CN115801137A

CN115801137A - Signal processing method and system of optical communication receiving end

Info

Publication number: CN115801137A
Application number: CN202211309090.3A
Authority: CN
Inventors: 程宁
Original assignee: Innolight Technology Suzhou Ltd
Current assignee: Innolight Technology Suzhou Ltd
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2023-03-14

Abstract

The disclosure relates to a signal processing method and system for an optical communication receiving end. The method comprises the following steps: receiving an optical signal and converting the optical signal into an electrical signal; carrying out high-pass filtering on the electric signal to obtain a first processed signal; filtering the first processed signal by using a self-adaptive filter to obtain a second processed signal; and acquiring a difference value between the electric signal and the first processing signal, and adjusting the parameter setting of the adaptive filter according to the difference value so as to change the filtering characteristic of the adaptive filter. By adopting the method, the noise of the transmitted signal can be effectively filtered, and the quality of signal transmission is improved.

Description

Signal processing method and system of optical communication receiving end

Technical Field

The present disclosure relates to the field of data transmission technologies, and in particular, to a signal processing method and system for an optical communication receiving end.

Background

With the increasing transmission rate of data centers, pulse amplitude modulation has been widely used in short-distance optical interconnects and optical transmission systems. However, in an actual transmission system, a light emitting end, a light receiving end and an optical fiber connector all cause reflection, an optical signal passes through a plurality of reflecting end faces in a transmission process to cause a multipath interference effect, and a pulse amplitude modulation signal is more easily influenced by the multipath interference effect.

In order to reduce the influence of MPI, the return loss of the connectors in the optical module and the optical fiber link can be strictly limited, but in an actual optical fiber link that has been laid, because there are many connectors and the return loss of the connectors is difficult to control below an ideal value, noise generated by multipath interference effect can bring a large optical power cost to signal transmission.

Disclosure of Invention

Accordingly, in order to solve the above technical problems, it is necessary to provide a signal processing method and system for an optical communication receiving end, which can effectively filter the influence of noise and improve the signal transmission quality.

In a first aspect, an embodiment of the present disclosure provides a signal processing method at an optical communication receiving end. The method comprises the following steps:

receiving an optical signal and converting the optical signal into an electrical signal;

carrying out high-pass filtering on the electric signal to obtain a first processed signal;

filtering the first processed signal by using a self-adaptive filter to obtain a second processed signal;

and acquiring a difference value between the electric signal and the first processing signal, and adjusting the parameter setting of the adaptive filter according to the difference value so as to change the filtering characteristic of the adaptive filter.

In one embodiment, obtaining a difference between the electrical signal and the first processed signal, and adjusting a parameter setting of the adaptive filter according to the difference to change a filtering characteristic of the adaptive filter includes:

obtaining a difference value between the electric signal and the first processing signal;

and adjusting the parameter setting of the adaptive filter according to the difference value so as to change the filtering characteristic of the adaptive filter and obtain an adjusted adaptive filter, wherein the adjusted adaptive filter is used for filtering the next first processing signal.

In one embodiment, the adjusting the parameter setting of the adaptive filter according to the difference value to change the filtering characteristic of the adaptive filter includes:

determining a target parameter matched with the difference value based on the incidence relation between the difference value and the parameter of the adaptive filter;

and adjusting the parameter setting of the adaptive filter according to the target parameter so as to change the filtering characteristic of the adaptive filter.

In one embodiment, the determining, based on the correlation between the difference and the parameter of the adaptive filter, the target parameter that matches the difference includes:

acquiring a third processing signal, wherein the third processing signal is obtained by filtering the electric signal by using a low-pass filter, and the third processing signal and the received optical power are in a positive correlation;

determining a normalized processing signal matched with the electric signal according to the difference value and the third processing signal;

and determining target parameters matched with the normalized processing signal based on the incidence relation between the normalized processing signal and the parameters of the adaptive filter.

In one embodiment, the adaptive filter includes a digital adaptive filter, and the filtering the first processed signal with the adaptive filter to obtain a second processed signal includes:

performing analog-to-digital conversion processing on the first processing signal to obtain a first digital processing signal;

and filtering the first digital processing signal by adopting a self-adaptive filter to obtain a second processing signal.

In one embodiment, the optical signal is obtained by performing dc balanced encoding and modulation on an original optical signal.

In one embodiment, after obtaining the second processed signal, the method further includes:

and performing signal recovery processing on the second processed signal to obtain a recovered signal.

In one embodiment, the receiving the optical signal and converting the optical signal into an electrical signal includes:

acquiring an optical signal sent by a signal source;

and performing photoelectric conversion on the optical signal to obtain a converted signal, and amplifying the converted signal to obtain an electric signal.

In one embodiment, the parameters of the adaptive filter include the number of taps, and the adjusting the parameter setting of the adaptive filter according to the difference value to change the filtering characteristic of the adaptive filter includes:

determining a target tap number corresponding to the difference value based on the incidence relation between the difference value and the tap number of the adaptive filter;

and adjusting the tap number of the adaptive filter according to the target tap number so as to change the filtering characteristic of the adaptive filter.

In a second aspect, the embodiment of the present disclosure further provides a signal processing apparatus at an optical communication receiving end. The device comprises:

the receiving module is used for receiving optical signals and converting the optical signals into electric signals;

the first filtering module is used for carrying out high-pass filtering on the electric signal to obtain a first processed signal;

the second filtering module is used for filtering the first processing signal by adopting a self-adaptive filter to obtain a second processing signal;

and the adjusting module is used for acquiring a difference value between the electric signal and the first processing signal and adjusting the parameter setting of the adaptive filter according to the difference value so as to change the filtering characteristic of the adaptive filter.

In one embodiment, the adjusting module includes:

an obtaining module, configured to obtain a difference between the electrical signal and the first processed signal;

and the first adjusting submodule is used for adjusting the parameter setting of the adaptive filter according to the difference value so as to change the filtering characteristic of the adaptive filter and obtain an adjusted adaptive filter, wherein the adjusted adaptive filter is used for carrying out filtering processing on the next first processing signal.

In one embodiment, the first adjusting sub-module includes:

a first determining module, configured to determine a target parameter matched with the difference value based on an association relationship between the difference value and a parameter of an adaptive filter;

and the adjusting unit is used for adjusting the parameter setting of the adaptive filter according to the target parameter so as to change the filtering characteristic of the adaptive filter.

In one embodiment, the adjusting unit includes:

the acquisition module is used for acquiring a third processing signal, wherein the third processing signal is obtained by filtering the electric signal by using a low-pass filter, and the third processing signal and the received optical power are in a positive correlation;

a second determining module, configured to determine, according to the difference and the third processed signal, a normalized processed signal matched with the electrical signal;

and the third determination module is used for determining the target parameter matched with the normalized processing signal based on the incidence relation between the normalized processing signal and the parameter of the adaptive filter.

In one embodiment, the adaptive filter includes a digital adaptive filter, and the second filtering module includes:

the conversion module is used for carrying out analog-to-digital conversion processing on the first processing signal to obtain a first digital processing signal;

and the filtering submodule is used for carrying out filtering processing on the first digital processing signal by utilizing the adjusted adaptive filter to obtain a second processing signal.

In one embodiment, the second filtering module is followed by:

and the recovery module is used for performing signal recovery processing on the second processed signal to obtain a recovered signal.

In one embodiment, the receiving module includes:

the acquisition submodule is used for acquiring an optical signal sent by a signal source;

and the amplifying module is used for performing photoelectric conversion on the optical signal to obtain a converted signal and amplifying the converted signal to obtain an electric signal.

In one embodiment, the parameters of the adaptive filter include a number of taps, and the adjusting module includes:

a fourth determining module, configured to determine, based on an association relationship between the difference and the number of taps of the adaptive filter, a target number of taps corresponding to the difference;

and the second adjusting submodule is used for adjusting the tap number of the adaptive filter according to the target tap number so as to change the filtering characteristic of the adaptive filter.

In a third aspect, an embodiment of the present disclosure further provides a signal processing system at an optical communication receiving end, where the system includes:

the photoelectric detector is used for receiving an optical signal and converting the optical signal into an electric signal;

the high-pass filter is used for carrying out high-pass filtering processing on the electric signal to obtain a first processed signal;

and the adaptive filter is used for performing filtering processing on the first processed signal to obtain a second processed signal, wherein the parameter of the adaptive filter is obtained by adjusting according to the difference between the electric signal received by the photoelectric detector and the corresponding first processed signal.

In one embodiment, the adaptive filter includes:

and the adaptive filter is used for performing filtering processing on the first processed signal to obtain a second processed signal, wherein the parameter of the adaptive filter is obtained by adjusting according to the difference value between the last electric signal and the corresponding first processed signal.

In one embodiment, the system further comprises:

the analog-to-digital converter is used for performing analog-to-digital conversion processing on the first processing signal to obtain a first digital processing signal;

the adaptive filter includes:

and the digital adaptive filter is used for performing filtering processing on the first digital processing signal to obtain a second processing signal, wherein the parameter of the adaptive filter is obtained by adjusting according to the difference value between the electric signal received by the photoelectric detector and the corresponding first processing signal.

In one embodiment, the system further comprises:

and the decoder is used for decoding the second processed signal to obtain a recovered signal.

In a fourth aspect, an embodiment of the present disclosure further provides a computer device. The computer device comprises a memory storing a computer program and a processor implementing the steps of the method according to any of the embodiments of the present disclosure when executing the computer program.

In a fifth aspect, the disclosed embodiments also provide a computer-readable storage medium. The computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method of any of the embodiments of the present disclosure.

In a sixth aspect, the disclosed embodiments also provide a computer program product. The computer program product comprising a computer program that when executed by a processor implements the steps of the method of any of the embodiments of the present disclosure.

According to the embodiment of the disclosure, a received optical signal is converted into an electrical signal, a first processed signal obtained by filtering the electrical signal through a high-pass filter is obtained, a parameter of an adaptive filter is adjusted according to a difference value between the electrical signal and the first processed signal to change a filtering characteristic of the filter, the adjusted adaptive filter is obtained, the first processed signal is processed through the adaptive filter to obtain a second processed signal, and the parameter of the adaptive filter is dynamically adjusted according to the received electrical signal. The signal processing method of the embodiment adjusts the parameters of the filter according to the difference of the signals received by the optical detector, is suitable for more scenes, improves the precision of noise filtering, reduces the optical power cost of signal transmission, and ensures the quality of signal transmission. Noise is filtered through the adaptive filter, real-time adjustment can be carried out according to different noises under different scenes of different signals, so that the noise can be better inhibited, intersymbol interference caused by optical fiber dispersion or insufficient bandwidth of the receiver can be dynamically compensated, and the error rate of the receiver is minimized. After the received electric signal is subjected to high-pass filtering, partial noise can be filtered, the convergence speed of the adaptive filter can be higher, and the error after convergence is smaller; and the high-pass filtering is carried out, and then the self-adaptive filtering is carried out, so that the complexity of the self-adaptive filter is reduced.

Drawings

Fig. 1 is a diagram illustrating an application environment of a signal processing method at an optical communication receiving end according to an embodiment;

fig. 2 is a schematic flowchart of a signal processing method at an optical communication receiving end according to an embodiment;

fig. 3 is a schematic flowchart of a signal processing method at an optical communication receiving end according to an embodiment;

fig. 4 is a schematic structural diagram of a signal processing system at an optical communication receiving end in one embodiment;

FIG. 5 is a graph of bit error rate for signal transmission in one embodiment;

fig. 6 is a block diagram of a signal processing apparatus at an optical communication receiving end according to an embodiment;

FIG. 7 is a diagram illustrating an internal structure of a computer device according to an embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more clearly understood, the embodiments of the present disclosure are described in further detail below with reference to the accompanying drawings and the embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the embodiments of the disclosure and that no limitation to the embodiments of the disclosure is intended.

The signal processing method of the optical communication receiving end provided by the embodiment of the present disclosure may be applied to an application environment as shown in fig. 1.

Referring to fig. 1, an optical signal is converted into a current after passing through a photodetector, and is converted into a voltage signal and amplified by a transimpedance amplifier. The amplified signal is subjected to high-pass filter filtering to remove partial noise, is converted into a digital signal through an analog-to-digital converter, is subjected to further adaptive filtering through an adaptive filter, and is subjected to clock recovery, judgment and decoding to obtain a recovered signal, so that signal transmission is realized.

In the embodiment of the present disclosure, as shown in fig. 2, a method for processing a signal at an optical communication receiving end is provided, where the method includes the following steps:

step S210, receiving an optical signal and converting the optical signal into an electrical signal;

in the process of signal transmission, the optical communication receiving end receives an optical signal and performs photoelectric conversion on the optical signal to obtain a converted electrical signal, wherein the optical signal can be converted into the electrical signal through the optical detector. The method described in this embodiment can be applied to an optical receiver.

In other embodiments, in step S210, the optical signal is obtained by performing dc balance coding and modulation on an original optical signal.

Specifically, the signal source performs dc balance coding on the original optical signal to obtain a coded original optical signal. The encoding method of the dc-balanced encoding includes, but is not limited to, 8B10B encoding, MB810 encoding, 5S/6S encoding, and 27S/32S encoding. And modulating the coded signal to obtain a modulated optical signal, transmitting the modulated optical signal to a receiver, and performing photoelectric conversion to obtain an electric signal.

In the embodiment, the original optical signal is subjected to direct-current balance coding modulation and then is transmitted to the optical communication receiving end, so that the energy of the transmitted optical signal in a low frequency band near zero frequency is very low, and the preliminary noise filtering effect of high-pass filtering is improved; and then the difference between the electric signal obtained by subsequent conversion and the first processing signal can more accurately reflect the noise in the received signal, such as MPI noise, so that the accuracy of target filtering frequency response is improved, and the noise filtering effect of the adjusted adaptive filter is further improved.

In other embodiments, the receiving the optical signal and converting the optical signal into an electrical signal in step S210 includes:

acquiring an optical signal sent by a signal source;

Specifically, the signal processing method of the optical communication receiving end in this embodiment may be applied to an application scenario of optical signal transmission. The signal sent by the signal source is an optical signal, the optical signal is processed by the photoelectric conversion unit to obtain a converted signal, and the converted signal is amplified by the amplifier to obtain an electric signal. In one example, photoelectric conversion is performed using a photodetector, and amplification of the converted signal is achieved using a transimpedance amplifier. Specifically, the optical detector may be used to convert the optical signal into a current signal, and the current signal is converted into a voltage signal by the transpodal amplifier and amplified. In this embodiment, after the second processed signal is obtained, signal recovery processing may be performed on the second processed signal, where the signal recovery processing includes converting an electrical signal into an optical signal.

The embodiment realizes the application in the scene of optical signal transmission by performing photoelectric conversion and amplification on the optical signal sent by the signal source, can process the transmitted signal by using the mode of the embodiment in the scenes such as optical fiber communication and the like, ensures the quality of signal transmission, and reduces the noise of the transmitted signal; through photoelectric conversion and amplification, the subsequent high-pass filtering effect and the accuracy of filtering frequency response adjustment are improved, the filtering effect of the self-adaptive filter is further ensured, the noise content of the processed signals is reduced, and the effective transmission of the signals is realized.

Step S220, performing high-pass filtering on the electric signal to obtain a first processed signal;

and carrying out high-pass filtering processing on the electric signal to obtain a processed first processed signal, wherein the high-pass filtering processing is realized through a high-pass filter. The high-pass filter corresponds to a preset cut-off frequency, the first processing signal includes performing high-pass filtering on the electric signal, and the obtained frequency is higher than the preset cut-off frequency, and the preset cut-off frequency of the high-pass filter can be adjusted according to an actual application scenario, for example, can be set to 20MHz. In some possible implementations, the kind of the high pass filter may include, but is not limited to, a digital high pass filter, an analog high pass filter, wherein the kind of the analog high pass filter may include, but is not limited to, a resistance-capacitance filter (RC filter), a 4 th order Bessel (Bessel) filter, and the like, which is not limited by the present disclosure.

Step S230a, performing filtering processing on the first processed signal by using an adaptive filter to obtain a second processed signal;

and after the first processing signal is obtained, transmitting the first processing signal to an adaptive filter, and performing filtering processing through the adaptive filter to obtain a second processed signal after processing, wherein the adaptive filter is a filter which changes parameters and a structure of the filter by using an adaptive algorithm according to the change of the environment. The filtering process may include high-pass filtering, band-pass filtering, and the like, which is not limited by the present disclosure. The adaptive filter dynamically adjusts the frequency response according to the received first processed signal, and different first processed signals may have different frequency responses. The method for adjusting the frequency response by the adaptive filter may include, but is not limited to, an LMS (least-mean square) algorithm or an RLS (least squares) algorithm, which is not limited in this disclosure. In this embodiment, the signal noise removed by filtering may include, but is not limited to, MPI noise.

In other embodiments, in step S230a, the adaptive filter includes a digital adaptive filter, and the performing a filtering process on the first processed signal by using the adaptive filter to obtain a second processed signal includes:

Specifically, when the adaptive filter is used for filtering, analog-to-digital conversion processing is performed on the first processed signal, and the first processed signal is converted from an analog signal to a digital signal to obtain a first digital processed signal. And performing filtering processing on the first digital processing signal by using an adaptive filter to obtain a second processing signal, wherein in the embodiment, the adaptive filter uses a digital adaptive filter.

In this embodiment, the digital adaptive filter performs filtering processing on the analog-to-digital converted first processed signal to obtain a second processed signal, and compared with the analog adaptive filter, the digital adaptive filter is adopted to reduce the structural complexity of the adaptive filter while ensuring a noise filtering effect, and the signal processing method of the optical communication receiving end of this embodiment can be applied to more scenes.

In other embodiments, in step S230a, after the step of obtaining the second processed signal, the method further includes:

Specifically, a second processed signal is obtained, and the second processed signal is subjected to signal recovery processing to obtain a recovered signal. In one example, the signal recovery process includes clock recovery, decision and signal decoding, where clock recovery refers to a method of recovering a clock component from a transmitted signal. After clock recovery, decision and signal decoding processing, the transmitted signal can be recovered.

In this embodiment, after the second processed signal is obtained, the second processed signal is restored to obtain a restored signal, so that transmission of the signal is achieved.

Step S230b, obtaining a difference between the electrical signal and the first processed signal, and adjusting a parameter setting of the adaptive filter according to the difference, so as to change a filtering characteristic of the adaptive filter.

After the first processing signal is obtained, the difference value between the electric signal and the first processing signal is also determined, and the parameter setting of the adaptive filter is adjusted according to the difference value, so that the filtering characteristic of the adaptive filter is changed. Because there is a corresponding relationship between the parameters of the adaptive filter and the filter characteristics, the filter characteristics will be correspondingly changed by adjusting the parameters, and the filter characteristics will affect the filtering effect of the filter, wherein the filter characteristics include the frequency response of the filter. The first processing signal is obtained after the electric signal is subjected to high-pass filtering processing, so that a difference value between the electric signal and the first processing signal can be determined, and a positive correlation exists between the difference value and noise in the optical signal received by the optical communication receiving end. It can be understood that the purpose of the adaptive filter is to filter noise, and since there is a correspondence between noise and difference, parameters of the adaptive filter can be adjusted according to the difference.

In the embodiment of the present disclosure, the adaptive filter category may include a digital adaptive filter, an analog adaptive filter, an adaptive filter with a desired signal input, a blind equalization adaptive filter with only one input signal, and the like, wherein the digital adaptive filter may include a linear adaptive filter, such as an FIR (finite impulse response) filter, an IIR (infinite impulse response) filter, and a nonlinear filter, such as a DFE (Decision-Feedback Equalizer), which is not limited by the present disclosure.

It is understood that step S230a and step S230b may be executed simultaneously, or may be executed according to a preset sequence, for example, a signal delay device is added before the adaptive filter, so that step S230b may be executed first, and then step S230a may be executed, that is, the parameters are adjusted first, and after the adjustment is completed, the adjusted adaptive filter is used to filter the first processed signal. The present disclosure is not so limited. In an actual application scenario, when the filtering process and the parameter adjusting process are performed synchronously, the adaptive filter in step S230a may include the adaptive filter before being adjusted in step S230b, and may include the adaptive filter after being adjusted in step S230 b. In the embodiment of the present disclosure, the filtering process and the parameter adjustment of the adaptive filter may be set to be a continuous dynamic process, that is, in the process of signal transmission, the adaptive filter performs the filtering process while performing the parameter adjustment according to the acquired first signal until the signal transmission is finished.

In other embodiments, in step S230b, obtaining a difference value between the electrical signal and the first processed signal, and adjusting a parameter setting of the adaptive filter according to the difference value to change a filtering characteristic of the adaptive filter includes:

Specifically, when adjusting the parameter setting of the adaptive filter, the difference between the electrical signal and the first processed signal is determined, and the parameter setting of the adaptive filter is adjusted according to the difference. There is a correlation between the parameter setting of the adaptive filter and the filter characteristic, so that the parameter of the adaptive filter changes and the filter characteristic of the adaptive filter changes correspondingly. And obtaining an adjusted adaptive filter after adjusting the parameters, and performing filtering processing on a next first processed signal by using the adjusted adaptive filter, wherein the next first processed signal may include a first processed signal corresponding to a received next optical signal, and may further include a subsequent processed signal output by the high-pass filter after the current first processed signal. It can be understood that, in this embodiment, the signal transmission process is continuous, the parameter adjustment of the adaptive filter is dynamic adjustment, and is a continuous process, the filtering process of the adaptive filter is also a continuous process, and the speed of signal transmission is faster than the adjustment speed of the adaptive filter, so that the parameter adjustment of the adaptive filter is used to perform the filtering process on the first processed signal. Because continuity exists among signals, the filtering processing is carried out while the parameters of the self-adaptive filter are dynamically adjusted, and the better filtering effect can be achieved while the filtering efficiency is ensured.

In another embodiment, as shown in fig. 3, in step S230b, the adjusting the parameter setting of the adaptive filter according to the difference value to change the filtering characteristic of the adaptive filter includes:

step S232, determining a target parameter matched with the difference value based on the incidence relation between the difference value and the parameter of the adaptive filter;

step S233, adjusting the parameter setting of the adaptive filter according to the target parameter to change the filtering characteristic of the adaptive filter.

Specifically, the adaptive filter functions to filter out noise, and there is a correlation between the difference value and the noise, so that the correlation between the difference value and the parameter of the adaptive filter can be determined. According to the incidence relation between the difference value and the parameters of the adaptive filter, the target parameters corresponding to the difference value can be determined and obtained. According to the target parameter, the adaptive filter is adjusted, and it can be understood that, in this embodiment, the filter characteristic of the adjusted adaptive filter enables the adaptive filter to have a better filtering effect on noise in the corresponding electrical signal. In general, different differences correspond to different parameters of the adaptive filter, and the correlation between the differences and the parameters of the adaptive filter may be determined in advance according to an actual application scenario. The parameters of the filter include filtering parameters that can affect the filtering effect of the filter, the filtering effects of the adaptive filters corresponding to different filtering parameters are usually different, and the parameters of the filter may include, but are not limited to, parameters such as the number of taps, tap coefficients, and step factors. In some possible implementations, the parameter of the filter is set to be the number of taps, and the correlation between the parameter of the filter and the difference may include a positive correlation, that is, the larger the difference is, the larger the number of taps is, wherein the difference is the difference between the electrical signal and the first processed signal. When the correlation between the difference value and the noise is set, the difference value is the difference value between the electric signal and the first processing signal, a preset coefficient can be set according to the actual application scene and the relation between the difference value and the noise, after the difference value is determined, a target parameter is directly obtained according to the difference value and the preset coefficient, for example, if the filter parameter is the tap number, the preset coefficient can be determined and obtained according to the order and the cut-off frequency of the high-pass filter.

According to the embodiment, the difference value of the electric signal and the first processing signal is obtained, the target parameter is determined according to the incidence relation between the difference value and the filter parameter, and the parameter of the adaptive filter is adjusted to be the target parameter, so that the filtering characteristic of the adjusted adaptive filter meets the requirement, the adjustment of the filtering characteristic of the adaptive filter according to the change of the electric signal is realized, the adjusted adaptive filter can effectively filter noise in the electric signal, the flexibility is high, the adaptive filter can be suitable for various scenes, the target parameter is determined according to the relation between the difference value and the parameter, the adjusting mode is simple and accurate, and the effectiveness of noise filtering is further ensured.

In other embodiments, in step S232, the determining, based on the correlation between the difference and the parameter of the adaptive filter, the target parameter matching the difference includes:

determining a normalized processing signal matched with the electric signal according to the difference and the third processing signal;

Specifically, when the target parameter is determined, the high-pass filter is used for performing high-pass filtering processing on the electric signal to obtain a first processed signal, and a difference value between the electric signal and the first processed signal is determined. Wherein the difference can be considered to have a positive correlation with the noise in the electrical signal. And performing low-pass filtering processing on the electric signal by using a low-pass filter to obtain a third processed signal, wherein the third processed signal has a positive correlation with the received optical power, and the received optical power can be determined according to the third processed signal. And determining a normalized processing signal according to the difference and the third processing signal, wherein the normalized processing signal has an association relation with the noise of the electric signal. In other possible implementations, the normalized processed signal may be determined according to a ratio of the difference to the third processed signal. In other possible implementation manners, a first coefficient may be set according to an association relationship between the difference and the noise, a second coefficient may be determined according to an association relationship between the third processed signal and the received optical power, a noise signal may be determined by using the difference and the first coefficient, a received optical signal may be determined by using the third processed signal and the second coefficient, and a normalized processed signal may be determined by using a ratio between the noise signal and the received optical signal. It is to be understood that, after determining the difference and the third processed signal, other possible implementations may also be utilized to obtain the normalized processed signal, which is not limited by the present disclosure. The normalized processing signal may include, but is not limited to, normalized noise power, a signal having a correspondence relationship with the noise power, and the like. And determining to obtain target parameters matched with the normalization processing signal according to the incidence relation between the normalization processing signal and the parameters of the adaptive filter. In other possible implementation manners, the incidence relation between the normalization processing signal and the parameter of the filter can be directly determined and obtained according to the actual application scene, and after the normalization processing signal is determined and obtained, the corresponding target filtering parameter is determined according to the preset incidence relation.

In the embodiment, the third processed signal is obtained through the low-pass filter, the normalized processed signal is determined by combining the difference value between the electric signal and the first processed signal, and then the parameter of the adaptive filter is determined according to the normalized processed signal.

In other embodiments, in step S230b, the adjusting the parameter setting of the adaptive filter according to the difference value to change the filtering characteristic of the adaptive filter includes:

Specifically, the parameters of the adaptive filter include the number of taps, and when the parameters of the adaptive filter are set, the adjustment of the number of taps of the filter is included. And determining the target tap number corresponding to the obtained difference value according to the incidence relation between the difference value and the tap number. The correlation between the difference between the electrical signal and the first processed signal and the noise exists, and the correlation between the tap number and the noise filtering effect of the adaptive filter exists, so that the correspondence between the difference and the tap number can be established according to the correlation, and different differences generally correspond to different tap numbers. And adjusting the adaptive filter according to the target tap number to obtain the adjusted adaptive filter, wherein the frequency characteristic of the adjusted adaptive filter has a corresponding relation with the electric signal. It will be appreciated that the frequency characteristic of the adaptive filter comprises the frequency response of the filter.

In the embodiment, the tap number of the adaptive filter is adjusted through the difference value between the electric signal and the first processing signal, so that the reasonability of the tap number of the adaptive filter is ensured while the frequency characteristic of the adjusted adaptive filter meets the requirement, and the problem of resource waste caused by too large tap number or the problem of poor filter performance caused by too small tap number is avoided.

In other embodiments, the parameter setting of the adaptive filter may also be directly adjusted according to the magnitude of the difference until the adjusted filtering characteristic meets a preset condition, where the preset condition may be obtained according to the actual application scenario setting.

According to the embodiment of the disclosure, a received optical signal is converted into an electrical signal, a first processed signal obtained by filtering the electrical signal through a high-pass filter is obtained, a parameter of an adaptive filter is adjusted according to a difference value between the electrical signal and the first processed signal to change a filtering characteristic of the filter, the adjusted adaptive filter is obtained, the first processed signal is processed through the adaptive filter to obtain a second processed signal, and the parameter of the adaptive filter is dynamically adjusted according to the received electrical signal. The signal processing method of the embodiment adjusts the parameters of the filter according to the difference of the signals received by the optical detector, is suitable for more scenes, improves the precision of noise filtering, reduces the optical power cost of signal transmission, and ensures the quality of signal transmission. Noise is filtered through the adaptive filter, real-time adjustment can be carried out according to different noises of different signals under different scenes, so that the noise can be better suppressed, intersymbol interference caused by optical fiber dispersion or insufficient bandwidth of the receiver can be dynamically compensated, and the error rate of the receiver is minimized. After the received electric signal is subjected to high-pass filtering, partial noise can be filtered, the convergence speed of the adaptive filter can be higher, and the error after convergence is smaller; and the high-pass filtering is carried out, and then the self-adaptive filtering is carried out, so that the complexity of the self-adaptive filter is reduced.

Fig. 4 is a block diagram illustrating a signal processing system according to an exemplary embodiment, and referring to fig. 4, an optical signal is converted into a current signal by a photodetector, and is converted into a voltage signal by a transimpedance amplifier and amplified. The amplified signal is filtered by an analog high-pass filter, then sent to an analog-to-digital converter to be converted into a digital signal, and filtered by a self-adaptive filter to obtain a filtered signal. And performing clock recovery, judgment and decoding on the filtered signal to obtain a recovered binary code stream, thereby realizing signal transmission. The adaptive filter corresponds to filtering parameters including the number of taps and tap coefficients, and if the number of taps is selected too large, the logic resources of the digital chip are wasted, which leads to increase of cost and power consumption, and if the number of taps is selected too small, the performance of the adaptive filter is reduced. In this embodiment, in the signal processing process, the tap number and the tap coefficient of the adaptive filter are dynamically adjusted. In one example, the tap coefficients may be adjusted by training historical data or by blind equalization, which is not limited by this disclosure. In the present embodiment, the number of taps is determined according to the magnitude of the noise of the signal (or may be determined according to the spectrum of the noise); since the difference between the input and output signals of the high-pass filter can approximately reflect the magnitude of noise (such as MPI noise) in this embodiment, the number of taps of the adaptive filter can be determined according to the difference and a preset coefficient. Wherein the preset coefficients are set in relation to the received optical power, high pass filter parameters, which may include, but are not limited to, filter order, filter cut-off frequency. When the received optical power is determined, low-pass filtering is carried out on the amplified signal through a low-pass filter, the obtained voltage value is in direct proportion to the received optical power, and the received optical power is determined according to the obtained voltage value; and carrying out high-pass filtering on the amplified signal through a high-pass filter, subtracting the power of the output signal from the power of the input signal to obtain a power difference value, wherein the power difference value is in direct proportion to the noise, and determining the noise power through a power meter. And determining the ratio of the noise power to the received optical power as normalized noise power. And determining to obtain the tap number according to the normalized noise power and a preset value, wherein the preset value is a more appropriate coefficient value determined according to an actual application scene, and the tap number can be determined in an integer mode.

FIG. 5 is a diagram according to an exampleReferring to fig. 5, the error rate graph of signal transmission shown in the exemplary embodiment shows that, under 25Gbaud/s rate PAM4 modulated optical transmission, there is a difference in error rates corresponding to different scenarios. In this embodiment, the MPI noise is set to-23 dB, and it can be seen that the MPI noise of-23 dB has a large influence on the error rate, and the error rate difference is several orders of magnitude compared to the noise-free error rate. The forward error correction code KP4FEC is usually adopted, and the error correction threshold is 2.4 × 10 ^-4 The noisy ber curve shown in the figure cannot reach the correction threshold of KP4FEC, i.e. when MPI noise is-23 dB, the normal receiver cannot achieve error-free transmission even with KP4 FEC. According to the bit error rate curve obtained by the receiver in the figure by adopting a high-pass filter, such as a simulated high-pass filter, including but not limited to a common RC filter, it can be seen that after the bandwidth of the high-pass filter is optimized, the bit error rate curve under noise is obviously improved, and compared with a common receiver, the bit error rate is reduced by two orders of magnitude under the condition of-12 dBm receiving optical power, but the bit error rate is still larger. Referring to the graph in the figure, it can be seen that after the adaptive filter is adopted, the frequency response of the receiver can be dynamically adjusted according to the noise magnitude and the frequency spectrum, and the bit error rate is lower compared with that of a common high-pass filter. After the direct current balance coding is combined, the error rate is further reduced. On the basis of direct current balance coding, a fixed analog filter is combined with a self-adaptive digital filter, so that a smaller bit error rate is realized.

According to the embodiment of the disclosure, by combining direct current balance coding, high-pass filtering and adaptive filtering, noise can be effectively filtered, the error rate is reduced, and the quality of signal transmission is improved.

It should be understood that, although the steps in the flowcharts of the figures are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not limited to being performed in the exact order illustrated and, unless explicitly stated herein, may be performed in other orders. Moreover, at least some of the steps in the figures may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed alternately or at least partially in sequence with other steps or other steps.

Based on the same inventive concept, the embodiment of the present disclosure further provides a signal processing apparatus for implementing the signal processing method of the optical communication receiving end. The implementation scheme for solving the problem provided by the apparatus is similar to the implementation scheme described in the above method, so specific limitations in the signal processing apparatus embodiments of one or more optical communication receiving ends provided below may refer to the above limitations on the signal processing method of the optical communication receiving end, and are not described herein again.

In one embodiment, as shown in fig. 6, there is provided a signal processing apparatus 600 at an optical communication receiving end, including:

a receiving module 610, configured to receive an optical signal and convert the optical signal into an electrical signal;

the first filtering module 620 is configured to perform high-pass filtering on the electrical signal to obtain a first processed signal;

a second filtering module 630, configured to perform filtering processing on the first processed signal by using an adaptive filter to obtain a second processed signal;

an adjusting module 640, configured to obtain a difference between the electrical signal and the first processed signal, and adjust a parameter setting of the adaptive filter according to the difference, so as to change a filtering characteristic of the adaptive filter.

In one embodiment, the adjustment module includes:

In one embodiment, the first adjusting submodule includes:

In one embodiment, the adjusting unit includes:

the acquisition module is used for acquiring a third processed signal, wherein the third processed signal is obtained by filtering the electric signal by using a low-pass filter, and the third processed signal and the received optical power are in a positive correlation relationship;

a second determining module, configured to determine a normalized processing signal matched with the electrical signal according to the difference and the third processing signal;

In one embodiment, the adaptive filter comprises a digital adaptive filter, and the second filtering module comprises:

and the filtering submodule is used for filtering the first digital processing signal by using the adjusted adaptive filter to obtain a second processing signal.

In one embodiment, the optical signal is obtained by performing dc balance coding on an original optical signal and modulating the original optical signal.

In one embodiment, the second filtering module is followed by:

In one embodiment, the receiving module includes:

In one embodiment, the parameters of the adaptive filter include a number of taps, and the adjustment module includes:

All or part of each module in the signal processing device of the optical communication receiving end can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent of a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, there is provided a signal processing system of an optical communication receiving end, the system including:

In one embodiment, the adaptive filter includes:

and the adaptive filter is used for carrying out filtering processing on the first processed signal to obtain a second processed signal, wherein the parameter of the adaptive filter is obtained by adjusting according to the difference value between the last electric signal and the corresponding first processed signal.

In one embodiment, the system further comprises:

the adaptive filter includes:

In one embodiment, the system further comprises:

In one embodiment, a computer device is provided, which may be a server, and the internal structure thereof may be as shown in fig. 7. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operating system and the computer program to run on the non-volatile storage medium. The database of the computer device is used for storing data such as optical signals, electric signals, first processed signals, second processed signals and the like. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a signal processing method of an optical communication receiving end.

It will be appreciated by those skilled in the art that the configuration shown in fig. 7 is a block diagram of only a portion of the configuration associated with the embodiments of the present disclosure, and does not constitute a limitation on the computing devices to which the embodiments of the present disclosure may be applied, and that a particular computing device may include more or less components than those shown in the drawings, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is further provided, which includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method embodiments when executing the computer program.

In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

In an embodiment, a computer program product is provided, comprising a computer program which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

It should be noted that, the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, presented data, etc.) related to the embodiments of the present disclosure are information and data authorized by the user or sufficiently authorized by each party.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, databases, or other media used in the embodiments provided by the embodiments of the disclosure may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include a Read-Only Memory (ROM), a magnetic tape, a floppy disk, a flash Memory, an optical Memory, a high-density embedded nonvolatile Memory, a resistive Random Access Memory (ReRAM), a Magnetic Random Access Memory (MRAM), a Ferroelectric Random Access Memory (FRAM), a Phase Change Memory (PCM), a graphene Memory, and the like. Volatile Memory can include Random Access Memory (RAM), external cache Memory, and the like. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), for example. The databases involved in the various embodiments provided by the embodiments of the present disclosure may include at least one of relational databases and non-relational databases. The non-relational database may include, but is not limited to, a block chain based distributed database, and the like. The processors referred to in the embodiments provided in the disclosure may be general processors, central processing units, graphics processors, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., without being limited thereto.

All possible combinations of the technical features in the above embodiments may not be described for the sake of brevity, but should be considered as being within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express a few implementations of the embodiments of the present disclosure, and the descriptions thereof are specific and detailed, but not construed as limiting the scope of the claims of the embodiments of the present disclosure. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the concept of the embodiments of the present disclosure, and these are all within the scope of the embodiments of the present disclosure. Therefore, the scope of the embodiments of the present disclosure should be determined by the appended claims.

Claims

1. A signal processing method at an optical communication receiving end, the method comprising:

2. The method of claim 1, wherein obtaining a difference between the electrical signal and the first processed signal, and adjusting a parameter setting of the adaptive filter based on the difference to change a filtering characteristic of the adaptive filter comprises:

3. The method of claim 1, wherein the adjusting the parameter setting of the adaptive filter according to the difference value to change the filtering characteristic of the adaptive filter comprises:

4. The method of claim 3, wherein determining the target parameter matching the difference value based on the correlation between the difference value and the parameter of the adaptive filter comprises:

5. The method of claim 1, wherein the adaptive filter comprises a digital adaptive filter, and wherein the filtering the first processed signal with the adaptive filter to obtain a second processed signal comprises:

6. The method of claim 1, wherein the optical signal is obtained by performing dc-balanced encoding and modulation on an original optical signal.

7. The method of claim 1, wherein obtaining the second processed signal is followed by:

8. The method of claim 1, wherein receiving the optical signal and converting the optical signal into an electrical signal comprises:

acquiring an optical signal sent by a signal source;

9. The method of claim 1, wherein the parameters of the adaptive filter include a number of taps, and wherein adjusting the parameter setting of the adaptive filter based on the difference to change the filtering characteristics of the adaptive filter comprises:

10. A signal processing system at an optical communication receiving end, the system comprising:

11. The system of claim 10, wherein the adaptive filter comprises:

12. The system of claim 10, further comprising:

the adaptive filter includes: