WO2019010681A1

WO2019010681A1 - Dispersion compensation method and apparatus

Info

Publication number: WO2019010681A1
Application number: PCT/CN2017/092853
Authority: WO
Inventors: 周杰; 张亮; 左天健; 周恩波
Original assignee: 华为技术有限公司
Priority date: 2017-07-13
Filing date: 2017-07-13
Publication date: 2019-01-17
Also published as: CN110463151A

Abstract

A dispersion compensation method and apparatus, for use in resolving the optical fiber dispersion problem in an application scenario of communication between one sending side and multiple receiving sides. The method specifically comprises: a sending side obtains a subcarrier allocation result, the subcarrier allocation result comprising subcarriers allocated to at least two receiving sides according to a signal-to-noise ratio result of transmission signals between the sending side and the at least two receiving sides; and the sending side performs dispersion compensation on subcarriers allocated to the receiving sides corresponding to different communication distances according to a correspondence between communication distances and dispersion compensation values.

Description

Dispersion compensation method and device

Technical field

The present application relates to the field of optical fiber communication technologies, and in particular, to a dispersion compensation method and apparatus.

Background technique

With the rapid development of mobile Internet applications (such as high-definition video, 3D live broadcast, virtual reality, etc.), the system performance requirements for short-distance optical communication are getting higher and higher. For short-range optical communications, device cost and power consumption are major considerations for system performance. At present, in short-distance optical communication, more applications are direct detection techniques. The direct detection technology uses the light intensity carrying information to transmit to the receiving end, so that the receiving end converts the optical signal into an electrical signal after receiving the optical signal.

When applying direct detection technology in short-distance optical communication, the problem of fiber dispersion must be considered. That is, the optical signal transmitted by the transmitting end is transmitted to the receiving end after being transmitted through the optical fiber, and the dispersion generated by the optical fiber transmission causes the electrical signal after the conversion of the receiving end. Power fading occurs. At present, the commonly used method for solving fiber dispersion is mainly for an application scenario in which a transmitting end communicates with a receiving end, and the transmitting end compensates a pre-configured dispersion compensation value for the electrical signal, and then converts the compensated electrical signal into an optical signal. Send to the receiving end to solve the problem of fiber dispersion. However, there is currently no good solution in an application scenario where one sender communicates with multiple receivers.

Summary of the invention

The embodiment of the present application provides a dispersion compensation method and device to solve the fiber dispersion problem in an application scenario in which a transmitting end communicates with multiple receiving ends.

In a first aspect, the embodiment of the present application provides a dispersion compensation method, where the method can be applied to a transmitting end, the transmitting end communicates with at least two receiving ends, and the transmitting end and the at least two receiving ends The communication distance between the terminals is different, the method includes: the sending end acquires a subcarrier allocation result, where the subcarrier allocation result includes a signal that is based on a signal transmitted between the sending end and the at least two receiving ends The noise ratio result is a subcarrier allocated by the at least two receiving ends. Then, the transmitting end performs dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value.

The foregoing solution provides a fiber dispersion solution for an application scenario in which a transmitting end communicates with multiple receiving ends. Since the communication distance between the transmitting end and the different receiving end is different, the generated dispersion is different, thereby requiring The dispersion compensation value is different. Compared with the dispersion compensation method in the prior art, the same dispersion value is compensated for different transmission distances. In the embodiment of the present application, the dispersion value corresponding to the transmission distance is compensated for each transmission distance, which effectively alleviates one. The fading phenomenon caused by fiber dispersion in the application scenario where the transmitting end communicates with multiple receiving ends helps to improve the performance of the optical communication system.

In a possible design, when the sending end obtains the subcarrier allocation result, the sending end may be implemented by: sending, by the sending end, the detecting to the at least two receiving ends respectively on the multiple subcarriers included in the preset carrier a signal, and receiving a signal to noise ratio result determined by the detection signal sent by each of the at least two receiving ends; the signal to noise ratio result includes a corresponding one of each of the preset carriers Signal to noise ratio value. And the transmitting end determines that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest one of the plurality of signal to noise ratio values corresponding to the i th subcarrier; The signal to noise ratio result of a signal to noise ratio value is sent by the first receiving end; The number is not greater than a positive integer of the number of subcarriers included in the preset carrier. The transmitting end then allocates the ith subcarrier to the first receiving end, and the first receiving end is any one of at least two receiving ends.

In the above design, the transmitting end can ensure that the signal-to-noise ratio corresponding to each sub-carrier after being allocated is the largest among the multiple SNR values corresponding to the sub-carrier, thereby contributing to improving system performance.

In a possible design, the sending end obtains the subcarrier allocation result, and may be implemented by: sending, by the sending end, the detecting to the at least two receiving ends respectively on the multiple subcarriers included in the preset carrier a signal, and receiving a signal to noise ratio result determined by the detection signal sent by each of the at least two receiving ends; the signal to noise ratio result includes a corresponding one of each of the preset carriers Signal to noise ratio value. The transmitting end determines that the second signal to noise ratio value corresponding to the jth subcarrier in the preset carrier is the largest of the plurality of signal to noise ratio values corresponding to the jth subcarrier; The signal to noise ratio result of the second signal to noise ratio is sent by the second receiving end; the j is taken over a positive integer not greater than the number of subcarriers included in the preset carrier. And assigning the jth subcarrier to the second receiving end. Afterwards, the transmitting end determines a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the second receiving end, and determines a signal to noise ratio value corresponding to each subcarrier allocated to the third receiving end. And a value, the second receiving end and the third receiving end are any two of the at least two receiving ends. Finally, the transmitting end adjusts when the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end exceeds a preset range a subcarrier allocated to the second receiving end and a subcarrier allocated to the third receiving end, such that a sum value corresponding to the subcarrier allocated to the second receiving end is allocated to the third receiving end The difference between the sum values corresponding to the subcarriers is within a preset range.

Optionally, the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the subcarrier corresponding to the third receiving end is not exceeded by the sending end. In the noise ratio range, the subcarriers allocated to the second receiving end and the subcarriers allocated to the third receiving end are no longer adjusted.

In the above design, the transmitting end may ensure that the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end is in a preset signal to noise ratio range. Therefore, since the signal-to-noise ratio value is inversely proportional to the error rate, the difference between the error rate of the second receiving end and the error rate of the third receiving end is within a preset error rate range, which is helpful for improvement. System performance.

Optionally, the obtaining, by the sending end, the subcarrier allocation result may be implemented by: sending, by the sending end, the detecting signals to the at least two receiving ends on the multiple subcarriers included in the preset carrier, and receiving a signal to noise ratio result determined by the detection signal sent by each of the at least two receiving ends; the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier . The transmitting end determines that the second signal to noise ratio value corresponding to the jth subcarrier in the preset carrier is the largest of the plurality of signal to noise ratio values corresponding to the jth subcarrier; The signal to noise ratio result of the second signal to noise ratio is sent by the second receiving end; the j is taken over a positive integer not greater than the number of subcarriers included in the preset carrier. The transmitting end allocates the jth subcarrier to the second receiving end. Afterwards, the transmitting end determines a modulation format corresponding to each subcarrier according to the subcarrier allocated for the second receiving end and the subcarrier allocated for the third receiving end, and determines the transmission of the second receiving end according to the modulation format corresponding to each subcarrier. The capacity and the transmission capacity of the third receiving end determine whether the transmission capacity of the second receiving end or the transmission capacity of the third receiving end meets the system requirement. If it is determined that the transmission capacity of the second receiving end or the transmission capacity of the third receiving end does not meet the system requirement, the transmitting end adjusts the subcarrier allocated to the second receiving end and the subcarrier allocated to the third receiving end according to the system requirement, so that the adjusted second The transmission capacity of the receiving end meets the system requirements, and the adjusted transmission capacity of the third receiving end meets the system requirements. After determining that the adjusted transmission capacity of the first receiving end and the adjusted transmission capacity of the second receiving end satisfy the system requirements, the transmitting end does not adjust the subcarrier allocated to the second receiving end and The subcarrier allocated for the first receiving end.

Optionally, after determining that the transmission capacity of the second receiving end and the transmission capacity of the third receiving end meet the system requirements, the transmitting end may further determine the transmission capacity of the adjusted second receiving end and the adjusted transmission capacity of the third receiving end. Whether the difference is within the preset transmission capacity range. If it is determined that the difference between the adjusted transmission capacity of the second receiving end and the adjusted transmission capacity of the third receiving end exceeds the preset transmission capacity range, the transmitting end adjusts to the subcarrier allocated by the second receiving end and is the third receiving The subcarriers allocated by the terminal are such that the difference between the adjusted transmission capacity of the second receiving end and the adjusted transmission capacity of the third receiving end is within a preset transmission capacity range. If the difference between the transmission capacity of the first receiving end and the adjusted transmission capacity of the second receiving end is within the preset transmission capacity, the transmitting end is no longer adjusted to the subcarrier allocated by the second receiving end. And a subcarrier allocated for the first receiving end.

In the above design, the transmitting end may make the transmission capacity of the second receiving end and the transmission capacity of the third receiving end satisfy the system requirement, and make the difference between the transmission capacity of the second receiving end and the transmission capacity of the third receiving end be at the preset transmission capacity. Scope, which helps to improve system performance.

In a possible design, after the transmission end performs dispersion compensation for the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value, the transmitting end respectively sends the information to the transmitting end. A signal of each of the at least two receiving ends is subjected to Fourier transform. And then mapping the Fourier-transformed signal sent to the fourth receiving end to the dispersion-compensated sub-carrier allocated to the fourth receiving end, and performing inverse Fourier transform on the mapped signal and transmitting The fourth receiving end is any one of the at least two receiving ends.

In the above design, after the dispersion is compensated for the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value, the transmitting end transmits the Fourier transform to the fourth receiving end. The signal is mapped to the sub-carrier allocated for the fourth receiving end and is subjected to dispersion compensation, which helps to alleviate the fading phenomenon of the electrical signal received by the fourth receiving end.

Optionally, the transmitting end may also perform the dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value (that is, the transmitting end is allocated to the child allocated to the fourth receiving end. Before the carrier performs dispersion compensation, the time domain signal sent to the fourth receiving end is Fourier transformed. The Fourier transformed signal transmitted to the fourth receiving end is then mapped onto the subcarriers allocated for the fourth receiving end. Then, the signal after mapping the subcarriers is compensated for the dispersion compensation value corresponding to the communication distance between the fourth receiving end and the transmitting end (corresponding to the subcarrier compensation allocated to the fourth receiving end between the fourth receiving end and the transmitting end) The dispersion compensation value corresponding to the communication distance). Finally, the compensated signal is subjected to inverse Fourier transform and then sent to the fourth receiving end.

In the above design, the transmitting end compensates the dispersion compensation value corresponding to the communication distance between the fourth receiving end and the transmitting end for the signal after mapping the subcarrier, which helps to alleviate the fading phenomenon of the electrical signal received by the fourth receiving end.

In a second aspect, the embodiment of the present application provides a dispersion compensation apparatus, where the apparatus is applied to a transmitting end, the transmitting end communicates with at least two receiving ends, and the transmitting end and the at least two receiving ends The communication distance is different, the device includes: an allocation unit, configured to acquire a subcarrier allocation result, where the subcarrier allocation result includes a signal and noise based on a signal transmitted between the transmitting end and the at least two receiving ends The result is a subcarrier allocated to the at least two receiving ends; a compensation unit, configured to allocate, according to a correspondence between the communication distance and the dispersion compensation value, a different communication distance included in the subcarrier allocation result acquired by the allocation unit The corresponding subcarriers of the receiving end perform dispersion compensation.

In a possible design, the allocating unit is specifically configured to receive each of the at least two receiving ends And a signal to noise ratio result of the signal transmitted between each of the receiving end and the transmitting end, and the signal to noise ratio result sent by the at least two receiving ends is allocated to the at least two receiving ends Subcarrier.

In a possible design, the allocating unit is configured to send a sounding signal to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receive each of the at least two receiving ends. a signal to noise ratio result determined by the receiving end based on the detection signal; the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier. And determining that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest one of the plurality of signal to noise ratio values corresponding to the i th subcarrier; wherein the first signal to noise ratio is included The signal to noise ratio result of the value is sent by the first receiving end; the i is taken over a positive integer not greater than the number of subcarriers included in the preset carrier. The ith subcarrier is then allocated to the first receiving end, and the first receiving end is any one of at least two receiving ends.

In a possible design, the allocating unit is configured to send a sounding signal to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receive each of the at least two receiving ends. a signal to noise ratio result determined by the receiving end based on the detection signal; the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier. And determining, by the second signal-to-noise ratio value corresponding to the j-th sub-carrier, the second signal-to-noise ratio corresponding to the j-th sub-carrier; wherein the second signal-to-noise ratio is included The signal-to-noise ratio result of the value is sent by the second receiving end; the j takes a positive integer not greater than the number of subcarriers included in the preset carrier, and allocates the jth subcarrier to the first Two receiving ends. And determining a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the second receiving end, and determining a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the third receiving end, The second receiving end and the third receiving end are any two of the at least two receiving ends. And adjusting to the second when the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end exceeds a preset range a subcarrier allocated by the receiving end and a subcarrier allocated to the third receiving end, such that a sum value corresponding to the subcarrier allocated to the second receiving end and a subcarrier corresponding to the third receiving end are allocated The difference between the values is within the preset range.

In one possible design, the apparatus further includes a Fourier transform unit and an inverse Fourier transform unit.

The Fourier transform unit is configured to send, to the compensation unit, the dispersion to the subcarriers corresponding to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value, and then send the The signal at each of the two receiving ends is Fourier transformed. The compensation unit is further configured to map, by the Fourier transform unit, the signal transformed by the Fourier transform unit to the fourth receiver, and the dispersion-compensated subcarrier, the The four receiving ends are any one of the at least two receiving ends. The inverse Fourier transform unit is configured to perform inverse Fourier transform on the signal mapped by the compensation unit, and then send the signal to the fourth receiving end.

Alternatively, the Fourier transform unit is configured to send to the compensation unit according to the correspondence between the communication distance and the dispersion compensation value, before performing dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances. a signal of each of the at least two receiving ends is subjected to Fourier transform; the allocating unit is further configured to map the signal transformed by the Fourier transform unit sent to the fourth receiving end to the On the subcarrier allocated by the fourth receiving end, the fourth receiving end is any one of the at least two receiving ends; the compensation unit is configured to allocate according to the correspondence between the communication distance and the dispersion compensation value. When the subcarriers of the receiving end corresponding to the different communication distances are used for the chromatic dispersion compensation included in the subcarrier allocation result obtained by the unit, specifically used for mapping the subcarriers according to the correspondence between the communication distance and the dispersion compensation value for the allocation unit The signal is subjected to dispersion compensation; the inverse Fourier transform unit is configured to perform inverse on the compensated signal of the compensation unit After the Fourier transform to a fourth reception end.

In a third aspect, the embodiment of the present application further provides a sending end, where the sending end communicates with at least two receiving ends, and a communication distance between the sending end and the at least two receiving ends is different. The transmitting includes a processor for storing a software program, the processor for reading a software program stored in the memory and implementing the method provided by any one of the first aspect or the first aspect above .

In a fourth aspect, the embodiment of the present application further provides a computer storage medium, where the software program stores a software program, where the software program can implement the first aspect or the first one when being read and executed by one or more processors Any of the aspects provided by the design.

In a fifth aspect, an embodiment of the present application provides a computer program product comprising instructions, when executed on a computer, causing a computer to perform the method provided by any one of the above first aspect or the first aspect.

DRAWINGS

FIG. 1 is a schematic structural diagram of a communication system according to an embodiment of the present application;

2 is a schematic diagram of a signal to noise ratio result of an electrical signal converted by each receiving end of three receiving ends according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of signal to noise ratio results corresponding to three receiving ends according to an embodiment of the present disclosure;

4 is a schematic diagram of a result of dividing a frequency band by a transmitting end for three receiving ends according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of a dispersion compensation apparatus according to an embodiment of the present disclosure;

FIG. 6A is a comparison diagram of a signal to noise ratio after a dispersion compensation value corresponding to 80 km and a dispersion compensation value corresponding to 40 km are respectively compensated for a receiving end with a communication distance of 80 km according to an embodiment of the present disclosure;

FIG. 6B is a comparison diagram of a signal to noise ratio after a dispersion compensation value corresponding to 40 km and a dispersion compensation value corresponding to 80 km are respectively compensated for a receiving end with a communication distance of 40 km according to an embodiment of the present disclosure;

FIG. 6C is a comparison diagram of a signal to noise ratio after a dispersion compensation value corresponding to 80 km and a dispersion compensation value corresponding to 60 km are respectively compensated for a receiving end with a communication distance of 80 km according to an embodiment of the present disclosure;

6D is a comparison diagram of signal to noise ratios after the compensation end of the communication distance of 40 km is compensated for the dispersion compensation value corresponding to 40 km and the dispersion compensation value corresponding to 60 km, respectively, provided by the embodiment of the present application;

FIG. 7 is a schematic structural diagram of a short-distance optical communication system according to an embodiment of the present disclosure;

FIG. 8A is a schematic structural diagram of a DDMZM according to an embodiment of the present disclosure;

FIG. 8B is a schematic diagram of a power modulation curve of a DDMZM according to an embodiment of the present application; FIG.

FIG. 9 is a schematic flowchart diagram of a dispersion compensation method according to an embodiment of the present disclosure;

10 is a schematic diagram of a signal to noise ratio result of a first receiving end and a signal to noise ratio result of a second receiving end according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a subcarrier allocated by a transmitting end to a first receiving end, and a subcarrier allocated by a transmitting end to a second receiving end according to an embodiment of the present disclosure;

FIG. 12 is a comparison diagram of system capacity when the transmission end solves the fiber dispersion problem by using the existing solution 1 and the existing solution 2 and the dispersion compensation method provided by the embodiment of the present application;

FIG. 13 is a diagram showing a bit error rate-signal-to-noise ratio corresponding to a receiving end when performing dispersion compensation by the prior art point-to-point dispersion compensation method according to the prior art and the dispersion compensation method provided by the embodiment of the present application. a comparison chart of the curves;

FIG. 14 is a schematic structural diagram of a dispersion compensation apparatus according to an embodiment of the present disclosure;

FIG. 15 is a schematic structural diagram of a terminal implementation manner according to an embodiment of the present disclosure.

Detailed ways

Referring to FIG. 1 , a communication system provided by an embodiment of the present application. The system includes a sender and multiple receivers. The communication distance between the transmitting end and the plurality of receiving ends is different. In FIG. 1, one transmitting end and three receiving ends are taken as an example. During the process of communication between the transmitting end and the receiving end through the optical fiber, power fading occurs due to fiber dispersion. When the communication distance between the transmitting end and the different receiving end is different, the situation in which power fading occurs is different.

Taking the communication system shown in FIG. 1 as an example, the communication distance between the transmitting end and the first receiving end is 10 km, and the communication distance between the transmitting end and the second receiving end is 40 km, between the transmitting end and the third receiving end. The communication distance is 80 km, and the transmitting end transmits optical signals to the three receiving ends on the plurality of subcarriers included in the carrier whose frequency range is [0, 36] GHz. The optical signals transmitted by the transmitting end are respectively transmitted to the three receiving ends after being transmitted through the optical fiber, and the three receiving ends respectively convert the received optical signals into electrical signals. Referring to FIG. 2, each receiving end of the three receiving ends is converted. The signal-to-noise ratio of the subsequent electrical signal results in a signal-to-noise ratio corresponding to each subcarrier in the carrier having a frequency range of [0, 36] GHz. It can be seen from FIG. 2 that the signal-to-noise ratio values of the receiving ends of different communication distances are not the same for the same subcarrier. That is to say, for the same subcarrier, the power fading corresponding to the receiving end of different communication distances is different.

At present, there are commonly used methods for solving fiber dispersion. The existing solution 1: for the receiving end of different communication distances, whether the signal-to-noise ratio of the receiving end exceeds a preset threshold to divide the frequency band, and the signal-to-noise ratio exceeds a preset threshold to consider that the frequency band is available. If the signal-to-noise ratio does not exceed the preset threshold, the frequency band is considered unusable, so as to avoid transmitting the optical signal to the receiving end in a frequency band with a relatively bad fading condition, thereby solving the problem of fiber dispersion.

Taking the communication system shown in FIG. 1 as a preset threshold value of -3 db, the communication distance between the transmitting end and the first receiving end is 25 km, and the communication distance between the transmitting end and the second receiving end is 50 km, and the transmitting end The communication distance with the third receiving end is 100 km. It is assumed that the carrier frequency band that can be used for communication between the transmitting end and the receiving end is [0, 10] GHz. Referring to FIG. 3, the signal-to-noise ratio results corresponding to the three receiving ends are respectively shown. For the first receiving end, the frequency band corresponding to the signal-to-noise ratio value exceeding -3db is [0, 5.9] GHz, so the first receiving end can use the frequency band [0, 5.9] GHz; similarly, the second receiving end can use the frequency band [ 0, 4.2] GHz and [9, 10] GHz, and the band [4.2, 9] GHz cannot be used. The third receiving end can use the bands [0, 2.9] GHz and [6.3, 9] GHz instead of the bands [2.9, 6.3] GHz and [9, 10] GHz. Referring specifically to FIG. 4, the result of dividing the frequency band for the three receiving ends at the transmitting end.

However, when the problem of fiber dispersion is solved by the method in which the transmitting end allocates different subcarriers for the receiving ends of different communication distances, the signal to noise ratio values of all the transmitting ends on some subcarriers are less than a preset threshold, then these subcarriers It is not available. Taking the signal-to-noise ratio result shown in FIG. 3 and the result of dividing the frequency band shown in FIG. 4 as an example, the signal-to-noise ratio of the first receiving end in the frequency band [5.9, 6.3] GHz is less than -3 db, so The first receiving end cannot use the frequency band [5.9,6.3] GHz; the second receiving end has a signal-to-noise ratio value of less than -3 db in the frequency band [5.9, 6.3] GHz, so the second receiving end cannot use the frequency band as [5.9, 6.3] GHz; the signal-to-noise ratio of the third receiver at the band [5.9, 6.3] GHz is also less than -3 db, so the third receiver can also use the band [5.9, 6.3] GHz. Therefore, the band is [5.9, 6.3] GHz is not available, resulting in wasted resources.

In addition to the existing scheme 1, the currently used method for solving the fiber dispersion has the existing scheme 2: the transmitting end compensates a pre-configured dispersion compensation value for the electrical signal, and then converts the compensated electrical signal into an optical signal for transmission to the receiving. To solve the problem of fiber dispersion. Specifically, as shown in FIG. 5, the transmitting end compensates a pre-configured dispersion compensation value by the dispersion compensation module, and then passes through a digital-to-analog converter (English: digital to analog converter, DAC) and parallel two-electrode Mach. Del modulator (English: dual-drive mach-zehnder modulator, Abbreviation: DDMZM) Converts the dispersion-compensated electrical signal into an optical signal. The transmitting end sends the converted optical signal to the receiving end through a single mode fiber (English: single mode fiber, SMF for short), so that the receiving end passes the filter and the optical receiving module after receiving the optical signal (English: Receiver optical) Sub assembly, referred to as: ROSA), oscilloscope (English: oscilloscope, abbreviation: OSC) and digital signal processing module (English: digital signal process, referred to as: DSP) converts the received optical signal into an electrical signal.

However, in an application scenario where a transmitting end communicates with multiple receiving ends, the communication distance between the transmitting end and the different receiving ends is different, and thus the corresponding dispersion is different, so that the required dispersion compensation values are different. Therefore, compensating the same dispersion compensation value for different communication distances may result in excessive or insufficient compensation for signals transmitted to some receiving ends, so that the signals received by these receiving ends still generate power fading, which seriously affects system performance.

For example, the communication distance between the transmitting end and the first receiving end is 80 km, and the communication distance between the transmitting end and the second receiving end is 40 km. For the first receiving end and the second receiving end, the same dispersion compensation value is compensated. When the compensated dispersion compensation value is a dispersion compensation value corresponding to 40 km, as shown in FIG. 6A, the signal-to-noise ratio result of the signal received by the first receiving end after compensating for the dispersion compensation value corresponding to 40 km corresponds to the compensation of 80 km. Comparing the signal-to-noise ratio results of the received signals after the dispersion compensation value, it can be seen that when the dispersion compensation value corresponding to 40 km is compensated for the first receiving end, the signal received by the first receiving end still generates due to insufficient compensation. Power fading. When the compensated dispersion compensation value is a dispersion compensation value corresponding to 80 km, as shown in FIG. 6B, the signal-to-noise ratio result of the signal received by the second receiving end after compensating the dispersion compensation value corresponding to 40 km corresponds to the compensation of 80 km. Comparing the signal-to-noise ratio results of the received signals after the dispersion compensation value, it can be seen that when the dispersion compensation value corresponding to 80 km is compensated for the second receiving end, the signal received by the second receiving end is still generated due to excessive compensation. Power fading. When the compensated dispersion compensation value is a dispersion compensation value corresponding to 60 km, as shown in FIG. 6C, the signal-to-noise ratio result of the signal received by the first receiving end after compensating for the dispersion compensation value corresponding to 60 km corresponds to the compensation of 80 km. Comparing the signal-to-noise ratio results of the received signal after the dispersion compensation value, it can be seen that when the dispersion compensation value corresponding to 60 km is compensated for the signal transmitted to the first receiving end, the signal received by the first receiving end still generates power. Decline. And, as shown in FIG. 6C, the signal-to-noise ratio result of the signal received by the second receiving end after compensating the dispersion compensation value corresponding to 40 km and the signal-to-noise ratio result of the signal received after compensating the dispersion compensation value corresponding to 60 km For comparison, it can be seen that when the dispersion compensation value corresponding to 60 km is compensated for the signal transmitted to the second receiving end, the signal received by the second receiving end still generates power fading.

Based on this, the embodiment of the present application provides a dispersion compensation method and device to solve the fiber dispersion problem in an application scenario in which a transmitting end communicates with multiple receiving ends. The method and the device are based on the same inventive concept. Since the principles of the method and the device for solving the problem are similar, the implementation of the device and the method can be referred to each other, and the repeated description is not repeated.

In order to make the embodiments of the present application easier to understand, the following description of the embodiments of the present application is to be construed as a limitation of the scope of the claims.

The signal-to-noise ratio (SNR) is a parameter that describes the proportional relationship between the active component and the noise component in the signal.

The conjugate signal refers to two signals with equal modulo values and opposite phases.

System requirements refer to the system's preset performance requirements for the receiver. The performance requirements include transmission capacity, signal-to-noise ratio, transmission capacity range, signal-to-noise ratio range, and so on. If the preset transmission capacity is 28Gb/s, when the actual transmission capacity of the receiving end is greater than or equal to 28Gb/s, the receiving end satisfies the system requirements, and vice versa, the system requirements are not met; or, the preset signal-to-noise ratio is 13dB. When the signal-to-noise ratio of the signal received by the receiving end is greater than or equal to 13 dB, the receiving end satisfies the system requirement, and vice versa, the system requirement is not met. Or, the preset transmission capacity ranges from [2, 4] Gb/s, when any two receivers When the difference of transmission capacity is within the range of [2, 4] Gb/s, the two receivers satisfy the system requirements, and vice versa, the system requirements are not met; or, the preset signal-to-noise ratio range [0, 1] dB, When the difference between the signal-to-noise ratios of the signals received by any two receiving ends is within the range of [0, 1] dB, then the two receiving ends satisfy the system requirements, and vice versa, the system requirements are not met, and so on.

Multiple means two or more.

In addition, it should be understood that in the description of the present application, the terms "first", "second" and the like are used only to distinguish the purpose of description, and are not to be understood as indicating or implying relative importance, nor as an indication. Or suggest the order.

The embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

A short-range optical communication system provided by an embodiment of the present application includes a transmitting end and a plurality of receiving ends. The communication distance between the sending end and the multiple receiving ends is different. The short-range optical communication system may be a communication system as shown in FIG. 1.

The short-distance optical communication system includes two receiving ends, which are respectively a first receiving end and a second receiving end. For details, refer to FIG. 7 , which is a short-distance optical communication system provided by an embodiment of the present application. The schematic diagram shows that in the short-distance optical communication system, the transmitting end can include a signal generating module, a dispersion compensation module, a digital-to-analog converter (English: digital to analog converter, referred to as DAC), and DDMZM. The signal generation module or the dispersion compensation module may be implemented by one or more general-purpose processors, which may be central processing units (CPUs), or digital processing units, and the like.

The signal generating module is configured to generate a time domain signal that is sent to the first receiving end and the second receiving end.

Specifically, the signal generating module may generate a time domain signal sent to the first receiving end and the second receiving end by:

The signal generating module first generates a binary bit sequence and then converts the binary bit sequence into a frequency domain signal, wherein when converting the binary bit sequence into a frequency domain signal, the positive frequency and the negative of the frequency domain signal are guaranteed The frequency is a conjugate signal. Then, the signal generating module converts the frequency domain signal into a time domain signal by inverse Fourier transform, wherein the number of sampling points when the frequency domain signal passes the inverse Fourier transform may be 512 points. Finally, the signal generating module adds the converted time domain signal and the synchronization signal to obtain a time domain signal transmitted to the first receiving end and the second receiving end.

The dispersion compensation module is configured to separately perform dispersion compensation on the time domain signal sent to the first receiving end and the time domain signal sent to the second receiving end.

The DAC is used to convert the dispersion-compensated signal that has undergone the dispersion compensation module into an analog signal.

DDMZM is used to convert the analog signal obtained by DAC conversion into an optical signal. FIG. 8A is a schematic structural diagram of a DDMZM according to an embodiment of the present application. The DDMZM includes two phase modulators (English: phase modulation, PM for short): upper arm PM and lower arm PM, each of which includes a radio frequency (English: radio frequency, abbreviated as: RF) port and a bias Set the port. The operating state of the DDMZM can be controlled by adjusting the voltage difference between the two bias ports included in the two PMs, for example, when the phase difference of the voltages of the two bias ports included in the two PMs is π/2, DDMZM In the best working condition. When adjusting the two bias port offsets at 1/2 of the power modulation curve, referring to the power modulation curve shown in Figure 8B, the DDMZM converts the electrical signal approximately linearly to the optical signal. The DDMZM also includes an optical input port and a light output port.

In the short-range optical communication system, the first receiving end and the second receiving end may each include a filter, a ROSA, an OSC, and a DSP module.

The filter is used for filtering the noise of the out-of-band amplifier spontaneous emission noise (English: amplifier spontaneous emission noise, referred to as ASE) in the optical signal received by the receiving end.

ROSA is used to convert an optical signal that filters out ASE noise into an electrical signal.

The OSC is used to convert an electrical signal obtained by ROSA conversion into a digital signal.

DSP for processing digital signals obtained by OSC conversion.

Based on the short-distance optical communication system shown in FIG. 7 , the embodiment of the present application provides a dispersion compensation method. As shown in FIG. 9 , the dispersion compensation method can be applied to a dispersion compensation module at a transmitting end, and the dispersion compensation method may specifically include as follows:

S901, the sending end acquires a subcarrier allocation result, where the subcarrier allocation result includes a signal to noise ratio result based on a signal transmitted between the transmitting end and the at least two receiving ends, where the at least two receiving ends are Allocated subcarriers.

S902. The transmitting end performs dispersion compensation on the subcarriers allocated to the receiving ends corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value.

In the embodiment of the present application, the subcarrier allocation result is obtained by the sending end, where the subcarrier allocation result includes a signal to noise ratio result based on the transmitted signal between the transmitting end and the at least two receiving ends, and the result is at least two The subcarriers allocated by the receiving end are then subjected to dispersion compensation for the subcarriers allocated to the receiving ends corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value. Since the communication distance between the transmitting end and the different receiving end is different, the generated dispersion is different, and thus the required dispersion compensation value is different. Compared with the prior art dispersion compensation method, the same dispersion value is compensated for different transmission distances, In the embodiment of the present application, the chromatic dispersion value corresponding to the transmission distance is compensated for each transmission distance, which effectively mitigates the fading phenomenon caused by fiber dispersion in an application scenario in which a transmitting end communicates with multiple receiving ends, and helps to improve optical communication. System performance.

In a possible implementation manner, the sending end obtains a subcarrier allocation result, which can be implemented as follows:

A1, the sending end sends a sounding signal to the two receiving ends on the plurality of subcarriers included in the preset carrier, and receives a determination based on the detection signal sent by each receiving end of the two receiving ends. The signal to noise ratio results. The signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier.

Referring to FIG. 10, the result of the signal-to-noise ratio of the first receiving end and the signal-to-noise ratio of the second receiving end, wherein the communication distance between the transmitting end and the first receiving end is 40 km, and the transmitting end and the second receiving end are The communication distance between the two is 80km.

The detection signal may be a quadrature phase shift keying (QPSK) or a binary phase shift keying (BPSK). It can also be an octal phase shift keying signal (8 phase shift keying, 8PSK for short), and other signals. The embodiment of the present application is not specifically limited herein.

A2, the sending end determines that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest of the two signal to noise ratio values corresponding to the i th subcarrier; The signal to noise ratio result of the first signal to noise ratio value is sent by the first receiving end; the i is taken over a positive integer not greater than the number of subcarriers included in the preset carrier. The i-th subcarrier is then allocated to the first receiving end to determine a subcarrier allocated for the first receiving end. Based on the same method, the transmitting end determines the subcarrier allocated for the second receiving end.

When the short-distance optical communication system further includes a third receiving end, the sending end determines the method for the sub-carrier allocated by the third receiving end, and the method for determining the sub-carrier allocated by the transmitting end to the first receiving end, The application examples are not repeated here.

Specifically, taking the signal-to-noise ratio result shown in FIG. 10 as an example, the sub-carrier allocated by the transmitting end to be determined by the first receiving end and the sub-carrier allocated to the second receiving end may be implemented as follows:

B1. The transmitting end makes the reference signal to noise ratio SNR_Ref equal to the signal to noise ratio result SNR40 of the first receiving end.

B2, the sender compares the SNR value of each of the SNR80 and SNR_Ref subcarriers with respect to the signal to noise ratio of the second receiver.

B3, the transmitting end determines a subcarrier in which the SNR80 is greater than the SNR_Ref in the preset carrier, and allocates the subcarrier in the preset carrier with the SNR80 greater than the SNR_Ref to the second receiving end, and allocates the subcarrier in the preset carrier with the SNR80 less than or equal to the SNR_Ref The first receiving end determines the subcarrier allocated for the first receiving end, and determines the subcarrier allocated for the second receiving end.

For example, in combination with the signal-to-noise ratio corresponding to each subcarrier shown in FIG. 10, on the 19th to 47th subcarriers, the SNR value of SNR80 is smaller than the SNR value of SNR_Ref (that is, SNR40), and thus the 19th to 47th subcarriers are used. Assigned to the first receiving end. On the 47th to 67th subcarriers, the SNR value of SNR80 is greater than the SNR value of SNR_Ref, so the 47th to 67th subcarriers are allocated to the second receiving end. Specifically, as shown in FIG. 11, the subcarrier allocated to the first receiving end by the transmitting end and the subcarrier allocated by the transmitting end to the second receiving end are used. The corresponding frequency of the subcarriers is gradually increased from the 0th subcarrier to the 140th subcarrier, and the intervals of the center frequencies of any two adjacent subcarriers are equal.

Of course, the transmitting end can also make SNR_Ref equal to the signal-to-noise ratio result SNR80 of the second receiving end, and compare SNR40 with SNR_Ref. The transmitting end determines the subcarrier in the preset carrier with the SNR 40 greater than the SNR_Ref, and allocates the subcarrier in the preset carrier with the SNR 40 greater than the SNR_Ref to the first receiving end, and allocates the subcarrier in the preset carrier with the SNR 40 less than or equal to the SNR_Ref to the first carrier. The second receiving end determines the subcarrier allocated for the first receiving end, and determines the subcarrier allocated for the second receiving end.

In another possible implementation manner, the sending end obtains the subcarrier allocation result, and may also be implemented as follows:

C1, the sending end sends a sounding signal to the two receiving ends on the plurality of subcarriers included in the preset carrier, and receives, according to the detection signal, the sending signal sent by each receiving end of the two receiving ends. The signal to noise ratio results. The signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier. Go to step C2.

The detection signal may be QPSK, BPSK, or 8PSK, and may be other signals. The embodiment of the present application is not limited herein.

C2, the sending end determines that the first signal to noise ratio value corresponding to the jth subcarrier in the preset carrier is the largest of the two signal to noise ratio values corresponding to the jth subcarrier. If the signal to noise ratio result including the first signal to noise ratio value is sent by the first receiving end, assigning the jth subcarrier to the first receiving end, if the first signal to noise is included The signal to noise ratio result of the ratio is sent by the second receiving end, and the jth subcarrier is allocated to the second receiving end. Thereby determining the subcarriers allocated for the first receiving end and determining the subcarriers allocated for the second receiving end. Go to step C3.

C3. The transmitting end determines a sum of signal to noise ratio values corresponding to respective subcarriers allocated to the first receiving end, and a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the second receiving end. Perform step C4

C4. The difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the first receiving end exceeds a preset signal to noise ratio range. And adjusting a subcarrier allocated to the first receiving end and a subcarrier allocated to the second receiving end, so that a sum value corresponding to the subcarrier allocated to the second receiving end is the first receiving The difference between the sum values corresponding to the subcarriers allocated by the terminal is within a preset signal to noise ratio range.

Optionally, the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the subcarrier corresponding to the first receiving end is not exceeded by the sending end. In the noise ratio range, the subcarriers allocated to the second receiving end and the subcarriers allocated to the first receiving end are no longer adjusted.

When the short-distance optical communication system further includes a third receiving end, the transmitting end determines the sub-load allocated to the third receiving end. For the method of the wave, the method for determining the sub-carrier allocated by the first receiving end by the transmitting end may be specifically referred to in the step C1 to the step C4, and details are not repeatedly described herein.

In a further possible implementation manner, the sending end obtains the subcarrier allocation result, and may also be implemented as follows:

D1 to D2, see the above C1 to C2, and will not be described again here.

D3, the transmitting end determines a modulation format corresponding to each subcarrier according to the subcarrier allocated for the first receiving end and the subcarrier allocated for the second receiving end, and determines the transmission of the first receiving end according to the modulation format corresponding to each subcarrier. The capacity and the transmission capacity of the second receiving end, if it is determined that the transmission capacity of the first receiving end or the transmission capacity of the second receiving end does not satisfy the system requirement, step D4 is performed.

Specifically, the transmitting end determines, according to a signal to noise ratio corresponding to the mth subcarrier in the signal to noise ratio result of the first receiving end, a modulation format corresponding to the mth subcarrier, where the mth subcarrier is allocated by the transmitting end to the first receiving end. Any one of the subcarriers, so that the transmitting end determines the modulation format corresponding to each of the subcarriers allocated by the first receiving end, and then determines the first receiving end according to the modulation format of each subcarrier allocated for the first receiving end. Transmission capacity. For the manner of determining the transmission capacity according to the modulation format, refer to the determination scheme provided by the prior art, which is not repeatedly described in the embodiment of the present application.

For example, referring to the subcarrier allocation result shown in FIG. 11, the 19th to 47th subcarriers and the 67th to 95th subcarriers are allocated to the first receiving end, and then the 19th subunit is determined according to the signal to noise ratio value corresponding to the 19th subcarrier. a modulation format corresponding to the carrier, and determining a modulation format corresponding to each of the 20th to 47th subcarriers and the 67th to 95th subcarriers based on the same method, according to the determined 19th to 47th subcarriers, 67th to 95th The modulation format corresponding to each of the subcarriers determines the transmission capacity of the first receiving end.

For the method for determining the transmission capacity of the second receiving end, refer to the method for determining the transmission capacity of the first receiving end, which is not described in the embodiment of the present application.

D4, the transmitting end adjusts the subcarrier allocated to the first receiving end and the subcarrier allocated to the second receiving end according to system requirements, so that the adjusted transmission capacity of the first receiving end satisfies the system requirement and the adjusted transmission capacity of the second receiving end Meet system requirements. Optionally, after step D4 is performed, step D5 is performed.

D5, the transmitting end determines that the adjusted difference between the transmission capacity of the first receiving end and the adjusted transmission capacity of the second receiving end exceeds the preset transmission capacity range, and adjusts to the subcarrier allocated by the first receiving end and is the second The subcarriers allocated by the receiving end are such that the difference between the adjusted transmission capacity of the first receiving end and the adjusted transmission capacity of the second receiving end is within a preset transmission capacity range.

Optionally, the transmitting end does not adjust to the second receiving end when determining that the difference between the adjusted transmission capacity of the first receiving end and the adjusted transmission capacity of the second receiving end is within a preset transmission capacity range. The allocated subcarriers and the subcarriers allocated for the first receiving end.

When the short-distance optical communication system further includes a third receiving end, the transmitting end determines the method for the sub-carrier allocated by the third receiving end. For details, refer to step D1 to step D5, where the transmitting end determines that the first receiving end is allocated. The method of subcarriers is not repeated here.

In the embodiment of the present application, the transmitting end allocates the subcarrier allocated to the first receiving end and the subcarrier allocated to the second receiving end according to the preset signal to noise ratio range, so that the sum value corresponding to the subcarrier of the first receiving end is The sum value corresponding to the subcarriers of the second receiving end meets the system requirements, and the subcarriers allocated to the first receiving end and the subcarriers allocated to the second receiving end are adjusted so that the subcarriers allocated to the first receiving end The difference between the corresponding sum value and the sum value corresponding to the subcarrier allocated for the second receiving end is within a preset signal to noise ratio range. In addition, since the first receiving end is divided The sum of the signal to noise ratios of the assigned subcarriers is proportional to the transmission capacity determined by the subcarriers allocated for the first receiving end. The preset signal to noise ratio range is determined based on the preset transmission capacity range, or the preset transmission capacity range is determined based on the preset signal to noise ratio range. Therefore, the difference between the transmission capacity of the first receiving end and the transmission capacity of the second receiving end is within a preset transmission capacity range; since the signal to noise ratio is inversely proportional to the error rate, the error of the electrical signal after the first receiving end is converted. The difference between the rate and the error rate of the electrical signal converted by the second receiving end is within a preset error rate range. Therefore, after the subcarrier allocation result is obtained by the above manner, the subcarriers are allocated to each receiving end according to the SNR corresponding to each subcarrier transmitted by the different receiving end, according to the preset signal to noise ratio. The range or preset transmission capacity range is adjusted to the subcarriers allocated to each receiver, which can improve system performance, such as transmission capacity.

Optionally, on the one hand, after the transmission end allocates dispersion compensation to the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value (that is, the transmitting end is allocated to the first After the subcarriers at the receiving end and the subcarriers allocated to the second receiving end are respectively subjected to dispersion compensation, the transmitting end may perform Fourier transform on the time domain signal generated by the signal generating module. Afterwards, the transmitting end maps the Fourier-transformed frequency domain signal to the dispersion-compensated subcarrier allocated to the first receiving end, and then performs inverse Fourier transform on the mapped signal. Send to the first receiver. And transforming the Fourier-transformed frequency domain signal onto the dispersion-dispensed subcarrier allocated to the second receiving end, and then performing inverse Fourier transform on the mapped signal and transmitting to the second receiving end.

When the short-distance optical communication system further includes a third receiving end, after the transmitting end performs dispersion compensation on the sub-carrier allocated for the third receiving end, the transmitting end maps the Fourier-transformed frequency domain signal to the transmitting end. The dispersion-compensated subcarriers allocated to the third receiving end are then subjected to inverse Fourier transform for the mapped signals and then sent to the third receiving end.

On the other hand, the transmitting end may also perform the dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence relationship between the communication distance and the dispersion compensation value (that is, the transmitting end is for the child allocated to the first receiving end. The time domain signal generated by the signal generation module is subjected to Fourier transform before the carrier and the subcarriers allocated to the second receiving end are respectively subjected to dispersion compensation.

The Fourier transformed signal transmitted to the first receiving end is then mapped onto the subcarriers allocated for the first receiving end. Then, the signal after mapping the subcarriers is compensated for the dispersion compensation value corresponding to the communication distance between the first receiving end and the transmitting end (corresponding to the compensation between the first receiving end and the transmitting end for the subcarrier allocated to the first receiving end) The dispersion compensation value corresponding to the communication distance). Finally, the compensated signal is subjected to inverse Fourier transform and then sent to the first receiving end.

And translating the Fourier transformed signal sent to the second receiving end onto the subcarrier allocated for the second receiving end. Then, for the signal after mapping the subcarriers, the dispersion compensation value corresponding to the communication distance between the second receiving end and the transmitting end is compensated (corresponding to the compensation between the second receiving end and the transmitting end for the subcarrier allocated to the second receiving end) The dispersion compensation value corresponding to the communication distance). Finally, the compensated signal is subjected to inverse Fourier transform and then sent to the second receiving end.

The following takes the first receiving end as an example, and specifically describes a process in which the transmitting end sends the signal after the inverse Fourier transform to the first receiving end. In the embodiment of the present application, the process in which the transmitting end sends the signal after the inverse Fourier transform to the second receiving end is the same as the process in which the transmitting end sends the signal after the inverse Fourier transform to the first receiving end, so The process of transmitting the signal after the inverse Fourier transform to the second receiving end is performed by the transmitting end, and the process of transmitting the signal after the inverse Fourier transform to the first receiving end by the transmitting end, the embodiment of the present application is no longer here. Repeat the details.

Specifically, the sending end sends the signal after the inverse Fourier transform to the first receiving end, which can be adopted as follows achieve:

E1, the transmitting end loads a cyclic prefix (English: cyclic prefix, referred to as CP) on the signal after the inverse Fourier transform.

The embodiment of the present application helps to improve the anti-dispersion performance of the short-distance optical communication system by loading the cyclic prefix on the signal after the inverse Fourier transform.

E2, the transmitting end converts the signal loaded with the CP into an analog signal through the DAC, and determines the real part I of the analog signal and the imaginary part Q of the analog signal.

E3, the transmitting end processes the real part I of the analog signal through the electric domain driver and the attenuator respectively, and processes the imaginary part Q of the analog signal through the electric domain driver and the attenuator respectively.

E4, the transmitting end outputs the processed real part I of the analog signal and the processed imaginary part Q of the analog signal to the DDMZM shown in FIG. 7, respectively, thereby converting the analog signal into an optical signal, and then converting the converted signal. The optical signal is sent to the first receiving end.

Specifically, the transmitting end can input the processed real part I of the analog signal to the RF port of the upper arm PM of the DDMZM, and input the processed imaginary part Q to the RF port of the lower arm PM of the DDMZM, thereby driving the DDMZM. The two PMs work. The optical input port of the DDMZM receives a continuous light (English: continuous wave, referred to as CW), and the two PMs of the DDMZM convert the received continuous light into the analog signal under the driving of the analog signal. Light signal.

When the short-distance optical communication system further includes a third receiving end, the transmitting end sends the signal after the inverse Fourier transform to the third receiving end, and specifically, the transmitting end will undergo the inverse Fourier transform. The process of sending the signal to the first receiving end is not repeated here.

The following describes the process of processing the received optical signal by the first receiving end by taking the first receiving end as an example. In the embodiment of the present application, the process of processing the received optical signal by the first receiving end is the same as the process of processing the received optical signal by the second receiving end, so the second receiving end performs the received optical signal. For the process of processing, refer to the process of processing the received optical signal by the first receiving end, and details are not repeatedly described herein.

Specifically, the first receiving end processes the received optical signal, which can be implemented as follows:

F1. After receiving the optical signal, the first receiving end filters the received optical signal through the filter to filter out the ASE noise.

F2. The first receiving end converts the optical signal filtering the ASE noise into an electrical signal through the ROSA.

F3. The first receiving end converts the converted electrical signal into a digital signal through the OSC.

F4, the first receiving end processes the converted digital signal through the digital DSP.

When the short-distance optical communication system further includes a third receiving end, the third receiving end processes the received optical signal, and specifically, the process of processing the received optical signal by the first receiving end, The embodiments of the present application are not repeated here.

In the embodiment of the present application, the subcarrier allocation result is obtained by the sending end, where the subcarrier allocation result includes a signal to noise ratio result based on the transmitted signal between the transmitting end and the at least two receiving ends, and the result is at least two The subcarriers allocated by the receiving end are then subjected to dispersion compensation for the subcarriers allocated to the receiving ends corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value. Since the communication distance between the transmitting end and the different receiving end is different, the generated dispersion is different, and thus the required dispersion compensation value is different. Compared with the prior art dispersion compensation method, the same dispersion value is compensated for different transmission distances, In the embodiment of the present application, the chromatic dispersion value corresponding to the transmission distance is compensated for each transmission distance, which effectively alleviates the fading caused by fiber dispersion in an application scenario in which a transmitting end communicates with multiple receiving ends. Falling phenomenon helps to improve the performance of optical communication systems. And, when the transmitting end is a subcarrier allocated to the at least two receiving ends based on a signal to noise ratio result of a signal transmitted between the at least two receiving ends, adjusting, according to a preset signal to noise ratio range, each receiving The subcarriers allocated by the terminal are such that the sum values corresponding to the subcarriers allocated by each receiver satisfy the system requirements.

As shown in FIG. 12, the system capacity (that is, the sum of the transmission capacities of the receiving ends in the system) is solved by the dispersion compensation method provided by the existing scheme 1 and the existing scheme 2 and the embodiment of the present application. Comparison chart. Wherein, when the transmitting end solves the fiber dispersion problem through the existing solution 1, the system capacity reached by the transmitting end is 44 Gb/s; when the transmitting end solves the fiber dispersion problem through the existing solution 2, the system capacity reached by the transmitting end is 47 Gb/s; When the transmitting end solves the fiber dispersion problem by using the dispersion compensation method provided by the embodiment of the present application, the system capacity reached by the transmitting end is 60 Gb/s. It can be seen that the dispersion compensation method provided by the embodiment of the present application improves the system capacity to a certain extent, thereby improving system performance.

Referring to FIG. 13 , the bit error rate-signal-to-noise ratio curve corresponding to the receiving end after dispersion compensation by the dispersion compensation method provided by the embodiment of the present application is performed after the dispersion compensation is performed by the prior art point-to-point dispersion compensation method. In the comparison chart, the “56Gb/s 80km” curve is the error code after the dispersion compensation of the receiving end with the communication distance of 80km by using the point-to-point dispersion compensation method in the prior art with the system capacity of 56Gb/s. Rate-signal-to-noise ratio curve; the “56Gb/s40km” curve is the error after dispersion compensation for the receiver with a communication distance of 40km using the point-to-point dispersion compensation method in the prior art with a system capacity of 56Gb/s. The rate-signal-to-noise ratio curve; the "28Gb/s 80km" curve and the "28Gb/s 40km" curve are respectively used in the case where the system capacity is 56Gb/s, and the dispersion compensation method provided by the embodiment of the present application is used for the communication distance. The bit error rate-signal-to-noise ratio curve after dispersion compensation is performed at the receiving end of 80 km, and the bit error rate-signal-to-noise ratio curve after dispersion compensation is performed on the receiving end with a communication distance of 40 km. It can be seen from FIG. 13 that, when the signal-to-noise ratio is the same, the error rate after the dispersion compensation by the point-to-point dispersion compensation method in the prior art is greater than the dispersion compensation method provided by the embodiment of the present application. The bit error rate, as shown in Figure 13, the "56Gb/s 80km" curve has a signal-to-noise ratio of 23 corresponding to the bit error rate and the "56Gb/s 40km" curve has a signal-to-noise ratio of 23 corresponding to the bit error rate. The rate is higher than the error rate corresponding to the signal-to-noise ratio of 23 in the "28Gb/s 40km" curve and the error rate corresponding to the signal-to-noise ratio of 23 in the "28Gb/s 80km" curve. Therefore, the present application implements The dispersion compensation method provided by the example reduces the bit error rate and improves the system performance compared to the conventional point-to-point dispersion compensation method.

Based on the same inventive concept as the method embodiment, the embodiment of the present invention provides a dispersion compensation device, which can be applied to a dispersion compensation module at a transmitting end, or can be used as a dispersion compensation device when the dispersion compensation device is implemented in software. Dispersion compensation module at the transmitting end. The transmitting end communicates with the at least two receiving ends, and the communication distance between the sending end and the at least two receiving ends is different, specifically for implementing the method described in the embodiments described in FIG. 1 to FIG. The structure of the device is as shown in FIG. 14, and includes a distribution unit 1401 and a compensation unit 1402, wherein:

The allocating unit 1401 is configured to obtain a subcarrier allocation result, where the subcarrier allocation result includes a signal to noise ratio result based on a signal transmitted between the transmitting end and the at least two receiving ends, where the at least two receiving ends are Allocated subcarriers.

The compensation unit 1402 is configured to perform dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances included in the subcarrier allocation result acquired by the allocating unit 1401 according to the correspondence between the communication distance and the dispersion compensation value.

Optionally, the allocating unit 1401 is configured to receive a signal to noise ratio result of a signal transmitted between each of the receiving ends and the sending end sent by each receiving end of the at least two receiving ends, and And assigning a subcarrier to the at least two receiving ends based on a signal to noise ratio result respectively sent by the at least two receiving ends.

Optionally, the allocating unit 1401 is configured to send a sounding signal to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receive each of the at least two receiving ends. And a signal to noise ratio result determined based on the sounding signal; the signal to noise ratio result includes a signal to noise ratio value corresponding to each of the preset carriers. And determining that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest one of the plurality of signal to noise ratio values corresponding to the i th subcarrier; wherein the first signal to noise ratio is included The signal to noise ratio result of the value is sent by the first receiving end; the i is taken over a positive integer not greater than the number of subcarriers included in the preset carrier. The ith subcarrier is then allocated to the first receiving end, and the first receiving end is any one of at least two receiving ends.

Optionally, the allocating unit 1401 is configured to send a sounding signal to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receive each of the at least two receiving ends. And a signal to noise ratio result determined based on the sounding signal; the signal to noise ratio result includes a signal to noise ratio value corresponding to each of the preset carriers. And determining, by the second signal-to-noise ratio value corresponding to the j-th sub-carrier, the second signal-to-noise ratio corresponding to the j-th sub-carrier; wherein the second signal-to-noise ratio is included The signal-to-noise ratio result of the value is sent by the second receiving end; the j takes a positive integer not greater than the number of subcarriers included in the preset carrier, and allocates the jth subcarrier to the first Two receiving ends. And determining a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the second receiving end, and determining a sum of signal to noise ratio values corresponding to the respective subcarriers allocated to the third receiving end, The second receiving end and the third receiving end are any two of the at least two receiving ends. And adjusting to the second when the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end exceeds a preset range a subcarrier allocated by the receiving end and a subcarrier allocated to the third receiving end, such that a sum value corresponding to the subcarrier allocated to the second receiving end and a subcarrier corresponding to the third receiving end are allocated The difference between the values is within the preset range.

Optionally, the apparatus may further include a Fourier transform unit 1403 and an inverse Fourier transform unit 1404.

The Fourier transform unit 1403 is configured to: after the compensation unit 1402 performs dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value, respectively A signal of each of the at least two receiving ends is subjected to Fourier transform. The compensating unit 1402 is further configured to map, by using the Fourier transform unit 1403, the signal that is sent to the fourth receiving end to the sub-carrier that is allocated to the fourth receiving end and is subjected to dispersion compensation. The fourth receiving end is any one of the at least two receiving ends. The inverse Fourier transform unit 1404 is configured to perform inverse Fourier transform on the signal after the mapping by the compensation unit 1402, and then send the signal to the fourth receiving end.

Alternatively, the Fourier transform unit 1403 is configured to send, respectively, the compensation unit 1402 according to the correspondence between the communication distance and the dispersion compensation value, before performing dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances. Performing a Fourier transform on the signal of each of the at least two receiving ends; the allocating unit 1401 is further configured to map the signal transformed by the Fourier transform unit 1403 to the fourth receiving end To the subcarrier allocated for the fourth receiving end, the fourth receiving end is any one of the at least two receiving ends; the compensating unit 1402 is in accordance with the correspondence between the communication distance and the dispersion compensation value And performing the chromatic dispersion compensation on the subcarriers that are allocated to the receiving end corresponding to the different communication distances, and the specificity is used for the allocation according to the correspondence between the communication distance and the dispersion compensation value. The unit 1401 maps the signals after the subcarriers to perform dispersion compensation; the inverse Fourier transform unit 1404 is configured to The signal compensation element 1402 is sent to the inverse Fourier transform of the fourth receiver.

The division of the modules in the embodiment of the present application is schematic, and is only a logical function division. In actual implementation, there may be another division manner. In addition, each functional module in each embodiment of the present application may be integrated into one processing. Device In addition, it may be physically present alone, or two or more modules may be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

Wherein, when the integrated module can be implemented in the form of hardware, as shown in FIG. 15, the processor 1501, the memory 1502, and the communication interface 1503 can be included. The physical hardware corresponding to the allocation unit 1401, the compensation unit 1402, the Fourier transform unit 1403, and the inverse Fourier transform unit 1404 may be the processor 1501. The processor 1501 can be a central processing unit (English: central processing unit, CPU for short), or a digital processing unit or the like. The processor 1501 transmits and receives data through the communication interface 1503. The memory 1502 is configured to store a program executed by the processor 1501.

The specific connection medium between the processor 1501, the memory 1502, and the communication interface 1503 is not limited in the embodiment of the present application. In the embodiment of the present application, the memory 1502, the processor 1501, and the communication interface 1503 are connected by a bus 1504 in FIG. 15, and the bus is indicated by a thick line in FIG. 15, and the connection manner between other components is only schematically illustrated. , not limited to. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 15, but it does not mean that there is only one bus or one type of bus.

The memory 1502 may be a volatile memory (English: volatile memory), such as a random access memory (English: random-access memory, abbreviation: RAM); the memory 1502 may also be a non-volatile memory (English: non-volatile memory) For example, read-only memory (English: read-only memory, abbreviation: ROM), flash memory (English: flash memory), hard disk (English: hard disk drive, abbreviation: HDD) or solid state drive (English: solid-state drive Abbreviation: SSD), or memory 1502 is any other medium that can be used to carry or store desired program code in the form of an instruction or data structure and that can be accessed by a computer, but is not limited thereto. The memory 1502 may be a combination of the above memories.

The processor 1501 is configured to execute the program code stored in the memory 1502, and is specifically configured to perform the method described in the foregoing embodiments of the present invention, and may be implemented by referring to the corresponding embodiments in FIG. 1 to FIG. Narration.

The embodiments described herein are for illustrative purposes only and are not intended to limit the present application, and the functional modules in the embodiments and embodiments of the present application may be combined with each other without conflict.

In the embodiment of the present application, the subcarrier allocation result is obtained by the sending end, where the subcarrier allocation result includes a signal to noise ratio result based on the transmitted signal between the transmitting end and the at least two receiving ends, and the result is at least two The subcarriers allocated by the receiving end are then subjected to dispersion compensation for the subcarriers allocated to the receiving ends corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value. Since the communication distance between the transmitting end and the different receiving end is different, the generated dispersion is different, and thus the required dispersion compensation value is different. Compared with the prior art dispersion compensation method, the same dispersion value is compensated for different transmission distances, In the embodiment of the present application, the chromatic dispersion value corresponding to the transmission distance is compensated for each transmission distance, which effectively alleviates the fading phenomenon caused by fiber dispersion in an application scenario in which a transmitting end communicates with multiple receiving ends, and improves to a certain extent. The system capacity reduces the bit error rate and helps to improve the performance of the optical communication system.

And, when the transmitting end is a subcarrier allocated to the at least two receiving ends based on a signal to noise ratio result of a signal transmitted between the at least two receiving ends, adjusting, according to a preset signal to noise ratio range, each receiving The subcarriers allocated by the terminal are such that the signal to noise ratio and the value corresponding to the subcarriers allocated by each receiver satisfy the system requirements.

Those skilled in the art will appreciate that embodiments of the present application can be provided as a method, system, or computer program product. Thus, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment in combination of software and hardware. Moreover, the application can employ a meter implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer usable program code embodied therein. The form of the computer program product.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

It is apparent that those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, it is intended that the present invention cover the modifications and variations of the embodiments of the present invention.

Claims

A dispersion compensation method, wherein the method is applied to a transmitting end, the transmitting end communicates with at least two receiving ends, and a communication distance between the transmitting end and the at least two receiving ends is different , the method includes:

The transmitting end acquires a subcarrier allocation result, where the subcarrier allocation result includes a signal to noise ratio result based on a transmission signal between the transmitting end and the at least two receiving ends, which is allocated to the at least two receiving ends Subcarrier

The transmitting end performs dispersion compensation on the subcarriers allocated to the receiving ends corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value.
The method of claim 1, wherein the obtaining, by the transmitting end, the subcarrier allocation result comprises:

Sending, by the sending end, the sounding signals to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receiving, by the receiving end, the determining, a signal to noise ratio result; the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier;

Determining, by the sending end, that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest one of the plurality of signal to noise ratio values corresponding to the i th subcarrier; wherein the first The signal to noise ratio result of the signal to noise ratio is sent by the first receiving end; the i is taken over a positive integer not greater than the number of subcarriers included in the preset carrier;

The transmitting end allocates the i th subcarrier to the first receiving end, and the first receiving end is any one of at least two receiving ends.
The method of claim 1, wherein the obtaining, by the transmitting end, the subcarrier allocation result comprises:

Sending, by the sending end, the sounding signals to the at least two receiving ends on the plurality of subcarriers included in the preset carrier, and receiving, by the receiving end, the determining, a signal to noise ratio result; the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier;

Determining, by the sending end, that the second signal to noise ratio value corresponding to the jth subcarrier in the preset carrier is the largest one of the plurality of signal to noise ratio values corresponding to the jth subcarrier; wherein the second The signal to noise ratio result of the signal to noise ratio is sent by the second receiving end; the j is taken over a positive integer not greater than the number of subcarriers included in the preset carrier;

The transmitting end allocates the jth subcarrier to the second receiving end;

Determining, by the transmitting end, a sum of signal to noise ratio values corresponding to respective subcarriers allocated by the second receiving end, and determining a sum of signal to noise ratio values corresponding to respective subcarriers allocated to the third receiving end The second receiving end and the third receiving end are any two of the at least two receiving ends;

When the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end exceeds the preset signal to noise ratio range, Adjusting a subcarrier allocated to the second receiving end and a subcarrier allocated to the third receiving end, so that a sum value corresponding to the subcarrier allocated to the second receiving end is allocated to the third receiving end The difference between the sum values corresponding to the subcarriers is within the preset signal to noise ratio range.
The method according to any one of claims 1 to 3, characterized in that, according to the correspondence between the communication distance and the dispersion compensation value, the transmitting end performs dispersion compensation for the subcarriers allocated to the receiving end corresponding to different communication distances. The method further includes:

Transmitting, by the transmitting end, a signal sent to each of the at least two receiving ends by Fourier transform;

Transmitting, by the transmitting end, the Fourier-transformed signal sent to the fourth receiving end to the dispersion-compensated subcarrier allocated to the fourth receiving end, and performing inverse Fourier on the mapped signal Transmitted and transmitted, the fourth receiving end is any one of the at least two receiving ends.
A dispersion compensation device, wherein the device is applied to a transmitting end, the transmitting end communicates with at least two receiving ends, and a communication distance between the transmitting end and the at least two receiving ends is different The device includes:

An allocating unit, configured to obtain a subcarrier allocation result, where the subcarrier allocation result includes, by using a signal to noise ratio result of a signal transmitted between the transmitting end and the at least two receiving ends, the at least two receiving ends are allocated Subcarrier

The compensation unit is configured to perform dispersion compensation on the subcarriers allocated to the receiving end corresponding to different communication distances included in the subcarrier allocation result acquired by the allocating unit according to the correspondence between the communication distance and the dispersion compensation value.
The device according to claim 5, wherein the allocating unit is specifically configured to:

Receiving a signal to noise ratio result of a signal transmitted between each of the receiving ends and the transmitting end sent by each of the at least two receiving ends;

And assigning a subcarrier to the at least two receiving ends based on a signal to noise ratio result respectively sent by the at least two receiving ends.
The device according to claim 6, wherein the allocating unit is specifically configured to:

Sending a sounding signal to the at least two receiving ends on a plurality of subcarriers included in the preset carrier, and receiving a signal to noise ratio determined by each of the at least two receiving ends based on the sounding signal As a result, the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier;

Determining that the first signal to noise ratio value corresponding to the i th subcarrier in the preset carrier is the largest of the plurality of signal to noise ratio values corresponding to the i th subcarrier; wherein the first signal to noise ratio value is included The signal to noise ratio result is sent by the first receiving end; the i is taken over a positive integer not greater than the number of subcarriers included in the preset carrier;

And allocating the ith subcarrier to the first receiving end, where the first receiving end is any one of at least two receiving ends.
The device according to claim 6, wherein the allocating unit is specifically configured to:

Sending a sounding signal to the at least two receiving ends on a plurality of subcarriers included in the preset carrier, and receiving a signal to noise ratio determined by each of the at least two receiving ends based on the sounding signal As a result, the signal to noise ratio result includes a signal to noise ratio value corresponding to each subcarrier in the preset carrier;

Determining, by the second signal to noise ratio value corresponding to the jth subcarrier, the second signal to noise ratio value corresponding to the jth subcarrier; wherein the second signal to noise ratio value is included The signal-to-noise ratio result is sent by the second receiving end; the j is taken over a positive integer not greater than the number of subcarriers included in the preset carrier;

Allocating the jth subcarrier to the second receiving end;

Determining a sum of signal to noise ratio values corresponding to respective subcarriers allocated to the second receiving end, and determining a sum of signal to noise ratio values corresponding to respective subcarriers allocated to the third receiving end, where The second receiving end and the third receiving end are any two of the at least two receiving ends;

Adjusting to the difference when the difference between the sum value corresponding to the subcarrier allocated to the second receiving end and the sum value corresponding to the subcarrier allocated to the third receiving end exceeds a preset signal to noise ratio range a subcarrier allocated by the second receiving end and a subcarrier allocated to the third receiving end, so that a sum value corresponding to the subcarrier allocated to the second receiving end corresponds to a subcarrier allocated for the third receiving end The difference between the sum values is within the preset signal to noise ratio range.
The apparatus according to any one of claims 5 to 8, wherein the apparatus further comprises a Fourier transform unit and an inverse Fourier transform unit:

The Fourier transform unit is configured to send, to the compensation unit, the dispersion to the subcarriers corresponding to the receiving end corresponding to different communication distances according to the correspondence between the communication distance and the dispersion compensation value, and then send the a signal of each of the two receiving ends is subjected to Fourier transform;

The compensation unit is further configured to map, by the Fourier transform unit, the signal transformed by the Fourier transform unit to the fourth receiver, and the dispersion-compensated subcarrier, the The four receiving ends are any one of the at least two receiving ends;

The inverse Fourier transform unit is configured to perform inverse Fourier transform on the signal mapped by the compensation unit, and then send the signal to the fourth receiving end.
A transmitting end, wherein the transmitting end communicates with at least two receiving ends, and a communication distance between the transmitting end and the at least two receiving ends is different, and the device includes a memory and a processor. ;

The memory is configured to store a program executed by the processor;

The processor is configured to execute the program stored in the memory to perform the method of any one of claims 1 to 4.
A computer storage medium, characterized in that the computer readable storage medium stores computer executable instructions for causing the computer to perform the method of any one of claims 1 to 4.