variations are possible based on the content of the embodiments described herein. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the embodiments, thereby enabling those skilled in the art to better understand and utilize this specification. This specification is limited only 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: include: Acquiring a received signal and extracting a target pilot code, and calculating a signal-to-noise ratio estimation value based on 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; Determining the number of signal subband decompositions and the length of the compensation filter based on predetermined signal decomposition parameters and the signal-to-noise ratio estimate, wherein both the number of signal subband decompositions and the length of the compensation filter are ≥4, and the step of determining the signal decomposition parameters comprises: forming at least two signal-to-noise ratio intervals based on at least one preset threshold value; Establish an inverse correlation between the signal-to-noise ratio interval and the signal decomposition parameter, wherein a high signal-to-noise ratio interval corresponds to a low signal subband decomposition number and a low compensation filter length, and the signal subband 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 be L=2j and L≥4, j is a natural number; Determining a lower limit of the signal subband decomposition number based on a ratio between a preset subband bandwidth and a total bandwidth of the received signal, and determining the lower limit as the signal subband decomposition number corresponding to a maximum signal-to-noise ratio interval; 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 for each signal subband based on the compensation filter length, and performing group delay compensation on each signal subband based on the compensation coefficient; A target signal is generated based on the compensated signal subbands.

2. The method according to claim 1, characterized in that Calculating a signal-to-noise ratio estimate based on a target pilot code in the received signal includes: An original pilot code is obtained, and the signal-to-noise ratio estimation value is calculated according to the original pilot code and the target pilot code.

3. The method according to claim 1, characterized in that Calculating a filter compensation coefficient for each signal subband based on the compensation filter length includes: Get the original guidance 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, wherein the subcode length of the first subcode or the second subcode is N, where N is a natural number; Construct the received signal matrix Y of the kth second subcode k , Y k The number of rows is N+1-L k , Y k The number of columns is L k , where L k represents the compensation filter length of the kth signal subband, Y k The first line is the signal value of L consecutive second subcodes, the nth line is the signal value of L consecutive second subcodes shifted n-1 times by the first line, and the left boundary of the first line is y k [0], the N+1-L k The right edge of the row is y k [N-1], or, the right edge of the first row is y k [0], the N+1-L k The left edge of the row is y k [N-1], or the left edge of the first row is y k [N-1], N+1-L k The right edge of the row is y k [0], or, the right edge of the first row is y k [N-1], N+1-L k The left edge of the row is y k [0], k, n are natural numbers, k∈[1, M], n∈[0, NL k ]; Construct the expected response vector S of the kth signal subband k , the expected response vector is the original pilot code, and the received signal matrix Y k The length of the first column is N+1-L k The signal value of constitutes the transpose vector of the vector; Combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, wherein the filter compensation coefficient is composed of L compensation sub-coefficients, and each compensation sub-coefficient corresponds to a coefficient of a corresponding position of the filter.

4. The method according to claim 3, characterized in that Combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the kth signal subband, including: According to the preset first calculation formula, combined with the received signal matrix Y k and the expected response vector S k , calculate the filter compensation coefficient of the k-th signal subband, wherein the first calculation formula includes: Among them, W k represents the filter compensation coefficient, Indicates Y k The conjugate transpose of .

5. The method according to claim 1, wherein The method further comprises: Post-equalization processing is performed on the target signal, and group delay changes of the target signal are dynamically tracked to perform dynamic compensation.

6. The method according to any one of claims 1 to 5, characterized in that After determining the number of signal subband decompositions and the compensation filter length corresponding to the received signal, the method further includes: Obtaining an original pilot code, and calculating an average group delay of the target pilot code with respect to the original pilot code; Obtaining a subband group delay of each signal subband, and calculating a group delay difference between each subband group delay and the average group delay; When the group delay difference is greater than a preset offset threshold, if the subband group delay is greater than the average group delay, increasing the compensation filter length of the corresponding signal subband based on a preset first step value; If the subband group delay is less than the average group delay, reducing the compensation filter length of the corresponding signal subband based on a preset second step value; wherein the updated compensation filter length L is constrained to be 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 length of each signal subband is not updated.

7. The method according to any one of claims 1 to 5, characterized in that Also includes: Analyzing the target signal to determine a frame synchronization result; If the frame synchronization result indicates that the lock is maintained, it means that the target signal meets the requirements; If the frame synchronization result indicates that the lock is still lost, the steps of acquiring the received signal and extracting the target pilot code, and calculating the signal-to-noise ratio estimation value based on the target pilot code are performed again.

8. A high-order modulation signal group delay distortion compensation device based on sub-band decomposition, characterized in that: include: an acquisition module configured to acquire a received signal and extract a target pilot code, and calculate a signal-to-noise ratio estimation value based on the target pilot code, wherein the received signal is a single symbol rate signal that has been subjected to timing synchronization processing, and the received signal is a digital signal; The determination module is configured to determine the number of signal subband decompositions and the compensation filter length based on a predetermined signal decomposition parameter and the signal-to-noise ratio estimation value, wherein the number of signal subband decompositions and the compensation filter length are both ≥4, and the step of determining the signal decomposition parameter comprises: 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 parameter, wherein a high signal-to-noise ratio interval corresponds to a low number of signal subband decompositions and a low compensation filter length, and the number of signal subband decompositions M is constrained to M=2 i and M ≥ 4, i is a natural number, the compensation filter length L is constrained to be L = 2j and L ≥ 4, j is a natural number; determining a lower limit of the number of signal subband decompositions based on a ratio of a preset subband bandwidth to a total bandwidth of the received signal, and determining the lower limit as the number of signal subband decompositions corresponding to a maximum signal-to-noise ratio interval; a decomposition module configured to decompose the received signal based on the signal sub-band decomposition number to obtain at least four signal sub-bands; 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; The generating module is configured to generate a target signal based on the compensated signal sub-bands.

9. A computing device, characterized in that include: memory and 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 high-order modulation signal group delay distortion compensation method based on sub-band decomposition according to any one of claims 1 to 7 are implemented.

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