WO2023115315A1

WO2023115315A1 - Receiver, receiving method and optical communication system

Info

Publication number: WO2023115315A1
Application number: PCT/CN2021/139996
Authority: WO
Inventors: 周雷
Original assignee: 华为技术有限公司
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2023-06-29

Abstract

Disclosed in the present application is a receiver, which is applied to the field of optical communications. The receiver comprises an optical equalizer, a sampling frequency difference estimation module and a voltage conversion module, wherein the optical equalizer is used for adjusting, according to a delay line control signal, the power of an optical signal received by the receiver, so as to obtain a first optical signal; the sampling frequency difference estimation module is used for acquiring an optical domain sampling frequency difference of the optical equalizer according to the first optical signal; the voltage conversion module is used for converting the optical domain sampling frequency difference into a new delay line control signal; and the optical equalizer is also used for adjusting, according to the new delay line control signal, the power of the optical signal received by the receiver. In the present application, a delay line control signal is adjusted by means of an optical domain sampling frequency difference, such that a more accurate delay line control signal can be obtained, thereby improving the reliability of noise elimination.

Description

Receiver, receiving method and optical communication system

technical field

The present application relates to the field of optical communication, in particular to a receiver, a receiving method and an optical communication system.

Background technique

In the field of optical communication, transmitters and receivers transmit optical signals through optical fibers. However, noise can interfere with the optical signal during transmission. For this reason, the receiver can reduce the impact of noise through an optical equalizer.

For example, FIG. 1 is a schematic structural diagram of an optical equalizer. As shown in FIG. 1 , an optical equalizer 100 includes a delay line 101 , a delay line 102 , a power regulator 103 , a power regulator 104 , a power regulator 105 and an optical coupler 106 . The optical equalizer 100 is used for receiving the first optical signal and dividing the first optical signal into three beams of optical signals. The three beams of optical signals pass through the power regulators 103-105 respectively. Wherein, the optical signal passing through the power regulator 104 passes through the delay line 101 . The optical signal passing through the power regulator 105 passes through the delay line 101 and the delay line 102 . The delay line 101 and the delay line 102 are used to adjust the delay of the optical signal according to the delay line control signal. The optical coupler 106 is used to couple three beams of optical signals and output a second optical signal. After passing through the delay line 101 and the delay line 102, the three beams of optical signals are also referred to as three adjacent symbols. The optical equalizer 100 adjusts the delay between adjacent symbols in the first optical signal according to the delay line control signal, thereby reducing noise in the first optical signal to obtain a second optical signal. The amplitude of the second optical signal can be expressed by Equation 1.

Y＝A×x1+B×x2+C×x3 Formula 1

Wherein, Y is the amplitude of the second optical signal. x1, x2 and x3 are the magnitudes of 3 adjacent symbols. The values of x1, x2 and x3 are related to the delay between adjacent symbols. A is the adjustment coefficient of the power regulator 103 . B is the adjustment coefficient of the power regulator 104 . C is the adjustment coefficient of the power regulator 105 .

However, in practical applications, there may be errors in the delay between adjacent symbols. The error may also be referred to as the optical domain sampling frequency difference. The sampling frequency difference in the optical domain will lead to inaccurate amplitudes of x1, x2 or x3 in the foregoing formula, thereby affecting the amplitude of the second optical signal. Therefore, the optical domain sampling frequency difference will reduce the reliability of noise cancellation.

Contents of the invention

The present application provides a receiver, a receiving method, and an optical communication system. A more accurate delay line control signal can be obtained by adjusting the delay line control signal by optical domain sampling frequency difference, thereby improving the reliability of noise cancellation.

The first aspect of the present application provides a receiver. The receiver includes an optical equalizer, a sampling frequency difference estimation module and a voltage conversion module. The optical equalizer is used to reduce noise in the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. Alternatively, the optical equalizer is used to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. The sampling frequency difference estimating module is used to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal. The voltage conversion module is used to convert the optical domain sampling frequency difference into a new delay line control signal. The optical equalizer is also used to adjust the power of the optical signal received by the receiver according to the new delay line control signal.

In this application, by adjusting the delay line control signal through the optical domain sampling frequency difference, a more accurate delay line control signal can be obtained, thereby improving the reliability of denoising.

In an optional manner of the first aspect, the receiver further includes a photoelectric conversion module and an analog-to-digital converter. The photoelectric conversion module is used for converting the first optical signal into a first analog electrical signal. The analog-to-digital converter is used to convert the first analog electrical signal into a first digital electrical signal. The sampling frequency difference estimating module is used to obtain the optical domain sampling frequency difference according to the first digital electrical signal or the first analog electrical signal. Wherein, the sampling frequency difference estimating module may obtain the optical domain sampling frequency difference by measuring the first optical signal, or obtain the optical domain sampling frequency difference by measuring the electrical signal. When the sampling frequency difference estimating module measures the first optical signal, the sampling frequency difference estimating module needs both an optical device and an electrical device. When the sampling frequency difference estimating module measures electrical signals, the sampling frequency difference estimating module may only need electrical devices. Therefore, the present application can reduce the cost of the receiver.

In an optional manner of the first aspect, the first analog electrical signal includes a clock signal. The receiver also includes electrical filters. The electrical filter is used to obtain the clock signal in the first analog electrical signal. The analog-to-digital converter is also used to adjust the sampling frequency according to the clock signal to obtain the adjusted sampling frequency. The analog-to-digital converter is used to convert the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency. Wherein, the sampling frequency of the analog-to-digital converter will affect the accuracy of the acquired optical domain sampling frequency difference. In the present application, the sampling frequency error of the analog-to-digital converter is firstly reduced through the clock signal, and then the optical domain sampling frequency difference of the first digital electrical signal is obtained. Therefore, the present application can improve the accuracy of the acquired optical domain sampling frequency difference, thereby improving the reliability of denoising.

In an optional manner of the first aspect, the receiver further includes a switch. When the switch is in the first state, the optical equalizer is used to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. When the switch is in the second state, the photoelectric conversion module is also used to convert the optical signal received by the receiver into a second analog electrical signal. At this time, the optical signal received by the receiver does not pass through the optical equalizer. The analog-to-digital converter is also used to convert the second analog electrical signal into a second digital electrical signal. The sampling frequency difference estimating module is further configured to obtain the first electrical domain sampling frequency difference of the analog-to-digital converter according to the second digital electrical signal. The analog-to-digital converter is also used to adjust the sampling frequency according to the sampling frequency difference of the first electrical domain to obtain an adjusted sampling frequency. The analog-to-digital converter is used to convert the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency. Wherein, by adding a switch in the receiver, the sampling frequency error of the analog-to-digital converter can be reduced, thereby improving the accuracy of the obtained sampling frequency difference in the optical domain. Moreover, the present application requires only minor changes to the transmitter, thereby improving the adaptability of the scene.

In an optional manner of the first aspect, when the switch is in the second state, the analog-to-digital converter is further configured to convert the second analog electrical signal into a second digital electrical signal according to the adjusted sampling frequency. The sampling frequency difference estimating module is further configured to obtain a second electrical domain sampling frequency difference of the analog-to-digital converter according to the second digital electrical signal. When the sampling frequency difference of the second electrical domain is smaller than the first threshold, the switch is in the first state. Wherein, the sampling frequency error of the analog-to-digital converter can be further reduced by adjusting the sampling frequency of the analog-to-digital converter multiple times. Therefore, the present application can improve the accuracy of the acquired optical domain sampling frequency difference, thereby improving the reliability of denoising.

In an optional manner of the first aspect, the first optical signal includes a synchronization sequence. The receiver also includes a sequence generator. The sequence generator is used to generate reference synchronization sequences. The sampling frequency difference estimation module is used to obtain the optical domain sampling frequency difference through the synchronization sequence and the reference synchronization sequence. Wherein, when the synchronization sequence is not used, the receiver may need to adjust the delay line control signal several times to obtain a better delay line control signal. By using the synchronous sequence, the times of adjusting the control signal of the delay line can be reduced, thereby improving the efficiency of adjustment.

In an optional manner of the first aspect, the synchronization sequence is a pseudo-random sequence. Among them, the autocorrelation of the pseudo-random sequence is good, but the cross-correlation is poor, so the anti-interference ability is strong. Therefore, the optical domain sampling frequency difference obtained through the pseudo-random sequence is more accurate, thereby improving the reliability of denoising.

In an optional manner of the first aspect, if the optical domain sampling frequency difference is greater than the second threshold, the voltage converting module is configured to convert the optical domain sampling frequency difference into a new delay line control signal. Among them, there must be deviation in the delay of the delay line. Adjusting the delay line control signal if there is a deviation will waste resources of the receiver. The present application sets a second threshold, and when the optical domain sampling frequency difference is less than or equal to the second threshold, the receiver does not adjust the delay line control signal. Therefore, the present application can save resources of the receiver.

The second aspect of the present application provides a receiving method. The receiving method is applied to the receiver. The receiving method includes the following steps: the receiver adjusts the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. The receiver acquires the optical domain sampling frequency difference of the optical equalizer according to the first optical signal. The receiver converts the optical domain sampling frequency difference into a new delay line control signal. The receiver adjusts the power of the optical signal received by the receiver according to the new delay line control signal.

In an optional manner of the second aspect, the receiver converts the first optical signal into a first analog electrical signal. The receiver converts the first analog electrical signal into a first digital electrical signal. The receiver acquires the optical domain sampling frequency difference according to the first analog electrical signal or the first digital electrical signal.

In an optional manner of the second aspect, the first analog electrical signal includes a clock signal, and the receiving method further includes the following step: the receiver obtains the clock signal from the first analog electrical signal. The receiver adjusts the sampling frequency according to the clock signal to obtain the adjusted sampling frequency. The receiver converts the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency.

In an optional manner of the second aspect, when the switch is in the first state, the receiver adjusts the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. The receiving method further includes the following steps: when the switch is in the second state, the receiver converts the optical signal received by the receiver into a second analog electrical signal. The receiver converts the second analog electrical signal into a second digital electrical signal. The receiver acquires the first electrical domain sampling frequency difference according to the second digital electrical signal. The receiver adjusts the sampling frequency according to the sampling frequency difference in the first electrical domain to obtain the adjusted sampling frequency. The receiver converts the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency.

In an optional manner of the second aspect, the receiving method further includes the following step: when the switch is in the second state, the receiver converts the second analog electrical signal into a second digital electrical signal according to the adjusted sampling frequency. The receiver acquires the second electrical domain sampling frequency difference according to the second digital electrical signal. When the sampling frequency difference of the second electrical domain is smaller than the first threshold, the receiver puts the switch in the first state.

In an optional manner of the second aspect, the first digital electrical signal includes a synchronization sequence. The receiving method also includes the following steps: the receiver generates a reference synchronization sequence. The receiver obtains the optical domain sampling frequency difference through the synchronization sequence and the reference synchronization sequence.

In an optional manner of the second aspect, if the optical domain sampling frequency difference is greater than the second threshold, the receiver converts the optical domain sampling frequency difference into a new delay line control signal.

The third aspect of the present application provides an optical communication system. An optical communication system includes a transmitter and a receiver. The transmitter is used to send an optical signal to the receiver. The receiver is configured to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. The receiver is used to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal. The receiver is used to convert the optical domain sampling frequency difference into a new delay line control signal. The receiver is used to adjust the power of the optical signal received by the receiver according to the new delay line control signal.

In an optional manner of the third aspect, the receiver is further configured to convert the first optical signal into a first analog electrical signal, and convert the first analog electrical signal into a first digital electrical signal. The receiver is used to obtain the optical domain sampling frequency difference according to the first digital electrical signal or the first analog electrical signal.

In an optional manner of the third aspect, the transmitter is further configured to generate an optical signal received by the receiver according to the first analog electrical signal, where the first analog electrical signal includes a clock signal. The receiver is also used to obtain a clock signal from the first analog electrical signal. The receiver is also used to adjust the sampling frequency according to the clock signal to obtain the adjusted sampling frequency. The receiver is used for converting the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency.

In an optional manner of the third aspect, when the switch is in the first state, the receiver is configured to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal. When the switch is in the second state, the receiver is also used to convert the optical signal received by the receiver into a second analog electrical signal. The receiver is also used to convert the second analog electrical signal into a second digital electrical signal. The receiver is also used to obtain the first electrical domain sampling frequency difference according to the second digital electrical signal. The receiver is also used to adjust the sampling frequency according to the first electrical domain sampling frequency difference to obtain the adjusted sampling frequency. The receiver is used for converting the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency.

In an optional manner of the third aspect, when the switch is in the second state, the receiver is further configured to convert the second analog electrical signal into a second digital electrical signal according to the adjusted sampling frequency. The receiver is also used to obtain the second electrical domain sampling frequency difference according to the second digital electrical signal. When the sampling frequency difference of the second electrical domain is smaller than the first threshold, the receiver is used to place the switch in the first state.

In an optional manner of the third aspect, the first optical signal includes a synchronization sequence. The receiver is also used to generate a reference synchronization sequence. The receiver is used to obtain the optical domain sampling frequency difference through the synchronization sequence and the reference synchronization sequence.

In an optional manner of the third aspect, if the optical domain sampling frequency difference is greater than the second threshold, the receiver is configured to convert the optical domain sampling frequency difference into a new delay line control signal.

Description of drawings

FIG. 1 is a schematic structural diagram of an optical equalizer;

Fig. 2a is the first structural schematic diagram of the receiver provided in the embodiment of the present application;

Figure 2b is a second structural schematic diagram of the receiver provided in the embodiment of the present application

FIG. 3 is a third structural schematic diagram of the receiver provided in the embodiment of the present application;

FIG. 4 is a fourth schematic structural diagram of the receiver provided in the embodiment of the present application;

FIG. 5 is a fifth schematic structural diagram of the receiver provided in the embodiment of the present application;

FIG. 6 is a schematic structural diagram of a sampling frequency difference estimation module provided in an embodiment of the present application;

FIG. 7 is a schematic flowchart of a receiving method provided in an embodiment of the present application;

FIG. 8 is a schematic structural diagram of an optical communication system provided in an embodiment of the present application.

Detailed ways

Embodiments of the present application provide a receiver, a receiving method, and an optical communication system. A more accurate delay line control signal can be obtained by adjusting a delay line control signal by sampling a frequency difference in the optical domain, thereby improving the reliability of noise cancellation. It should be understood that "first", "second" and the like used in the present application are only used for the purpose of distinguishing and describing, and cannot be interpreted as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, reference numerals and/or letters are repeated in the various figures of this application for the sake of brevity and clarity. Repetition does not imply a strictly limited relationship between the various embodiments and/or configurations.

The receiver in this application is applied in the field of optical communication. In the field of optical communication, the receiver can reduce the impact of noise through an optical equalizer. For example, in FIG. 1 , the optical equalizer 100 can adjust the delay between adjacent symbols in the first optical signal according to the delay line control signal, so as to reduce the noise in the first optical signal and obtain the second optical signal. When there is an error in the delay between adjacent symbols, it will affect the amplitude of the second optical signal, thereby reducing the reliability of noise cancellation.

To this end, the present application provides a receiver. Fig. 2a is a first structural schematic diagram of the receiver provided in the embodiment of the present application. As shown in FIG. 2 a , the receiver 200 includes an optical equalizer 201 , a sampling frequency difference estimation module 202 and a voltage conversion module 203 .

The optical equalizer 201 includes delay lines. The optical equalizer 201 is configured to reduce noise in the optical signal received by the receiver 200 according to the delay line control signal to obtain a first optical signal. Alternatively, the optical equalizer 201 is configured to adjust the power of the optical signal received by the receiver 200 according to the delay line control signal to obtain the first optical signal. The amplitude of the first optical signal is related to the delay between adjacent symbols in the optical signal received by the receiver 200 . The delay between adjacent symbols is obtained according to the delay line control signal applied to the delay line. For example, in FIG. 1 , the relationship between the amplitude of the first optical signal and the delay line can be expressed by Formula 1. For the description of Equation 1 and the optical equalizer 201 , reference may be made to the related description of the optical equalizer 100 in FIG. 1 . It should be understood that the optical equalizer 100 in FIG. 1 is only an example. In practical applications, those skilled in the art can make adaptive modifications to the optical equalizer 100 as required. For example, in FIG. 1, optical equalizer 100 may include more or fewer delay lines and power regulators. In this application, the optical equalizer in FIG. 1 will be taken as an example for description.

In Equation 1, x1, x2 and x3 are the magnitudes of 3 adjacent symbols. The values of x1, x2 and x3 are related to the delay between adjacent symbols. Assume that in Figure 1, there are ideal delays y1 and y2 between adjacent symbols. For example, when the communication frequency between the receiver and the transmitter is 1 Gbit/s, y1 and y2 are 1 nanosecond. y1 corresponds to the delay line 101 . y2 corresponds to the delay line 102 . y1 is obtained according to the delay line control signal d1. y2 is obtained according to the delay line control signal d2. However, the actual delays between adjacent symbols are y11 and y12. According to the aforementioned principle of the optical equalizer, it can be known that the delay error between adjacent symbols is called the optical domain sampling frequency difference. Therefore, the optical domain sampling frequency difference may be the difference between y11 and y1, and the difference between y12 and y2. At this time, the unit of the optical domain sampling frequency difference is time length.

According to the aforementioned principle of the optical equalizer, it can be known that there is a mapping relationship between the delay between adjacent symbols and the amplitude of the first optical signal. Therefore, through the mapping relationship, the optical domain sampling frequency difference of the optical equalizer 201 can also be expressed as the difference in the amplitude of the first optical signal, that is, the optical domain sampling frequency difference can be the difference between the first optical signals Y1 and Y2. The first optical signal Y1 is the reference amplitude of the first optical signal obtained according to y1 and y2. The first optical signal Y2 is the amplitude of the first optical signal obtained according to y11 and y12. At this time, the receiver 200 may store the reference amplitude of the first optical signal. After receiving the first optical signal, the sampling frequency difference estimation module 202 acquires the amplitude of the first optical signal. Afterwards, the sampling frequency difference estimating module 202 calculates the difference between the amplitude of the first optical signal and the reference amplitude to obtain the sampling frequency difference in the optical domain. At this time, the unit of the optical domain sampling frequency difference is amplitude or power.

The voltage conversion module 203 is configured to receive the optical domain sampling frequency difference from the sampling frequency difference estimation module 202, and convert the optical domain sampling frequency difference into a new delay line control signal. According to the principle of the optical equalizer, there is a mapping relationship between the sampling frequency difference in the optical domain and the delay line control signal. According to the mapping relationship, the voltage conversion module 203 adjusts the delay line control signal according to the optical domain sampling frequency difference to obtain a new delay line control signal. The optical equalizer 201 is used to adjust the power of the optical signal received by the receiver 200 according to the new delay line control signal.

In this application, the receiver can adjust the delay line control signal according to the optical domain sampling frequency difference, so that the delay y11 between adjacent symbols approaches y1, and y12 approaches y2. When y11 approaches y1 and y12 approaches y2, the amplitude of the first optical signal is closer to an ideal value, thereby improving the reliability of denoising.

According to the communication principle, there is also a mapping relationship between the amplitude of the first optical signal and the amplitude of the electrical signal. Therefore, through the mapping relationship, the optical domain sampling frequency difference can also be expressed as the difference in the amplitude of the electrical signal. For example, Fig. 2b is a second structural schematic diagram of the receiver provided in the embodiment of the present application. As shown in FIG. 2 b , the receiver 200 includes an optical equalizer 201 , a photoelectric conversion module 204 , an analog-to-digital converter 205 , a sampling frequency difference estimation module 202 and a voltage conversion module 203 . The optical equalizer 201 is configured to adjust the power of the optical signal received by the receiver 200 according to the delay line control signal to obtain the first optical signal. The photoelectric conversion module 204 is used for converting the first optical signal into a first analog electrical signal. The analog-to-digital converter 205 is used to convert the first analog electrical signal into a first digital electrical signal. The sampling frequency difference estimating module 202 is configured to obtain the optical domain sampling frequency difference of the optical equalizer 201 according to the first digital electrical signal. Specifically, the reference amplitude of the first digital electrical signal may be stored in the receiver 200 . After receiving the first digital electrical signal, the sampling frequency difference estimation module 202 acquires the amplitude of the first digital electrical signal. Afterwards, the sampling frequency difference estimation module 202 calculates the difference between the amplitude of the first digital electrical signal and the reference amplitude to obtain the optical domain sampling frequency difference. The voltage conversion module 203 is configured to receive the optical domain sampling frequency difference from the sampling frequency difference estimation module 202, and convert the optical domain sampling frequency difference into a new delay line control signal. 203 The optical equalizer 201 is used to adjust the power of the optical signal received by the receiver 200 according to the new delay line control signal.

It should be understood that, in practical applications, the optical domain sampling frequency difference may also be expressed as a difference in amplitude of an analog electrical signal. At this time, the receiver 200 may store the reference amplitude of the first analog electrical signal. After receiving the first analog electrical signal, the sampling frequency difference estimation module acquires the amplitude of the first analog electrical signal. Afterwards, the sampling frequency difference estimating module calculates the difference between the amplitude of the first analog electrical signal and the reference amplitude to obtain the optical domain sampling frequency difference.

In practical applications, the sampling frequency of the analog-to-digital converter 205 may deviate. The deviation will cause the optical domain sampling frequency difference measured by the sampling frequency difference estimation module 202 to be inaccurate. Inaccurate optical domain sampling frequency difference will affect the reliability of denoising. To this end, before the sampling frequency difference estimation module 202 measures the optical domain sampling frequency difference, the receiver 200 may adjust the sampling frequency of the analog-to-digital converter 205 . Various ways of adjusting the sampling frequency of the analog-to-digital converter 205 are described separately below. Moreover, in the following description, the receiver 200 shown in FIG. 2b will be taken as an example to describe the receiver provided by this application.

The receiver 200 adjusts the sampling frequency of the analog-to-digital converter 205 according to the clock signal. Fig. 3 is a third structural schematic diagram of the receiver provided in the embodiment of the present application. As shown in FIG. 3 , on the basis of FIG. 2 b , the receiver 200 further includes an electrical filter 301 . According to the foregoing description, it can be known that the photoelectric conversion module 204 can obtain the first analog-to-digital electrical signal according to the first optical signal. The first analog digital electrical signal carries a clock signal and a data signal. The electrical filter 301 is used to receive the first analog digital electrical signal, and obtain a data signal and a clock signal according to the first analog digital electrical signal. The electrical filter 301 is used to transmit clock signals and data signals to the analog-to-digital converter 205 . The analog-to-digital converter 205 is used to adjust the sampling frequency according to the clock signal to obtain the adjusted sampling frequency. The analog-to-digital converter 205 is configured to convert the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency. After adjusting the sampling frequency of the analog-to-digital converter 205, the sampling frequency difference estimating module 202 is configured to obtain the optical domain sampling frequency difference of the first digital electrical signal. Therefore, the present application can improve the accuracy of the acquired optical domain sampling frequency difference, thereby improving the reliability of denoising.

It should be understood that in order to prevent the clock signal from affecting the data signal. The frequency spectrum of clock signal and data signal can be staggered. At this time, the receiver 200 may further include a frequency shift module. After the clock signal is obtained by the electrical filter 301, the frequency shift module is used to perform proper spectrum shift on the clock signal.

The receiver 200 adjusts the sampling frequency of the analog-to-digital converter 205 according to the switch. Fig. 4 is a fourth schematic structural diagram of the receiver provided in the embodiment of the present application. As shown in FIG. 4 , on the basis of FIG. 2 b , the receiver 200 further includes a switch 401 .

First, the receiver 200 is used to place the switch 401 in the second state. When the switch 401 is in the second state, the switch 401 is used to transmit the optical signal received by the receiver 200 to the photoelectric conversion module 204 . The photoelectric conversion module 204 is used to convert the optical signal received by the receiver 200 into a second analog electrical signal. The photoelectric conversion module 204 is used for transmitting the second analog electrical signal to the analog-to-digital converter 205 . The analog-to-digital converter 205 is used to convert the second analog electrical signal into a second digital electrical signal. The sampling frequency difference estimating module 202 is configured to obtain the first electrical domain sampling frequency difference according to the second digital electrical signal. When the sampling frequency of the analog-to-digital converter 205 deviates, the amplitude of the second digital electrical signal will change. Therefore, the sampling frequency difference estimating module 202 can obtain the first electrical domain sampling frequency difference by measuring the amplitude of the second digital electrical signal. Specifically, the reference amplitude of the second digital electrical signal may be stored in the receiver 200 . After receiving the second digital electrical signal, the sampling frequency difference estimation module 202 acquires the amplitude of the second digital electrical signal. Afterwards, the sampling frequency difference estimating module 202 calculates the difference between the amplitude of the second digital electrical signal and the reference amplitude to obtain the first electrical domain sampling frequency difference. The sampling frequency difference estimating module 202 is configured to transmit the first electrical domain sampling frequency difference to the analog-to-digital converter 205 . The analog-to-digital converter 205 is configured to adjust the sampling frequency according to the first electrical domain sampling frequency difference to obtain an adjusted sampling frequency.

Second, the receiver 200 is used to place the switch 401 in the first state. When the switch 401 is in the first state, the switch 401 is used to transmit the optical signal received by the receiver 200 to the optical equalizer 201 . The optical equalizer 201 is configured to reduce noise in the optical signal received by the receiver 200 according to the delay line control signal to obtain a first optical signal. The photoelectric conversion module 204 is used for converting the optical signal received by the receiver 200 into a second analog electrical signal. The photoelectric conversion module 204 is used for converting the first optical signal into a first analog electrical signal. The photoelectric conversion module 204 is used for transmitting the first analog electrical signal to the analog-to-digital converter 205 . The analog-to-digital converter 205 is used to obtain the optical domain sampling frequency difference of the first analog electrical signal. The voltage conversion module 203 is configured to receive the optical domain sampling frequency difference from the sampling frequency difference estimation module 202, and convert the optical domain sampling frequency difference into a new delay line control signal. The optical equalizer 201 is used to adjust the power of the optical signal received by the receiver 200 according to the new delay line control signal.

In the embodiment of the present application, the receiver 200 first bypasses the optical equalizer 201 so that the optical domain sampling frequency difference of the optical equalizer 201 will not affect the first electrical domain sampling frequency difference. After eliminating the influence of the sampling frequency difference in the first electrical domain, the receiver 200 further reduces the influence of the sampling frequency difference in the optical domain on the denoising. Therefore, the present application can improve the reliability of noise cancellation. Moreover, in the embodiment of the present application, the changes to the transmitter are small, so that the adaptability of the scene can be improved.

In the foregoing description of FIG. 4 , the receiver 200 adjusts the sampling frequency of the analog-to-digital converter 205 once. In practical applications, one adjustment does not necessarily eliminate the sampling frequency difference between the electrical domain and the optical domain. Therefore, the receiver 200 can adjust the sampling frequency of the analog-to-digital converter multiple times. Specifically, after the analog-to-digital converter 205 adjusts the sampling frequency according to the first electrical domain sampling frequency difference to obtain the adjusted sampling frequency, the receiver 200 still puts the switch 401 in the second state. At this time, the switch 401 is used to transmit the optical signal received by the receiver 200 to the photoelectric conversion module 204 . The photoelectric conversion module 204 is used for converting the optical signal received by the receiver 200 into a second analog electrical signal. The analog-to-digital converter 205 is used to convert the second analog electrical signal into a second digital electrical signal according to the adjusted sampling frequency. The sampling frequency difference estimating module is used to obtain the sampling frequency difference of the second electrical domain according to the second digital electrical signal. When the second electric domain sampling frequency difference is smaller than the first threshold, the receiver 200 puts the switch 401 in the first state. When the second electrical domain sampling frequency difference is greater than or equal to the first threshold, the receiver 200 still puts the switch 401 in the second state. The receiver 200 repeats the aforementioned steps in the second state until the electrical domain sampling frequency difference of the second digital electrical signal is smaller than the first threshold. Therefore, by adjusting the sampling frequency of the analog-to-digital converter multiple times, the sampling frequency error of the analog-to-digital converter can be further reduced, thereby improving the reliability of noise cancellation.

According to the foregoing description of FIG. 4 , it can be known that the receiver 200 can acquire the optical domain sampling frequency difference of the first digital electrical signal, and adjust the delay line control signal according to the optical domain sampling frequency difference. However, in practical applications, in order to improve the reliability of noise cancellation, the receiver 200 needs to obtain a relatively accurate delay line control signal. Therefore, the receiver 200 may need to go through multiple cycles to obtain a relatively accurate delay line control signal. In order to reduce the number of cycles and improve the adjustment efficiency, the receiver 200 can acquire the optical domain sampling frequency difference according to the synchronization sequence.

Fig. 5 is a fifth structural schematic diagram of the receiver provided in the embodiment of the present application. As shown in FIG. 5 , on the basis of FIG. 4 , the receiver 200 further includes a sequence generator 501 . The sequence generator 501 is used to generate a reference sequence, and transmit the reference sequence to the sampling frequency difference estimation module 202 . When the switch 401 is in the first state, the sampling frequency difference estimating module 202 is configured to receive the first digital electrical signal from the analog-to-digital converter 205 . The first digital electrical signal includes a synchronization sequence and a data signal. The sampling frequency difference estimation module 202 is used for comparing the synchronization sequence with the reference sequence to obtain the optical domain sampling frequency difference. Alignment can be a correlation operation between a synchronous sequence and a reference sequence. The synchronization sequence and the reference sequence can be pseudo-random sequences. The sampling frequency difference estimation module 202 is used for transmitting the optical domain sampling frequency difference to the voltage conversion module 203 . The sampling frequency difference estimation module 202 is used for outputting data signals. For example, the receiver also includes a processor. The processor is used for receiving the data signal and performing data processing on the data signal.

In practical applications, there must be a deviation in the delay of the delay line, that is, there must be a difference in the optical domain sampling frequency of the first electrical signal. If the delay line control signal is adjusted if there is a deviation, the resources of the receiver 200 will be wasted. For this reason, the present application may set a second threshold. When the optical domain sampling frequency difference acquired by the sampling frequency difference estimation module 202 is greater than the second threshold, the receiver 200 adjusts the delay line control signal according to the optical domain sampling frequency difference. When the optical domain sampling frequency difference is less than or equal to the second threshold, the receiver 200 does not adjust the delay line control signal according to the optical domain sampling frequency difference. Therefore, the embodiment of the present application can save the resources of the receiver 200 .

It should be understood that the receivers 200 in the aforementioned Fig. 2a to Fig. 5 are just some examples provided in this application. In practical applications, those skilled in the art can make adaptive modifications to the receiver 200 according to requirements. Adaptive modifications may include one or more of the following.

For example, in FIG. 5 , the sampling frequency difference estimation module 202 includes a clock recovery module and an optical equalizer sampling frequency estimation module. FIG. 6 is a schematic structural diagram of a sampling frequency difference estimation module provided in an embodiment of the present application. As shown in FIG. 6 , the sampling frequency difference estimation module 202 includes a clock recovery module 601 and an optical equalizer sampling frequency estimation module 602 . When the switch 401 is in the second state, the clock recovery module 601 is used for receiving the second digital electrical signal from the analog-to-digital converter 205 . The clock recovery module 601 is configured to obtain the first electrical domain sampling frequency difference according to the second digital electrical signal, and transmit the first electrical domain sampling frequency difference to the analog-to-digital converter 205 . The clock recovery module 601 is also configured to transmit the second digital electrical signal to the optical equalizer sampling frequency estimation module 602 . The optical equalizer sampling frequency estimating module 602 is configured to output the second digital electrical signal. When the switch 401 is in the first state, the clock recovery module 601 is configured to receive the first digital electrical signal from the analog-to-digital converter 205 and transmit the first digital electrical signal to the optical equalizer sampling frequency estimation module 602 . The optical equalizer sampling frequency estimating module 602 is configured to obtain the optical domain sampling frequency difference of the first digital electrical signal, and transmit the optical domain sampling frequency difference to the voltage conversion module (not shown in FIG. 6 ). The optical equalizer sampling frequency estimation module 602 is also configured to output the first digital electrical signal.

For example, in FIGS. 3 to 5 , the receiver 200 further includes a clock module. In FIG. 3 , the clock module is used to receive a clock signal from an electrical filter 301 . The clock module is used to convert the clock signal into a sampling clock signal of the analog-to-digital converter 205 , and transmit the sampling clock signal to the analog-to-digital converter 205 . In FIG. 4 or FIG. 5 , the clock module is used to receive the first electrical domain sampling frequency difference from the sampling frequency difference estimating module 202 . The clock module is used to convert the sampling frequency difference of the first electrical domain into an adjusted sampling clock signal of the analog-to-digital converter 205 . The adjusted sampling clock signal includes sampling signal+sampling frequency difference. The clock module is used to transmit the adjusted sampling clock signal to the analog-to-digital converter 205 .

For example, in FIGS. 2 a to 5 , the voltage conversion module 203 includes a voltage converter and a digital-to-analog converter. The voltage converter receives the optical domain sampling frequency difference from the sampling frequency difference estimation module 202, and converts the optical domain sampling frequency difference into a digital electrical signal. Digital-to-analog converters are used to convert digital electrical signals into analog electrical signals. The analog electrical signal is the delay line control signal.

For example, in FIG. 2b the receiver 200 also includes a sequence generator 501 . The sequence generator 501 is used to generate a reference sequence. The sampling frequency difference estimation module 202 is used for receiving the first digital electrical signal from the analog-to-digital converter 205 . The synchronization sequence is carried in the first digital electrical signal. The sampling frequency difference estimation module 202 is used to obtain the optical domain sampling frequency difference according to the synchronization sequence and the reference sequence. The sampling frequency difference estimation module 202 is also configured to output the first digital electrical signal.

For example, in FIG. 4 , the sampling frequency difference estimation module 202 may be located before the photoelectric conversion module 204 . At this time, when the switch 401 is in the second state, the switch 401 is used to transmit the optical signal received by the receiver 200 to the photoelectric conversion module 204 . When the switch 401 is in the first state, the switch 401 is used to transmit the optical signal received by the receiver 200 to the optical equalizer 201 . The optical equalizer 201 is configured to reduce noise in the optical signal received by the receiver 200 according to the delay line control signal to obtain a first optical signal. The optical equalizer 201 is configured to transmit the first optical signal to the sampling frequency difference estimation module 202 . The sampling frequency difference estimating module 202 is configured to obtain the optical domain sampling frequency difference of the optical equalizer 201 according to the first optical signal. The sampling frequency difference estimation module 202 is also configured to transmit the first optical signal to the photoelectric conversion module 204 . For descriptions of other modules, reference may be made to related descriptions in FIG. 4 .

For example, in Figures 2a to 5, the receiver 200 also includes a processor and a memory. The processor is used for performing data processing on the first digital electrical signal. The processor may be a central processing unit (central processing unit, CPU), a network processor (network processor, NP) or a combination of CPU and NP. The processor can also be a hardware chip or other general purpose processor. The aforementioned hardware chip may be an application specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The memory is used for storing the first digital electrical signal. Memory can be volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. Wherein, the non-volatile memory can be read-only memory (read-only memory, ROM), programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), or flash memory wait. The volatile memory may be random access memory (RAM).

The receiver provided in this application is described above, and the receiving method provided in this application is described below. FIG. 7 is a schematic flowchart of a receiving method provided in an embodiment of the present application. As shown in Fig. 7, the receiving method includes the following steps.

In step 701, the receiver adjusts the power of the optical signal received by the receiver according to the delay line control signal to obtain a first optical signal. The receiver includes an optical equalizer. Before photoelectric conversion is performed on the optical signal received by the receiver, the receiver uses an optical equalizer to reduce noise in the optical signal received by the receiver to obtain a first optical signal. Delay lines are included in the optical equalizer. The delay line control signal is used to control the delay of the delay line.

In step 702, the receiver obtains the optical domain sampling frequency difference of the optical equalizer according to the first optical signal. Wherein, the receiver may also include a photoelectric conversion module and an analog-to-digital converter. After reducing the noise in the optical signal received by the receiver, the receiver converts the first optical signal into a first analog electrical signal through the photoelectric conversion module. After obtaining the first analog electrical signal, the receiver converts the first analog electrical signal into a first digital electrical signal through an analog-to-digital converter. The receiver can obtain the optical domain sampling frequency difference of the optical equalizer by measuring the first optical signal, the first analog electrical signal or the first digital electrical signal.

In step 703, the receiver converts the optical domain sampling frequency difference into a new delay line control signal. The optical domain sampling frequency difference may be the difference between the amplitude of the first digital electrical signal and the reference amplitude, or the difference between the amplitude of the first optical signal and the reference amplitude, or the difference between the amplitude of the first analog electrical signal and The difference between the reference magnitudes. The receiver converts the difference to a new delay line control signal.

In step 704, the receiver adjusts the power of the optical signal received by the receiver according to the new delay line control signal. It should be understood that, for the description of the receiving method in this application, reference may be made to the relevant description of the receiver in FIGS. 2a to 6 above. For example, the first analog electrical signal includes a clock signal. The receiver obtains a clock signal from the first analog electrical signal. The receiver adjusts the sampling frequency according to the clock signal to obtain the adjusted sampling frequency. The receiver converts the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency. For another example, the receiver also adjusts the sampling frequency of the analog-to-digital converter through a switch. For another example, the first digital electrical signal includes a synchronization sequence. The receiver obtains the optical domain sampling frequency difference through the synchronization sequence and the reference synchronization sequence. For example, after step 704, the receiver may repeatedly perform steps 701 to 702. The receiver acquires the optical domain sampling frequency difference of the optical equalizer again. If the optical domain sampling frequency difference of the optical equalizer is greater than the second threshold, the receiver repeats step 703, step 704, step 701 and step 702 until the optical domain sampling frequency difference of the optical equalizer is less than or equal to the second threshold.

It should be understood that, in order to ensure the reliability of noise cancellation for a long time, the receiver may periodically perform steps 701 to 704. For example, the receiver performs step 701 to step 704 at least once every hour.

The receiving method in this application is described above, and the optical communication system provided in this application is described below. FIG. 8 is a schematic structural diagram of an optical communication system provided in an embodiment of the present application. As shown in FIG. 8 , an optical communication system 800 includes a transmitter 801 and a receiver 802 . The transmitter 801 and the receiver 802 are connected by optical fiber. The transmitter 801 is used to transmit the optical signal received by the receiver 802 to the receiver 802 . The receiver 802 is configured to adjust the power of the optical signal received by the receiver 802 according to the delay line control signal to obtain the first optical signal. The receiver 802 is further configured to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal. The receiver 802 is also used to convert the optical domain sampling frequency difference into a new delay line control signal. The receiver 802 is also configured to adjust the power of the optical signal received by the receiver 802 according to the new delay line control signal.

It should be understood that, for the related description of the receiver 802, reference may be made to the description of the receiver in the preceding FIG. 2a to FIG. 6 . For example, the transmitter 801 is configured to generate an optical signal received by the receiver 802 according to the first analog electrical signal. The first analog electrical signal carries a data signal and a clock signal. The receiver 802 is configured to filter out a clock signal from the first analog electrical signal, adjust the sampling frequency according to the clock signal, and obtain an adjusted sampling frequency. The receiver 802 is configured to convert the first analog electrical signal into a first digital electrical signal according to the adjusted sampling frequency. For another example, the transmitter 801 is configured to generate the first analog electrical signal according to the first digital electrical signal. The synchronization sequence is included in the first digital electrical signal. Receiver 802 is used to generate a reference sequence. The receiver 802 is configured to obtain the optical domain sampling frequency difference according to the synchronization sequence and the reference sequence.

In practical applications, the transmitter 801 can also implement functions similar to those of the receiver 802 . Specifically, the receiver 802 is used to transmit an optical signal to the transmitter 801 . The transmitter 801 is configured to adjust the power of the optical signal received by the transmitter 801 according to the delay line control signal to obtain a second optical signal. The transmitter 801 is further configured to convert the second optical signal into a third analog electrical signal, and convert the third analog electrical signal into a third digital electrical signal. The transmitter 801 is also used to convert the third analog electrical signal into a third digital electrical signal. The transmitter 801 is also configured to acquire the optical domain sampling frequency difference of the third digital electrical signal. The transmitter 801 is also used to convert the optical domain sampling frequency difference into a new delay line control signal. The transmitter 801 is also configured to adjust the power of the optical signal received by the transmitter 801 according to the new delay line control signal. Therefore, for the description of the transmitter 801, reference is made to the description of the receiver in FIGS. 2a to 6 above.

The above is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the application, and should cover Within the protection scope of this application.

Claims

A receiver, characterized in that it includes an optical equalizer, a sampling frequency difference estimation module and a voltage conversion module, wherein:

The optical equalizer is used to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal;

The sampling frequency difference estimating module is configured to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal;

The voltage conversion module is used to convert the optical domain sampling frequency difference into a new delay line control signal;

The optical equalizer is further configured to adjust the power of the optical signal received by the receiver according to the new delay line control signal.
The receiver according to claim 1, wherein the receiver further comprises a photoelectric conversion module and an analog-to-digital converter;

The photoelectric conversion module is used to convert the first optical signal into a first analog electrical signal;

The analog-to-digital converter is used to convert the first analog electrical signal into a first digital electrical signal;

The sampling frequency difference estimating module is used to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal includes: the sampling frequency difference estimating module is used to obtain the optical domain sampling frequency difference according to the first digital electrical signal or the The first analog electrical signal obtains the optical domain sampling frequency difference.
The receiver according to claim 2, wherein the first analog electrical signal comprises a clock signal, and the receiver further comprises an electrical filter;

the electrical filter is used to obtain the clock signal in the first analog electrical signal;

The analog-to-digital converter is also used to adjust the sampling frequency according to the clock signal to obtain the adjusted sampling frequency;

The analog-to-digital converter converting the first analog electrical signal into a first digital electrical signal includes: the analog-to-digital converter converting the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency The first digital electrical signal.
The receiver according to claim 2, further comprising a switch;

The optical equalizer is configured to adjust the power of the optical signal received by the receiver according to the delay line control signal, and obtaining the first optical signal includes: when the switch is in the first state, the optical equalizer is configured to control the power of the optical signal according to the delay line adjusting the power of the optical signal received by the receiver to obtain the first optical signal;

When the switch is in the second state, the photoelectric conversion module is further configured to convert the optical signal received by the receiver into a second analog electrical signal;

The analog-to-digital converter is also used to convert the second analog electrical signal into a second digital electrical signal;

The sampling frequency difference estimating module is further configured to obtain the first electrical domain sampling frequency difference of the analog-to-digital converter according to the second digital electrical signal;

The analog-to-digital converter is further configured to adjust the sampling frequency according to the first electrical domain sampling frequency difference to obtain an adjusted sampling frequency;

The analog-to-digital converter converting the first analog electrical signal into a first digital electrical signal includes: the analog-to-digital converter converting the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency The first digital electrical signal.
The receiver according to claim 4, wherein when the switch is in the second state, the analog-to-digital converter is further configured to convert the second analog electrical signal according to the adjusted sampling frequency is the second digital electrical signal;

The sampling frequency difference estimating module is further configured to obtain a second electrical domain sampling frequency difference of the analog-to-digital converter according to the second digital electrical signal;

When the sampling frequency difference of the second electrical domain is less than a first threshold, the switch is in the first state.
The receiver according to any one of claims 1 to 5, wherein the first optical signal includes a synchronization sequence, and the receiver further includes a sequence generator;

The sequence generator is used to generate a reference synchronization sequence;

The sampling frequency difference estimating module is used to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal, including: the sampling frequency difference estimating module is used to pass the synchronization sequence and the reference synchronization sequence Obtain the optical domain sampling frequency difference.
The receiver according to claim 6, wherein the synchronization sequence is a pseudo-random sequence.
A receiving method, characterized by comprising:

adjusting the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal;

Acquiring the optical domain sampling frequency difference of the optical equalizer according to the first optical signal;

converting the optical domain sampling frequency difference into a new delay line control signal;

Adjusting the power of the optical signal received by the receiver according to the new delay line control signal.
The receiving method according to claim 8, further comprising:

converting the first optical signal to a first analog electrical signal;

converting the first analog electrical signal into a first digital electrical signal;

The acquiring the optical domain sampling frequency difference of the optical equalizer according to the first optical signal includes: acquiring the optical domain sampling frequency difference according to the first analog electrical signal or the first digital electrical signal.
The receiving method according to claim 9, wherein the first analog electrical signal comprises a clock signal, and the method further comprises:

obtaining the clock signal from the first analog electrical signal;

adjusting the sampling frequency according to the clock signal to obtain the adjusted sampling frequency;

Converting the first analog electrical signal into a first digital electrical signal includes: converting the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency.
The receiving method according to claim 9, characterized in that,

The adjusting the power of the optical signal received by the receiver according to the delay line control signal to obtain the first optical signal includes: when the switch is in the first state, adjusting the optical signal received by the receiver according to the delay line control signal power to obtain the first optical signal;

The method further includes: when the switch is in the second state, converting the optical signal received by the receiver into a second analog electrical signal; converting the second analog electrical signal into a second digital electrical signal; according to The second digital electrical signal acquires a first electrical domain sampling frequency difference; adjusts the sampling frequency according to the first electrical domain sampling frequency difference to obtain an adjusted sampling frequency;

The converting the first analog electrical signal into a first digital electrical signal includes: converting the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency.
The receiving method according to claim 11, further comprising:

when the switch is in the second state, converting the second analog electrical signal into the second digital electrical signal according to the adjusted sampling frequency;

Obtaining a second electrical domain sampling frequency difference according to the second digital electrical signal;

When the sampling frequency difference of the second electrical domain is less than a first threshold, the switch is placed in the first state.
The receiving method according to any one of claims 8 to 12, wherein the first optical signal includes a synchronization sequence;

The method also includes: generating a reference synchronization sequence;

The acquiring the optical domain sampling frequency difference of the optical equalizer according to the first optical signal includes: acquiring the optical domain sampling frequency difference through the synchronization sequence and the reference synchronization sequence.
An optical communication system, characterized in that it includes a transmitter and a receiver, wherein:

the transmitter is configured to send an optical signal to the receiver;

The receiver is configured to adjust the power of the optical signal received by the receiver according to the delay line control signal to obtain a first optical signal, obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal, and set The optical domain sampling frequency difference is converted into a new delay line control signal, and the power of the optical signal received by the receiver is adjusted according to the new delay line control signal.
The optical communication system according to claim 14, wherein the receiver is further configured to convert the first optical signal into a first analog electrical signal, and convert the first analog electrical signal into a first digital electric signal;

The receiver being used to obtain the optical domain sampling frequency difference of the optical equalizer according to the first optical signal includes: the receiver being used to obtain the optical domain sampling frequency difference according to the first digital electrical signal or the first analog electrical signal The optical domain sampling frequency difference.
The optical communication system according to claim 15, wherein the transmitter is further configured to generate an optical signal received by the receiver according to a first analog electrical signal, and the first analog electrical signal includes a clock signal:

The receiver is further configured to acquire the clock signal from the first analog electrical signal, adjust the sampling frequency according to the clock signal, and obtain the adjusted sampling frequency;

The receiver being used to convert the first analog electrical signal into the first digital electrical signal includes: the receiver being used to convert the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency A digital electrical signal.
The optical communication system according to claim 15, wherein,

The receiver is configured to adjust the power of the optical signal received by the receiver according to the delay line control signal, and obtaining the first optical signal includes: when the switch is in the first state, the receiver is configured to control the power of the optical signal according to the delay line adjusting the power of the optical signal received by the receiver to obtain the first optical signal;

When the switch is in the second state, the receiver is further configured to convert the optical signal received by the receiver into a second analog electrical signal, and convert the second analog electrical signal into a second digital electrical signal, Acquiring a first electrical domain sampling frequency difference according to the second digital electrical signal, and adjusting a sampling frequency according to the first electrical domain sampling frequency difference to obtain an adjusted sampling frequency;

The receiver being used to convert the first analog electrical signal into the first digital electrical signal includes: the receiver being used to convert the first analog electrical signal into the first digital electrical signal according to the adjusted sampling frequency A digital electrical signal.
The optical communication system according to claim 17, wherein when the switch is in the second state, the receiver is further configured to convert the second analog electrical signal into The second digital electrical signal, obtaining a second electrical domain sampling frequency difference according to the second digital electrical signal;

When the second electrical domain sampling frequency difference is less than a first threshold, the receiver is configured to put the switch in the first state.
The optical communication system according to any one of claims 14 to 18, wherein the first optical signal comprises a synchronization sequence;

The receiver is also used to generate a reference synchronization sequence;

The receiver being used to acquire the optical domain sampling frequency difference of the optical equalizer according to the first optical signal includes: the receiver being used to acquire the optical domain sampling by using the synchronization sequence and the reference synchronization sequence frequency difference.