Baseline drift correction circuit, baseline drift correction method and communication system

Abstract

The present invention provides a baseline drift correction circuit, a baseline drift correction method and a communication system, which relate to the field of communication technology. The baseline drift correction circuit can obtain a desired compensation signal according to a decision signal output by a decision device and an initial received signal output by a high-pass filter; perform exponential curve fitting on the desired compensation signal to obtain a signal gain value and a growth rate; determine a low-pass filter compensation signal according to a cutoff frequency corresponding to the growth rate and the decision signal; determine a target compensation signal according to the signal gain value and the low-pass filter compensation signal; perform baseline drift compensation on the initial received signal using the target compensation signal, and output the target received signal to the decision device for symbol decision. In this way, the signal gain value and cutoff frequency of the high-pass characteristic of the communication system to the signal waveform are adaptively fitted, and then the compensation signal of the baseline drift is adjusted, thereby improving the accuracy of the offset compensation and thus improving the stability of the performance of the communication system.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a baseline drift correction circuit, a baseline drift correction method and a communication system. Background Art

[0002] High-speed data communication technology is widely used in communication networks. In recent years, with the rapid development of new energy automobile industry, industrial robots and artificial intelligence, various emerging industries have higher and higher demands for data transmission speed. Taking the smart car industry as an example, smart cars transmit various data collected by various sensors in real time to central processing chips and dedicated high-computing chips for data fusion and powerful neural network calculation, thereby achieving powerful perception capabilities. With the explosive growth of sensor data (such as high-definition cameras, laser radars, millimeter-wave radars, etc. covering the car body), how to transmit this data at high speed and stably has become a very critical part of automotive intelligence. In-vehicle SerDes (Serializer / Deserializer) and in-vehicle Ethernet technology play an important role in this. However, both SerDes and Ethernet will face the problem of baseline drift.

[0003] In wired communication systems such as SerDes and Ethernet, baseline drift is often caused by transformers that implement full-duplex coupling and separation (i.e., transformers are used to isolate the signal transmission path and can effectively separate the signals on the transmit and receive paths). When a waveform passes through the transformer, DC droop (waveform distortion) occurs. This is because transformers often exhibit high-pass characteristics and can be approximated as a high-pass filter.

[0004] Existing baseline drift compensation schemes generally assume that the high-pass characteristics of the transformer are known, that is, the cutoff frequency of the high-pass filter is known, and a limited frequency selection range is tried, and then the appropriate signal compensation gain is obtained based on LMS adaptive iteration using the front and back errors of the decision maker. However, this scheme still has the problem of inaccurate offset compensation, which can easily cause unstable communication system performance. Summary of the invention

[0005] The object of the present invention is to provide a baseline drift correction circuit, a baseline drift correction method and a communication system to improve the accuracy of offset compensation, thereby improving the stability of communication system performance.

[0006] In a first aspect, the present invention provides a baseline drift correction circuit, which is applied to a communication system including a high-pass filter and a decision device; the baseline drift correction circuit includes:

[0007] A data collector, wherein the input end of the data collector is respectively connected to the output end of the high-pass filter and the output end of the decision device; the data collector is used to obtain the expected compensation signal according to the decision signal output by the decision device and the initial receiving signal output by the high-pass filter;

[0008] An exponential fitter, the input end of which is connected to the output end of the data collector; the exponential fitter is used to perform exponential curve fitting on the expected compensation signal output by the data collector to obtain the signal gain value and growth rate;

[0009] A low-pass filter, wherein the input end of the low-pass filter is respectively connected to the output end of the exponential fitter and the output end of the decision device; the low-pass filter is used to determine the low-pass filter compensation signal according to the cut-off frequency corresponding to the growth rate and the decision signal output by the decision device;

[0010] A multiplier, the multiplier is connected to the output end of the exponential fitter and the output end of the low-pass filter respectively; the multiplier is used to determine the target compensation signal according to the signal gain value and the low-pass filter compensation signal;

[0011] A compensator, wherein the input end of the compensator is respectively connected to the output end of the multiplier and the output end of the high-pass filter, and the output end of the compensator is connected to the input end of the decision device; the compensator is used to use the target compensation signal to perform baseline drift compensation on the initial received signal output by the high-pass filter, and output the target received signal to the decision device for symbol decision.

[0012] Furthermore, the data collector includes a subtractor, and the subtractor is used to perform a subtraction operation on the decision signal and the initial received signal to obtain a desired compensation signal.

[0013] Furthermore, the exponential fitter is specifically used to: obtain an input data sequence consisting of expected compensation signals of multiple sampling points at uniform time intervals; calculate the signal gain value and growth rate based on the logarithm of the target data sequence and a preset linear regression matrix; wherein the target data sequence is the input data sequence or a denoised data sequence obtained by denoising the input data sequence.

[0014] Furthermore, the exponential fitter is also used to solve , and the first parameter value and the second parameter value obtained by solving are used as the signal gain value and growth rate respectively; where, X represents the linear regression matrix, , ones ( length ( t ),1) indicates the number of rows is t A matrix with a length of , a column of 1, and all elements are 1, t Indicates the time interval is sp of NThe time vector composed of sampling points, t’ express t The transpose of X’ express X The transpose of Z’ Represents the transpose of the logarithm of the target data series.

[0015] Furthermore, the low-pass filter is specifically used to: Substitute the growth rate into the formula , solve for the cutoff frequency; calculate the time constant based on the cutoff frequency; substitute the time constant into the formula , calculate the bilinear transformation parameters; determine the low-pass filter compensation signal according to the bilinear transformation parameters, the decision signal at the current moment, the decision signal at the previous moment, and the order and type of the low-pass filter; wherein, fc represents the cut-off frequency, k represents the growth rate, F Indicates the preset sampling frequency, A represents the bilinear transformation parameters, RC _ lf Represents the time constant.

[0016] Furthermore, the low-pass filter is a first-order infinite impulse response filter; the expression of the low-pass filter compensation signal is as follows:

[0017] ;

[0018] ;

[0019] ;

[0020] ;

[0021] in, LPF [ n ]express n The low-pass filter compensation signal at the moment, LPF [ n -1] indicates n Low-pass filter compensation signal at time -1, D [ n ]express n The judgment signal of the moment, D [ n -1] indicates n -1 decision signal at time.

[0022] Furthermore, the multiplier is specifically used to: The target compensation signal is calculated; wherein, BLW [ n ]express n The target compensation signal at the moment,g Indicates the signal gain value, LPF [ n ]express n The low-pass filtered compensation signal at the moment.

[0023] Furthermore, the compensator is specifically used to: The target received signal is calculated; wherein, y [ n ]express n The target receives the signal at the moment, HF [ n ]express n The initial received signal at time BLW [ n ]express n The target compensation signal at that moment.

[0024] In a second aspect, the present invention further provides a baseline drift correction method, which is applied to the baseline drift correction circuit of the first aspect; the baseline drift correction method comprises:

[0025] Obtaining a desired compensation signal according to a decision signal output by the decision device and an initial receiving signal output by the high-pass filter;

[0026] Perform exponential curve fitting on the expected compensation signal to obtain the signal gain value and growth rate;

[0027] Determine a low-pass filter compensation signal according to a cutoff frequency corresponding to the growth rate and a decision signal output by the decision device;

[0028] Determine a target compensation signal according to the signal gain value and the low-pass filter compensation signal;

[0029] The target compensation signal is used to compensate the baseline drift of the initial received signal, and the target received signal is output to the decision device for symbol decision.

[0030] In a third aspect, the present invention further provides a communication system, comprising a high-pass filter, a decision device and the baseline drift correction circuit of the first aspect, wherein the baseline drift correction circuit is connected to the high-pass filter and the decision device respectively.

[0031] In the baseline drift correction circuit, baseline drift correction method and communication system provided by the embodiment of the present invention, the baseline drift correction circuit can obtain the expected compensation signal according to the decision signal output by the decider and the initial received signal output by the high-pass filter; perform exponential curve fitting on the expected compensation signal to obtain the signal gain value and growth rate; determine the low-pass filter compensation signal according to the cutoff frequency corresponding to the growth rate and the decision signal output by the decider; determine the target compensation signal according to the signal gain value and the low-pass filter compensation signal; use the target compensation signal to perform baseline drift compensation on the initial received signal, and output the target received signal to the decider for symbol decision. In this way, the signal gain value and cutoff frequency of the high-pass characteristic of the signal waveform of the communication system are adaptively fitted by the baseline drift correction circuit, and then the compensation signal of the baseline drift is adjusted, the accuracy of the offset compensation is improved, and thus the stability of the performance of the communication system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a baseline drift correction circuit provided by an embodiment of the present invention;

[0034] Figure 2 A signal flow diagram of a baseline drift correction circuit provided by an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of a step response of a communication system provided by an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of a curve for adaptive optimization of gain value provided by an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of a curve for adaptive optimization of cutoff frequency provided by an embodiment of the present invention;

[0038] Figure 6 A flowchart of a baseline drift correction method provided by an embodiment of the present invention.

[0039] Icons: 101-data collector; 102-exponential fitter; 103-low-pass filter; 104-multiplier; 105-compensator. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] SerDes is a technology for high-speed data transmission that can convert information on multiple parallel data lines into one or more high-speed serial lines, thereby reducing the number of pins and signal paths required for connection. Both SerDes and Ethernet face the problem of baseline drift. Existing baseline drift compensation schemes assume that the high-pass characteristics of the transformer are known, but actual communication systems often cannot be modeled with a single high-pass filter characteristic, and existing baseline drift compensation schemes only focus on how to adaptively obtain the gain of the compensation signal, without caring about the cutoff frequency of the compensation signal, which results in inaccurate baseline offset compensation values, lack of compensation for some frequency points, and unstable system performance. Based on this, a baseline drift correction circuit, a baseline drift correction method, and a communication system provided in an embodiment of the present invention use a baseline drift correction algorithm based on exponential fitting to achieve correction of baseline drift occurring in the field of data communication.

[0042] To facilitate understanding of this embodiment, a baseline drift correction circuit disclosed in an embodiment of the present invention is first introduced in detail.

[0043] An embodiment of the present invention provides a baseline drift correction circuit, which is applied to a communication system including a high-pass filter and a decision device, and the communication system may be, but is not limited to, a wired communication system such as SerDes or Ethernet. Figure 1 As shown, the baseline drift correction circuit includes:

[0044] A data collector 101, wherein the input end of the data collector 101 is connected to the output end of the high-pass filter and the output end of the decision device respectively; the data collector 101 is used to obtain the expected compensation signal according to the decision signal output by the decision device and the initial receiving signal output by the high-pass filter;

[0045] An exponential fitter 102, the input end of which is connected to the output end of the data collector 101; the exponential fitter 102 is used to perform exponential curve fitting on the desired compensation signal output by the data collector 101 to obtain a signal gain value and a growth rate;

[0046] A low-pass filter 103, wherein the input end of the low-pass filter 103 is respectively connected to the output end of the exponential fitter 102 and the output end of the decision device; the low-pass filter 103 is used to determine the low-pass filter compensation signal according to the cutoff frequency corresponding to the growth rate and the decision signal output by the decision device;

[0047] A multiplier 104, the multiplier 104 is connected to the output end of the exponential fitter 102 and the output end of the low-pass filter 103 respectively; the multiplier 104 is used to determine the target compensation signal according to the signal gain value and the low-pass filter compensation signal;

[0048] Compensator 105, the input end of compensator 105 is respectively connected to the output end of multiplier 104 and the output end of the high-pass filter, and the output end of compensator 105 is connected to the input end of the decision device; compensator 105 is used to use the target compensation signal to compensate the baseline drift of the initial received signal output by the high-pass filter, and output the target received signal to the decision device for symbol decision.

[0049] In this embodiment, the output of the transformer is fitted by an exponential function. The output of the transformer is in the form of exp(-t / RC). Therefore, the growth rate of the exponential curve is related to the time constant of the transformer (which belongs to the analog circuit). The specific relationship is: the growth rate is the negative reciprocal of the time constant of the analog circuit filter implemented based on two analog devices, resistor R and capacitor C. Therefore, the cut-off frequency can be calculated based on the growth rate.

[0050] The baseline drift correction circuit provided in the embodiment of the present invention can adaptively fit the signal gain value and cutoff frequency of the high-pass characteristic of the communication system to the signal waveform through the exponential fitter 102, and then adjust the compensation signal of the baseline drift. This baseline drift correction method taking the cutoff frequency into consideration improves the accuracy of the offset compensation, thereby improving the stability of the communication system performance.

[0051] Optionally, the data collector 101 may be a subtractor, which is used to perform a subtraction operation on the decision signal and the initial received signal to obtain a desired compensation signal, that is, the desired compensation signal = the decision signal - the initial received signal.

[0052] Optionally, the exponential fitter 102 is specifically used to: obtain an input data sequence consisting of a plurality of sampling points with uniform time intervals and desired compensation signals; calculate a signal gain value and a growth rate according to the logarithm of the target data sequence and a preset linear regression matrix; wherein the target data sequence is the input data sequence or a denoised data sequence obtained by denoising the input data sequence. The denoising process may be, but is not limited to, a moving average denoising process.

[0053] The expected compensation signal at time nW [ n ] to perform exponential curve fitting, taking the waveform of a first-order RC low-pass filter as an example, ,in g is the signal gain value (i.e. the initial value of the exponential curve), k is the growth rate, k is the time constant related parameter of the transformer. You can choose a uniform interval of sp of N The expected compensation signal of sampling points is taken as the input data sequence of the fitting, and the time vector composed of the sampling points is recorded as t Taking moving average denoising as an example, moving average denoising can be performed based on a preset window length. This denoising method smoothes the original data by calculating the average value of a series of sampling points, thereby reducing noise. It has the advantages of being simple and easy to implement, effectively removing random noise, retaining trend information, being suitable for real-time applications, having adjustable parameters (i.e., the window length can be adjusted to suit different application scenarios), and having high computational efficiency.

[0054] The above linear regression matrix can be constructed as follows: .in, ones ( length ( t ),1) indicates the number of rows is t A matrix with a length of , a column of 1, and all elements are 1, t Indicates the time interval is sp of N The time vector composed of sampling points, t’ express t The transpose of . X for N A vector with two rows and two columns, for example, suppose sp =1, N =5, yes ,but:

[0055] .

[0056] Furthermore, the exponential fitter 102 is also used to solve , and obtain a column vector consisting of two parameter values, and use the first parameter value and the second parameter value obtained by solving as the signal gain value and growth rate respectively; where, X represents the linear regression matrix, , ones ( length ( t ),1) indicates the number of rows is t The length (that is, the number of sampling points) N ), a matrix with 1 column and all elements are 1, tIndicates the time interval is sp of N The time vector composed of sampling points, t’ express t The transpose of X’ express X The transpose of Z’ Represents the transpose of the logarithm of the target data sequence. It should be noted that X for N A vector with 2 rows and 2 columns, is a vector of 2 rows and 2 columns, Z’ for N A column vector with 1 row and 1 column. is a column vector with 2 rows and 1 column, is a column vector with 2 rows and 1 column.

[0057] It should be noted that the exponential fitter 102 may also use other fitting methods to obtain the signal gain value and growth rate, such as nonlinear least squares method, or other optimization algorithms such as genetic algorithm and simulated annealing.

[0058] Optionally, in order to realize the RC filter in a digital manner, the low-pass filter 103 is specifically used to: Substitute the growth rate into the formula , solve for the cutoff frequency; calculate the time constant based on the cutoff frequency; substitute the time constant into the formula , calculate the bilinear transformation parameters; determine the low-pass filter compensation signal according to the bilinear transformation parameters, the decision signal at the current moment, the decision signal at the previous moment, and the order and type of the low-pass filter; wherein, fc represents the cut-off frequency, k represents the growth rate, F Indicates the preset sampling frequency, A represents the bilinear transformation parameters, RC _ lf Represents the time constant.

[0059] The low-pass filter 103 may be an analog filter, such as an RC filter or an RL filter, or a digital filter, such as a finite impulse response filter (FIR filter) or an infinite impulse response filter (IIR filter). In addition, the embodiment of the present invention does not limit the order of the low-pass filter 103, that is, the low-pass filter 103 may be of any order. Taking the low-pass filter as a first-order RC filter as an example, its time constant can be calculated by the following formula: ,in, RC _ lf represents the time constant, F Indicates the preset sampling frequency, k Represents the growth rate.

[0060] For the low-pass filter 103, taking a first-order IIR filter as an example, there is , the transfer function is , the general equation of the transfer function corresponding to any order is: ;in, y [ n ]for n Output at the moment, y [ n -1] n -1 time output, x [ n ]for n Input at the moment, x [ n -1] n -1 time input, a1, b0, b1 are filter coefficients, Y ( z )for z The output of the domain, X ( z )for z The input of the domain, b k and a l are the filter coefficients, M is the order of the numerator polynomial (i.e., the maximum number of delayed samples in the forward path), N is the order of the denominator polynomial (i.e. the maximum number of samples delayed in the feedback path), z −1 Represents the unit delay operator, at the sampling time k , z −1 x [ k ]= x [ k −1].

[0061] Optionally, the low-pass filter 103 is a first-order infinite impulse response filter; the expression of the low-pass filter compensation signal is as follows:

[0062] ;

[0063] ;

[0064] ;

[0065] ;

[0066] in, LPF [ n ]express n The low-pass filter compensation signal at the moment, LPF [ n -1] indicates n Low-pass filter compensation signal at time -1, D [ n ]express n The judgment signal of the moment, D [ n -1] indicates n -1 decision signal at time.

[0067] Optionally, the multiplier 104 is specifically used to: The target compensation signal is calculated; wherein, BLW [ n ]express n The target compensation signal at the moment, g Indicates the signal gain value, LPF [ n ]express n The low-pass filtered compensation signal at the moment.

[0068] Optionally, the compensator 105 may be an adder, and the compensator 105 is specifically used to: The target received signal is calculated; wherein, y [ n ]express n The target receives the signal at the moment, HF [ n ]express n The initial received signal at time BLW [ n ]express n The target compensation signal at that moment.

[0069] For ease of understanding, the following takes the target data sequence as the denoised data sequence obtained by performing moving average denoising on the input data sequence as an example. Figure 2 The above-mentioned baseline drift correction circuit is introduced. Figure 2 In the figure, HPF refers to High-Pass Filter, and LPF refers to Low-Pass Filter 103 .

[0070] like Figure 2 As shown, the transmitted signal at time n is x [ n ], the output after HPF is HF [ n ], the received signal of the decision device, i.e., Slicer, is y [ n ], the decision signal output by Slicer is D [ n ], the error signal is e [n ], the baseline drift compensation signal is BLW [ n ] The received signal before it is sent to the decision maker HF [ n ] to compensate for baseline drift The decision error is: The expected compensation signal is: .

[0071] The baseline drift compensation signal (i.e., target compensation signal) can be obtained through the following process:

[0072] 1. Expected compensation signal W [ n ] to perform exponential curve fitting, taking the waveform of a first-order RC low-pass filter as an example, ,in g is the signal gain value, k is the growth rate, which is also the time constant related parameter of the transformer.

[0073] Specifically, suppose that the uniform interval is selected as sp of N The expected compensation signal of sampling points is taken as the fitting input, where the time vector composed of the sampling points is recorded as t .right W [ t ] (i.e. the above input data sequence) as the window length L The moving average denoising is obtained .Pick The logarithm of . Construct the linear regression matrix: . Solution: , obtained by two parameter values params (1) and params (2) is a column vector, where g The first parameter value params (1) k The second parameter value params (2).

[0074] 2. Calculate the cutoff frequency of the RC low-pass filter: , taking a first-order RC low-pass filter as an example, the time constant is: .

[0075] 3. Obtain parameters based on Bilinear Transform: .

[0076] 4. Taking the first-order IIR filter as an example, the output of the low-pass filter is:

[0077] ;

[0078] ;

[0079] ;

[0080] ;

[0081] 5. Calculate the baseline drift compensation value: .

[0082] In this way, the baseline drift correction circuit adopts a mixed digital-analog circuit, and adaptively fits the amplitude gain value of the communication system's high-pass characteristics of the signal waveform (including but not limited to the transformer's high-pass characteristics) through an exponential fitting baseline drift correction method, that is, a digitally implemented baseline drift compensation method. g and the cutoff frequency fc Based on the adaptive algorithm of decision error, a real-time feedback network is used to adjust the baseline drift compensation signal.

[0083] In order to verify the baseline drift correction effect of the above baseline drift correction circuit, Figure 3 As shown in Figure 1, we can see that the system quickly adapts to the baseline drift and compensates for it. Figure 4 As shown in , the gain value is adaptively optimized and converges to the target value 1; Figure 5 As shown, the cutoff frequency adaptive optimization is achieved and converges to a stable value near 9MHz.

[0084] The embodiment of the present invention further provides a baseline drift correction method, which is applied to the above-mentioned baseline drift correction circuit. Figure 6 The flowchart of a baseline drift correction method shown in FIG. 1 is a flowchart of a baseline drift correction method, and the baseline drift correction method includes the following steps S610 to S650:

[0085] Step S610: acquiring a desired compensation signal according to the decision signal output by the decider and the initial received signal output by the high-pass filter.

[0086] Step S620: performing exponential curve fitting on the expected compensation signal to obtain a signal gain value and a growth rate.

[0087] Step S630, determining a low-pass filter compensation signal according to the cutoff frequency corresponding to the growth rate and the decision signal output by the decision device.

[0088] Step S640: determining a target compensation signal according to the signal gain value and the low-pass filter compensation signal.

[0089] Step S650, using the target compensation signal to perform baseline drift compensation on the initial received signal, and outputting the target received signal to the decision device for symbol decision.

[0090] The baseline drift correction method provided by the embodiment of the present invention can obtain the expected compensation signal according to the decision signal output by the decider and the initial received signal output by the high-pass filter; perform exponential curve fitting on the expected compensation signal to obtain the signal gain value and growth rate; determine the low-pass filter compensation signal according to the cutoff frequency corresponding to the growth rate and the decision signal output by the decider; determine the target compensation signal according to the signal gain value and the low-pass filter compensation signal; use the target compensation signal to perform baseline drift compensation on the initial received signal, and output the target received signal to the decider for symbol decision. In this way, the signal gain value and cutoff frequency of the high-pass characteristic of the communication system to the signal waveform are adaptively fitted by the baseline drift correction circuit, and then the compensation signal of the baseline drift is adjusted, the accuracy of the offset compensation is improved, and thus the stability of the performance of the communication system is improved.

[0091] The embodiment of the present invention further provides a communication system, including a high-pass filter, a decision device and the above-mentioned baseline drift correction circuit, wherein the baseline drift correction circuit is connected to the high-pass filter and the decision device respectively.

[0092] The baseline drift correction method and communication system provided in this embodiment have the same implementation principle and technical effects as those of the aforementioned baseline drift correction circuit embodiment. For the sake of brief description, for matters not mentioned in the baseline drift correction method and communication system embodiment, reference may be made to the corresponding contents in the aforementioned baseline drift correction circuit embodiment.

[0093] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0094] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0095] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A baseline drift correction circuit, characterized in that: Applicable to a communication system including a high-pass filter and a decision device; the baseline drift correction circuit includes: A data collector, wherein the input end of the data collector is respectively connected to the output end of the high-pass filter and the output end of the decision device; the data collector is used to obtain a desired compensation signal according to the decision signal output by the decision device and the initial receiving signal output by the high-pass filter; An exponential fitter, the input end of which is connected to the output end of the data collector; the exponential fitter is used to perform exponential curve fitting on the desired compensation signal output by the data collector to obtain a signal gain value and a growth rate; A low-pass filter, wherein the input end of the low-pass filter is respectively connected to the output end of the exponential fitter and the output end of the decision device; the low-pass filter is used to determine a low-pass filter compensation signal according to the cutoff frequency corresponding to the growth rate and the decision signal output by the decision device; A multiplier, the multiplier being connected to an output end of the exponential fitter and an output end of the low-pass filter respectively; the multiplier being used to determine a target compensation signal according to the signal gain value and the low-pass filter compensation signal; A compensator, wherein the input end of the compensator is respectively connected to the output end of the multiplier and the output end of the high-pass filter, and the output end of the compensator is connected to the input end of the decision device; the compensator is used to use the target compensation signal to perform baseline drift compensation on the initial received signal output by the high-pass filter, and output the target received signal to the decision device for symbol decision.

2. The baseline drift correction circuit according to claim 1, characterized in that: The data collector includes a subtractor, and the subtractor is used to perform a subtraction operation on the decision signal and the initial received signal to obtain the expected compensation signal.

3. The baseline drift correction circuit according to claim 1, characterized in that: The exponential fitter is specifically used to: obtain an input data sequence consisting of expected compensation signals of multiple sampling points at uniform time intervals; calculate the signal gain value and the growth rate based on the logarithm of the target data sequence and a preset linear regression matrix; wherein the target data sequence is the input data sequence or a denoised data sequence obtained by denoising the input data sequence.

4. The baseline drift correction circuit according to claim 3, characterized in that: The exponential fitter is also used to solve: , and the first parameter value and the second parameter value obtained by solving are respectively used as the signal gain value and the growth rate; wherein, X represents the linear regression matrix, , ones ( length ( t ),1) indicates the number of rows is t A matrix with a length of , a column number of 1, and all elements are 1, t Indicates the time interval is sp of N The time vector composed of sampling points, t’ express t The transpose of X’ express X The transpose of Z’ Represents the transpose of the logarithm of the target data sequence.

5. The baseline drift correction circuit according to claim 1, characterized in that: The low-pass filter is specifically used to: Substitute the growth rate into the formula , solve to get the cut-off frequency; calculate the time constant according to the cut-off frequency; substitute the time constant into the formula , calculate and obtain bilinear transformation parameters; determine the low-pass filter compensation signal according to the bilinear transformation parameters, the decision signal at the current moment, the decision signal at the previous moment, and the order and type of the low-pass filter; wherein, fc represents the cut-off frequency, k represents the growth rate, F Indicates the preset sampling frequency, A represents the bilinear transformation parameters, RC _ lf represents the time constant.

6. The baseline drift correction circuit according to claim 5, characterized in that: The low-pass filter is a first-order infinite impulse response filter; the expression of the low-pass filter compensation signal is as follows: ； ； ； ； in, LPF [ n ]express n The low-pass filter compensation signal at the moment, LPF [ n -1] indicates n Low-pass filter compensation signal at time -1, D [ n ]express n The judgment signal of the moment, D [ n -1] indicates n -1 decision signal at time.

7. The baseline drift correction circuit according to claim 1, characterized in that: The multiplier is specifically used to: The target compensation signal is calculated; wherein, BLW [ n ]express n The target compensation signal at the moment, g represents the signal gain value, LPF [ n ]express n The low-pass filtered compensation signal at the moment.

8. The baseline drift correction circuit according to claim 1, characterized in that: The compensator is specifically used to: The target received signal is calculated; wherein, y [ n ]express n The target receives the signal at the moment, HF [ n ]express n The initial received signal at time BLW [ n ]express n The target compensation signal at that moment.

9. A baseline drift correction method, characterized in that: A baseline drift correction circuit applied to any one of claims 1 to 8; the baseline drift correction method comprising: Acquire a desired compensation signal according to a decision signal output by the decider and an initial received signal output by the high-pass filter; Performing exponential curve fitting on the expected compensation signal to obtain a signal gain value and a growth rate; Determining a low-pass filtering compensation signal according to a cutoff frequency corresponding to the growth rate and a decision signal output by the decision device; Determining a target compensation signal according to the signal gain value and the low-pass filtering compensation signal; The target compensation signal is used to perform baseline drift compensation on the initial received signal, and the target received signal is output to the decision device for symbol decision.

10. A communication system, characterized in that: It comprises a high-pass filter, a decision device and a baseline drift correction circuit according to any one of claims 1 to 8, wherein the baseline drift correction circuit is connected to the high-pass filter and the decision device respectively.

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