阅读说明：本技术 一种信号处理方法及相关设备 (Signal processing method and related equipment ) 是由 赵也 万金 艾哈迈德·穆罕默德·易卜拉欣·米得拉 于 2020-04-10 设计创作，主要内容包括：本申请实施例公开了一种信号处理方法及相关设备。本申请实施例方法包括：对具有ISI的第一信号进行ISI估计得到第一估计信息,并对具有ISI的第一信号进行滤波得到第二信号。根据第一估计信息对第二信号进行ISI补偿得到第一补偿信息。根据第一补偿信息进行前向纠错FEC校验得到第一软信息。根据第一估计信息和第一软信息对第二信号进行ISI补偿得到第二补偿信息。根据第二补偿信息对第一信号进行ISI估计得到第二估计信息。由于利用了FEC校验反馈的第一软信息,因此第二补偿信息相对于第一补偿信息更准确,那么结合第二补偿信息进行ISI估计得到的第二估计信息也比第一估计信息更精确,即提高了ISI的估计精度。(The embodiment of the application discloses a signal processing method and related equipment. The method in the embodiment of the application comprises the following steps: the first signal with ISI is subjected to ISI estimation to obtain first estimation information, and the first signal with ISI is subjected to filtering to obtain a second signal. And performing ISI compensation on the second signal according to the first estimation information to obtain first compensation information. And carrying out Forward Error Correction (FEC) check according to the first compensation information to obtain first soft information. And performing ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information. And performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information. Because the first soft information fed back by the FEC check is used, the second compensation information is more accurate relative to the first compensation information, and the second estimation information obtained by estimating the ISI in combination with the second compensation information is more accurate than the first estimation information, that is, the estimation accuracy of the ISI is improved.)

1. A signal processing method, comprising:

carrying out ISI estimation on a first signal with intersymbol interference (ISI) to obtain first estimation information, and filtering the first signal with ISI to obtain a second signal, wherein the first estimation information is used for expressing the estimated ISI;

according to the first estimation information, performing ISI compensation on the second signal to obtain first compensation information;

carrying out Forward Error Correction (FEC) check according to the first compensation information to obtain first soft information;

according to the first estimation information and the first soft information, performing ISI compensation on the second signal to obtain second compensation information;

and performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information, wherein the second estimation information is used for representing the estimated ISI magnitude.

2. The method of claim 1, wherein after obtaining second compensation information by performing ISI compensation on the second signal according to the first estimation information and the first soft information, the method further comprises:

performing FEC check according to the second compensation information to obtain second soft information;

according to the first estimation information and the second soft information, ISI compensation is carried out on the second signal to obtain third compensation information;

and performing ISI estimation on the first signal according to the third compensation information to obtain third estimation information, where the third estimation information is used to indicate the estimated ISI size.

3. The method according to claim 1 or 2, wherein after obtaining second estimation information by performing ISI estimation on the first signal according to the second compensation information, the method further comprises:

according to the second estimation information, performing ISI compensation on the second signal to obtain fourth compensation information;

performing FEC check according to the fourth compensation information to obtain third soft information;

according to the second estimation information and the third soft information, performing ISI compensation on the second signal to obtain fifth compensation information;

and performing ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, where the fourth estimation information is used to indicate the estimated ISI size.

4. The signal processing method according to any one of claims 1 to 3, wherein performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information comprises:

determining channel noise according to the first signal and the second compensation information;

and performing spectrum estimation on the channel noise to obtain the second estimation information.

5. A signal processing apparatus, comprising an ISI estimation module, an ISI compensation module, and an FEC module;

the ISI estimation module is configured to perform ISI estimation on a first signal with ISI to obtain first estimation information, filter the first signal with ISI to obtain a second signal, and send the first estimation information and the second signal to the ISI compensation module, where the first estimation information is used to indicate an estimated size of the ISI;

the ISI compensation module is used for carrying out ISI compensation on the second signal according to the first estimation information to obtain first compensation information and sending the first compensation information to the FEC module;

the FEC module is used for carrying out FEC check according to the first compensation information to obtain first soft information and sending the first soft information to the ISI compensation module;

the ISI compensation module is configured to perform ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and send the second compensation information to the ISI estimation module and the FEC module;

the ISI estimation module is configured to perform ISI estimation on the first signal according to the second compensation information to obtain second estimation information, and send the second estimation information to the ISI compensation module, where the second estimation information is used to indicate an estimated size of the ISI.

6. The signal processing apparatus of claim 5, wherein the ISI compensation module comprises at least a first ISI compensator, a second ISI compensator, and a first delay;

the first ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and send the first compensation information to the FEC module;

the FEC module is configured to perform FEC check according to the first compensation information to obtain first soft information, and send the first soft information to the second ISI compensator;

the first delayer is configured to control the second ISI compensator to receive the first estimation information and the second signal at a first time instant, the first time instant being after a time instant at which the first ISI compensator receives the first estimation information and the second signal;

the second ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and send the second compensation information to the ISI estimation module and the FEC module.

7. The signal processing apparatus of claim 6, wherein the ISI compensation module further comprises a third ISI compensator and a second delayer;

the FEC module is configured to perform FEC check according to the second compensation information to obtain second soft information, and send the second soft information to the third ISI compensator;

the second delay is configured to control the third ISI compensator to receive the first estimation information and the second signal at a second time instant, the second time instant being after a time instant at which the second ISI compensator receives the first estimation information and the second signal;

the third ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and send the third compensation information to the ISI estimation module and the FEC module;

the ISI estimation module is further configured to perform ISI estimation on the first signal according to the third compensation information to obtain third estimation information, where the third estimation information is used to indicate the estimated ISI size.

8. The signal processing apparatus according to claim 6 or 7,

the first ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and send the fourth compensation information to the FEC module;

the FEC module is configured to perform FEC check according to the fourth compensation information to obtain third soft information, and send the third soft information to the second ISI compensator;

the first delay is configured to control the second ISI compensator to receive the second estimation information and the second signal at a third time, the third time being after a time at which the first ISI compensator receives the second estimation information;

the second ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and send the fifth compensation information to the ISI estimation module and the FEC module;

the ISI estimation module is further configured to perform ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, where the fourth estimation information is used to indicate the estimated size of the ISI.

9. The signal processing apparatus of claim 5, wherein the ISI compensation module comprises at least a first ISI compensator, a second ISI compensator, and a first delay, and wherein the FEC module comprises at least a first FEC decoder and a second FEC decoder;

the first ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and send the first compensation information to the first FEC decoder;

the first FEC decoder is used for carrying out FEC check according to the first compensation information to obtain first soft information and sending the first soft information to the second ISI compensator;

the first delayer is configured to control the second ISI compensator to receive the first estimation information and the second signal at a first time instant, the first time instant being after a time instant at which the first ISI compensator receives the first estimation information and the second signal;

the second ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and send the second compensation information to the ISI estimation module and the second FEC decoder.

10. The signal processing apparatus of claim 9, wherein the ISI compensation module further comprises a third ISI compensator and a second delayer, and the FEC module further comprises a third FEC decoder;

the second FEC decoder is configured to perform FEC check according to the second compensation information to obtain second soft information, and send the second soft information to the third ISI compensator;

the second delay is configured to control the third ISI compensator to receive the first estimation information and the second signal at a second time instant, the second time instant being after a time instant at which the second ISI compensator receives the first estimation information and the second signal;

the third ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and send the third compensation information to the ISI estimation module and the third FEC decoder;

the ISI estimation module is further configured to perform ISI estimation on the first signal according to the third compensation information to obtain third estimation information, where the third estimation information is used to indicate the estimated ISI size.

11. The signal processing apparatus according to claim 9 or 10,

the first ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and send the fourth compensation information to the first FEC decoder;

the first FEC decoder is configured to perform FEC check according to the fourth compensation information to obtain third soft information, and send the third soft information to the second ISI compensator;

the first delay is configured to control the second ISI compensator to receive the second estimation information and the second signal at a third time, the third time being after a time at which the first ISI compensator receives the second estimation information;

the second ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and send the fifth compensation information to the ISI estimation module and the second FEC decoder;

the ISI estimation module is further configured to perform ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, where the fourth estimation information is used to indicate the estimated size of the ISI.

12. The signal processing apparatus according to any of claims 5 to 11, wherein the ISI estimation module is specifically configured to:

determining channel noise according to the first signal and the second compensation information;

and performing spectrum estimation on the channel noise to obtain the second estimation information.

13. A receiver, comprising:

the receiver front end and the digital processing chip are connected through a line;

the front end of the receiver is used for converting the received optical signal into an electric signal and transmitting the electric signal to the digital processing chip;

the digital processing chip is used for executing the signal processing method of any one of claims 1 to 4.

14. A digital processing chip, characterized in that it comprises a processor and a memory, said memory and said processor being connected by a line, said memory having stored therein instructions, said processor being adapted to execute the signal processing method according to any of claims 1 to 4.

Technical Field

The present application relates to the field of communications, and in particular, to a signal processing method and related device.

Background

In order to meet the increase of 5G, clouding, high-definition video data and the like, the optical transmission capacity and the further differentiation and refinement of scenes are accelerated while the optical transmission bandwidth is expanded. The capacity continues to evolve rapidly from 100G to 200G, 400G, 600G and even 800G. In the transmission interval, different channel intervals are also adapted to different transmission distances, and when the channel interval is smaller than the transmission data bandwidth, intersymbol interference (ISI) is introduced, especially in a high modulation format large capacity scenario, which greatly affects the transmission distance.

The ISI compensation technique is required at the data receiving end to eliminate the ISI effect as much as possible. One way that is currently available is for the ISI estimation device to perform an ISI estimation on the signal from the equalizer to obtain the filter coefficients. Then, the ISI compensation device performs ISI compensation according to the filter coefficients and feeds back the ISI compensated signal to the ISI estimation device. Further, the ISI estimation device performs ISI estimation on the signal from the equalizer in combination with the ISI-compensated signal, thereby implementing iterative compensation of ISI. However, when the error rate of the equalizer output is high, a large error rate still exists depending on the output of the ISI compensation iteration, and the estimation accuracy of the ISI is low.

Disclosure of Invention

The embodiment of the application provides a signal processing method and related equipment, and improves estimation accuracy of ISI.

In a first aspect, the present application provides a signal processing method, including: the first signal with ISI is subjected to ISI estimation to obtain first estimation information, and the first signal with ISI is subjected to filtering to obtain a second signal. And performing ISI compensation on the second signal according to the first estimation information to obtain first compensation information. And performing FEC check according to the first compensation information to obtain first soft information. And performing ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information. And performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information. The first estimation information and the second estimation information may specifically be filter coefficients used to indicate the estimated ISI level.

In this embodiment, since the first soft information fed back by the FEC check is used, the second compensation information is more accurate with respect to the first compensation information, and the second estimation information obtained by estimating the ISI in combination with the second compensation information is more accurate than the first estimation information, that is, the estimation accuracy of the ISI is improved.

In some possible embodiments, after obtaining the second compensation information by performing ISI compensation on the second signal according to the first estimation information and the first soft information, the method further includes: and performing FEC check according to the second compensation information to obtain second soft information. And performing ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information. And performing ISI estimation on the first signal according to the third compensation information to obtain third estimation information, wherein the third estimation information is used for indicating the estimated ISI size.

In this embodiment, information iteration may be continued between ISI compensation and FEC check, and the more the number of iterations, the higher the accuracy of ISI compensation, and accordingly, the estimation accuracy of ISI is further improved.

In some possible embodiments, after performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information, the method further includes: and performing ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information. And performing FEC check according to the fourth compensation information to obtain third soft information. And according to the second estimation information and the third soft information, performing ISI compensation on the second signal to obtain fifth compensation information. And performing ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, wherein the fourth estimation information is used for indicating the estimated ISI size.

In this embodiment, after the update results in new estimation information, the above steps may be repeated to further update the estimation information, so that the result of the ISI estimation is more accurate.

In some possible embodiments, estimating the ISI from the first signal according to the second compensation information to obtain the second estimation information includes: and determining the channel noise according to the first signal and the second compensation information. And carrying out spectrum estimation on the channel noise to obtain second estimation information.

In this embodiment, a specific implementation for ISI estimation is provided, which improves the practicality of the scheme.

In a second aspect, the present application provides a signal processing apparatus comprising an ISI estimation module, an ISI compensation module, and an FEC module. The ISI estimation module is configured to perform ISI estimation on a first signal with ISI to obtain first estimation information, filter the first signal with ISI to obtain a second signal, and send the first estimation information and the second signal to the ISI compensation module, where the first estimation information is used to indicate a size of the estimated ISI. The ISI compensation module is used for carrying out ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and sending the first compensation information to the FEC module. The FEC module is used for carrying out FEC check according to the first compensation information to obtain first soft information and sending the first soft information to the ISI compensation module. The ISI compensation module is used for carrying out ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and sending the second compensation information to the ISI estimation module and the FEC module. The ISI estimation module is used for carrying out ISI estimation on the first signal according to the second compensation information to obtain second estimation information and sending the second estimation information to the ISI compensation module, wherein the second estimation information is used for expressing the estimated ISI size.

In some possible embodiments, the ISI compensation module comprises at least a first ISI compensator, a second ISI compensator, and a first delay. The first ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and send the first compensation information to the FEC module. The FEC module is configured to perform FEC check according to the first compensation information to obtain first soft information, and send the first soft information to the second ISI compensator. The first delayer is adapted to control the second ISI compensator to receive the first estimate information and the second signal at a first time instant, which is after a time instant at which the first ISI compensator receives the first estimate information and the second signal. The second ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and send the second compensation information to the ISI estimation module and the FEC module.

In some possible embodiments, the ISI compensation module further comprises a third ISI compensator and a second delayer. The FEC module is configured to perform FEC check according to the second compensation information to obtain second soft information, and send the second soft information to the third ISI compensator. The second delayer is adapted to control the third ISI compensator to receive the first estimate information and the second signal at a second time instant, which is after the time instant at which the second ISI compensator receives the first estimate information and the second signal. The third ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and send the third compensation information to the ISI estimation module and the FEC module. The ISI estimation module is further configured to perform ISI estimation on the first signal according to third compensation information to obtain third estimation information, where the third estimation information is used to indicate a size of the estimated ISI.

In some possible embodiments, the first ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and send the fourth compensation information to the FEC module. And the FEC module is used for carrying out FEC check according to the fourth compensation information to obtain third soft information and sending the third soft information to the second ISI compensator. The first delay is arranged to control the second ISI compensator to receive the second estimate information and the second signal at a third time instant, the third time instant being after the time instant at which the second estimate information was received by the first ISI compensator. The second ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and send the fifth compensation information to the ISI estimation module and the FEC module. The ISI estimation module is further configured to perform ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, where the fourth estimation information is used to indicate a size of the estimated ISI.

In some possible embodiments, the ISI compensation module comprises at least a first ISI compensator, a second ISI compensator, and a first delay, and the FEC module comprises at least a first FEC decoder and a second FEC decoder. The first ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and send the first compensation information to the first FEC decoder. The first FEC decoder is used for carrying out FEC check according to the first compensation information to obtain first soft information and sending the first soft information to the second ISI compensator. The first delayer is adapted to control the second ISI compensator to receive the first estimate information and the second signal at a first time instant, which is after a time instant at which the first ISI compensator receives the first estimate information and the second signal. The second ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and send the second compensation information to the ISI estimation module and the second FEC decoder.

In some possible embodiments, the ISI compensation module further comprises a third ISI compensator and a second delayer, and the FEC module further comprises a third FEC decoder. And the second FEC decoder is used for carrying out FEC check according to the second compensation information to obtain second soft information and sending the second soft information to the third ISI compensator. The second delayer is adapted to control the third ISI compensator to receive the first estimate information and the second signal at a second time instant, which is after the time instant at which the second ISI compensator receives the first estimate information and the second signal. The third ISI compensator is configured to perform ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and send the third compensation information to the ISI estimation module and the third FEC decoder. The ISI estimation module is further configured to perform ISI estimation on the first signal according to third compensation information to obtain third estimation information, where the third estimation information is used to indicate a size of the estimated ISI.

In some possible embodiments, the first ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and send the fourth compensation information to the first FEC decoder. And the first FEC decoder is used for carrying out FEC check according to the fourth compensation information to obtain third soft information and sending the third soft information to the second ISI compensator. The first delay is arranged to control the second ISI compensator to receive the second estimate information and the second signal at a third time instant, the third time instant being after the time instant at which the second estimate information was received by the first ISI compensator. The second ISI compensator is configured to perform ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and send the fifth compensation information to the ISI estimation module and the second FEC decoder. The ISI estimation module is further configured to perform ISI estimation on the first signal according to the fifth compensation information to obtain fourth estimation information, where the fourth estimation information is used to indicate a size of the estimated ISI.

In some possible embodiments, the ISI estimation module is specifically configured to: and determining the channel noise according to the first signal and the second compensation information. And carrying out spectrum estimation on the channel noise to obtain second estimation information.

In a third aspect, an embodiment of the present application provides a receiver, which includes a receiver front end and a digital processing chip, where the receiver front end and the digital processing chip are connected by a line. The front end of the receiver is used for converting the received optical signal into an electric signal and transmitting the electric signal to the digital processing chip. The digital processing chip is used for executing the signal processing method as described in any one of the embodiments of the first aspect.

In a fourth aspect, an embodiment of the present application provides a digital processing chip, which includes a processor and a memory, where the memory and the processor are connected by a line, and the memory stores instructions, and the processor is configured to execute the signal processing method described in any one of the embodiments of the first aspect.

In the embodiment of the present application, first, ISI estimation is performed on a first signal with ISI to obtain first estimation information, and the first signal is filtered to obtain a second signal. And finally, performing ISI compensation on the second signal according to the first estimation information to obtain first compensation information. And then, performing FEC check according to the first compensation information to obtain first soft information. And performing ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information. And then, according to the second compensation information, performing ISI estimation on the first signal to obtain second estimation information. Through the above description, since the first soft information fed back by the FEC check is used, the second compensation information is more accurate with respect to the first compensation information, and the second estimation information obtained by performing ISI estimation in combination with the second compensation information is also more accurate than the first estimation information, that is, the estimation accuracy of ISI is improved.

Drawings

Fig. 1 is a schematic diagram of a receiver according to the present application;

fig. 2 is a schematic diagram of an embodiment of a signal processing method in the present application;

FIG. 3 is a schematic diagram of a signal processing apparatus according to the present application;

FIG. 4 is a schematic diagram of another structure of the signal processing apparatus of the present application;

FIG. 5 is a schematic diagram of another structure of the signal processing apparatus of the present application;

fig. 6 is a schematic diagram of a possible receiver structure.

Detailed Description

The embodiment of the application provides a signal processing method and related equipment. It should be noted that the terms "first," "second," "third," and "fourth," etc. in the description and claims of this application and the above-mentioned drawings are used for distinguishing between similar elements and not necessarily for limiting a particular order or sequence. It is to be understood that the terms so described are interchangeable under appropriate circumstances such that the embodiments described herein are capable of operation in other sequences than described of illustrated herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, article, or apparatus.

The present application can be applied to a receiver, and fig. 1 is a schematic structural diagram of the receiver in the present application. In the receiver 10, a receiver front end 102 receives a service signal with impairment from a channel and mixes the signal with a signal from a local laser 101, then the receiver front end 102 converts the mixed optical signal into an electrical signal and outputs the electrical signal to an analog-to-digital conversion module 103, the analog-to-digital conversion module 103 converts the electrical signal into a digital signal and outputs the digital signal to a dispersion compensator 104, the dispersion compensator 104 compensates dispersion generated during transmission of the signal, an equalizer 105 is used for polarization demultiplexing and channel impairment compensation, a phase recovery module 106 is used for performing phase recovery on the signal output by the equalizer 105 and outputting the phase-recovered signal to an inter-symbol interference (ISI) estimation module 107, the ISI estimation module 107 is used for estimating ISI and filtering the phase-recovered signal to whiten noise, and then, outputting the filtered signal to an ISI compensation module 108, where the ISI compensation module 108 is configured to eliminate ISI influence and output decision information to a Forward Error Correction (FEC) module 109, and the FEC module 109 processes the decision information and then outputs soft information to the ISI compensation module 108, so as to complete information iteration between the ISI compensation module 108 and the FEC module 109, thereby improving system performance.

It should be noted that, the original signal transmitted by the transmitter may be subjected to channel interference when transmitted through the channel, so that the receiver will receive the signal with the impairment from the channel, and the frequency of the signal is narrowed when the signal passes through the ISI estimation module 107, and since the signal may include a plurality of sequences, mutual interference may occur between adjacent sequences, so that the phenomenon of ISI occurs.

In order to improve the estimation accuracy of ISI, the present application provides a signal processing method. The signal processing method may be applied to the receiver 10, and in particular, the signal processing method may be applied to a signal processing apparatus (including the ISI estimation module 107, the ISI compensation module 108, and the FEC module 109) in the receiver 10. The signal processing method in the present application is explained in detail below.

Fig. 2 is a schematic diagram of an embodiment of a signal processing method in the present application. In this example, the signal processing method includes the following steps.

201. The ISI estimation is performed on the first signal with ISI to obtain first estimation information, and the first signal is filtered to obtain a second signal.

In this embodiment, first estimation information needs to be obtained by performing ISI estimation on a first signal with ISI, where the first estimation information may specifically be a filter coefficient used to indicate a size of the estimated ISI. And then, filtering the first signal according to the first estimation information to obtain a second signal. It should be understood that the signal output by the equalizer 105 includes color noise, and the FEC module 109 needs to be an input signal including white noise, so that the first signal including color noise can be subjected to whitening filtering by the ISI estimation module 107 to obtain a second signal including white noise.

It should be noted that ISI estimation in this application may be understood as a form of channel estimation, i.e. a process of estimating model parameters of a certain assumed channel model from received data, and a specific estimation result in this application is a filter coefficient. It should be understood that "second estimation information" and "third estimation information" appearing hereinafter refer to filter coefficients, and are not described in detail hereinafter.

202. And performing ISI compensation on the second signal according to the first estimation information to obtain first compensation information.

In this embodiment, the ISI compensation may use a compensation technique of a Sequence detection algorithm, such as a Dual-path minimum Mean square error (BCJR) algorithm and a Maximum Likelihood Sequence Estimation (MLSE) algorithm. In addition, ISI compensation may also employ compensation techniques of an equalization algorithm, such as a time domain based or frequency domain based time domain Decision Feedback Equalization (DFE) algorithm. The present application does not limit the compensation technique employed for ISI compensation.

It should be noted that the first compensation information specifically refers to decision information, and the decision information may be information obtained through soft decision or information obtained through hard decision, which is not limited herein. It should be understood that "second compensation information" and "third compensation information" appearing hereinafter refer to the decision information after ISI compensation, and are not described in detail hereinafter.

203. And performing FEC check according to the first compensation information to obtain first soft information.

In this embodiment, the ISI compensation may be further followed by FEC check to improve system performance, and specifically, the FEC check may decode the received signal according to a specified algorithm, so as to find out and correct an error code generated in a transmission process. The FEC check may use a conventional FEC decoding technique (e.g., a Low-density Parity-check (LDPC) algorithm) to perform error check to recover the original signal. In the present application, the FEC check mode is soft decision check, that is, soft information is output after FEC check.

204. And performing ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information.

And after the FEC check is completed on the first compensation information, combining the first soft information and the first estimation information obtained after the FEC check to perform ISI compensation on the second signal again to obtain second compensation information. It will be appreciated that using the correct information fed back by the FEC check makes the second compensation information more accurate relative to the first compensation information.

Optionally, in some possible embodiments, to further improve the accuracy of ISI compensation, information iteration may be continued between ISI compensation and FEC check, and the more iterations, the higher the accuracy of ISI compensation. For example, after the second compensation information is obtained, FEC check is performed according to the second compensation information to obtain second soft information. And further, according to the first estimation information and the second soft information, performing ISI compensation on the second signal to obtain third compensation information. It should be appreciated that the third compensation information is more accurate relative to the second compensation information.

It should be noted that, because of the feedback delay of the FEC check, the smaller the number of iterations is, the faster the system convergence speed is. After the system converges, the more the iteration times, the more accurate the feedback information after FEC check, and the larger the feedback delay, the more the consumed resources. Therefore, in practical applications, the number of iterations may be selected according to different requirements, and is not limited herein.

205. And performing ISI estimation on the first signal according to the second compensation information to obtain second estimation information.

In this embodiment, the updated second compensation information may be further utilized to perform ISI estimation on the first signal, so as to obtain second estimation information by updating. Since the second compensation information is more accurate with respect to the first compensation information, the second estimation information obtained by estimating the ISI in combination with the second compensation information is also more accurate than the first estimation information, i.e. the estimation accuracy of the ISI is improved.

It should be understood that, since information iteration may be performed continuously between ISI compensation and FEC check, in practical applications, compensation information obtained after any iteration may be used to perform a new ISI estimation, which is not limited herein. For example, the third estimation information may be obtained by performing ISI estimation on the first signal according to the third compensation information. It should be appreciated that the third estimated information is more accurate than the second estimated information.

Optionally, in some possible embodiments, after the new estimation information is obtained by updating, the above steps 201 to 205 may be further repeatedly performed to further update the estimation information, so that the result of the ISI estimation is more accurate. For example, after the second estimation information is obtained, ISI compensation is performed on the second signal according to the second estimation information to obtain fourth compensation information. And then, performing FEC check according to the fourth compensation information to obtain third soft information. And then, according to the second estimation information and the third soft information, performing ISI compensation on the second signal to obtain fifth compensation information. And further, according to the fifth compensation information, performing ISI estimation on the first signal to obtain fourth estimation information. It should be appreciated that the fourth estimated information is more accurate than the third estimated information.

It should be noted that there are various ways of estimating ISI, which are described separately below.

The first method adopts a spectrum estimation algorithm to estimate the ISI, and comprises the following specific steps.

First, channel noise is determined based on the first signal and the second compensation information. Further, the channel noise is subjected to spectrum estimation by using a spectrum estimation algorithm, and estimation information (i.e., a filter coefficient) is obtained. Wherein, in some possible embodiments, the channel noise may be determined according to a difference between the first signal and the second compensation information. Alternatively, if the second compensation information is hard decision information, the channel noise may be determined directly from the hard decision information and the first signal. If the second compensation information is soft decision information, the channel noise can be determined directly according to the soft decision information and the first signal, and the channel noise can be determined according to the hard decision information and the first signal.

Second, the ISI estimation is performed using a Least Mean Square (LMS) algorithm, a Least Square (LS) algorithm, or a Minimum Mean Square Error (MMSE) algorithm. It should be noted that the second type of algorithm is only suitable for use with the equalization algorithm in the ISI compensation technique. In particular, the second type of algorithm can be divided into the following two ways.

In the first mode, second compensation information can be obtained after ISI compensation is performed on the second signal by using an equalization algorithm technology. Then, the channel noise is determined according to the first signal before whitening filtering and the second compensation information. Next, a spectrum estimation algorithm is used to perform spectrum estimation on the channel noise, so as to obtain estimation information (i.e., filter coefficients). And then, updating the filter coefficient by LS algorithm or MMSE algorithm according to the estimation information. Wherein, in some possible embodiments, the channel noise may be determined according to a difference between the first signal and the second compensation information. Alternatively, if the second compensation information is hard decision information, the channel noise may be determined directly from the hard decision information and the first signal. If the second compensation information is soft decision information, the channel noise can be determined directly according to the soft decision information and the first signal, and the channel noise can be determined according to the hard decision information and the first signal.

Mode two, the estimation information (i.e., filter coefficients) is initialized. And then, carrying out ISI compensation on the second signal by adopting an equalization algorithm technology to obtain second compensation information. Next, an error value is determined based on the second signal and the second compensation information. Further, the estimation information (i.e., the filter coefficient) is updated using the LMS algorithm based on the first signal and the error value.

In the embodiment of the present application, first, ISI estimation is performed on a first signal with ISI to obtain first estimation information, and the first signal is filtered to obtain a second signal. And finally, performing ISI compensation on the second signal according to the first estimation information to obtain first compensation information. And then, performing FEC check according to the first compensation information to obtain first soft information. And performing ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information. And then, according to the second compensation information, performing ISI estimation on the first signal to obtain second estimation information. Through the above description, since the first soft information fed back by the FEC check is used, the second compensation information is more accurate with respect to the first compensation information, and the second estimation information obtained by performing ISI estimation in combination with the second compensation information is also more accurate than the first estimation information, that is, the estimation accuracy of ISI is improved.

The signal processing method in the embodiment of the present application is described above, and the signal processing apparatus in the embodiment of the present application is described below.

Fig. 3 is a schematic structural diagram of a signal processing apparatus according to the present application. The signal processing apparatus 30 comprises an ISI estimation module 301, an ISI compensation module 302 and an FEC module 303. The ISI estimation module 301 performs ISI estimation on a first signal with ISI to obtain first estimation information, and filters the first signal to obtain a second signal, and then sends the first estimation information and the second signal to the ISI compensation module 302. The ISI compensation module 302 performs ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and sends the first compensation information to the FEC module 303. The FEC module 303 performs FEC check according to the first compensation information to obtain first soft information, and sends the first soft information to the ISI compensation module 302. The ISI compensation module 302 performs ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and sends the second compensation information to the ISI estimation module 301 and the FEC module 303. The ISI estimation module 301 performs ISI estimation on the first signal according to the second compensation information to obtain second estimation information, and sends the second estimation information to the ISI compensation module.

It will be appreciated that the signal processing apparatus shown in fig. 3 is used to implement the signal processing method in the embodiment shown in fig. 2 described above. In particular, the ISI estimation module 301 is configured to perform step 201 and step 205 in the embodiment shown in fig. 2. The ISI compensation module 302 is used to perform step 202 and step 204 in the embodiment shown in fig. 2. FEC module 303 is configured to perform step 203 in the embodiment shown in fig. 2.

It should be noted that information iteration may be performed between the ISI compensation module 302 and the FEC module 303, where a plurality of ISI compensators may be arranged in the ISI compensation module 302, and the plurality of ISI compensators iterate with the FEC module 303. Alternatively, the FEC module 303 may also be provided with a plurality of FEC decoders, and a plurality of ISI compensators iterate with the plurality of FEC decoders. These two iteration modes are described in detail below.

The first, multiple ISI compensators iterate with the FEC module.

Fig. 4 is a schematic structural diagram of another signal processing apparatus according to the present application. The ISI compensation module 302 includes N ISI compensators and N-1 delays, where N is an integer greater than 1. Specifically, the ISI estimation module 301 transmits the first estimation information and the second signal to each ISI compensator. The ISI compensator 1 performs ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and sends the first compensation information to the FEC module 303. The FEC module 303 performs FEC check according to the first compensation information to obtain first soft information, and sends the first soft information to the ISI compensator 2. In order to align the time when the ISI compensator receives the first soft information with the time when the first estimation information and the second signal are received, considering the processing delay of the FEC module 303, the first estimation information and the second signal need to be transmitted to the ISI compensator 2 using the delay unit 1, that is, the time when the ISI compensator 2 receives the first estimation information and the second signal is after the time when the ISI compensator 1 receives the first estimation information and the second signal. Further, the ISI compensator 2 performs ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and may send the second compensation information to the ISI estimation module 301 and the FEC module 303.

It is to be understood that the ISI estimation module 301 may perform ISI estimation on the first signal according to the second compensation information fed back by the ISI compensator 2 to obtain second estimation information, or may update the estimation information according to the compensation information fed back by any one of the ISI compensators 3 to N. For example, the FEC module 303 performs FEC check according to the second compensation information to obtain second soft information, and sends the second soft information to the ISI compensator 3. The delayer 2 delays the transmission of the first estimated information and the second signal to the ISI compensator 3 such that the input of the second soft information to the ISI compensator 3 is time aligned with the input of the first estimated information and the second signal to the ISI compensator 3. Further, the ISI compensator 3 performs ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and may send the third compensation information to the ISI estimation module 301 and the FEC module 303. The ISI estimation module 301 performs ISI estimation on the first signal according to the third compensation to obtain third estimation information.

In some possible embodiments, after the estimation information is updated by the ISI estimation module 301, each ISI compensator and FEC module 303 may also perform a new iteration based on the updated estimation information. For example, the ISI compensator 1 performs ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and sends the fourth compensation information to the FEC module 303. The FEC module 303 performs FEC check according to the fourth compensation information to obtain third soft information, and sends the third soft information to the ISI compensator 2. The delayer 1 delays the transmission of the first estimated information and the second signal to the ISI compensator 2 such that the input of the third soft information to the ISI compensator 2 is time aligned with the input of the first estimated information and the second signal to the ISI compensator 2. The ISI compensator 2 performs ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and so on for iteration. The ISI estimation module 301 may update the estimation information according to the compensation information fed back by any of the ISI compensators.

Alternatively, the delay size set by the delay unit may be determined by the processing delay of the delay unit and the processing delay of the FEC module 303. For example, if the processing delay of the delay is D0, the processing delay of the FEC module 303 is D1, then the delay set by the delay unit 1 is D0+ D1, the delay set by the delay unit 2 is 2 x (D0+ D1), and so on, the delay set by the delay unit N is N x (D0+ D1). It should be understood that the delay unit may be implemented by a register or a Random Access Memory (RAM), and is not limited herein.

The second, multiple ISI compensators iterate with multiple FEC decoders.

Fig. 5 is a schematic structural diagram of another signal processing apparatus according to the present application. The ISI compensation module 302 includes N ISI compensators and N-1 delays, and the FEC module 303 includes N FEC decoders, where N is an integer greater than 1. Specifically, the ISI estimation module 301 transmits the first estimation information and the second signal to each ISI compensator. The ISI compensator 1 performs ISI compensation on the second signal according to the first estimation information to obtain first compensation information, and sends the first compensation information to the FEC decoder 1. The FEC decoder 1 performs FEC check according to the first compensation information to obtain first soft information, and sends the first soft information to the ISI compensator 2. The delayer 1 delays the transmission of the first estimation information and the second signal to the ISI compensator 2 such that the input of the first soft information to the ISI compensator 2 is time aligned with the input of the first estimation information and the second signal to the ISI compensator 2. The ISI compensator 2 performs ISI compensation on the second signal according to the first estimation information and the first soft information to obtain second compensation information, and may send the second compensation information to the ISI estimation module 301. And the ISI estimation module carries out ISI estimation on the first signal according to the second compensation information to obtain second estimation information.

It is to be understood that the ISI estimation module 301 may also update the estimation information according to the compensation information fed back by any one of the ISI compensators 3 to N. For example, the ISI compensator 2 sends the second compensation information to the FEC decoder 2. The FEC decoder 2 performs FEC check according to the second compensation information to obtain second soft information, and sends the second soft information to the ISI compensator 3. The delayer 2 delays the transmission of the first estimated information and the second signal to the ISI compensator 2 such that the input of the second soft information to the ISI compensator 3 is time aligned with the input of the first estimated information and the second signal to the ISI compensator 3. The ISI compensator 3 performs ISI compensation on the second signal according to the first estimation information and the second soft information to obtain third compensation information, and may send the third compensation information to the ISI estimation module 301 and the FEC module 303. The ISI estimation module 301 performs ISI estimation on the first signal according to the third compensation to obtain third estimation information.

In some possible embodiments, after the estimation information is updated by the ISI estimation module 301, each ISI compensator and each FEC decoder may further perform a new iteration based on the updated estimation information. For example, the ISI compensator 1 performs ISI compensation on the second signal according to the second estimation information to obtain fourth compensation information, and sends the fourth compensation information to the FEC decoder 1. The FEC decoder 1 performs FEC check according to the fourth compensation information to obtain third soft information, and sends the third soft information to the ISI compensator 2. The delayer 1 delays the transmission of the first estimated information and the second signal to the ISI compensator 2 such that the input of the third soft information to the ISI compensator 2 is time aligned with the input of the first estimated information and the second signal to the ISI compensator 2. The ISI compensator 2 performs ISI compensation on the second signal according to the second estimation information and the third soft information to obtain fifth compensation information, and so on for iteration. The ISI estimation module 301 may update the estimation information according to the compensation information fed back by any of the ISI compensators.

The present application further provides a receiver, where the following describes a receiver in an embodiment of the present application:

fig. 6 is a schematic diagram of a possible receiver structure. The receiver comprises a receiver front end 601 and a digital processing chip 602, wherein the receiver front end 601 and the digital processing chip 602 are connected with each other through a line. The receiver front end 601 is configured to convert a received optical signal into an electrical signal and transmit the electrical signal to the digital processing chip 602. Digital processing chip 602 is used to perform the method steps of the embodiment shown in fig. 2. In a possible implementation, the digital processing chip 602 may include the dispersion compensator 104, the equalizer 105, the phase recovery module 106, the ISI estimation module 107, the ISI compensation module 108, and the FEC module 109 shown in fig. 1, specifically, the electrical signal received by the digital processing chip 902 may be sequentially processed by the dispersion compensator 104, the equalizer 105, and the phase recovery module 106, and then the ISI estimation module 107, the ISI compensation module 108, and the FEC module 109 execute the signal processing method provided in this application. The processing flow of the ISI estimation module 107, the ISI compensation module 108, and the FEC module 109 may refer to the related description in fig. 3 to fig. 5, and will not be described herein again.

The embodiment of the application also provides a digital processing chip. The digital processing chip has integrated therein a processor and one or more interfaces for implementing the signal processing method in the embodiment shown in fig. 2 described above. When integrated with memory, the digital processing chip may perform the method steps of any one or more of the foregoing embodiments. When the digital processing chip is not integrated with the memory, the digital processing chip can be connected with the external memory through an interface. The digital processing chip implements the signal processing method in the above embodiments according to a program code stored in an external memory.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a random access memory, or the like. Specifically, for example: the processing unit or processor may be a central processing unit, a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

When implemented in software, the method steps described in the above embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Finally, it should be noted that: the above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.