An adaptive equalization method and device, and SerDes equipment

Abstract

The present invention provides an adaptive equalization method and device, and a SerDes device, including: receiving an input signal with a predicted frequency characteristic, and equalizing the input signal through an equalizer; obtaining frequency information of the equalized input signal; adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristic of the input signal, until obtaining the target configuration parameters that make the frequency information of the equalized input signal consistent with the known frequency characteristic. The present invention evaluates the data equalization of the receiving end based on the frequency domain and adjusts the equalizer accordingly, does not rely on the clock recovery circuit, and can achieve fast and accurate adaptive equalization.

Description

Technical Field

[0001] The present invention relates to the field of data transmission, and in particular to an adaptive equalization method and device, and a SerDes device. Background Art

[0002] Serializer / Deserializer (SerDes) is one of the mainstream technologies for high-speed serial data communication. It is widely used in Ethernet, fiber-optic communication and other fields due to its low cost, high speed and strong anti-interference ability. In order to achieve high-speed data transmission, it is usually necessary to add an equalization mechanism to the SerDes product to offset the influence of channel attenuation between the transmitter and the receiver. This function is usually implemented by the receiver, and the continuous time linear equalization (CTLE) is a commonly used equalization method.

[0003] like Figure 4 In the system shown, the ideal CTLE completely balances the influence of the channel, and obtains a flat frequency response curve and sufficient bandwidth at the output of the CTLE, so that the data sent by the transmitter can be correctly received at the output of the CTLE.

[0004] Patent 201621091015.4 "Circuit for enabling equalization circuit to adapt" provides a variety of improved CTLE adaptive equalization circuits, all of which measure the equalization effect of CTLE by evaluating inter-symbol interference (ISI) based on the time domain.

[0005] This time domain-based evaluation method is very dependent on the normal operation of clock recovery. However, clock recovery has a slow response speed, high equalization requirements and strong uncertainty in the entire SerDes. That is, the clock recovery module needs the CTLE to equalize the signal to a better state and wait for a long time before it can work properly. This leads to slow CTLE adaptation. If the initial configuration of the CTLE deviates too much from the channel response, the clock recovery will not work properly, and the CTLE adaptation cannot continue, forming a deadlock.

[0006] In today's high-speed SerDes protocol, four-level pulse amplitude modulation PAM4 is the mainstream encoding scheme. PAM4 uses four different levels to represent data. Compared with PAM2, the amplitude difference between adjacent levels is smaller. It requires that the overall frequency response after equalization is not more than 2.5dB under-equalized or over-equalized in the frequency range of interest, otherwise data of different levels will be confused and cause bit errors. Therefore, higher requirements are placed on the equalization capability of the receiving end.

[0007] Therefore, a new adaptive equalization method is needed that can quickly and accurately adjust the equalization capability of the equalizer according to the channel response. Summary of the invention

[0008] One of the purposes of the present invention is to overcome at least some of the deficiencies in the prior art and to provide an adaptive equalization method and apparatus, and a SerDes device.

[0009] The technical solution provided by the present invention is as follows:

[0010] An adaptive equalization method, comprising:

[0011] receiving an input signal having a predicted frequency characteristic and equalizing the input signal through an equalizer;

[0012] Obtaining frequency information of the equalized input signal;

[0013] The configuration parameters of the equalizer are adjusted according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained, and the target configuration parameters make the frequency information of the equalized input signal consistent with the known frequency characteristics.

[0014] In some embodiments, the input signal is a pseudo-random binary sequence PRBS signal.

[0015] In some embodiments, obtaining frequency information of the equalized input signal includes:

[0016] The analog-to-digital converter ADC is used to sample the equalized input signal, and the frequency information of the equalized input signal is obtained through fast Fourier transform FFT calculation.

[0017] In some embodiments, the frequency information of the equalized input signal is obtained through fast Fourier transform (FFT) calculation, including:

[0018] Extract data from the sampled data to perform fast Fourier transform (FFT) calculation;

[0019] The FFT result is low-pass filtered, and the frequency information after the low-pass filtering is used as the frequency information of the equalized input signal.

[0020] In some embodiments, adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained includes:

[0021] Divide the frequencies contained in the equalized input signal into a number of non-overlapping frequency bands, and calculate the relative strengths between the frequency bands based on the frequency information of the equalized input signal;

[0022] Adjusting the first configuration parameter of the equalizer according to the difference between the relative strengths of the various frequency bands and the relative strengths of the corresponding frequency bands in the known frequency characteristics, so that the difference is within an allowable error range;

[0023] calculating the total power of the signal output by the adjusted equalizer;

[0024] The second configuration parameter of the equalizer is adjusted according to the difference between the overall power and the preset range, so that the overall power is within the preset range.

[0025] In some embodiments, the configuration parameters of the equalizer include a first configuration parameter for adjusting low frequency gain / mid frequency gain / high frequency gain, and a second configuration parameter for adjusting the overall gain;

[0026] Adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained, including:

[0027] The frequency of the input signal is divided into non-overlapping high frequency band, medium frequency band and low frequency band, and the average power of the three frequency bands is obtained according to the frequency information of the equalized input signal;

[0028] Taking one of the three frequency bands as the reference frequency band, the difference in average power of the other two frequency bands relative to the reference frequency band is calculated respectively;

[0029] Adjusting the first configuration parameter of the equalizer so that the difference between the average powers of the other two frequency bands and the reference frequency band meets the requirement of the difference between the average powers of the corresponding frequency bands in the known frequency characteristics;

[0030] calculating the total power of the signal output by the adjusted equalizer;

[0031] The second configuration parameter of the equalizer is adjusted so that the overall power is within a preset range.

[0032] In some embodiments, the ADC is sampled at 2 times the Nyquist frequency and uses a 4-point FFT.

[0033] The present invention also provides an adaptive equalization device, comprising:

[0034] an equalizer for receiving an input signal having a predicted frequency characteristic and equalizing the input signal;

[0035] A frequency domain information acquisition module, used to acquire frequency information of the equalized input signal;

[0036] The parameter adjustment module is used to adjust the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained, and the target configuration parameters make the frequency information of the equalized input signal consistent with the known frequency characteristics.

[0037] In some embodiments, the frequency domain information acquisition module is further used to sample the equalized input signal using an analog-to-digital converter ADC, and obtain the frequency information of the equalized input signal through fast Fourier transform FFT calculation.

[0038] The present invention further provides a SerDes device, comprising a receiving end, wherein the receiving end comprises the adaptive equalization device for a high-speed serial interface described in any of the aforementioned embodiments.

[0039] The adaptive equalization method, device, and SerDes device provided by the present invention can at least bring the following beneficial effects: the present invention evaluates the data equalization of the receiving end based on the frequency domain and adjusts the equalizer accordingly, excluding clock recovery from the adaptive equalization loop, thereby achieving fast and accurate adaptation of the equalization capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The following will explain the preferred implementation mode in a clear and understandable manner with reference to the accompanying drawings, and further explain the above-mentioned characteristics, technical features, advantages and implementation methods of an adaptive equalization method and apparatus, and a SerDes device.

[0041] Figure 1 is a flow chart of an embodiment of an adaptive equalization method for a high-speed serial interface of the present invention;

[0042] Figure 2 It is a structural schematic diagram of an embodiment of an adaptive equalization device for a high-speed serial interface of the present invention;

[0043] Figure 3 is a structural schematic diagram of an embodiment of a SerDes device of the present invention;

[0044] Figure 4 This is a schematic diagram of the principle of CTLE equalization in the SerDes system;

[0045] Figure 5 It is the frequency domain distribution diagram of 4-point FFT;

[0046] Figure 6 It is a flow chart of another embodiment of an adaptive equalization method for a high-speed serial interface of the present invention.

[0047] Description of Figure Numbers:

[0048] 210. Equalizer, 220. Frequency domain information acquisition module, 230. Parameter adjustment module, 10. Receiving end, 20. Adaptive equalization device. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0050] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0051] One embodiment of the present invention, as Figure 1 As shown, an adaptive equalization method for a high-speed serial interface, used in a SerDes device, includes:

[0052] Step S100: The transmitting end sends an input signal with a predicted frequency characteristic.

[0053] The receiving end performs the following processing:

[0054] Step S200: receiving an input signal with a predicted frequency characteristic;

[0055] Step S300: using an equalizer to equalize the received input signal;

[0056] Step S400: Obtaining frequency information of the equalized input signal;

[0057] Step S500: Adjust the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal, until the target configuration parameters are obtained so that the frequency information of the equalized input signal matches the known frequency characteristics.

[0058] Specifically, in this embodiment, the frequency information of a signal and the frequency characteristics of a signal have the same meaning, and refer to the frequency components contained in the signal and their relative strengths. It can be described by the frequency values ​​and amplitudes and phase values ​​of the contained frequency components, or by spectrum distribution, or by both.

[0059] First, the SerDes transmitter sends an input signal to the SerDes receiver. The input signal is an analog signal and must have a predictable frequency characteristic, such as a certain spectrum distribution or a certain frequency distribution.

[0060] The input signal can be a pseudo-random binary sequence PRBS (Pseudo-Random Binary Sequence) or encoded business data with frequency characteristics similar to those of PRBS data. For example, by scrambling the business data at the transmitter and then transmitting it, a spectrum similar to that of PRBS data can be obtained. Alternatively, an encoding method with frequency characteristics different from those of PRBS can be used, as long as the frequency characteristics of the encoded business data are certain and predictable.

[0061] The equalizer is used to equalize the received signal to compensate for the distortion and attenuation of the signal during transmission, and can adjust the compensation degree of specific frequencies of the signal according to the configuration parameters.

[0062] After receiving the input signal, the receiver obtains the equalized analog signal through the equalizer, and then obtains the frequency information of the equalized analog signal (the frequency domain information of the equalized analog signal can be obtained by ADC sampling the equalized analog signal and then discrete Fourier transform DFT or fast Fourier transform FFT). The frequency information must at least contain data of three frequency points: low frequency (LF), intermediate frequency (MF), and high frequency (HF), as well as the overall power (H TOTAL ). The low frequency point refers to the 0Hz frequency point, the medium frequency point refers to the 1 / 2 Nyquist frequency point, and the high frequency point refers to the Nyquist frequency point. The Nyquist frequency is the maximum frequency carried by the input signal. In the field of Serdes, half of the baud rate is generally called the Nyquist frequency. This is because when the transmitter uses the baud rate to transmit data, the maximum frequency it can carry is half of the baud rate. According to the Nyquist sampling principle, lossless sampling can be achieved by sampling at least twice the Nyquist frequency.

[0063] Since the input signal sent by the transmitter has specific frequency characteristics, their frequency characteristics are used as the target of the frequency response of the equalizer output end. The frequency response of the equalizer is adjusted by adjusting the configuration parameters of the equalizer so that the frequency information of the equalized input signal is aligned with the target, thereby obtaining the target configuration parameters.

[0064] The frequency information of the equalized input signal is consistent with the known frequency characteristics, which means that the relative strengths of the frequency components contained in the frequency information of the equalized input signal are the same as the corresponding relative strengths in the known frequency characteristics or are within the allowable error range, and the overall power of the equalized input signal is within a preset range, such as not less than a first threshold. The relative strengths of the frequency components can be measured by the difference in amplitude or power in dB.

[0065] In one embodiment, the configuration parameters of the equalizer include a first configuration parameter and a second configuration parameter. In order to reduce the complexity of parameter adjustment, the frequencies contained in the input signal are divided into a number of non-overlapping frequency bands, and the relative strengths between the frequency bands are calculated. The first configuration parameter of the equalizer is adjusted according to the difference between the relative strengths between the frequency bands in the equalized input signal and the relative strengths of the corresponding frequency bands in the known frequency characteristics, so that the relative strengths between the frequency bands are the same as the known frequency characteristics or within the allowable error range. The relative strengths between the frequency bands can be measured by the difference in average amplitude / power of the two frequency bands in dB. On this basis, the overall power of the signal output by the adjusted equalizer is calculated, and the second configuration parameter of the equalizer is adjusted according to the difference between the second configuration parameter and the preset range. The overall gain is increased by adjusting the second configuration parameter, and all frequency components are amplified at the same time, so that the overall power meets the requirements.

[0066] The equalizer includes a continuous time linear equalizer (CTLE), which adjusts the frequency response to combat signal attenuation and noise in transmission.

[0067] Taking the equalizer CTLE as an example, assuming that the CTLE has independent low-frequency gain adjustment, intermediate-frequency gain adjustment, and overall gain adjustment capabilities, there are two sets of configuration parameters, namely, the first configuration parameter is used to adjust the gain of a single frequency band, and the second configuration parameter is used to adjust the overall gain. Taking the input signal as a PRBS signal as an example, the PBRS data has the following known frequency characteristics:

[0068] ;

[0069] ;

[0070] in, , , They are the average power of the low frequency band LFB, the mid-frequency band MFB, and the high frequency band HFB. That is, in the spectrum of PRBS, the average power of the mid-frequency band is 2.5dB higher than the average power of the high frequency band, and the average power of the low frequency band is 4dB higher than the average power of the high frequency band. The bandwidth of the high, mid, and low frequency bands is the same. The low frequency band is centered on the low frequency point LF, the mid frequency band is centered on the mid frequency point MF, and the high frequency band is centered on the high frequency point HF.

[0071] The frequency of the input signal is also divided into three segments: high, medium and low. The low frequency segment is centered on the low frequency point LF, the medium frequency segment is centered on the medium frequency point MF, and the high frequency segment is centered on the high frequency point HF. The frequency information of the equalized input signal is obtained, and the average power of the high, medium and low frequency bands of the corresponding input signal is obtained according to the frequency information of the equalized input signal.

[0072] The high frequency band is taken as the reference frequency band, and the average power differences of the other two frequency bands relative to the reference frequency band are calculated respectively. The first configuration parameter of the CTLE is adjusted according to the average power differences of the other two frequency bands relative to the reference frequency band, that is, the average power differences of the middle and low frequency bands relative to the high frequency band are made to meet the requirements of the average power difference of the corresponding frequency bands in the known frequency characteristics through low frequency gain adjustment and middle frequency gain adjustment, as described in the above-mentioned equations (1) and (2).

[0073] Then calculate the total power of the signal output by the adjusted CTLE ,according to The difference between the threshold and the second configuration parameter of the CTLE is adjusted, that is, the overall gain is adjusted to make the overall power reach a suitable position, so that a set of target configuration parameters that make the CTLE output amplitude suitable and well balanced can be obtained.

[0074] The above examples can also be modified. For example, the equalizer has independent low-frequency gain and high-frequency gain adjustment capabilities, or has independent intermediate-frequency gain and high-frequency gain adjustment capabilities. Similar operations can also be used to first adjust the relative strength between each frequency band, and then adjust the overall power, so as to find the target configuration parameters of the equalizer.

[0075] This embodiment evaluates the data equalization of the receiving end based on the frequency domain and adjusts the equalizer accordingly. It does not rely on the clock recovery circuit and excludes the clock recovery circuit from the adaptive equalization loop, thereby achieving fast and accurate equalization capability adaptation of the equalizer, improving the loop speed, being insensitive to the initial configuration of the equalizer, and reducing the startup time of the receiving end.

[0076] In one embodiment, step S400 includes:

[0077] The analog-to-digital converter ADC is used to sample the equalized input signal, and the frequency information of the equalized input signal is obtained through fast Fourier transform FFT calculation.

[0078] Specifically, the amplitude and phase of a specific frequency component in the input signal can be obtained through FFT, and the corresponding power can be further obtained.

[0079] In one embodiment, the ADC is sampled at 2 times the Nyquist frequency and uses a 4-point FFT.

[0080] Taking a 4-point FFT as an example, the FFT output results include the DC component X[0], X[1] (amplitude and phase at 1 / 2 Nyquist frequency), X[2] (amplitude and phase at Nyquist frequency), and X[3] (amplitude and phase at -1 / 2 Nyquist frequency).

[0081] Assuming the baud rate is 56Gsps, the frequencies corresponding to the 4-point FFT results are 0, 14GHz, 28GHz, and -14GHz, respectively. Figure 5 As shown, fs is the sampling rate, which is equal to 56GHz; 1 / 2*fs is the Nyquist frequency point, which is equal to 28GHz; the entire signal frequency domain can be divided into the following three frequency bands: BIN#0 represents the low frequency band LFB (-7GHz~7GHz), BIN#1 represents the mid-frequency band MFB (7GHz~21GHz), and BIN#2 represents the high frequency band HFB (21GHz~35GHz). Considering that the bandwidth of each frequency band is the same, the power at the center of each frequency band can be approximated as the average power of the corresponding frequency band.

[0082] 4-point FFT requires less data, which can reduce resource consumption and hardware costs. However, since the number of samples used by 4-point FFT is small, the FFT result may fluctuate greatly due to the specific value of the sample and has greater randomness. Therefore, it is recommended to perform low-pass filtering on the FFT result when using 4-point FFT to smooth the spectrum and obtain a more stable and representative spectrum estimate.

[0083] The ADC can also use a sampling rate higher than 2 times the Nyquist frequency and use a high-point FFT for spectrum estimation. In this way, accurate frequency information can be obtained without low-pass filtering the FFT result.

[0084] In one embodiment, step S400 includes:

[0085] An analog-to-digital converter ADC is used to sample the equalized input signal, and data is extracted from the sampled data for fast Fourier transform FFT calculation; the FFT result is low-pass filtered, and the frequency information after the low-pass filtering is used as the frequency information of the equalized input signal.

[0086] One embodiment of the present invention, as Figure 2 As shown, an adaptive equalization device 20 includes:

[0087] An equalizer 210, for receiving an input signal having a predicted frequency characteristic and equalizing the input signal;

[0088] The frequency domain information acquisition module 220 is used to acquire the frequency information of the equalized input signal;

[0089] The parameter adjustment module 230 is used to adjust the configuration parameters of the equalizer according to the difference between the frequency information of the input signal after equalization and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained. The target configuration parameters are configuration parameters that make the frequency information of the input signal after equalization match the known frequency characteristics.

[0090] The frequency information of the equalized input signal includes at least data of three frequency points: low frequency, medium frequency, and high frequency, and includes the overall power. The low frequency refers to the 0 Hz frequency point, the medium frequency refers to the 1 / 2 Nyquist frequency point, and the high frequency refers to the Nyquist frequency point.

[0091] In one embodiment, the input signal is a pseudo-random binary sequence PRBS signal.

[0092] In one embodiment, the parameter adjustment module is also used to divide the frequencies contained in the equalized input signal into a number of non-overlapping frequency bands, and calculate the relative strength between each frequency band based on the frequency information of the equalized input signal; adjust the first configuration parameter of the equalizer based on the difference between the relative strength between each frequency band and the relative strength of the corresponding frequency band in the known frequency characteristics, so that the difference is within the allowable error range; calculate the overall power of the signal output by the adjusted equalizer; and adjust the second configuration parameter of the equalizer based on the difference between the overall power and the preset range, so that the overall power is within the preset range.

[0093] In one embodiment, the equalizer includes a continuous time linear equalizer CTLE, and the configuration parameters of the CTLE include a first configuration parameter for adjusting low frequency gain / middle frequency gain / high frequency gain, and a second configuration parameter for adjusting the overall gain.

[0094] The parameter adjustment module is also used to divide the frequency of the input signal into non-overlapping high frequency band, medium frequency band and low frequency band, and obtain the average power of the three frequency bands according to the frequency information of the equalized input signal; take one of the three frequency bands as the reference frequency band, and calculate the difference in average power of the other two frequency bands relative to the reference frequency band; adjust the first configuration parameter of the CTLE so that the difference in average power of the other two frequency bands relative to the reference frequency band meets the requirement of the difference in average power of the corresponding frequency band in the known frequency characteristics; calculate the overall power of the signal output by the adjusted CTLE; adjust the second configuration parameter of the CTLE so that the overall power is within a preset range.

[0095] In one embodiment, the frequency domain information acquisition module is further used to sample the equalized input signal using an analog-to-digital converter ADC, and obtain the frequency information of the equalized input signal through fast Fourier transform FFT calculation.

[0096] In one embodiment, the frequency domain information acquisition module is also used to sample the equalized input signal using an analog-to-digital converter ADC, extract data from the sampled data for fast Fourier transform FFT calculation; low-pass filter the FFT result, and use the frequency information after the low-pass filter as the frequency information of the equalized input signal.

[0097] In one embodiment, the ADC is sampled at 2 times the Nyquist frequency and uses a 4-point FFT.

[0098] It should be noted that the embodiment of the adaptive equalization device provided by the present invention and the embodiment of the adaptive equalization method provided above are based on the same inventive concept and can achieve the same technical effect. Therefore, other specific contents of the embodiment of the adaptive equalization device can refer to the contents of the embodiment of the adaptive equalization method provided above.

[0099] One embodiment of the present invention, as Figure 3 As shown, a SerDes device includes a receiving end 10, and the receiving end 10 includes an adaptive equalization device 20 for a high-speed serial interface according to any of the aforementioned embodiments.

[0100] The SerDes device may also include a transmitter that sends an input signal having a predetermined frequency characteristic.

[0101] The adaptive equalization device 20 of the receiving end 10 receives an input signal, uses an equalizer to equalize the input signal, and adaptively adjusts the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics, until the target configuration parameters are obtained so that the frequency information of the equalized input signal matches the known frequency characteristics.

[0102] The present invention also provides a specific implementation scenario example, in which the adaptive equalization method and device provided by the present application are applied to an actual SerDes system, such as Figure 6 As shown, the transmitter represents a device that sends data remotely, the channel represents all the connection parts connecting the transmitter to the receiver, and the receiver represents a device that receives the data sent by the transmitter and processes the received data.

[0103] The receiving end includes CTLE, ADC and digital signal processor DSP, which completes the FFT function. FFT, low-pass filtering, result judgment and configuration adjustment together constitute the frequency domain equalization result judgment part.

[0104] Sample holders, drivers, etc. can also be included between CTLE and ADC. CTLE and ADC are also used in normal business data paths, and they are integrated on-chip. Since the input and output data volume of FFT is large, the FFT part is also integrated on-chip. The running speed of low-pass filtering, result judgment, configuration adjustment and other functions is slow, and they can be implemented by DSP, integrated on-chip, or implemented off-chip.

[0105] The following steps are used to implement adaptive equalization at the receiving end:

[0106] 1. The transmitter sends automatically generated PRBS data or actual service data to the receiver. The SerDes protocol requires the transmitter to scramble the service data to meet the randomness requirement. Therefore, it can be considered that the encoded actual service data has a similar spectrum to the PRBS data.

[0107] 2. The receiving end receives data, obtains an analog signal after equalization through CTLE, and then obtains a storable digital signal through ADC. The digital signal obtains its frequency information through FFT operation. The frequency information contains at least data of three frequency points: low frequency, medium frequency, and high frequency, as well as the overall power. The low frequency refers to the 0Hz frequency point, the medium frequency refers to the 1 / 2 Nyquist frequency point, and the high frequency refers to the Nyquist frequency point. The Nyquist frequency is equal to half of the baud rate of the transmitting end.

[0108] The ADC sampling is performed at 2 times the Nyquist frequency, and the necessary frequency information is obtained through a 4-point FFT. The ADC sampling clock is equal to the transmitter baud rate, but does not need to be strictly synchronized with the transmitter clock.

[0109] 3. Perform low-pass filtering on the FFT results to eliminate the effects of local randomness.

[0110] 4. Compare the frequency response obtained after low-pass filtering with the target frequency response to obtain the equalization conditions of different frequency bands, so as to adjust the equalization capability of the CTLE accordingly and achieve an accurate CTLE equalization configuration.

[0111] Before the overall data channel is not working, a PRBS signal can be sent at the transmitter, and the target configuration parameters of the CTLE can be obtained through the above steps to complete the adaptive convergence of the CTLE. The configuration parameters of the CTLE can also be adaptively adjusted based on the actual scrambled service data after the overall transmitter is normal or the entire data channel is basically normal.

[0112] The adaptive equalization scheme provided in this embodiment can be implemented before the overall data path is not working, and can also be implemented while the overall data path is working. It does not rely on clock recovery, nor does it rely on correct data reception. It has good stability and can converge to the target value under any starting point and channel conditions.

[0113] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. An adaptive equalization method for a high-speed serial interface, characterized in that: include: receiving an input signal having a predicted frequency characteristic and equalizing the input signal through an equalizer; The analog-to-digital converter ADC is used to sample the equalized input signal, and the frequency information of the equalized input signal is obtained through fast Fourier transform FFT calculation; the frequency information is the frequency components contained in the signal and their relative strengths; adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until obtaining the target configuration parameters of the equalizer, wherein the target configuration parameters make the frequency information of the equalized input signal consistent with the known frequency characteristics; The step of adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal includes: Dividing the frequencies contained in the equalized input signal into a plurality of non-overlapping frequency bands, and calculating the relative strengths between the frequency bands according to the frequency information of the equalized input signal; adjusting the first configuration parameter of the equalizer according to the difference between the relative strengths of the various frequency bands and the relative strengths of the corresponding frequency bands in the known frequency characteristics, so that the difference is within an allowable error range; Calculating the overall power of the signal output by the equalizer after adjustment; The second configuration parameter of the equalizer is adjusted according to the difference between the overall power and the preset range, so that the overall power is within the preset range.

2. The adaptive equalization method for a high-speed serial interface according to claim 1, characterized in that: The input signal is a pseudo-random binary sequence PRBS signal.

3. The adaptive equalization method for a high-speed serial interface according to claim 1, characterized in that: The frequency information of the equalized input signal is obtained by fast Fourier transform (FFT) calculation, including: Extract data from the sampled data to perform fast Fourier transform (FFT) calculation; The FFT result is low-pass filtered, and the frequency information after the low-pass filtering is used as the frequency information of the equalized input signal.

4. The adaptive equalization method for a high-speed serial interface according to claim 1, characterized in that: The configuration parameters of the equalizer include a first configuration parameter for adjusting low-frequency gain / intermediate-frequency gain / high-frequency gain, and a second configuration parameter for adjusting the overall gain; Adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal until the target configuration parameters of the equalizer are obtained, including: Dividing the frequency of the input signal into non-overlapping high frequency band, medium frequency band and low frequency band, and obtaining average power of the three frequency bands according to the frequency information of the equalized input signal; Taking one of the three frequency bands as a reference frequency band, respectively calculating the difference in average power of the other two frequency bands relative to the reference frequency band; Adjusting the first configuration parameter of the equalizer so that the difference between the average powers of the other two frequency bands and the reference frequency band meets the requirement of the difference between the average powers of the corresponding frequency bands in the known frequency characteristics; Calculating the overall power of the signal output by the equalizer after adjustment; A second configuration parameter of the equalizer is adjusted so that the overall power is within a preset range.

5. The adaptive equalization method for high-speed serial interface according to claim 1, characterized in that: The ADC adopts 2 times Nyquist frequency sampling and 4-point FFT.

6. An adaptive equalization device for a high-speed serial interface, characterized in that: include: an equalizer, for receiving an input signal having a predicted frequency characteristic and equalizing the input signal; The frequency domain information acquisition module is used to sample the equalized input signal using an analog-to-digital converter (ADC) and obtain the frequency information of the equalized input signal through fast Fourier transform (FFT) calculation; the frequency information is the frequency components contained in the signal and their relative strengths; A parameter adjustment module, configured to adjust the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal, until a target configuration parameter of the equalizer is obtained, wherein the target configuration parameter makes the frequency information of the equalized input signal consistent with the known frequency characteristics; wherein adjusting the configuration parameters of the equalizer according to the difference between the frequency information of the equalized input signal and the known frequency characteristics of the input signal comprises: Dividing the frequencies contained in the equalized input signal into a plurality of non-overlapping frequency bands, and calculating the relative strengths between the frequency bands according to the frequency information of the equalized input signal; adjusting the first configuration parameter of the equalizer according to the difference between the relative strengths of the various frequency bands and the relative strengths of the corresponding frequency bands in the known frequency characteristics, so that the difference is within an allowable error range; Calculating the overall power of the signal output by the equalizer after adjustment; The second configuration parameter of the equalizer is adjusted according to the difference between the overall power and the preset range, so that the overall power is within the preset range.

7. A SerDes device, comprising a receiving end, characterized in that: The receiving end includes the adaptive equalization device for high-speed serial interface according to claim 6.

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