Signal processing method and related apparatus and system

Abstract

Disclosed in the embodiments of the present application are a signal processing method and a related apparatus and system. A first optical signal sent by a sending device to a receiving device is a multi-wavelength signal, and after the first optical signal is transmitted by means of a channel, an interference signal may be generated due to the occurrence of a FWM phenomenon. The receiving device receives a second optical signal obtained after the first optical signal is transmitted by means of the channel, and performs detection on the second optical signal, so as to determine whether there is the interference signal generated due to FWM. Then, the receiving device can send a first frame to the sending device on the basis of a detection result of the second optical signal, such that the sending device determines, on the basis of the first frame, whether to adjust the wavelength of the first optical signal. It should be understood that if the detection result of the second optical signal indicates that there is an interference signal generated due to FWM, the first frame is used for instructing a sending end to adjust the wavelength of the first optical signal, so as to change a phase matching condition of FWM, thereby avoiding the occurrence of the FWM phenomenon and facilitating the improvement of the system performance.

Description

A signal processing method, related apparatus and system

[0001] This application claims priority to Chinese Patent Application No. 202411549830.X, filed with the State Intellectual Property Office of China on October 31, 2024, entitled “A Signal Processing Method and Related Apparatus and System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical communication, and more particularly to a signal processing method and related apparatus and system. Background Technology

[0003] In intensity modulation direct detection (IMDD) optical communication scenarios, the cost introduced by fiber nonlinearity is difficult to overcome. It usually requires suppression and compensation through reasonable system configuration, scheme design, or nonlinear algorithms with higher power consumption, such as reducing input light power, polarization interpolation, and non-equidistant wavelengths.

[0004] After the IMDD short-distance high-speed transmission system evolved from 2km to 10km, the wavelength scheme was changed from coarse wavelength division multiplexing (CWDM) to local area network wavelength division multiplexing (LAN-WDM), which has narrower spacing and lower dispersion, due to the increased dispersion cost. Since multiple wavelengths are located within the zero dispersion wavelength (ZDW) range, and the incident optical power is relatively high, the probability of fiber nonlinear four-wave mixing (FWM) increases significantly, leading to increased system performance costs, which is a problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a signal processing method, related apparatus, and system that can effectively avoid the occurrence of FWM phenomenon and improve system performance.

[0006] In a first aspect, embodiments of this application provide a signal processing method applied to a receiving device. Specifically, the receiving device receives a second optical signal after a first optical signal transmitted by a transmitting device has been transmitted through a channel. The first optical signal comprises optical signals of multiple wavelengths. The first optical signal may be subject to noise or other interference during transmission through the channel. For example, the first optical signal may experience four-wave mixing (FWM) during transmission through the channel, resulting in interference signals. Therefore, the second optical signal may have increased noise or other interference compared to the first optical signal. The receiving device then detects the second optical signal to determine whether interference signals caused by FWM exist. Furthermore, the receiving device sends a first frame to the transmitting device based on the detection result of the second optical signal, so that the transmitting device can determine whether to adjust the wavelength of the first optical signal based on the first frame.

[0007] In this embodiment, the receiving device can determine the information to be fed back to the transmitting device based on the detection result of the received second optical signal. This allows the transmitting device to know the transmission quality of the current optical signal in real time, thus helping to maintain good system performance in different scenarios. If the detection result of the second optical signal indicates that there is no interference signal caused by FWM, the receiving device should instruct the transmitting device to maintain the wavelength of the currently transmitted first optical signal. If the detection result of the second optical signal indicates that there is interference signal caused by FWM, the receiving device should instruct the transmitting device to adjust the wavelength of the currently transmitted first optical signal to change the phase matching condition of FWM, thereby avoiding the occurrence of FWM phenomenon and improving system performance.

[0008] In some possible implementations, the first frame is a data frame, which includes service data and preset bits. The preset bits are used to indicate whether the transmitting device should adjust the wavelength of the first optical signal. In this implementation, the receiving device can use the data frame sent to the transmitting device during the service transmission phase to carry the information that needs to be fed back. This achieves information feedback without affecting service transmission, resulting in good practical effects. Furthermore, using the preset bits reserved in the data frame to carry the information that needs to be fed back eliminates the need for additional expansion of the data frame, thus reducing the implementation cost.

[0009] In some possible implementations, the data frame includes forward error correction (FEC) codewords, which consist of service data and parity bits. In other words, the service data in the data frame is FEC encoded, improving the reliability of service data transmission.

[0010] In some possible implementations, each 8704 FEC codewords in the data frame includes 1024 preset bits to facilitate better standard compatibility.

[0011] In some possible implementations, the first frame is a training frame, and at least one bit in the control and / or state fields of the training frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal. In this implementation, the receiving device can use the training frame sent to the transmitting device during the link training (LT) phase to carry the information that needs to be fed back, thus expanding the applicable scenarios of this scheme. Furthermore, some bits in the control and state fields of the training frame have undefined uses and are reserved bytes, eliminating the need for further expansion of the training frame and resulting in lower implementation costs.

[0012] In some possible implementations, the first frame is a negotiation frame, where at least one bit in the base page and / or extended page of the negotiation frame is used to indicate whether the transmitting device should adjust the wavelength of the first optical signal. In this implementation, the receiving device can use the negotiation frame sent to the transmitting device during the auto-negotiation (AN) phase to carry the information that needs to be fed back, thus expanding the applicable scenarios of this scheme. Furthermore, some fields in the base page or extended page of the negotiation frame are not yet occupied, eliminating the need for additional expansion of the negotiation frame and resulting in lower implementation costs.

[0013] In some possible implementations, if the detection result of the second optical signal indicates the absence of interference, the first frame is used to instruct the transmitting device to maintain the wavelength of the first optical signal. In other words, the receiving device provides targeted feedback to the transmitting device based on the actual detection result of the second optical signal, allowing the transmitting device to know the current transmission quality of the optical signal in real time. If the transmission quality of the optical signal is good, no adjustment is needed from the transmitting device, thus helping to maintain good system performance for different scenarios.

[0014] In some possible implementations, if the detection result of the second optical signal indicates the presence of an interference signal, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal. That is, if the detection result of the second optical signal indicates the presence of an interference signal due to FWM (Fluid Wave Meter), the receiving device should notify the transmitting device to adjust the wavelength of the currently transmitted first optical signal to change the phase matching condition of the FWM, thereby avoiding the occurrence of the FWM phenomenon and improving system performance.

[0015] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of all or part of the optical signals in the first optical signal, thus enriching the ways in which the transmitting end can adjust the wavelength.

[0016] In some possible implementations, the first frame is used to instruct the transmitting device to gradually increase the wavelength of the first optical signal according to the wavelength adjustment precision, or the first frame is used to instruct the transmitting device to gradually decrease the wavelength of the first optical signal according to the wavelength adjustment precision. That is, the first frame is used to instruct the transmitting device to perform scanning wavelength adjustment according to the configured wavelength adjustment precision, which facilitates quickly finding the wavelength adjustment amount that meets the system performance requirements, thereby quickly suppressing the FWM phenomenon.

[0017] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal within the wavelength scanning range, which is equivalent to defining the wavelength scanning range and thus improving the efficiency of wavelength scanning.

[0018] In some possible implementations, after sending the first frame to the transmitting device, the method further includes: receiving a fourth optical signal after the third optical signal sent by the transmitting device has been transmitted through a channel, wherein the third optical signal is an optical signal obtained by the transmitting device adjusting the wavelength of the first optical signal; detecting the fourth optical signal to determine whether there is an interference signal; if the detection result of the fourth optical signal is that there is no interference signal, then sending a second frame to the transmitting device, the second frame being used to instruct the transmitting device to stop adjusting the wavelength of the first optical signal. In this implementation, as soon as the receiving device detects for the first time that the currently received optical signal does not have an interference signal caused by the FWM phenomenon during the wavelength adjustment process of the transmitting device, it immediately notifies the transmitting device to stop wavelength adjustment, which can achieve faster suppression of the FWM phenomenon.

[0019] In some possible implementations, after sending the first frame to the transmitting device, the method further includes: sequentially receiving multiple fourth optical signals obtained by transmitting multiple third optical signals transmitted by the transmitting device through a channel, wherein the multiple third optical signals are multiple optical signals obtained by the transmitting device adjusting the wavelength of the first optical signal across the wavelength scanning range; sequentially detecting the multiple fourth optical signals to determine the fourth optical signals without interference signals; determining a target wavelength adjustment amount from the wavelength adjustment amounts corresponding to the fourth optical signals without interference signals; and sending a second frame to the transmitting device, the second frame being used to instruct the transmitting device to adjust the wavelength of the first optical signal according to the target wavelength adjustment amount and then fix the wavelength. In this implementation, after the transmitting device has traversed all wavelengths within the wavelength scanning range, the receiving device selects the most suitable wavelength adjustment amount and informs the transmitting device to fix the wavelength. This is equivalent to not only effectively suppressing the FWM phenomenon but also selectively filtering wavelengths, which is more conducive to ensuring that the system can remain stable and unaffected by the FWM phenomenon.

[0020] In some possible implementations, there are multiple fourth optical signals without interference signals. Considering that the larger the wavelength adjustment, the greater the corresponding temperature change, and the greater the impact on system performance, the selected target wavelength adjustment is the wavelength adjustment with the smallest absolute value among the wavelength adjustments corresponding to the fourth optical signals without interference signals. This is more conducive to suppressing the FWM phenomenon and also helps to reduce the impact on the laser.

[0021] In some possible implementations, there are multiple fourth optical signals free from interference. Considering that some lasers in the transmitting end have relatively poor wavelength stability, wavelength drift may occur during actual use due to aging or changes in ambient temperature. The wavelength adjustment amount corresponding to the fourth optical signal free from interference includes at least one wavelength adjustment range. The target wavelength adjustment amount is the median of the target wavelength adjustment range among the medians of at least one wavelength adjustment range, and the absolute value of the median of the target wavelength adjustment range is the smallest among the medians of at least one wavelength adjustment range. That is to say, when selecting the most suitable wavelength adjustment amount, the receiving device needs to take the wavelength drift factor into account. The median of the wavelength adjustment range selected from multiple wavelength adjustment ranges that meet the system performance requirements is the most suitable wavelength adjustment amount. In this way, even if the laser wavelength may drift, selecting this wavelength adjustment amount can still suppress the FWM phenomenon, improving the reliability of this solution.

[0022] In some possible implementations, detecting the second optical signal includes: converting the second optical signal into an electrical signal and detecting the electrical signal; if a target signal with an amplitude greater than a threshold is detected within the effective frequency range of the electrical signal, the target signal is determined to be an interference signal. This implementation provides a specific method for nonlinear detection of optical signals, specifically performing nonlinear detection on the electrical signal after photoelectric conversion, so as to accurately detect interference signals caused by the FWM phenomenon that affect or reduce the service signal.

[0023] In some possible implementations, if the detection result of the second optical signal indicates the presence of an interference signal, the first frame is also used to instruct the transmitting device to reduce the emission power, which also helps to avoid the occurrence of FWM (Free-Wide) phenomenon. If the detection result of the second optical signal indicates the absence of an interference signal, the first frame is also used to instruct the transmitting device not to adjust the emission power.

[0024] Secondly, embodiments of this application provide a signal processing method applied to a transmitting device. Specifically, the transmitting device sends a first optical signal to a receiving device, the first optical signal comprising optical signals of multiple wavelengths. A second optical signal, after transmission through a channel, is received and detected by the receiving device. Then, the transmitting device receives a first frame sent by the receiving device based on the detection result of the second optical signal, wherein the detection result of the second optical signal indicates the presence of interference signals generated by FWM (Frequency Wavelength Modulation). Furthermore, the transmitting device determines whether to adjust the wavelength of the first optical signal based on the first frame.

[0025] In some possible implementations, the first frame is a data frame, which includes service data and preset bits, which are used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0026] In some possible implementations, the data frame includes an FEC codeword, which comprises service data and a parity bit. That is, the service data in the data frame is FEC encoded, improving the reliability of service data transmission.

[0027] In some possible implementations, each 8704 FEC codewords in the data frame includes 1024 preset bits to facilitate better standard compatibility.

[0028] In some possible implementations, the first frame is a training frame, and at least one bit in the control field and / or state field of the training frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0029] In some possible implementations, the first frame is a negotiation frame, and at least one bit in the base page and / or extended page of the negotiation frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0030] In some possible implementations, the method further includes: if the detection result of the second optical signal is that there is no interference signal, then maintaining the wavelength of the first optical signal according to the first frame.

[0031] In some possible implementations, the method further includes: if the detection result of the second optical signal indicates the presence of an interference signal, adjusting the wavelength of the first optical signal according to the first frame. Specifically, the transmitting device includes a temperature controller (TEC), which can adjust the TEC according to the first frame to change the ambient temperature of the laser in the transmitting device, thereby changing the wavelength of the light emitted by the laser, and thus adjusting the wavelength of the first optical signal.

[0032] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of all or part of the optical signals in the first optical signal.

[0033] In some possible implementations, the first frame is used to instruct the transmitting device to gradually increase the wavelength of the first optical signal according to the wavelength adjustment precision, or the first frame is used to instruct the transmitting device to gradually decrease the wavelength of the first optical signal according to the wavelength adjustment precision.

[0034] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal within the wavelength scanning range.

[0035] In some possible implementations, after the transmitting device adjusts the wavelength of the first optical signal according to the first frame, the method further includes: sending a third optical signal to the receiving device, wherein the third optical signal is an optical signal obtained by the transmitting device adjusting the wavelength of the first optical signal, and a fourth optical signal after the third optical signal is transmitted through the channel is received and detected by the receiving device, the detection result of the fourth optical signal being used to indicate whether there is an interference signal; if the detection result of the fourth optical signal is that there is no interference signal, receiving a second frame from the receiving device; and stopping the adjustment of the wavelength of the first optical signal according to the second frame.

[0036] In some possible implementations, after the transmitting device adjusts the wavelength of the first optical signal according to the first frame, the method further includes: sequentially transmitting a plurality of third optical signals, wherein the plurality of third optical signals are multiple optical signals obtained by the transmitting device adjusting the wavelength of the first optical signal by traversing the wavelength scanning range, and the plurality of third optical signals are respectively transmitted through the channel to a plurality of fourth optical signals which are received and detected by the receiving device; receiving a second frame from the receiving device, the second frame being used to instruct the transmitting device to adjust the wavelength of the first optical signal according to a target wavelength adjustment amount and then fix the wavelength, wherein the target wavelength adjustment amount is determined by the receiving device from the wavelength adjustment amount corresponding to the fourth optical signal where there is no interference signal; adjusting the wavelength of the first optical signal according to the target wavelength adjustment amount and then fixing the wavelength.

[0037] In some possible implementations, there are multiple fourth optical signals that do not have interference signals, and the target wavelength adjustment amount is the wavelength adjustment amount with the smallest absolute value among the wavelength adjustment amounts corresponding to the fourth optical signals that do not have interference signals.

[0038] In some possible implementations, there are multiple fourth optical signals without interference signals, and the wavelength adjustment amount corresponding to the fourth optical signal without interference signals includes at least one wavelength adjustment amount interval. The target wavelength adjustment amount is the median of the target wavelength adjustment amount interval among the medians of the at least one wavelength adjustment amount interval. The absolute value of the median of the target wavelength adjustment amount interval is the smallest among the medians of the at least one wavelength adjustment amount interval.

[0039] In some possible implementations, if the detection result of the second optical signal indicates the presence of an interference signal, the first frame is further used to instruct the transmitting device to reduce its emission power. If the detection result of the second optical signal indicates the absence of an interference signal, the first frame is further used to instruct the transmitting device not to adjust its emission power.

[0040] Thirdly, embodiments of this application provide a signal processing apparatus applied to a receiving device. This signal processing apparatus includes a transceiver unit and a processing unit. The transceiver unit is configured to: receive a second optical signal after a first optical signal transmitted by a transmitting device has been transmitted through a channel, wherein the first optical signal includes optical signals of multiple wavelengths. The processing unit is configured to: detect the second optical signal to determine whether interference signals generated by FWM exist. The transceiver unit is configured to: send a first frame to the transmitting device based on the detection result of the second optical signal, so that the transmitting device determines whether to adjust the wavelength of the first optical signal based on the first frame.

[0041] In some possible implementations, the first frame is a data frame, which includes service data and preset bits, which are used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0042] In some possible implementations, the data frame includes an FEC codeword, which comprises service data and a parity bit. That is, the service data in the data frame is FEC encoded, improving the reliability of service data transmission.

[0043] In some possible implementations, each 8704 FEC codewords in the data frame includes 1024 preset bits to facilitate better standard compatibility.

[0044] In some possible implementations, the first frame is a training frame, and at least one bit in the control field and / or state field of the training frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0045] In some possible implementations, the first frame is a negotiation frame, and at least one bit in the base page and / or extended page of the negotiation frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0046] In some possible implementations, if the detection result of the second optical signal is that there is no interference signal, the first frame is used to instruct the transmitting device to maintain the wavelength of the first optical signal.

[0047] In some possible implementations, if the detection result of the second optical signal is that there is an interference signal, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal.

[0048] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of all or part of the optical signals in the first optical signal.

[0049] In some possible implementations, the first frame is used to instruct the transmitting device to gradually increase the wavelength of the first optical signal according to the wavelength adjustment precision, or the first frame is used to instruct the transmitting device to gradually decrease the wavelength of the first optical signal according to the wavelength adjustment precision.

[0050] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal within the wavelength scanning range.

[0051] In some possible implementations, after sending the first frame to the transmitting device, the receiving unit is further configured to: receive a fourth optical signal after the third optical signal sent by the transmitting device has been transmitted through the channel, wherein the third optical signal is an optical signal obtained by the transmitting device adjusting the wavelength of the first optical signal. The processing unit is further configured to: detect the fourth optical signal to determine whether there is an interference signal. If the detection result of the fourth optical signal is that there is no interference signal, the transceiver unit is further configured to: send a second frame to the transmitting device, the second frame being used to instruct the transmitting device to stop adjusting the wavelength of the first optical signal.

[0052] In some possible implementations, after sending the first frame to the transmitting device, the transceiver unit is further configured to: sequentially receive multiple fourth optical signals obtained by transmitting multiple third optical signals sent by the transmitting device through a channel, wherein the multiple third optical signals are multiple optical signals obtained by the transmitting device adjusting the wavelength of the first optical signal across a wavelength scanning range. The processing unit is further configured to: sequentially detect the multiple fourth optical signals to determine the fourth optical signals without interference signals; and determine the target wavelength adjustment amount from the wavelength adjustment amounts corresponding to the fourth optical signals without interference signals. The transceiver unit is further configured to: send a second frame to the transmitting device, the second frame being used to instruct the transmitting device to adjust the wavelength of the first optical signal according to the target wavelength adjustment amount and then fix the wavelength.

[0053] In some possible implementations, there are multiple fourth optical signals that do not have interference signals, and the target wavelength adjustment amount is the wavelength adjustment amount with the smallest absolute value among the wavelength adjustment amounts corresponding to the fourth optical signals that do not have interference signals.

[0054] In some possible implementations, there are multiple fourth optical signals without interference signals, and the wavelength adjustment amount corresponding to the fourth optical signal without interference signals includes at least one wavelength adjustment amount interval. The target wavelength adjustment amount is the median of the target wavelength adjustment amount interval among the medians of the at least one wavelength adjustment amount interval. The absolute value of the median of the target wavelength adjustment amount interval is the smallest among the medians of the at least one wavelength adjustment amount interval.

[0055] In some possible implementations, the processing unit is specifically used to: convert the second optical signal into an electrical signal and detect the electrical signal; if a target signal with an amplitude greater than a threshold is detected within the effective frequency range of the electrical signal, then the target signal is determined to be an interference signal.

[0056] In some possible implementations, if the detection result of the second optical signal indicates the presence of an interference signal, the first frame is further used to instruct the transmitting device to reduce its emission power. If the detection result of the second optical signal indicates the absence of an interference signal, the first frame is further used to instruct the transmitting device not to adjust its emission power.

[0057] Fourthly, embodiments of this application provide a signal processing apparatus applied to a transmitting device. The signal processing apparatus includes a transceiver unit and a processing unit. The transceiver unit is configured to: transmit a first optical signal to a receiving device, the first optical signal including optical signals of multiple wavelengths, wherein a second optical signal, after transmission through a channel, is received and detected by the receiving device; and receive a first frame transmitted by the receiving device based on the detection result of the second optical signal, wherein the detection result of the second optical signal is used to indicate whether interference signals generated by FWM exist. The processing unit is configured to: determine whether to adjust the wavelength of the first optical signal based on the first frame.

[0058] In some possible implementations, the first frame is a data frame, which includes service data and preset bits, which are used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0059] In some possible implementations, the data frame includes an FEC codeword, which comprises service data and a parity bit. That is, the service data in the data frame is FEC encoded, improving the reliability of service data transmission.

[0060] In some possible implementations, each 8704 FEC codewords in the data frame includes 1024 preset bits to facilitate better standard compatibility.

[0061] In some possible implementations, the first frame is a training frame, and at least one bit in the control field and / or state field of the training frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0062] In some possible implementations, the first frame is a negotiation frame, and at least one bit in the base page and / or extended page of the negotiation frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

[0063] In some possible implementations, if the detection result of the second optical signal is that there is no interference signal, the processing unit is used to maintain the wavelength of the first optical signal according to the first frame.

[0064] In some possible implementations, if the detection result of the second optical signal is that there is an interference signal, the processing unit is used to adjust the wavelength of the first optical signal according to the first frame.

[0065] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of all or part of the optical signals in the first optical signal.

[0066] In some possible implementations, the first frame is used to instruct the transmitting device to gradually increase the wavelength of the first optical signal according to the wavelength adjustment precision, or the first frame is used to instruct the transmitting device to gradually decrease the wavelength of the first optical signal according to the wavelength adjustment precision.

[0067] In some possible implementations, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal within the wavelength scanning range.

[0068] In some possible implementations, after the transmitting device adjusts the wavelength of the first optical signal according to the first frame, the transceiver unit is further configured to: transmit a third optical signal to the receiving device, wherein the third optical signal is an optical signal obtained by the transmitting device adjusting the wavelength of the first optical signal; a fourth optical signal, after the third optical signal is transmitted through the channel, is received and detected by the receiving device; the detection result of the fourth optical signal is used to indicate whether there is an interference signal; if the detection result of the fourth optical signal indicates that there is no interference signal, a second frame is received from the receiving device. The processing unit is further configured to: stop adjusting the wavelength of the first optical signal according to the second frame.

[0069] In some possible implementations, after the transmitting device adjusts the wavelength of the first optical signal according to the first frame, the transceiver unit is further configured to: sequentially transmit a plurality of third optical signals, wherein the plurality of third optical signals are multiple optical signals obtained by the transmitting device adjusting the wavelength of the first optical signal across a wavelength scanning range, and the plurality of fourth optical signals, after being transmitted through the channel respectively, are received and detected by the receiving device; receive a second frame from the receiving device, the second frame being used to instruct the transmitting device to adjust the wavelength of the first optical signal according to a target wavelength adjustment amount and then fix the wavelength, wherein the target wavelength adjustment amount is determined by the receiving device from the wavelength adjustment amounts corresponding to the fourth optical signals where no interference signals exist. The processing unit is further configured to: adjust the wavelength of the first optical signal according to the target wavelength adjustment amount and then fix the wavelength.

[0070] In some possible implementations, there are multiple fourth optical signals that do not have interference signals, and the target wavelength adjustment amount is the wavelength adjustment amount with the smallest absolute value among the wavelength adjustment amounts corresponding to the fourth optical signals that do not have interference signals.

[0071] In some possible implementations, there are multiple fourth optical signals without interference signals, and the wavelength adjustment amount corresponding to the fourth optical signal without interference signals includes at least one wavelength adjustment amount interval. The target wavelength adjustment amount is the median of the target wavelength adjustment amount interval among the medians of the at least one wavelength adjustment amount interval. The absolute value of the median of the target wavelength adjustment amount interval is the smallest among the medians of the at least one wavelength adjustment amount interval.

[0072] In some possible implementations, if the detection result of the second optical signal indicates the presence of an interference signal, the first frame is further used to instruct the transmitting device to reduce its emission power. If the detection result of the second optical signal indicates the absence of an interference signal, the first frame is further used to instruct the transmitting device not to adjust its emission power.

[0073] Fifthly, embodiments of this application provide a chip for performing the methods described in any of the first or second aspects.

[0074] Sixthly, embodiments of this application provide an optical module, which includes a processor and an interface. The interface is used to transmit and receive signals, and the processor is used to execute the methods described in either the first or second aspect. For example, the interface is used to transmit signals from the processor or to transmit received signals to the processor.

[0075] In a seventh aspect, embodiments of this application provide a network device. The transmitting device includes a host-side device and an optical module as described in the sixth aspect. For example, the optical module is used to convert electrical signals from the host-side device into optical signals and transmit the optical signals. As another example, the optical module is used to convert received optical signals into electrical signals and transmit the electrical signals to the host-side device.

[0076] Eighthly, embodiments of this application provide a communication system that includes multiple network devices as described in the seventh aspect, wherein the multiple network devices are used to send optical signals to each other.

[0077] Ninthly, this application provides a computer-readable storage medium storing instructions that, when executed by a computer, cause the method described in any of the embodiments of the first or second aspect to be implemented.

[0078] In a tenth aspect, this application provides a computer program product including program instructions that, when executed, implement the method described in any of the embodiments of the first or second aspect.

[0079] In this embodiment, the first optical signal sent by the transmitting device to the receiving device is a multi-wavelength signal. After transmission through the channel, the first optical signal may generate interference signals due to the Front-Wave Movement (FWM) phenomenon. The receiving device receives the second optical signal after the first optical signal has been transmitted through the channel and detects the second optical signal to determine whether interference signals caused by FWM exist. Then, the receiving device can send a first frame to the transmitting device based on the detection result of the second optical signal to instruct the transmitting device whether to adjust the wavelength of the first optical signal. It should be understood that if the detection result of the second optical signal indicates the presence of interference signals caused by FWM, the first frame is used to instruct the transmitting end to adjust the wavelength of the first optical signal to change the phase matching condition of FWM, thereby avoiding the occurrence of FWM and improving system performance. Attached Figure Description

[0080] Figure 1 is a schematic diagram of a communication system applied in an embodiment of this application;

[0081] Figure 2 is a flowchart illustrating a signal processing method according to an embodiment of this application;

[0082] Figure 3 is a schematic diagram of the interference signal generated by the FWM phenomenon;

[0083] Figure 4 is a schematic diagram of a system scenario of the information processing method in an embodiment of this application;

[0084] Figure 5 is a schematic diagram of another system scenario of the information processing method in the embodiments of this application;

[0085] Figure 6 is a schematic diagram of selecting the wavelength adjustment amount in an embodiment of this application;

[0086] Figure 7 is a schematic diagram of the structure of a data frame in an embodiment of this application;

[0087] Figure 8 is a schematic diagram of the structure of a training frame in an embodiment of this application;

[0088] Figure 9 is a schematic diagram of the structure of a negotiation frame in an embodiment of this application;

[0089] Figure 10 is a schematic diagram of a signal processing device in an embodiment of this application;

[0090] Figure 11 is a schematic diagram of a structure of an optical module in an embodiment of this application;

[0091] Figure 12 is a schematic diagram of a network device in an embodiment of this application. Detailed Implementation

[0092] This application provides a signal processing method, related apparatus, and system. A receiving device detects multi-wavelength optical signals transmitted through a channel. If it detects that the multi-wavelength optical signals have experienced a flickering wave (FWM) during transmission, the receiving device sends information to a transmitting device, instructing the transmitting device to adjust the wavelength of at least one optical signal to avoid the FWM phenomenon, thereby improving system performance.

[0093] It should be noted that the terms "first," "second," etc., in this application specification, claims, and the accompanying drawings are used to distinguish similar objects, not to limit a specific order or sequence. It should be understood that the above terms can be used interchangeably where appropriate so that the embodiments described in this application can be implemented in an order other than that described in this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices. The term "and / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A or B can be represented as: A alone, A and B simultaneously, and B alone.

[0094] Figure 1 is a schematic diagram of a communication system applied in an embodiment of this application. As shown in Figure 1, the communication system includes a transmitting device 01, a transmitting processing module 02, a channel transmission medium 03, a receiving processing module 04, and a receiving device 05. Taking a data center network as an example, the transmitting device 01 and the receiving device 05 can be devices such as switches, routers, or servers. The transmitting device 01 is also referred to as the host at the transmitting end, and the receiving device 05 is also referred to as the host at the receiving end. The host can also be referred to as a host chip or host module. In the implementation of this application, the host can be a server. When the host is a server, the optical module in this embodiment can be connected to the server in a pluggable manner. For ease of description, the following description will use the transmitting device 01 and the receiving device 05 as examples of hosts. Exemplarily, the host includes, but is not limited to, a switch chip or a physical layer (PHY) chip, such as an application-specific integrated circuit (ASIC) chip. The channel transmission medium 03 can be an optical fiber. The transmitting device 01 and the transmitting processing module 02 can be connected via a channel, and the receiving device 05 and the receiving processing module 04 can also be connected via a channel. The type of this channel depends on the types of the transmitting and receiving processing modules 02 and 04. The channel type includes an electrical interface, such as an attachment unit interface (AUI) and a common electrical interface (or Common Electrical I / O, CEI). Alternatively, the channel can also be called an electrical link. For example, the channel can be a physical medium such as a printed circuit board (PCB) trace, copper cable, or connector. The transmitting and receiving processing modules 02 and 04 can be optical modules, electrical modules, or other modules that process data during transmission. For ease of explanation, the following description will assume that the transmitting and receiving processing modules 02 and 04 are optical modules. For example, this optical module can be a direct-detection optical module. It should be understood that the transmitting device 01, transmitting processing module 02, channel transmission medium 03, receiving processing module 04, and receiving device 05 in this communication system can all support bidirectional transmission or unidirectional transmission, and no specific limitation is made here.

[0095] It should be understood that an optical module is a hardware device that includes a transmitter optical sub-assembly (TOSA), a receiver optical sub-assembly (ROSA), and a microcontroller unit (MCU). A TOSA includes a laser and a modulator, while a ROSA includes a photodetector (PD). Depending on the type of optical module, some include an optical digital signal processor (oDSP) chip, while others do not.

[0096] It should be noted that the types of optical modules include, but are not limited to, normal optical modules, linear-drive pluggable optics (LPO) modules, near package optics (NPO) modules, co-packaged optics (CPO) modules, half-retimed optics (HRO) modules, linear receive optics (LRO) modules, and transmitter retimed optics (TRO) modules. In the embodiments of this application, LPO modules, NPO modules, CPO modules, HRO modules, LRO modules, and TRO modules can also be referred to as LPO optical modules, NPO optical modules, CPO optical modules, HRO optical modules, LRO optical modules, and TRO optical modules.

[0097] It should be understood that the functions that a typical optical module can perform include, but are not limited to, digital signal processing (DSP) and clock data recovery (CDR). The current mainstream approach is to use a DSP chip within the optical module; this chip can also be called an optical digital signal processor (oDSP) chip. Since DSP requires retiming, a typical optical module can also be called a retimed module. The typical optical module connects to the host via an attachment unit interface (AUI).

[0098] NPO and CPO modules lack a pluggable physical optical module package and are located closer to the host. NPO and CPO modules can also be referred to as optical engines. NPO or CPO technology is a technique for "encapsulating" the host and the optical engine. When NPO technology is used to encapsulate the host and optical engine, the optical engine can be called an NPO module. When CPO technology is used, the optical engine can be called a CPO module.

[0099] Considering the high power consumption of oDSP chips, the industry has proposed a solution that removes the oDSP chip from optical modules. This type of optical module is called an LPO (Low Point Optical Module), where the preprocessing and equalization of the electrical signal are handled by the host. In communication systems using LPO optical modules, because the LPO module lacks an oDSP chip, the electrical signal emitted by the host's serializer / deserializer (SERDES) is transmitted to the LPO module's optical transmitter via a passive electrical link within the host. This transmission undergoes a certain degree of degradation (from electrical link losses, filtering effects due to bandwidth limitations, and connector reflections), resulting in a degraded electrical signal. The optical transmitter converts this degraded electrical signal into an optical signal, thus the output optical signal is also degraded. The optical signal is further degraded by defects in the fiber optic link during transmission. At the optical receiver of the LPO module at the other end, the optical signal is converted back into an electrical signal. This electrical signal reaches the host directly without digital signal processing. The degradation of the optical signal via the fiber optic link and the damage caused by the passive electrical link in the host accumulates and is carried to the host's SERDES. In practical applications, the local host performs certain preprocessing on the transmitted electrical signals (pre-emphasis, equalization, etc.) to pre-compensate for damage caused by the host's passive electrical link and signal degradation introduced during the photoelectric conversion of the optical transmitter. The compensation and equalization capabilities of the remote host are mainly used to address the degradation of the optical signal through the fiber optic link, the signal degradation introduced during the photoelectric conversion of the optical receiver, and the damage to the electrical signal caused by the remote host's passive electrical link. Such complex signal processing requirements place high demands on the host's SERDEs, and may even lead to problems due to insufficient signal processing capabilities.

[0100] Therefore, the industry has proposed retaining some of the oDSP chip functionality in optical modules. For example, retaining oDSP chip functionality only on the transmitting side of the optical module, or only on the receiving side. Such optical modules are called HRO (High-Resolution Oscillator) optical modules. As an example, an optical module that retains oDSP chip functionality on the transmitting side can be called an LRO (Low-Resolution Oscillator) or TRO (Turbo-Resolution Oscillator) optical module. The optical signal performance emitted by this module is better, meets standards and has sufficient margin, and can achieve interoperability with ordinary optical modules, simplifying factory calibration and testing on the transmitting side. However, the receiving side of the optical module lacks oDSP chip functionality, and signal processing still relies on the host's SERDES (Search Engine Dedicated Lines).

[0101] For ease of explanation, the two ends of an optical fiber channel will be referred to as the transmitter and receiver, respectively. The transmitter can also be called a transmitting device, and the receiver can also be called a receiving device. It should be understood that the names "transmitter" and "receiver" are based on one direction of optical signal transmission and do not limit their functions. That is, the transmitter also has the ability to receive signals, and the receiver also has the ability to transmit signals. For example, the transmitter and receiver can be optical modules. Alternatively, the transmitter and receiver can also be communication devices that include both optical modules and a host computer.

[0102] It should be noted that in scenarios where multiple wavelength optical signals are transmitted from the transmitter to the receiver, if multiple wavelengths are within the zero dispersion wavelength (ZDW) range and the incident optical power is high, the probability of fiber nonlinear four-wave mixing (FWM) increases significantly, leading to increased system performance costs. Therefore, this application provides a signal processing method that can effectively avoid the FWM phenomenon, thereby improving system performance. The signal processing method provided in this application is described in detail below.

[0103] Figure 2 is a schematic flowchart of a signal processing method according to an embodiment of this application. As shown in Figure 2, the signal processing method includes the following process.

[0104] 101. The transmitting end sends the first optical signal to the receiving end.

[0105] In this embodiment, the first optical signal transmitted from the transmitting end to the receiving end is a multi-wavelength optical signal, also known as a multiplexed optical signal, meaning the first optical signal includes multiple optical signals of different wavelengths. As an example, the optical module of the transmitting end includes multiple lasers, each capable of emitting light of different wavelengths. The modulator in the optical module modulates the service signal onto the multiple different wavelengths of light to form multiple optical signals of different wavelengths. It should be understood that the first optical signal may be subject to noise or other interference during transmission through the channel. For example, the first optical signal may experience FWM (Fluorescent Wavelength Modulation) during transmission through the channel, thus forming an interference signal. Therefore, for ease of distinction, the optical signal actually received by the receiving end is referred to as the second optical signal, which may have increased noise or other interference compared to the first optical signal.

[0106] 102. The receiving end converts the second optical signal after the first optical signal is transmitted through the channel into an electrical signal, and detects the electrical signal.

[0107] Specifically, the receiving end can convert the second optical signal into an electrical signal using a photodiode (PD). Since the received second optical signal includes multiple optical signals of different wavelengths, the electrical signal converted from the second optical signal also includes multiple electrical signals corresponding to the multiple optical signals of different wavelengths. The receiving end can detect these multiple electrical signals separately to determine whether there are interference signals caused by the front-wavelength interference (FWM) phenomenon in each wavelength of the optical signal. It should be understood that the emission wavelength of the laser in the transmitting end's optical module generally follows a normal distribution, and the emission wavelength of each laser may have a random wavelength offset relative to its center wavelength. If the first optical signal generates an FWM phenomenon during optical fiber transmission, after square-law detection by the receiving end's PD, one or more interference signals with frequencies related to the laser's emission wavelength will be detected. This interference signal can also be called narrowband crosstalk. Each wavelength of the optical signal may be affected by the FWM phenomenon during optical fiber transmission. Due to the randomness of the laser's emission wavelength offset, the frequency position of the interference signal generated by the FWM phenomenon on each wavelength of the optical signal may be different.

[0108] It should be understood that if the frequency of the interference signal generated by the FWM phenomenon is within the band and the amplitude is greater than the threshold, it indicates that the interference signal will affect the system performance. Here, "within the band" refers to the Nyquist frequency range of the electrical signal converted from the second optical signal. Specifically, the Nyquist frequency range is half the sampling frequency range or baud rate of the electrical signal; the Nyquist frequency range can also be called the effective frequency range. In other words, the frequency range of the electrical signal converted from the second optical signal can be divided into in-band and out-of-band. The "interference signal generated by the FWM phenomenon" mentioned in this application specifically refers to interference signals with frequencies within the band and amplitudes greater than the threshold, thus distinguishing them from out-of-band noise. These will not be elaborated upon further below. In addition, there may be low-frequency interference such as multipath interference (MPI) at low-frequency locations within the band. Since the frequency of the interference signal generated by the FWM phenomenon is usually located at a non-low-frequency location within the band, in other words, not every interference signal generated by the FWM phenomenon is located at a low-frequency location within the band. Therefore, by detecting multiple electrical signals, it is usually possible to distinguish the interference signal generated by the FWM phenomenon from low-frequency interference such as MPI, thereby accurately determining whether the FWM phenomenon has occurred when the first optical signal is transmitted through the channel.

[0109] Based on the above introduction, the characteristics of interference signals generated by the FWM phenomenon should meet the following conditions: the amplitude of the interference signal is greater than a threshold and the frequency of the interference signal is within the band. The threshold is mainly set to observe whether the amplitude of the interference signal generated by the FWM phenomenon is significantly greater than the amplitude of the in-band service signal. For example, the threshold could be -5dB or 0dB, etc., and is not specifically limited here. In other words, if the amplitude of the interference signal is greater than the threshold, it is considered to have a certain impact or cost on the service signal; otherwise, the interference signal can be ignored. The service signal is the signal generated by the transmitting end to carry service data. The frequency range of the service signal carried by each wavelength of the optical signal in the first optical signal is generally the same; the effective frequency range of the service signal is that of the in-band. In some possible scenarios, the ratio between the amplitude of the interference signal and the amplitude of the service signal can also be calculated. The magnitude of this ratio can be used to determine whether the interference signal has an impact or cost on the service signal.

[0110] It should be noted that the detection of the electrical signal converted from the second optical signal by the receiving end can also be called nonlinear detection. Specifically, it can determine whether there is interference signal caused by the FWM phenomenon by acquiring the noise spectrum of the electrical signal. This electrical signal includes multiple electrical signals corresponding to optical signals of multiple different wavelengths. The receiving end can acquire the noise spectrum of each of the multiple electrical signals and determine whether there is interference signal caused by the FWM phenomenon in the corresponding wavelength of the optical signal based on the noise spectrum of each electrical signal. By detecting multiple electrical signals, if at least one interference signal is located in a non-low frequency position within the band, and the amplitude of this interference signal is greater than a threshold, it indicates that the interference signal is caused by the FWM phenomenon and has already had a certain impact or cost on the service signal.

[0111] Furthermore, if it is determined that there are no interference signals caused by the FWM phenomenon in all wavelengths of the optical signal, the receiver feeds back to the transmitter to instruct the transmitter to maintain the wavelengths of all optical signals in the first optical signal. If it is determined that there are interference signals caused by the FWM phenomenon in at least one wavelength of the optical signal, the receiver feeds back to the transmitter to instruct the transmitter to adjust the wavelength of at least one optical signal in the first optical signal to avoid the recurrence of the FWM phenomenon.

[0112] Figure 3 illustrates the interference signal generated by the FWM phenomenon. As shown in Figure 3, the horizontal axis represents frequency (in GHz), and the vertical axis represents power spectral amplitude (in dB). It can be seen that when multiple optical signals of different wavelengths are transmitted through the channel, the frequency of the interference signal generated by the FWM phenomenon also shifts randomly due to the random wavelength shift. For example, as shown in Figure 3, the interference signal generated by the FWM phenomenon may appear at frequency positions of 10 GHz, 15 GHz, 20 GHz, or 35 GHz. The amplitude of the interference signal at these frequency positions is greater than the set threshold. Signals with amplitudes greater than the threshold near the 0 GHz frequency position may be low-frequency interference such as MPI.

[0113] 103. The receiving end determines whether there is interference signal caused by FWM phenomenon; if not, proceed to step 104; if yes, proceed to step 105.

[0114] As mentioned earlier, if the receiver detects interference signals caused by the FWM phenomenon, it needs to report back to the transmitter that wavelength adjustment is required. Conversely, if the receiver does not detect interference signals caused by the FWM phenomenon, it will report back to the transmitter that wavelength adjustment is not required.

[0115] 104. The receiving end sends frame 2 to the sending end.

[0116] Specifically, frame 2 sent by the receiver to the transmitter instructs the transmitter not to adjust the wavelength of the first optical signal, i.e., to maintain the wavelength of the first optical signal. In some possible scenarios, if no interference signal caused by the FWM phenomenon is detected, the receiver may not need to send feedback to the transmitter. The transmitter, not receiving feedback from the receiver, will maintain the wavelength of the first optical signal, which is equivalent to the receiver instructing the transmitter to maintain the wavelength of the first optical signal. For example, if no interference signal caused by the FWM phenomenon is detected, the frame sent by the receiver to the transmitter can be a traditional data frame, training frame, or negotiation frame, etc. This frame does not carry feedback information. Upon receiving the frame and finding no feedback information, the transmitter will maintain the wavelength of the first optical signal. Again, for example, if no interference signal caused by the FWM phenomenon is detected, the receiver may not need to send a frame to the transmitter. The transmitter, not receiving a frame, will maintain the wavelength of the first optical signal.

[0117] 105. The receiving end sends frame 1 to the sending end.

[0118] Specifically, frame 1 sent by the receiver to the transmitter is used to instruct the transmitter to adjust the wavelength of at least one optical signal in the first optical signal. Since the ZDW of the optical fiber is fixed, the phase matching condition of FWM can be changed by adjusting the wavelength of at least one optical signal in the first optical signal, thereby reducing the amplitude of the interference signal or changing the frequency position of the interference signal, and thus effectively avoiding the occurrence of FWM phenomenon.

[0119] 106. The transmitting end adjusts the wavelength of at least one optical signal in the first optical signal according to frame 1.

[0120] It should be noted that the embodiments of this application do not limit the specific wavelengths of several optical signals in the first optical signal that the transmitting end adjusts. In one possible scenario, the transmitting end can synchronously adjust the wavelengths of all wavelengths of the optical signals in the first optical signal. In another possible scenario, the transmitting end can also adjust the wavelengths of only a portion of the optical signals in the first optical signal. Which portion of the optical signal's wavelength is adjusted depends on which optical signals are related to the interference signal generated by the FWM phenomenon in the actual scenario. By adjusting the wavelength of this portion of the optical signal, the FWM phenomenon can be effectively suppressed. Several possible examples are described below. For example, in an 800 gigabits per second (Gbps) optical transmission scenario, the first optical signal includes four wavelengths of optical signals, which are denoted as wavelength 1, wavelength 2, wavelength 3, and wavelength 4 in order of wavelength size. The transmitting end can specifically adjust the wavelength of at least one of the wavelengths of wavelength 2 and wavelength 3. For example, in a 1.6 terabit per second (Tbps) optical transmission scenario, the first optical signal includes optical signals with a total of 8 wavelengths, which are denoted as wavelength 1, wavelength 2, wavelength 3, wavelength 4, wavelength 5, wavelength 6, wavelength 7, and wavelength 8 in order of wavelength size. The transmitting end can adjust the wavelength of at least one optical signal other than wavelength 1 and wavelength 8.

[0121] It should also be noted that the embodiments of this application do not limit the specific method of wavelength adjustment at the transmitting end. For example, the optical module at the transmitting end can be equipped with a temperature controller (TEC). By adjusting the TEC, the ambient temperature of the laser in the optical module is changed, thereby changing the wavelength of the light emitted by the laser. As an example, the optical module uses one TEC to adjust the temperature of all lasers, thereby achieving synchronous wavelength adjustment of optical signals of all wavelengths. As another example, the optical module is equipped with multiple TECs, each used to adjust the temperature of different lasers. By turning on one TEC and turning off the others, wavelength adjustment of optical signals of a certain wavelength can be achieved.

[0122] Figure 4 is a schematic diagram of a system scenario for the information processing method in this application embodiment. As shown in Figure 4, the transmitting unit at the transmitting end converts the electrical signal to be transmitted into an optical signal, and the optical signal transmitted by the transmitting unit is transmitted to the receiving unit at the receiving end via optical fiber. The receiving unit converts the received optical signal into an electrical signal, and the detection unit at the receiving end performs nonlinear detection on the electrical signal to determine whether there is interference signal caused by the FWM phenomenon during the optical fiber transmission process. If the detection unit determines that there is interference signal caused by the FWM phenomenon during the optical fiber transmission process, the detection unit sends information to the transmitting end to instruct the temperature controller at the transmitting end to adjust the temperature, thereby adjusting the wavelength of the optical signal transmitted by the transmitting unit. In one possible scenario, the optical module at the receiving end sends the information that needs to be fed back to the optical module at the transmitting end via an optical signal, so that the optical module at the transmitting end controls the temperature controller to adjust the temperature, thereby adjusting the wavelength of the optical signal transmitted by the transmitting unit. In another possible scenario, the receiving host transmits the required feedback information to the transmitting host via an electrical signal. The transmitting host then sends this information to the transmitting optical module, which in turn controls a temperature controller to adjust the temperature, thereby regulating the wavelength of the optical signal transmitted by the transmitting unit. Here, the electrical signal can be transmitted via cable or wirelessly. The scenario where the receiving end transmits the required feedback information to the transmitting end via an optical signal will be described in detail below.

[0123] Figure 5 is a schematic diagram of another system scenario for the information processing method in this application embodiment. As shown in Figure 5, both optical module 1 and optical module 2 include an oDSP chip, a transmitting unit, a receiving unit, a temperature controller, and a controller. The transmitting unit includes a laser and a modulator, the receiving unit includes a photodetector (PD), and the controller can specifically be a microcontroller unit (MCU). Both host 1 and host 2 include a PHY chip and a device controller, which can specifically be a central processing unit (CPU) or a field-programmable gate array (FPGA). The first side of the oDSP chip is used to connect to the PHY chip; this first side can be called the hostside. The second side of the oDSP chip is used to connect the transmitting unit and the receiving unit; this second side can be called the mediaside. This application embodiment does not limit the devices included in the hostside and mediaside. The first side is used to communicate with the host via a telecommunication channel. For example, the Serdes located on the first side of the oDSP chip communicate with the Serdes located on the PHY chip (Serdes not shown in Figure 5) via a telecommunication channel. The second side is used for communication with the transmitting and receiving units via telecommunication channels. In one implementation, the transmitting unit in optical module 1 is connected to the receiving unit in optical module 2 via an optical channel, and the transmitting unit in optical module 2 is connected to the receiving unit in optical module 1 via an optical channel. The controller is connected to the device controller via a management interface, which may be an inter-integrated circuit (IIC, I2C) interface, and the management protocol based on this management interface may be a common management interface specification (CMIS).

[0124] Specifically, the PHY chip of host 1 sends an electrical signal to the oDSP chip of optical module 1. This electrical signal can be a non-return-to-zero (NRZ) modulation signal or a four-level pulse amplitude modulation (PAM4) signal. The oDSP chip of optical module 1 can generate a quadrature phase shift keying (QPSK) signal or a 16-ary quadrature amplitude modulation (16QAM) signal based on the electrical signal sent by the PHY chip of host 1. The transmitting unit of optical module 1 modulates the electrical signal 1 from the oDSP chip onto an optical carrier to obtain optical signal 1, and transmits optical signal 1 through the optical fiber. The receiving unit of optical module 2 receives the optical signal 1 transmitted through the optical fiber and converts it back into an electrical signal 1. The oDSP chip of optical module 2 then performs nonlinear detection on the electrical signal 1 to determine whether there is interference signal caused by FWM (Fluorescent Wavelength Modulation) during the transmission of optical signal 1 through the optical fiber. The oDSP chip of optical module 2 sends information to the transmitting unit based on the detection result of electrical signal 1. This information can specifically be frame 1 or frame 2. The transmitting unit of optical module 2 generates optical signal 2 based on the information and transmits optical signal 2 to optical module 1 through optical fiber. The receiving unit of optical module 1 converts optical signal 2 into electrical signal 2 and sends electrical signal 2 to the oDSP chip. The oDSP chip of optical module 1 performs demodulation and other processing on electrical signal 2 to identify the information fed back by optical module 2 and sends the information to the controller. The controller of optical module 1 controls the temperature controller to adjust the temperature based on the information, thereby adjusting the wavelength of the optical signal transmitted by the transmitting unit of optical module 1.

[0125] It should be noted that there are several implementation methods for the transmitting end to adjust the wavelength of the first optical signal. In Embodiment 1, after receiving frame 1 from the receiving end, the transmitting end can adjust the wavelength of the first optical signal according to a pre-agreed implementation method; that is, the receiving end does not need to notify the transmitting end of the specific wavelength adjustment method. In Embodiment 2, frame 1 sent by the receiving end to the transmitting end not only indicates that the transmitting end needs to adjust the wavelength of the first optical signal, but also instructs the transmitting end on the specific method for adjusting the wavelength. The following detailed description mainly focuses on the example of the receiving end notifying the transmitting end of the specific method for adjusting the wavelength of the first optical signal.

[0126] It should be understood that this application does not limit the number of bits used for feedback information in the frame sent by the receiving end to the sending end, nor does it limit the indication content corresponding to the bit values ​​used for feedback information in the frame. The tables provided in the embodiments of this application are only some possible examples, and those skilled in the art can also implement feedback information to the sending end by making flexible changes based on them. For example, the number of bits in the table can be changed. As another example, the indication content corresponding to the bit values ​​in the table can also be changed.

[0127] Based on Embodiment 1 above, Table 1 below provides a possible example. As shown in Table 1, Frame 1 and Frame 2 can specifically use 2 bits to feed back information to the transmitting end. Different combinations of values ​​for these 2 bits are defined to indicate different content. For example, "00" is used to indicate that the transmitting end does not perform wavelength adjustment; "01" or "10" is used to indicate that the transmitting end performs wavelength adjustment. The transmitting end adjusts the wavelength of the first optical signal according to the implementation method agreed upon by both parties in advance. The implementation method agreed upon by both parties in advance includes, but is not limited to, wavelength adjustment accuracy, wavelength scanning direction, and wavelength scanning range; "11" is used to indicate that the transmitting end stops performing wavelength adjustment. That is, if "11" is received after the transmitting end starts wavelength adjustment, it means that the FWM phenomenon no longer occurs, and the transmitting end stops performing wavelength adjustment.

[0128] Table 1

[0129] Based on Embodiment 2 described above, in one possible scenario, frame 1 is specifically used to instruct the transmitting end to perform scanning wavelength adjustment according to the configured wavelength adjustment precision. Furthermore, frame 1 can also indicate the range of wavelength adjustment performed by the transmitting end, i.e., the wavelength scanning range. For example, frame 1 instructs the transmitting end to gradually increase the wavelength of at least one optical signal in the first optical signal within the wavelength scanning range according to the wavelength adjustment precision. As another example, frame 1 instructs the transmitting end to gradually decrease the wavelength of at least one optical signal in the first optical signal within the wavelength scanning range according to the wavelength adjustment precision. In other words, frame 1 is used to indicate the wavelength adjustment precision, the direction of wavelength scanning, and the wavelength scanning range. However, this embodiment does not limit the wavelength adjustment precision and the wavelength scanning range; for example, the wavelength adjustment precision can be 0.01 nm, and the wavelength scanning adjustment can be from -1 nm to 1 nm.

[0130] Table 2 below provides a possible example. As shown in Table 2, Frame 1 and Frame 2 can specifically use two bits to feed back information to the transmitting end. Different combinations of values ​​for these two bits are defined to indicate different content. For example, "00" is used to indicate that the transmitting end does not perform wavelength adjustment; "01" is used to indicate that the transmitting end gradually increases the wavelength of at least one optical signal in the first optical signal according to the wavelength adjustment accuracy, that is, performs a forward wavelength scan, and indicates the wavelength scan range; "10" is used to indicate that the transmitting end gradually decreases the wavelength of at least one optical signal in the first optical signal according to the wavelength adjustment accuracy, that is, performs a reverse wavelength scan, and indicates the wavelength scan range; "11" is used to indicate that the transmitting end stops performing wavelength adjustment. That is, if "11" is received after the transmitting end starts wavelength adjustment, it means that the FWM phenomenon no longer occurs, and the transmitting end stops performing wavelength adjustment.

[0131] Table 2

[0132] Based on Embodiment 2 described above, Frame 1 can also indicate whether the transmitting end is adjusting the wavelength of all or only a portion of the optical signals in the first optical signal. If it instructs the transmitting end to adjust the wavelength of only a portion of the optical signals in the first optical signal, Frame 1 can further indicate which specific optical signals' wavelengths the transmitting end is adjusting. Table 3 below provides a possible example, which is an extension of Table 2 above. As shown in Table 3, the bit types include first-class bits, second-class bits, and third-class bits. Specifically, the first-class bits include the two bits provided in Table 2 above. The second-class bits are an extension of Table 2 above by one bit. This one bit is used to indicate whether the transmitting end is adjusting the wavelength of all or only a portion of the optical signals in the first optical signal. For example, a value of "0" indicates that the transmitting end is adjusting the wavelength of all the optical signals in the first optical signal, and a value of "1" indicates that the transmitting end is adjusting the wavelength of only a portion of the optical signals in the first optical signal. The third type of bits extends the measurement in Table 2 by x bits. These x bits are used to indicate which wavelengths of optical signals the transmitter should adjust. Taking the first optical signal, which includes four wavelengths, as an example, there are 14 possible ways to adjust the wavelengths of some of the optical signals in the first optical signal. The third type of bits can specifically include four bits, and the binary numbers corresponding to the values ​​of these four bits represent these 14 possible wavelength adjustment methods. It should be understood that if frame 1 does not carry the extended second and third type of bits as shown in Table 3, the transmitter will adjust the wavelengths of all optical signals in the first optical signal by default.

[0133] Table 3

[0134] In some possible scenarios, if the receiver detects interference signals caused by the FWM phenomenon, in addition to instructing the transmitter to adjust the wavelength, the receiver can also instruct the transmitter to reduce the emission power, which also helps to avoid the FWM phenomenon. For example, the transmitter can reduce the emission power by reducing the bias current or modulation amplitude of the laser. Based on this, frame 1 can specifically instruct the transmitter to gradually reduce the emission power according to the power adjustment accuracy and indicate the range of power adjustment. In this embodiment, the power adjustment accuracy and the power adjustment range are not limited; for example, the power adjustment accuracy can be 0.2 dB, and the power adjustment range refers to the maximum adjustment amount of the emission power being less than 2 dB.

[0135] Table 4 below provides a possible example. As shown in Table 4, Frame 1 and Frame 2 can specifically use 2 bits to feed back information to the sending end. Different combinations of values ​​for these 2 bits are defined to indicate different content. For example, "00" is used to indicate that the sending end does not reduce the emission power; "01" is used to indicate that the sending end gradually reduces the emission power according to the power adjustment precision, and indicates the range of power adjustment; "10" is not defined; "11" is used to indicate that the sending end stops reducing the emission power. That is, if "11" is received after the sending end starts reducing the emission power, it means that the FWM phenomenon no longer occurs, and the sending end stops reducing the emission power.

[0136] Table 4

[0137] 107. The transmitting end sends a third optical signal to the receiving end.

[0138] Specifically, the optical signal obtained by adjusting the wavelength of at least one optical signal in the first optical signal according to frame 1 is denoted as the third optical signal. It should be understood that the third optical signal may be subject to noise or other interference during transmission through the channel. For example, the third optical signal may experience FWM (Fluid Wavelength Mode) during transmission through the channel, thus forming an interference signal. Therefore, for ease of distinction, the optical signal actually received by the receiver is denoted as the fourth optical signal, which may have increased noise or other interference compared to the third optical signal.

[0139] 108. The receiving end converts the fourth optical signal, which is transmitted through the channel from the third optical signal, into an electrical signal and detects the electrical signal.

[0140] It should be noted that the implementation of step 108 is similar to that of step 102 above, and will not be repeated here.

[0141] 109. The receiving end determines whether there is interference signal caused by FWM phenomenon. If yes, proceed to step 105; otherwise, proceed to step 110.

[0142] Specifically, if the receiver detects interference signals caused by the FWM phenomenon, the receiver needs to report to the transmitter that wavelength adjustment is required, that is, repeat the operation of step 105 above, instructing the transmitter to continue adjusting the wavelength of at least one optical signal in the first optical signal. Conversely, if the receiver does not detect interference, it indicates that the transmitter has avoided the FWM phenomenon through wavelength adjustment, and the receiver needs to instruct the transmitter to stop wavelength adjustment.

[0143] 110. The receiving end sends frame 3 to the sending end.

[0144] Specifically, frame 3 sent by the receiver to the transmitter is used to instruct the transmitter to stop adjusting the wavelength of at least one optical signal in the first optical signal.

[0145] 111. The transmitting end stops adjusting the wavelength of at least one optical signal in the first optical signal according to frame 3.

[0146] Once the transmitter receives frame 3 from the receiver, it can determine that the currently transmitted third optical signal will no longer experience FWM (Frequency Wavelength Mitigation) during channel transmission, and will have virtually no impact on system performance. As an example, the transmitter can control the TEC (Thermal Design Temperature) to stop temperature regulation, effectively maintaining the wavelengths of the currently transmitted optical signals.

[0147] In one possible implementation 1, after the transmitting end begins scanning wavelength adjustment according to the configured wavelength adjustment accuracy in step 106, the receiving end continuously performs nonlinear detection on the optical signal from the transmitting end. If the receiving end finds through a nonlinear detection that the currently received optical signal does not have interference signals caused by the FWM phenomenon, it indicates that the wavelength of the optical signal currently transmitted by the transmitting end meets the system performance requirements. In this case, the receiving end can immediately send frame 3 to the transmitting end to instruct the transmitting end to stop wavelength adjustment. Taking Tables 1-3 above as an example, if two bits in frame 3 sent by the receiving end to the transmitting end are "11", the transmitting end can stop wavelength adjustment.

[0148] In a possible implementation 2, after the transmitting end begins scanning wavelength adjustment according to the configured wavelength adjustment accuracy in step 106, the receiving end continuously performs nonlinear detection on the optical signal from the transmitting end. Unlike implementation 1, in this implementation 2, after the transmitting end has traversed all wavelengths within the wavelength scanning range, the receiving end may discover through nonlinear detection that multiple received optical signals do not contain interference signals caused by the FWM phenomenon. In other words, after the transmitting end has scanned all wavelengths, multiple wavelength adjustment values ​​may meet the system performance requirements. Therefore, based on the continuous nonlinear detection of the optical signal from the transmitting end, the receiving end can record multiple wavelength adjustment values ​​that meet the system performance requirements. Then, it selects the most suitable wavelength adjustment value from these multiple values ​​and sends this most suitable wavelength adjustment value to the transmitting end via frame 3. This allows the transmitting end to adjust the wavelength according to this most suitable wavelength adjustment value and then fix the wavelength, i.e., stop adjusting the wavelength after adjusting to the wavelength that meets the system performance requirements. It should be understood that if the transmitting end performs a forward wavelength scan, the wavelength adjustment amount is positive; if the transmitting end performs a reverse wavelength scan, the wavelength adjustment amount is negative. It should be noted that, given a fixed wavelength adjustment accuracy and wavelength scan direction, the receiving end can also deduce the wavelength adjustment process performed by the transmitting end based on these parameters. For example, the receiving end can know the wavelength adjustment amount at each moment after the transmitting end begins adjusting the wavelength. By combining this information with real-time detection results, the receiving end can record the wavelength adjustment amounts that meet the system performance requirements and those that do not.

[0149] For implementation method 2, a certain number of bits can be extended based on Table 1 above to indicate the most suitable wavelength adjustment amount selected by the receiving end. Table 5 below provides a possible example. As shown in Table 5, the bit types include first-type bits and fourth-type bits. Specifically, the first-type bits include the 2 bits provided in Table 1 above, and the fourth-type bits are 6 bits extended based on Table 1 above. These 6 bits are used to indicate the wavelength adjustment amount within the wavelength scanning range. Taking a wavelength scanning range of -0.1nm to 0.1nm and a wavelength adjustment accuracy of 0.01nm as an example, the wavelength scanning range includes 21 wavelength adjustment amounts. These 21 wavelength adjustment amounts are represented by the binary numbers corresponding to the values ​​of these 6 bits. For example, 010010 = 18 represents the 18th wavelength adjustment amount, and 010101 = 21 represents the 21st wavelength adjustment amount.

[0150] Table 5

[0151] By comparing Implementation Method 1 and Implementation Method 2, it can be seen that Implementation Method 1, during the wavelength adjustment process at the transmitting end, immediately notifies the transmitting end to stop wavelength adjustment as soon as the receiving end detects for the first time that there is no interference signal caused by the FWM phenomenon in the currently received optical signal. This means that Implementation Method 1 can suppress the FWM phenomenon more quickly. Implementation Method 2, after the transmitting end has traversed all wavelengths within the wavelength scanning range, has the receiving end select the most suitable wavelength adjustment amount and inform the transmitting end to fix the wavelength. This means that Implementation Method 2, while effectively suppressing the FWM phenomenon, can also perform targeted wavelength selection, which is more conducive to ensuring that the system can remain continuously and stably unaffected by the FWM phenomenon.

[0152] Figure 6 is a schematic diagram of the selection of wavelength adjustment amount in an embodiment of this application. As shown in Figure 6, the horizontal axis represents the wavelength adjustment amount (unit: nm), and the vertical axis represents the number of Monte Carlo (MC) simulations. Taking Figure 6 as an example, 7 MC simulations were performed. One curve corresponds to one parameter combination use case in the simulation. The wavelength scanning range is -1 nm to 1 nm, and the wavelength adjustment accuracy is 0.01 nm. Figure 6 shows 7 sets of wavelength adjustment amounts that meet the system performance requirements within the wavelength scanning range. It should be understood that if the wavelength adjustment amount meets the system performance requirements, it means that no interference signal caused by the FWM phenomenon is detected in the current environment. In Figure 6, if the vertical axis corresponding to the wavelength adjustment amount is in a high position, it means that the wavelength adjustment amount meets the system performance requirements; if the vertical axis corresponding to the wavelength adjustment amount is in a low position, it means that the wavelength adjustment amount does not meet the system performance requirements. The wavelength adjustment amounts selected in Embodiment 1 and Embodiment 2 above are described below using a set of wavelength adjustment amounts marked in Figure 6 as an example.

[0153] For the above-described implementation method 1, taking Figure 6 as an example, it is assumed that the transmitting end performs a reverse wavelength scan, that is, gradually reduces the wavelength. When the wavelength adjustment reaches around -0.2nm, the system performance requirements are met, which is the position marked by the solid circle in Figure 6. At this time, the transmitting end fixes the wavelength adjustment around -0.2nm according to the frame 3 sent by the receiving end and then stops the wavelength scan.

[0154] For the above-described implementation method 2, as an example, considering that a larger wavelength adjustment amount corresponds to a larger temperature change and a greater impact on system performance, the wavelength adjustment amount with the smallest absolute value among multiple wavelength adjustment amounts that meet system performance requirements is the most suitable wavelength adjustment amount. This is more conducive to suppressing the FWM phenomenon and also helps to reduce the impact on the laser. Taking a set of wavelength adjustment amounts marked in Figure 6 as an example, after the transmitting end scans all wavelengths within the wavelength scanning range, the system performance requirements are met when the wavelength adjustment amount is around 0.1 nm, which is the position marked by the circular dashed box in Figure 6. Furthermore, 0.1 nm is the wavelength adjustment amount with the smallest absolute value among all wavelength adjustment amounts that meet system performance requirements within the wavelength scanning range; therefore, 0.1 nm is the most suitable wavelength adjustment amount.

[0155] Regarding the above-described implementation method 3, as another example, considering that the laser wavelength may drift due to aging or changes in ambient temperature during actual use, the wavelength drift range is typically -0.1 nm to 0.1 nm. Therefore, the receiver needs to take the wavelength drift factor into account when selecting the most suitable wavelength adjustment amount. Specifically, at least one wavelength adjustment range that meets the system performance requirements can be selected from multiple wavelength adjustment amounts that satisfy the system performance requirements. It should be understood that the wavelength adjustment range includes multiple consecutive wavelength adjustment amounts, and all wavelength adjustment amounts in each selected wavelength adjustment range meet the system performance requirements. Furthermore, if there are multiple wavelength adjustment ranges that meet the system performance requirements, the wavelength adjustment range closest to the 0 position should be selected. In other words, by comparing the medians of multiple wavelength adjustment ranges that meet the system performance requirements, the wavelength adjustment range with the smallest absolute value of the median is closest to the 0 position. Based on this, the median of the wavelength adjustment range selected from multiple wavelength adjustment ranges that meet the system performance requirements is the most suitable wavelength adjustment. In this way, even if the wavelength of the laser may drift, selecting this wavelength adjustment can still suppress the FWM phenomenon, thus improving the reliability of this solution.

[0156] Taking the set of wavelength adjustment values ​​marked in Figure 6 as an example, assuming that the wavelength adjustment range is 0.2nm, it can be seen that the wavelength adjustment ranges of -1nm to -0.8nm, -0.8nm to -0.6nm, -0.6nm to -0.4nm, 0.2nm to 0.4nm, 0.4nm to 0.6nm, 0.6nm to 0.8nm, and 0.8nm to 1nm are all wavelength adjustment ranges that meet the system performance requirements. Among them, the medians of the wavelength adjustment ranges that meet the system performance requirements are -0.9nm, -0.7nm, -0.5nm, 0.3nm, 0.5nm, 0.7nm, and 0.9nm, respectively. Among these wavelength adjustment ranges, the absolute value of 0.3nm is the smallest. Therefore, 0.3nm is the most suitable wavelength adjustment value selected by the receiver, which is the median of the wavelength adjustment range marked by the solid rectangular box in Figure 6.

[0157] It should be noted that the frames sent from the receiver to the sender in the process shown in Figure 2 above can have several different implementations. Example 1: The frames sent from the receiver to the sender can specifically be data frames from the service transmission phase. Example 2: In the link training (LT) phase, a mechanism is provided for communication between the receiver and the sender before service goes live. This is achieved by continuously exchanging fixed-length training frames between the receiver and the sender to configure the sender's parameters, thereby optimizing system performance. In other words, the frames sent from the receiver to the sender can be training frames from the link training phase. Example 3: The frames sent from the receiver to the sender can be negotiation frames from the auto-negotiation (AN) phase. The following sections will provide a more detailed description of these examples.

[0158] For Example 1 above, Figure 7 is a schematic diagram of a data frame structure in an embodiment of this application. The receiving end performs forward error correction (FEC) encoding on the service data to be sent to the sending end to obtain multiple FEC codewords. FEC codewords can also be simply referred to as codewords. As shown in Figure 7, the data frame sent by the receiving end to the sending end includes multiple codewords. The service data, after FEC encoding, yields a check bit; that is, each FEC codeword includes service data and a check bit. For example, a Hamming (128, 120) code pattern is specifically used to perform FEC encoding on the service data, meaning each FEC codeword is 128 bits long, including 120 bits of service data, which can also be called information bits. Based on this, the receiving end also inserts preset bits into the data frame to carry information fed back to the sending end. Specifically, M preset bits can be inserted every N codewords, where N and M are both integers greater than or equal to 1. For example, M = 1024 preset bits can be inserted every N = 8704 codewords. The preset bits can be FEC encoded, or they can be left unencoded; this is not a limitation. It should be understood that all bits in the data frame other than codewords are considered preset bits. These preset bits are reserved to implement different functions according to actual needs. Preset bits can also be called padding bits, and this application does not limit their specific naming. In this embodiment, at least one bit from the preset bits is used to carry information fed back to the sending end, which can also be understood as being used as a feedback channel. In other words, regardless of how some bits in the preset bits are defined or renamed in the future, they still occupy the preset bit position and are essentially still considered preset bits. Therefore, as long as the preset bit position is occupied, regardless of its future use, definition, or name, this part of the bit can still be considered a preset bit. It should be noted that data frames can undergo other processing such as symbol mapping. Taking the mapping of 2 bits to 1 symbol as an example, the contents shown in Table 1, Table 2 or Table 4 can be indicated by one symbol, and frame 3 shown in Table 5 can be indicated by 4 symbols.

[0159] For Example 2 above, Figure 8 is a schematic diagram of the structure of a training frame in an embodiment of this application. As shown in Figure 8, the frame marker in the training frame is used to mark the start of the training frame. Specifically, it is composed of a special four-level pulse amplitude modulation (PAM4) sequence, for example, this sequence includes 16 consecutive 3s and 16 consecutive 0s. This sequence does not appear in the control domain, state domain, etc., so it can be used to mark the start of the training frame. The frame marker includes a 32-unit interval (UI); the control field is used to send command information; the status field is used to report the corresponding status of the link peer command; the training pattern is used to send a fixed pseudo-random binary sequence (PRBS) to test the link quality; a cell contains one bit. Some bits in the control field and status field of the training frame have undefined uses and are reserved fields used to carry information fed back to the sending end. For example, cells 0 to 4, cell 7, and cells 10 to 15 in the control field can all be reserved fields. For example, units 0 to 5 and 8 in the state domain can all be reserved fields. Embodiments of this application can utilize unused bits in the control domain and / or state domain to carry information fed back to the sending end. Embodiments of this application do not limit the number of bits used or their location.

[0160] For Example 3 above, Figure 9 is a schematic diagram of the structure of a negotiation frame in an embodiment of this application. As shown in Figure 9, the negotiation frame can specifically be a Differential Manchester Encoded (DME) frame. A DME frame includes a base page and a next page, where the next page is also called an extended page or additional page. Information can be transmitted through the base page when the device powers on, the link starts, or negotiation is performed. In the self-negotiation mechanism, information exceeding the base page can also be transmitted through the extended page. The base page and the extended page each include 48 bits. The base page includes multiple fields, and the extended page includes multiple fields. In this embodiment of the application, unused bits in the base page and / or the extended page can be used to carry information fed back to the sending end. This embodiment of the application does not limit the number of bits used or the location of the bits.

[0161] It should be understood that, to improve the reliability of frame transmission from the receiver to the sender, the information carried in each frame sent by the receiver to the sender can be copied multiple times, which is equivalent to repeatedly transmitting the information that needs to be fed back. Taking Table 2 as an example, assuming the content indicated by frame 1 is "01", 5 groups of "01" (10 bits in total) can be inserted into the data frame to repeat the transmission of this content. Taking Table 5 as an example, assuming the content indicated by the first type of bits in frame 3 is "11" and the content indicated by the second type of bits in frame 3 is "010010", 5 groups of "11" and 5 groups of "010010" (40 bits in total) can be inserted into the data frame to repeat the transmission of this content. It should be understood that if the reserved space in one data frame is insufficient to repeatedly transmit the information that needs to be fed back, then multiple data frames can be used to repeatedly transmit the information that needs to be fed back. Similarly, a similar method can be used to repeatedly transmit the information that needs to be fed back through training frames or negotiation frames, which will not be elaborated here.

[0162] It should be noted that, in addition to sending frames to provide feedback to the transmitter, in some scenarios, the receiver can also superimpose a modulation signal onto the optical signal it sends to the transmitter using a modulation processing method. Specifically, modulation processing involves superimposing a small-amplitude, low-frequency sine or cosine modulation signal onto the optical signal sent by the receiver. When this low-frequency sine or cosine modulation signal is superimposed on the optical signal, it modulates the intensity of the optical signal, effectively modulating the intensity of the optical signal using the low-frequency sine or cosine modulation signal. This low-frequency sine or cosine modulation signal can also be called a pilot signal; that is, the pilot signal can carry the information fed back to the transmitter.

[0163] Figure 10 is a schematic diagram of a signal processing device according to an embodiment of this application. As shown in Figure 10, the signal processing device includes a processing unit 201 and a transceiver unit 202. In one possible implementation, the signal processing device is applied to a transmitting end, and is used to perform the operations of the transmitting end in the above embodiments. For example, the transceiver unit 202 is used to perform the signal transmission and reception or information transmission and reception operations of the transmitting end in the embodiment shown in Figure 2, and the processing unit 201 is used to perform operations of the transmitting end in the embodiment shown in Figure 2 other than signal transmission and reception or information transmission and reception. In another possible implementation, the signal processing device is applied to a receiving end, and is used to perform the operations of the receiving end in the above embodiments. For example, the transceiver unit 202 is used to perform the signal transmission and reception or information transmission and reception operations of the receiving end in the embodiment shown in Figure 2, and the processing unit 201 is used to perform operations of the receiving end in the embodiment shown in Figure 2 other than signal transmission and reception or information transmission and reception.

[0164] It should be understood that the signal processing device shown in Figure 10 can also be implemented in other ways. For example, the unit division in the above device is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system. In addition, the functional units in the various embodiments of this application may be integrated into one processing unit, or they may be independent physical units, or two or more functional units may be integrated into one processing unit. The integrated unit described above can be implemented in hardware or in the form of software functional units.

[0165] Figure 11 is a schematic diagram of an optical module structure in an embodiment of this application. As shown in Figure 11, the optical module includes a processor 301 and an interface 302. The interface 302 can be a transceiver or an input / output interface. The interface 302 is used to receive signals from other devices and transmit them to the processor 301, or to send signals from the processor 301 to other devices. Optionally, the optical module may also include a memory 303, wherein the memory 303 is used to store program instructions and data. In one possible scenario, the optical module is applied to the transmitting end, and the processor 301 is used to perform operations of the transmitting end in the embodiment shown in Figure 2 other than signal transmission and reception or information transmission and reception. For example, the processor 301 includes the processing unit 201 shown in Figure 10. The interface 302 is used to perform the signal transmission and reception or information transmission and reception operations of the transmitting end in the embodiment shown in Figure 2. For example, the interface 302 includes the transceiver unit 202 shown in Figure 10. In another possible scenario, the optical module is applied to the receiving end, and the processor 301 is used to perform operations of the receiving end in the embodiment shown in FIG2, other than signal transmission and reception or information transmission and reception. For example, the processor 301 includes the processing unit 201 shown in FIG10. The interface 302 is used to perform the signal transmission and reception or information transmission and reception operations of the receiving end in the embodiment shown in FIG2. For example, the interface 302 includes the transceiver unit 202 shown in FIG10.

[0166] Figure 12 is a schematic diagram of a network device according to an embodiment of this application. As shown in Figure 12, the network device includes a host-side device 401 and an optical module 402. In one possible scenario, the network device acts as a transmitter, with the host-side device 401 sending electrical signals to the optical module 402, which converts the electrical signals into optical signals and transmits them through a channel. In another possible scenario, the network device acts as a receiver, with the optical module 402 converting the received optical signals into electrical signals and sending them to the host-side device 401. For example, the host-side device 401 may specifically be a switch, router, or server. It should be understood that the network device in this embodiment of the application has both transmitting and receiving functions.

[0167] This application also provides an Optical Transport Network (OTN) device, which includes line-side equipment and client-side equipment. The client-side equipment may also be referred to as a tributary-side equipment in some scenarios. The line-side equipment includes a processor and an interface. In one possible scenario, the OTN device is used at the transmitting end, and the processor performs operations at the transmitting end in the embodiment shown in Figure 2, other than signal transmission and reception or information transmission and reception. In another possible scenario, the OTN device is used at the receiving end, and the processor performs operations at the receiving end in the embodiment shown in Figure 2, other than signal transmission and reception or information transmission and reception. The interface can be a transceiver or an input / output interface, used to receive signals from other devices besides the line-side equipment and transmit them to the processor, or to send signals from the processor to other devices besides the line-side equipment.

[0168] This application also provides a chip. The chip integrates circuitry for implementing the functions of the processor 301 described above, and one or more interfaces. As an example, the chip integrates a memory. As another example, when the chip does not integrate a memory, it can be connected to an external memory via the interface. The chip can perform the method steps of any one or more of the foregoing embodiments. Alternatively, the chip can implement the actions performed by the processing and transmission device in the foregoing embodiments based on program code stored in the memory.

[0169] As an example, the chip in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor, any conventional processor, or a processing circuit that implements a specific function.

[0170] This application also provides a computer-readable storage medium including a program or instructions that, when run on a computer, cause the method performed as described in the above method embodiments to be implemented.

[0171] It should be understood that the processor mentioned in the embodiments of this application can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. The memory can exist independently and be connected to the processor, or the memory can be integrated with the processor.

[0172] As an example, the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor, any conventional processor, or a processing circuit that implements a specific function.

[0173] In embodiments of this application, the memory may be random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium may reside in an ASIC. Additionally, the ASIC may reside in a network device or a terminal device. Alternatively, the processor and storage medium may exist as discrete components in the network device or terminal device.

[0174] In the above embodiments, it can be implemented entirely or partially by software, hardware, firmware, or any combination thereof.

[0175] When implemented in hardware, the data transmission method provided in this application embodiment may be implemented without reading software code or instructions. For example, it may be implemented by CPU, DSP, ASIC, FPGA, other programmable logic devices, transistor logic devices, hardware components, or any combination thereof.

[0176] When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a terminal device, or other programmable device. The computer program or instructions can be stored in or transmitted through a computer-readable storage medium. The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a Digital Versatile Disc (DVD); or it can be a semiconductor medium, such as a solid-state disk (SSD).

[0177] Finally, it should be noted that the above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A signal processing method, characterized in that, include: The receiving device transmits a first optical signal, which is then transmitted through a channel to form a second optical signal, wherein the first optical signal includes optical signals of multiple wavelengths. The second optical signal is detected to determine whether there is any interference signal caused by four-wave mixing (FWM). The transmitting device sends a first frame to the transmitting device based on the detection result of the second optical signal, so that the transmitting device can determine whether to adjust the wavelength of the first optical signal based on the first frame.

2. The method according to claim 1, characterized in that, The first frame is a data frame, which includes service data and preset bits. The preset bits are used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

3. The method according to claim 2, characterized in that, The data frame includes a forward error correction (FEC) codeword, which includes the service data and a check bit.

4. The method according to claim 3, characterized in that, Each 8704 FEC codewords in the data frame includes 1024 preset bits.

5. The method according to claim 1, characterized in that, The first frame is a training frame, and at least one bit in the control field and / or state field of the training frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

6. The method according to claim 1, characterized in that, The first frame is a negotiation frame, and at least one bit in the base page and / or extended page of the negotiation frame is used to indicate whether the transmitting device adjusts the wavelength of the first optical signal.

7. The method according to any one of claims 1 to 6, characterized in that, If the detection result of the second optical signal is that there is no interference signal, the first frame is used to instruct the transmitting device to maintain the wavelength of the first optical signal.

8. The method according to any one of claims 1 to 6, characterized in that, If the detection result of the second optical signal indicates the presence of the interference signal, the first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal.

9. The method according to claim 8, characterized in that, The first frame is used to instruct the transmitting device to adjust the wavelength of all or part of the optical signals in the first optical signal.

10. The method according to claim 8 or 9, characterized in that, The first frame is used to instruct the transmitting device to gradually increase the wavelength of the first optical signal according to the wavelength adjustment accuracy, or the first frame is used to instruct the transmitting device to gradually decrease the wavelength of the first optical signal according to the wavelength adjustment accuracy.

11. The method according to any one of claims 8 to 10, characterized in that, The first frame is used to instruct the transmitting device to adjust the wavelength of the first optical signal within the wavelength scanning range.

12. The method according to any one of claims 8 to 11, characterized in that, After sending the first frame to the transmitting device, the method further includes: The device receives a fourth optical signal after the third optical signal transmitted by the transmitting device has been transmitted through a channel, wherein the third optical signal is an optical signal obtained by the transmitting device by adjusting the wavelength of the first optical signal; The fourth optical signal is detected to determine whether the interference signal exists; If the detection result of the fourth optical signal is that there is no interference signal, then a second frame is sent to the transmitting device. The second frame is used to instruct the transmitting device to stop adjusting the wavelength of the first optical signal.

13. The method according to any one of claims 8 to 11, characterized in that, After sending the first frame to the transmitting device, the method further includes: The system sequentially receives multiple fourth optical signals after multiple third optical signals transmitted by the transmitting device have been transmitted through the channel. The multiple third optical signals are multiple optical signals obtained by the transmitting device by adjusting the wavelength of the first optical signal across the wavelength scanning range. The plurality of fourth optical signals are detected sequentially to determine which fourth optical signals do not contain interference signals. The target wavelength adjustment amount is determined from the wavelength adjustment amount corresponding to the fourth optical signal that does not contain any interference signal; A second frame is sent to the transmitting device, the second frame being used to instruct the transmitting device to adjust the wavelength of the first optical signal according to the target wavelength adjustment amount and then fix the wavelength.

14. The method according to claim 13, characterized in that, There are multiple fourth optical signals that do not have interference signals, and the target wavelength adjustment amount is the wavelength adjustment amount with the smallest absolute value among the wavelength adjustment amounts corresponding to the fourth optical signals that do not have interference signals.

15. The method according to claim 13, characterized in that, There are multiple fourth optical signals without interference signals. The wavelength adjustment amount corresponding to the fourth optical signal without interference signals includes at least one wavelength adjustment amount interval. The target wavelength adjustment amount is the median of the target wavelength adjustment amount interval among the at least one wavelength adjustment amount interval. The absolute value of the median of the target wavelength adjustment amount interval is the smallest among the medians of the at least one wavelength adjustment amount interval.

16. The method according to any one of claims 1 to 15, characterized in that, Detecting the second optical signal includes: The second optical signal is converted into an electrical signal, and the electrical signal is detected. If a target signal with an amplitude greater than a threshold is detected within the effective frequency range of the electrical signal, then the target signal is determined to be the interference signal.

17. The method according to any one of claims 1 to 16, characterized in that, If the detection result of the second optical signal indicates the presence of the interference signal, the first frame is also used to instruct the transmitting device to reduce the emission power.

18. A signal processing method, characterized in that, include: A first optical signal is sent to a receiving device. The first optical signal includes optical signals of multiple wavelengths. A second optical signal, after the first optical signal is transmitted through a channel, is received and detected by the receiving device. The receiving device receives a first frame sent based on the detection result of the second optical signal, wherein the detection result of the second optical signal is used to indicate whether there is an interference signal generated by four-wave mixing (FWM). Determine whether to adjust the wavelength of the first optical signal based on the first frame.

19. A signal processing apparatus, characterized in that, include: Transceiver unit and processing unit; The transceiver unit is used to: receive a second optical signal after a first optical signal transmitted by a transmitting device has been transmitted through a channel, wherein the first optical signal includes optical signals of multiple wavelengths; The processing unit is used to: detect the second optical signal to determine whether there is an interference signal generated by four-wave mixing (FWM); The transceiver unit is configured to: send a first frame to the transmitting device based on the detection result of the second optical signal, so that the transmitting device determines whether to adjust the wavelength of the first optical signal based on the first frame.

20. A signal processing apparatus, characterized in that, include: Transceiver unit and processing unit; The transceiver unit is used to: send a first optical signal to a receiving device, the first optical signal including optical signals of multiple wavelengths, wherein the second optical signal after the first optical signal is transmitted through the channel is received and detected by the receiving device; The receiving device receives a first frame sent based on the detection result of the second optical signal, wherein the detection result of the second optical signal is used to indicate whether there is an interference signal generated by four-wave mixing (FWM). The processing unit is used to: determine whether to adjust the wavelength of the first optical signal based on the first frame.

21. A chip, characterized in that, The chip is used to perform the method as described in any one of claims 1 to 18.

22. An optical module, characterized in that, The optical module includes a processor and an interface, the interface being used for transmitting and receiving signals, and the processor being used for performing the method as described in any one of claims 1 to 18.

23. A network device, characterized in that, The network device includes a host-side device and an optical module as described in claim 22; the optical module is used to convert electrical signals from the host-side device into optical signals and transmit the optical signals, or the optical module is used to convert received optical signals into electrical signals and transmit the electrical signals to the host-side device.

24. A communication system, characterized in that, It includes a plurality of network devices as described in claim 23, wherein the plurality of network devices are used to send optical signals to each other.

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