Configuration parameter adjustment method for optical communication, apparatus, and system

Abstract

Embodiments of the present application disclose a configuration parameter adjustment method for optical communication, an apparatus, and a system. A first apparatus obtains control information, the control information being obtained on the basis of a coherent optical signal from a second apparatus. The coherent optical signal transmitted by a coherent transmitter of the second apparatus may be impaired or distorted due to changes in an operating environment, device aging, or the like. The control information obtained by the first apparatus may be impairment information of the coherent optical signal, or may be information related to impairment compensation of the coherent optical signal. The first apparatus sends to the second apparatus a signal comprising the control information, the control information being carried in AM information or a DSP frame. The second apparatus can adjust configuration parameters of the coherent transmitter thereof on the basis of the control information, so as to perform impairment compensation on a coherent optical signal subsequently transmitted by the coherent transmitter, thereby reducing the impact of impairment on system performance. Moreover, the control information and data are transmitted together, without requiring additional transmission bandwidth, thereby achieving low implementation costs.

Description

A method, apparatus, and system for adjusting configuration parameters in optical communication.

[0001] This application claims priority to Chinese Patent Application No. 202510126621.2, filed on January 27, 2025, entitled "A method, apparatus and system for adjusting configuration parameters in optical communication", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical communication, and in particular to a method, apparatus and system for adjusting configuration parameters in optical communication. Background Technology

[0003] Coherent optical transmission systems typically employ polarization division multiplexing (PDM) and in-phase and quadrature components (IQ) quadrature modulation to further enhance channel capacity. Coherent optical transmission systems offer advantages such as high bandwidth and low loss, making them suitable for scenarios requiring high-speed transmission. Unlike direct-detection optical signals, which utilize only amplitude variations to transmit data, coherent optical signals use both phase and amplitude information to transmit data, achieving higher spectral efficiency than direct-detection signals.

[0004] In practical applications, factors such as low manufacturing precision, changes in the working environment, and device aging can lead to damage or distortion of coherent optical signals. For example, damage or distortion of coherent optical signals includes skew of in-phase and quadrature components (IQ), skew between the two polarization directions, and power imbalance. Damage or distortion of coherent optical signals in coherent optical transmission systems is a problem that urgently needs to be addressed. Summary of the Invention

[0005] This application provides a method, apparatus, and system for adjusting configuration parameters in optical communication, which helps to reduce the impact of signal impairment on system performance.

[0006] Firstly, this application provides a method for adjusting configuration parameters in optical communication, specifically applied to a first device. In this application, the two ends of the communication system are referred to as the first device and the second device, for example, the first device and the second device are located at opposite ends of an optical fiber. The end containing the first device includes a first host and a first optical module, while the end containing the second device includes a second host and a second optical module. Specifically, the first device acquires control information based on a coherent optical signal from the second device. The coherent optical signal emitted by the coherent transmitter of the second device may be damaged or distorted due to changes in the operating environment or device aging. The control information acquired by the first device can be damage information of the coherent optical signal or information related to damage compensation for the coherent optical signal. The first device sends a signal including alignment marker (AM) information to the second device. The AM information carries the control information, meaning the second device can adjust the configuration parameters of its own coherent transmitter according to the control information to compensate for damage to the coherent optical signal emitted by subsequent coherent transmitters, thus reducing the impact of damage on system performance. Furthermore, the control information is transmitted to the second device along with the service data, eliminating the need for additional transmission bandwidth and resulting in lower implementation costs.

[0007] In some possible implementations, the AM information includes at least one of the unique pad (UP0), UP1, and UP2 fields carrying control information. It should be understood that the data receiver does not need to extract UP0, UP1, and UP2 for synchronization alignment; the bit values ​​in these three fields can be redefined to carry control information, and the number of available bits in these three fields is sufficient to support carrying control information.

[0008] In some possible implementations, the AM information includes a padding field that carries control information. The bits used to fill the padding field do not have fixed values ​​and can be used to carry control information. The padding field has a large number of usable bits, sufficient to support carrying control information. Furthermore, using the padding field to centrally carry control information makes the encapsulation and parsing of the control information easier to implement.

[0009] In some possible implementations, the signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried in the pad field of the first AM information is the same as the control information carried in the pad field of the second AM information. This is equivalent to carrying multiple identical control information entries in the pad fields of multiple AM ​​information entries. These multiple identical control information entries can mutually verify each other, thereby improving the reliability of the transmitted control information.

[0010] In some possible implementations, the signal comprises multiple channel data streams, each of which includes UP0, UP1, and UP2 fields. The UP0, UP1, and UP2 fields of any one of the multiple channel data streams carry control information. In this case, the number of usable bits in UP0, UP1, and UP2 within a single channel data stream is sufficient to support the carrying of control information. Furthermore, concentrating the control information within a single channel data stream simplifies the encapsulation and parsing of the control information.

[0011] In some possible implementations, the multiple channel data streams include a first channel data stream and a second channel data stream. The control information carried in the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried in the UP0, UP1, and UP2 fields of the second channel data stream. This is equivalent to repeatedly carrying multiple copies of the same control information in the UP0, UP1, and UP2 fields of multiple channel data streams. These multiple copies of the same control information can be cross-verified, thereby improving the reliability of the transmitted control information.

[0012] In some possible implementations, the signal comprises multiple data streams, each containing a UP0 field, a UP1 field, and a UP2 field. The UP0 field of each data stream carries control information. The UP0 field in the multiple data streams has a sufficient number of usable bits, which is beneficial for carrying control information. Furthermore, the multiple data streams can be processed synchronously. During the parsing of AM information at the data receiver, the UP0 field is processed before the UP1 and UP2 fields, eliminating the need to wait for the processing delays of the UP1 and UP2 fields, thus facilitating rapid reading of control information.

[0013] In some possible implementations, the control information carried in the UP0 field of multiple channel data streams is the same as the control information carried in the UP1 field of the same channel data streams. This is equivalent to carrying multiple copies of the same control information in the UP0 and UP1 fields of multiple channel data streams. These multiple copies of the same control information can be mutually verified, thereby improving the reliability of the transmitted control information.

[0014] In some possible implementations, the signal includes data, and the data is modulated in the same way as the control information. That is, the control information is transmitted in-band, and the data and control information are transmitted together through the same signal, which does not require additional transmission bandwidth or superimposed signals, thus reducing the implementation cost.

[0015] In some possible implementations, the first device is an optical module. The first device acquires control information by detecting a coherent optical signal from a second device to obtain the control information. In this implementation, the optical module has an optical digital signal processor (oDSP) chip and supports physical coding sublayer (PCS) operations. Specifically, control information can be acquired through the oDSP chip and transmitted back through AM insertion in the PCS operation. This means that the acquisition and transmission of control information are achieved through the optical module, without the need for host intervention, making the implementation simpler.

[0016] In some possible implementations, the first device is a host computer. The acquisition of control information by the first device includes: receiving an electrical signal sent by an optical module, whereby the optical module performs photoelectric conversion on a coherent optical signal from a second device; and detecting the electrical signal to obtain control information. In this implementation, the host computer integrates an oDSP chip. Specifically, the control information can be acquired through the oDSP chip and transmitted back through AM insertion in the PCS operation. This is equivalent to acquiring and transmitting control information through the host computer, thus enriching the applicable scenarios of this solution.

[0017] In some possible implementations, after the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further subjected to first forward error correction (FEC) encoding in the first device. Performing first FEC encoding on the control information and data helps improve the reliability of data and control information transmission.

[0018] In some possible implementations, the AM information and the data to be transmitted, after being encoded by the first FEC, are further encoded by the second FEC in the first device. Employing a concatenated encoding scheme that includes both the first and second FEC encoding further improves the reliability of data and control information transmission.

[0019] In some possible implementations, the first device is a host, and the acquisition of control information by the first device includes: receiving control information sent by the optical module, whereby the control information is obtained by the optical module detecting the coherent optical signal from the second device. In this implementation, the optical module has an oDSP chip, and the operation of the PCS is executed by the host. Specifically, the control information can be acquired through the oDSP chip, and the control information is transmitted back through AM insertion in the PCS operation. This is equivalent to achieving the acquisition and transmission of control information through the cooperation of the host and the optical module, enriching the applicable scenarios of this solution.

[0020] In some possible implementations, after the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further subjected to first FEC encoding in the first device. Performing first FEC encoding on the control information and data helps to improve the reliability of data and control information transmission.

[0021] In some possible implementations, the signal is transmitted to the second device via the optical module, and the AM information and the data to be transmitted, after being encoded by the first FEC, are further encoded by the second FEC in the optical module. Employing a concatenated encoding scheme including the first and second FEC encoding further improves the reliability of data and control information transmission.

[0022] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, offsets of in-phase and quadrature components (IQ), offset compensation values ​​of IQ, power imbalance in two polarization directions, power imbalance of IQ, bit error rate (BER) degrade, equalizer coefficients, precoding switch or filter coefficients. Various specific types of control information are provided here, expanding the impairment scenarios that this scheme can address.

[0023] Secondly, this application provides a method for adjusting configuration parameters in optical communication, specifically applied to a first device. In this application, the two ends of the communication system are referred to as the first device and the second device, for example, the first device and the second device are located at opposite ends of an optical fiber. The end containing the first device includes a first host and a first optical module, while the end containing the second device includes a second host and a second optical module. Specifically, the first device acquires control information based on a coherent optical signal from the second device. The coherent optical signal emitted by the coherent transmitter of the second device may be damaged or distorted due to changes in the working environment or device aging. The control information acquired by the first device can be damage information of the coherent optical signal or information related to damage compensation for the coherent optical signal. The first device sends a signal including a digital signal processing (DSP) frame to the second device. The DSP frame carries the control information, which means that the second device can adjust the configuration parameters of its own coherent transmitter according to the control information to compensate for damage to the coherent optical signal emitted by the subsequent coherent transmitter, thus reducing the impact of damage on system performance. Furthermore, by carrying control information through the DSP frame transmitting the service, no additional transmission bandwidth is required, resulting in a lower implementation cost.

[0024] In some possible implementations, the DSP frame includes pilot symbols that carry control information. That is, the control information is transmitted in-band, and data and control information are transmitted together via the same signal, eliminating the need for additional transmission bandwidth or superimposed signals, thus reducing implementation costs. Furthermore, it avoids using the payload symbols of the DSP frame intended for data transmission to carry control information, ensuring efficient data transmission.

[0025] In some possible implementations, a DSP frame in one polarization direction includes N symbols. Every M consecutive symbols in the N symbols include one pilot symbol and at least one payload symbol, where N = M × Q, and both Q and M are integers greater than 1. At least one of the Q pilot symbols carries control information. In other words, using at least one pilot symbol to carry control information while maintaining the original structure of the DSP frame is beneficial for compatibility with current DSP frame transmission schemes.

[0026] In some possible implementations, k consecutive pilot symbols out of the Q pilot symbols carry control information, where k is an integer greater than 1. It should be understood that carrying control information through multiple consecutive pilot symbols in the DSP frame facilitates faster reading of the control information from the DSP frame by the data receiver, saving parsing time.

[0027] In some possible implementations, at least three of the Q pilot symbols carry control information: the first pilot symbol, the second pilot symbol, and the third pilot symbol. The number of pilot symbols between the first and second pilot symbols is the same as the number between the second and third pilot symbols. In other words, multiple pilot symbols carrying control information are periodically selected from the DSP frame. The remaining pilot symbols in the DSP frame that do not carry control information still maintain periodicity, thus not affecting the original function of the pilot symbols. For example, this helps ensure the stability of synchronization and training functions.

[0028] In some possible implementations, M = 64, Q = 96; or, M = 64, Q = 114; or, M = 32, Q = 116.

[0029] In some possible implementations, the DSP frame includes padding symbols that carry control information. It should be understood that using undefined padding symbols to carry control information is beneficial for maintaining the stable implementation of the original functions of the pilot symbols in the DSP frame.

[0030] In some possible implementations, the padding symbols in a polarization direction include multiple subsets of padding symbols. The number of symbols in each pair of adjacent padding symbol subsets is the same, and at least one subset carries control information. That is, in the DSP frame, the multiple padding symbol subsets and the multiple pilot symbols adopt the same periodic distribution pattern. This is equivalent to the multiple padding symbol subsets being periodically inserted along with the pilot symbols during the DPS frame generation process, which is beneficial for compatibility with existing DSP frame generation methods.

[0031] In some possible implementations, k consecutive subsets of padding symbols within a plurality of padding symbol subsets carry control information, where k is an integer greater than 1. By using multiple consecutive subsets of padding symbols within the DSP frame to carry control information, the data receiver can quickly read the control information from the DSP frame, saving parsing time.

[0032] In some possible implementations, at least a first, second, and third subset of padding symbols carry control information. The number of symbols between the first and third padding symbol subsets is the same as the number of symbols between the second and third padding symbol subsets. Multiple subsets of padding symbols carrying control information are periodically selected from the DSP frame. The remaining subsets of padding symbols in the DSP frame that do not carry control information also remain periodic, so that some functions can be implemented as needed using the remaining subsets of padding symbols that do not carry control information.

[0033] In some possible implementations, DSP frames carry control information in two polarization directions, which helps to improve the transmission efficiency and reliability of control information, wherein the two polarization directions are orthogonal to each other.

[0034] In some possible implementations, the DSP frame carries multiple identical control information sets. That is, by repeatedly carrying the same control information within the DSP frame, multiple identical control information sets can be cross-verified, thereby improving the reliability of the transmitted control information.

[0035] In some possible implementations, multiple DSP frames in the signal carry the same control information. That is, by repeatedly carrying the same control information in multiple DSP frames, multiple identical control information can be mutually verified, thereby improving the reliability of the transmitted control information.

[0036] In some possible implementations, at least a first DSP frame, a second DSP frame, and a third DSP frame carry control information in the signal, and the number of DSP frames between the first and second DSP frames is the same as the number between the second and third DSP frames. Periodically selecting different DSP frames to carry control information helps ensure the implementation of the synchronization alignment function.

[0037] In some possible implementations, the first device is a host or an optical module, which expands the applicable scenarios of this solution.

[0038] In some possible implementations, the control information includes at least one of the following: offsets in the two polarization directions, offset compensation values ​​in the two polarization directions, IQ offset, IQ offset compensation value, power imbalance in the two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, and precoding switch or filter coefficients. Various specific types of control information are provided here, expanding the impairment scenarios that this solution can address.

[0039] Thirdly, this application provides a method for adjusting configuration parameters in optical communication, specifically applied to a second device. In this application, the two ends of the communication system are referred to as the first device and the second device, for example, the first device and the second device are located at opposite ends of an optical fiber. The end containing the first device includes a first host and a first optical module, while the end containing the second device includes a second host and a second optical module. Specifically, the second device sends a coherent optical signal to the first device and receives the signal sent by the first device. The signal sent by the first device includes AM information, which carries control information derived from the coherent optical signal. The coherent optical signal emitted by the coherent transmitter of the second device may be damaged or distorted due to changes in the working environment or device aging. The control information obtained by the first device can be damage information of the coherent optical signal or information related to damage compensation of the coherent optical signal. Furthermore, the second device can adjust the configuration parameters of its own coherent transmitter according to the control information to compensate for damage to the coherent optical signal emitted by subsequent coherent transmitters, which helps reduce the impact of damage on system performance. Moreover, the control information is transmitted to the second device along with the service data, without requiring additional transmission bandwidth, resulting in a low implementation cost.

[0040] In some possible implementations, the AM information includes at least one of the UP0, UP1, and UP2 fields that carries control information.

[0041] In some possible implementations, the AM information includes a pad field that carries control information.

[0042] In some possible implementations, the signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried in the pad field of the first AM information is the same as the control information carried in the pad field of the second AM information.

[0043] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, and the UP0, UP1, and UP2 fields of any one of the multiple channel data streams carry control information.

[0044] In some possible implementations, the multiple channel data streams include a first channel data stream and a second channel data stream, wherein the control information carried by the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried by the UP0, UP1, and UP2 fields of the second channel data stream.

[0045] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, with the UP0 field of the multiple channel data streams carrying control information.

[0046] In some possible implementations, the control information carried by the UP0 field of the multiple channel data streams is the same as the control information carried by the UP1 field of the multiple channel data streams.

[0047] In some possible implementations, the signal includes data, and the data is modulated in the same way as the control information.

[0048] In some possible implementations, the second device is an optical module or a host, and the second device adjusts the configuration parameters of the coherent transmitter according to the control information by: the second device reading the control information from the signal sent by the first device and adjusting the configuration parameters of the coherent transmitter according to the control information.

[0049] In some possible implementations, before the second device reads control information from the signal sent by the first device, the method further includes: the second device performing a first forward error correction (FEC) decoding on the signal sent by the first device.

[0050] In some possible implementations, before the second device performs a first FEC decoding on the signal sent by the first device, the method further includes: the second device performing a second FEC decoding on the signal sent by the first device.

[0051] In some possible implementations, the second device is an optical module, and the second device adjusts the configuration parameters of the coherent transmitter according to the control information by receiving control information sent by the host and adjusting the configuration parameters of the coherent transmitter according to the control information, wherein the control information is read by the host from the signal sent by the first device.

[0052] In some possible implementations, the signals sent by the first device are decoded by the host after a first FEC before the host reads the control information from the signals sent by the first device.

[0053] In some possible implementations, the method further includes: a second device performing a second FEC decoding on the signal sent by the first device before the host performs the first FEC decoding.

[0054] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, IQ offset, IQ offset compensation value, power imbalance in two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, precoding switch or filter coefficients.

[0055] Fourthly, this application provides a method for adjusting configuration parameters in optical communication, specifically applied to a second device. In this application, the two ends of the communication system are referred to as the first device and the second device, for example, the first device and the second device are located at opposite ends of an optical fiber. The end containing the first device includes a first host and a first optical module, while the end containing the second device includes a second host and a second optical module. Specifically, the second device sends a coherent optical signal to the first device and receives the signal sent by the first device. The signal sent by the first device includes a DSP frame, which carries control information derived from the coherent optical signal. The coherent optical signal emitted by the coherent transmitter of the second device may be damaged or distorted due to changes in the working environment or device aging. The control information obtained by the first device can be damage information of the coherent optical signal or information related to damage compensation of the coherent optical signal. Furthermore, the second device can adjust the configuration parameters of its own coherent transmitter according to the control information to compensate for damage in subsequent coherent optical signals emitted by the coherent transmitter, which helps reduce the impact of damage on system performance. Moreover, by carrying control information through the DSP frame transmitting the service, no additional transmission bandwidth is required, resulting in a lower implementation cost.

[0056] In some possible implementations, the DSP frame includes pilot symbols that carry control information.

[0057] In some possible implementations, a DSP frame in one polarization direction includes N symbols, and every M consecutive symbols in the N symbols include one pilot symbol and at least one payload symbol, N = M × Q, where Q and M are both integers greater than 1, and at least one pilot symbol in the Q pilot symbols carries control information.

[0058] In some possible implementations, k consecutive pilot symbols out of the Q pilot symbols carry control information, where k is an integer greater than 1.

[0059] In some possible implementations, at least three of the Q pilot symbols—a first pilot symbol, a second pilot symbol, and a third pilot symbol—carry control information, and the number of pilot symbols between the first and second pilot symbols is the same as the number of pilot symbols between the second and third pilot symbols.

[0060] In some possible implementations, M = 64, Q = 96; or, M = 64, Q = 114; or, M = 32, Q = 116.

[0061] In some possible implementations, the DSP frame includes padding symbols that carry control information.

[0062] In some possible implementations, the filling symbols in a polarization direction include multiple filling symbol subsets, where the number of symbols is the same between any two adjacent filling symbol subsets, and at least one filling symbol subset carries control information.

[0063] In some possible implementations, k consecutive subsets of padding symbols from multiple padding symbol subsets carry control information, where k is an integer greater than 1.

[0064] In some possible implementations, at least a first, a second, and a third subset of padding symbols carries control information, and the number of symbols between the first and third padding symbol subsets is the same as the number of symbols between the second and third padding symbol subsets.

[0065] In some possible implementations, the DSP frame carries control information in two polarization directions, which are orthogonal to each other.

[0066] In some possible implementations, the DSP frame carries multiple identical control information.

[0067] In some possible implementations, multiple DSP frames in the signal carry the same control information.

[0068] In some possible implementations, at least a first DSP frame, a second DSP frame, and a third DSP frame carry control information in the signal, and the number of DSP frames between the first DSP frame and the second DSP frame is the same as the number of DSP frames between the second DSP frame and the third DSP frame.

[0069] In some possible implementations, the second device is a host or an optical module.

[0070] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, IQ offset, IQ offset compensation value, power imbalance in two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, precoding switch or filter coefficients.

[0071] Fifthly, embodiments of this application provide a communication device, which includes a processing unit and a transceiver unit. The processing unit is configured to: acquire control information, which is obtained based on a coherent optical signal from a second device, and the control information is used to adjust the configuration parameters of the coherent transmitter of the second device. The transceiver unit is configured to: send a signal to the second device, the signal including alignment flag (AM) information, the AM information carrying the control information.

[0072] In some possible implementations, the AM information includes at least one of the UP0, UP1, and UP2 fields that carries control information.

[0073] In some possible implementations, the AM information includes a pad field that carries control information.

[0074] In some possible implementations, the signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried in the pad field of the first AM information is the same as the control information carried in the pad field of the second AM information.

[0075] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, and the UP0, UP1, and UP2 fields of any one of the multiple channel data streams carry control information.

[0076] In some possible implementations, the multiple channel data streams include a first channel data stream and a second channel data stream, wherein the control information carried by the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried by the UP0, UP1, and UP2 fields of the second channel data stream.

[0077] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, with the UP0 field of the multiple channel data streams carrying control information.

[0078] In some possible implementations, the control information carried by the UP0 field of the multiple channel data streams is the same as the control information carried by the UP1 field of the multiple channel data streams.

[0079] In some possible implementations, the signal includes data, and the data is modulated in the same way as the control information.

[0080] In some possible implementations, the first device is an optical module, and the processing unit is specifically used to detect coherent optical signals from the second device to obtain control information.

[0081] In some possible implementations, the first device is a host, and the processing unit is specifically used to: receive electrical signals sent by the optical module and detect the electrical signals to obtain control information.

[0082] In some possible implementations, after the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further encoded by the first forward error correction (FEC) in the first device.

[0083] In some possible implementations, the AM information and the data to be transmitted, which have been encoded by the first FEC, are further encoded by the second FEC in the first device.

[0084] In some possible implementations, the first device is a host, and the transceiver unit is specifically used to: receive control information sent by the optical module, the control information being obtained by the optical module detecting coherent optical signals from the second device.

[0085] In some possible implementations, after the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further encoded by the first FEC in the first device.

[0086] In some possible implementations, the signal is transmitted to the second device via the optical module, and the AM information and the data to be transmitted, after being encoded by the first FEC, are further encoded by the second FEC in the optical module.

[0087] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, IQ offset, IQ offset compensation value, power imbalance in two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, precoding switch or filter coefficients.

[0088] Sixthly, embodiments of this application provide a communication device, which includes a processing unit and a transceiver unit. The processing unit is configured to: acquire control information, which is obtained based on a coherent optical signal from a second device, and the control information is used to adjust the configuration parameters of the coherent transmitter of the second device. The transceiver unit is configured to: send a signal to the second device, the signal including a digital signal processing (DSP) frame, the DSP frame carrying the control information.

[0089] In some possible implementations, the DSP frame includes pilot symbols that carry control information.

[0090] In some possible implementations, a DSP frame in one polarization direction includes N symbols, and every M consecutive symbols in the N symbols include one pilot symbol and at least one payload symbol, N = M × Q, where Q and M are both integers greater than 1, and at least one pilot symbol in the Q pilot symbols carries control information.

[0091] In some possible implementations, k consecutive pilot symbols out of the Q pilot symbols carry control information, where k is an integer greater than 1.

[0092] In some possible implementations, at least three of the Q pilot symbols—a first pilot symbol, a second pilot symbol, and a third pilot symbol—carry control information, and the number of pilot symbols between the first and second pilot symbols is the same as the number of pilot symbols between the second and third pilot symbols.

[0093] In some possible implementations, M = 64, Q = 96; or, M = 64, Q = 114; or, M = 32, Q = 116.

[0094] In some possible implementations, the DSP frame includes padding symbols that carry control information.

[0095] In some possible implementations, the filling symbols in a polarization direction include multiple filling symbol subsets, where the number of symbols is the same between any two adjacent filling symbol subsets, and at least one filling symbol subset carries control information.

[0096] In some possible implementations, k consecutive subsets of padding symbols from multiple padding symbol subsets carry control information, where k is an integer greater than 1.

[0097] In some possible implementations, at least a first, a second, and a third subset of padding symbols carries control information, and the number of symbols between the first and third padding symbol subsets is the same as the number of symbols between the second and third padding symbol subsets.

[0098] In some possible implementations, DSP frames carry control information in two polarization directions, which helps to improve the transmission efficiency and reliability of control information, wherein the two polarization directions are orthogonal to each other.

[0099] In some possible implementations, the DSP frame carries multiple identical control information.

[0100] In some possible implementations, multiple DSP frames in the signal carry the same control information.

[0101] In some possible implementations, at least a first DSP frame, a second DSP frame, and a third DSP frame carry control information in the signal, and the number of DSP frames between the first DSP frame and the second DSP frame is the same as the number of DSP frames between the second DSP frame and the third DSP frame.

[0102] In some possible implementations, the first device is a host or an optical module, which expands the applicable scenarios of this solution.

[0103] In some possible implementations, the control information includes at least one of the following: offsets in the two polarization directions, offset compensation values ​​in the two polarization directions, IQ offset, IQ offset compensation value, power imbalance in the two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, and precoding switch or filter coefficients. Various specific types of control information are provided here, expanding the impairment scenarios that this solution can address.

[0104] In a seventh aspect, embodiments of this application provide a communication device, which includes a processing unit and a transceiver unit. The transceiver unit is configured to: transmit a coherent optical signal to a first device; and receive a signal transmitted by the first device, the signal including alignment flag (AM) information, the AM information carrying control information, the control information being obtained based on the coherent optical signal. The processing unit is configured to: adjust the configuration parameters of the coherent transmitter according to the control information.

[0105] In some possible implementations, the AM information includes at least one of the UP0, UP1, and UP2 fields that carries control information.

[0106] In some possible implementations, the AM information includes a pad field that carries control information.

[0107] In some possible implementations, the signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried in the pad field of the first AM information is the same as the control information carried in the pad field of the second AM information.

[0108] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, and the UP0, UP1, and UP2 fields of any one of the multiple channel data streams carry control information.

[0109] In some possible implementations, the multiple channel data streams include a first channel data stream and a second channel data stream, wherein the control information carried by the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried by the UP0, UP1, and UP2 fields of the second channel data stream.

[0110] In some possible implementations, the signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field, with the UP0 field of the multiple channel data streams carrying control information.

[0111] In some possible implementations, the control information carried by the UP0 field of the multiple channel data streams is the same as the control information carried by the UP1 field of the multiple channel data streams.

[0112] In some possible implementations, the signal includes data, and the data is modulated in the same way as the control information.

[0113] In some possible implementations, the second device is an optical module or a host, and the processing unit is specifically used to: read control information from the signal sent by the first device, and adjust the configuration parameters of the coherent transmitter according to the control information.

[0114] In some possible implementations, before the processing unit reads control information from the signal sent by the first device, the processing unit is further configured to: perform a first forward error correction (FEC) decoding on the signal sent by the first device.

[0115] In some possible implementations, before the processing unit performs first FEC decoding on the signal sent by the first device, the processing unit is further configured to perform second FEC decoding on the signal sent by the first device.

[0116] In some possible implementations, the second device is an optical module, and the processing unit is specifically used to: receive control information sent by the host and adjust the configuration parameters of the coherent transmitter according to the control information, wherein the control information is read by the host from the signal sent by the first device.

[0117] In some possible implementations, the signals sent by the first device are decoded by the host after a first FEC before the host reads the control information from the signals sent by the first device.

[0118] In some possible implementations, before the signal sent by the first device is decoded by the host via the first FEC, the processing unit is further configured to perform a second FEC decoding on the signal sent by the first device.

[0119] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, IQ offset, IQ offset compensation value, power imbalance in two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, precoding switch or filter coefficients.

[0120] Eighthly, embodiments of this application provide a communication device, which includes a processing unit and a transceiver unit. The transceiver unit is configured to: transmit a coherent optical signal to a first device; and receive a signal transmitted by the first device, the signal including a digital signal processing (DSP) frame, the DSP frame carrying control information obtained based on the coherent optical signal. The processing unit is configured to: adjust the configuration parameters of the coherent transmitter according to the control information.

[0121] In some possible implementations, the DSP frame includes pilot symbols that carry control information.

[0122] In some possible implementations, a DSP frame in one polarization direction includes N symbols, and every M consecutive symbols in the N symbols include one pilot symbol and at least one payload symbol, N = M × Q, where Q and M are both integers greater than 1, and at least one pilot symbol in the Q pilot symbols carries control information.

[0123] In some possible implementations, k consecutive pilot symbols out of the Q pilot symbols carry control information, where k is an integer greater than 1.

[0124] In some possible implementations, at least three of the Q pilot symbols—a first pilot symbol, a second pilot symbol, and a third pilot symbol—carry control information, and the number of pilot symbols between the first and second pilot symbols is the same as the number of pilot symbols between the second and third pilot symbols.

[0125] In some possible implementations, M = 64, Q = 96; or, M = 64, Q = 114; or, M = 32, Q = 116.

[0126] In some possible implementations, the DSP frame includes padding symbols that carry control information.

[0127] In some possible implementations, the filling symbols in a polarization direction include multiple filling symbol subsets, where the number of symbols is the same between any two adjacent filling symbol subsets, and at least one filling symbol subset carries control information.

[0128] In some possible implementations, k consecutive subsets of padding symbols from multiple padding symbol subsets carry control information, where k is an integer greater than 1.

[0129] In some possible implementations, at least a first, a second, and a third subset of padding symbols carries control information, and the number of symbols between the first and third padding symbol subsets is the same as the number of symbols between the second and third padding symbol subsets.

[0130] In some possible implementations, the DSP frame carries control information in two polarization directions, which are orthogonal to each other.

[0131] In some possible implementations, the DSP frame carries multiple identical control information.

[0132] In some possible implementations, multiple DSP frames in the signal carry the same control information.

[0133] In some possible implementations, at least a first DSP frame, a second DSP frame, and a third DSP frame carry control information in the signal, and the number of DSP frames between the first DSP frame and the second DSP frame is the same as the number of DSP frames between the second DSP frame and the third DSP frame.

[0134] In some possible implementations, the second device is a host or an optical module.

[0135] In some possible implementations, the control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, IQ offset, IQ offset compensation value, power imbalance in two polarization directions, power imbalance in IQ, BER degradation, equalizer coefficients, precoding switch or filter coefficients.

[0136] Ninthly, embodiments of this application provide a chip, the chip including a processor, the processor being configured to perform the methods described in any of the embodiments of the first to fourth aspects.

[0137] In a tenth aspect, embodiments of this application provide a communication device for performing the method as described in any of the embodiments of the first or second aspect.

[0138] Eleventhly, embodiments of this application provide a communication device for performing the method described in any of the embodiments of the third or fourth aspect.

[0139] In a twelfth aspect, embodiments of this application provide a communication device, which includes a control circuit and an interface circuit. The interface circuit is used to transmit and receive signals, and the control circuit is used to perform the method described in any embodiment of the first or second aspect.

[0140] In a thirteenth aspect, embodiments of this application provide a communication device, which includes a control circuit and an interface circuit. The interface circuit is used to transmit and receive signals, and the control circuit is used to perform the method described in any of the embodiments of the third or fourth aspect.

[0141] In a fourteenth aspect, embodiments of this application provide a communication system comprising a first device and a second device. The first device is configured to perform the method described in any embodiment of the first aspect, and the second device is configured to perform the method described in any embodiment of the third aspect. Alternatively, the first device is configured to perform the method described in any embodiment of the second aspect, and the second device is configured to perform the method described in any embodiment of the fourth aspect.

[0142] In a fifteenth aspect, 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 to fourth aspects to be implemented.

[0143] In a sixteenth aspect, this application provides a computer program product including program instructions that, when executed, implement the methods described in any of the embodiments of the first to fourth aspects. Attached Figure Description

[0144] Figure 1 is a schematic diagram of a communication system applied in an embodiment of this application;

[0145] Figure 2 is a schematic diagram of an implementation of an integrated coherent transmitter;

[0146] Figure 3 is a schematic diagram of another implementation of an integrated coherent transmitter;

[0147] Figure 4 is a schematic diagram of a protocol stack layer model architecture applicable to an embodiment of this application;

[0148] Figure 5 is a flowchart illustrating a configuration parameter adjustment method in an embodiment of this application;

[0149] Figure 6 is a schematic diagram of a system scenario for a configuration parameter adjustment method in an embodiment of this application;

[0150] Figure 7 is a schematic diagram of the operation process of a PCS;

[0151] Figure 8 is a schematic diagram of the distribution of AM groups in multiple channel data streams;

[0152] Figure 9(a) is a schematic diagram of an application scenario of the configuration parameter adjustment method in the embodiments of this application;

[0153] Figure 9(b) is a schematic diagram of another application scenario of the configuration parameter adjustment method in the embodiments of this application;

[0154] Figure 9(c) is a schematic diagram of another application scenario of the configuration parameter adjustment method in the embodiments of this application;

[0155] Figure 10(a) is a schematic diagram of one implementation method of framing in an embodiment of this application;

[0156] Figure 10(b) is a schematic diagram of another implementation of framing in the embodiments of this application;

[0157] Figure 10(c) is a schematic diagram of another embodiment of framing in this application.

[0158] Figure 10(d) is a schematic diagram of another embodiment of framing in this application;

[0159] Figure 11 is a schematic diagram of a DSP frame structure in an embodiment of this application;

[0160] Figure 12 is a schematic diagram of symbols on a constellation diagram according to an embodiment of this application;

[0161] Figure 13 is a schematic diagram of a pilot symbol generation structure in an embodiment of this application;

[0162] Figure 14 is a schematic diagram of another structure of the DSP frame in an embodiment of this application;

[0163] Figure 15 is a schematic diagram of a communication device in an embodiment of this application;

[0164] Figure 16 is a schematic diagram of another structure of the communication device in an embodiment of this application. Detailed Implementation

[0165] This application provides a method, apparatus, and system for adjusting configuration parameters in optical communication, which helps to reduce the impact of signal impairment on system performance.

[0166] To facilitate understanding of the embodiments of this application, the following points are made:

[0167] First, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0168] Second, "at least one" means one or more, and "more than one" means two or more (including two). "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can mean: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a, b, and c. Here, a, b, and c can be single or multiple.

[0169] Third, the terms "first," "second," and various numerical designations (e.g., #1, #2) are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. For example, they can be used to distinguish different indication information.

[0170] Fourth, 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 that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0171] Fifth, "for indicating" or "indication" can include both direct and indirect indication, or in other words, "for indicating" or "indication" can be explicit and / or implicit. For example, when describing information as indicating information I, it can include whether the information directly indicates I or indirectly indicates I, without implying that the information necessarily carries I. As another example, implicit indication can be based on the location and / or resources used for transmission; explicit indication can be based on one or more parameters, and / or one or more indices, and / or one or more bit patterns they represent.

[0172] 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, servers, or network interface cards (NICs). 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 (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. 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; specific limitations are not specified here.

[0173] In coherent optical communication scenarios, both the transmitting end processing module 02 and the receiving end processing module 04 can be coherent optical modules. A coherent optical module refers to an optical module that uses coherent communication technology to achieve data communication. Unlike direct-modulation and direct-detection optical signals, which only use amplitude changes in the optical signal to transmit data, coherent optical signals use both phase and amplitude information to transmit data, achieving a higher spectral efficiency than direct-detection signals. A coherent optical module includes a light source, an integrated coherent transmitter (ICT), an integrated coherent receiver (ICR), and a microcontroller unit (MCU). The ICT includes a driver amplifier and a modulator, while the ICR includes a mixer.

[0174] Figure 2 is a schematic diagram of an implementation of an integrated coherent transmitter. As shown in Figure 2, in order to obtain a coherent optical signal, a continuous wave (CW) light source signal is split in a 1:2 ratio. Two electro-optic modulators are used to modulate the two signals with the same rate onto two CW light source signals from the same source. Then, a delay line (DL) or a phase shifter (PS) is used to make a 90-degree (pi / 2) relative phase difference (delay) between the two modulated signals, thereby obtaining mutually orthogonal I-path (in-phase component) and Q-path (quadrature-phase component) signals. The two orthogonal signals are combined through a 2:1 power divider. At this time, the phase and amplitude information of the output coherent optical signal contains the two signals. Currently, coherent modulators primarily employ photonic chip technology based on integrated optics. The main material systems used in photonic chips include Si-on-Insulator (SiP), indium phosphate (InP), thin-film lithium niobate (TFLN), and silicon-based integrated TFLN. The fabrication process and technology of photonic chips are similar to semiconductor processes, but the process technology lags far behind complementary metal-oxide-semiconductor (CMOS) processes. Common nodes include 45nm, 65nm, 130nm, and 180nm SiP, as well as micrometer-scale photolithography. Due to the lower precision of the manufacturing process and the fluctuation in the film thickness of various material layers, the actual coherent optical modulators produced are not ideal. This includes the fact that the beam splitter ratio is not strictly 1:2, the two modulators are not completely identical, and the phase difference introduced by DL or PS is not strictly 90 degrees. All of these will lead to damage and distortion of the output coherent signal. Although coherent optical receivers have relatively complex digital signal processing (DSP) that can implement some algorithms to recover the distortion, this is undoubtedly a burden.

[0175] Figure 3 is a schematic diagram of another implementation of an integrated coherent transmitter. As shown in Figure 3, coherent optical transmission systems also widely utilize two orthogonal polarization modes supported by the optical fiber channel to further double the spectral efficiency. Two polarizations can be used to carry one coherent signal, including the aforementioned IQ orthogonal signals. For example, for a 50 GBaud channel, the spectral efficiency of a dual polarization (DP) 16-ary Quadrature Amplitude Modulation (16QAM) signal is doubled again. DP-16QAM can also be called polarization multiplexing (PM)-16QAM. The polarization-multiplexed coherent optical modulator can also be implemented using photonic chips. By splitting the CW light source to provide 1:4 to four modulators, coherent signals corresponding to the two polarization directions need to be transmitted using the two orthogonal polarization modes of the optical fiber. This can be achieved using a polarization splitting rotator (PSR) on an integrated chip. Therefore, there are four different signals, including the I-channel signal in the X-polarization direction, the Q-channel signal in the X-polarization direction, the I-channel signal in the Y-polarization direction, and the Q-channel signal in the Y-polarization direction. The I-channel signal in the X-polarization direction is also called X... I The component, the Q-path signal in the X-polarization direction, is also called the X-axis signal. Q The component, the I-channel signal in the Y-polarization direction, is also called the Y component. I The component, the Q-path signal in the Y-polarization direction, is also called the Y component. Q Quantity.

[0176] As shown in Figure 3, the coherent modulator chip has more unit devices, leading to more sources of deviation due to process and manufacturing. It requires compensation not only for inconsistencies between the I and Q paths in one polarization direction but also for inconsistencies between two polarization directions. Furthermore, with the increased number of unit devices on the chip, waveguide traces are introduced into the device layout to better meet packaging constraints, introducing additional losses and variations. For example, deviations caused by the power divider mainly manifest as power imbalance. Phase shifter deviations, waveguide trace length deviations on the chip, and propagation coefficient deviations caused by waveguide inhomogeneities mainly manifest as time delay skew, which includes offsets between the two polarization directions (XY skew) and IQ skew. As another example, modulators typically employ Mach-Zehnder modulators or micro-ring modulators, each requiring operation at a specific bias point; different bias points also introduce power imbalance. For example, the driver amplifier provides a high-speed analog electrical signal output with sufficient swing to drive the electro-optic modulator. A total of 4 driver amplifiers are required, usually in the same chip. The inconsistency in the relative time delay and swing output between the 4 driver signals is also one of the sources of distortion in the coherent optical signal output by the transmitter.

[0177] Besides signal distortion caused by coherent transmitters, polarization-multiplexed coherent signals in ordinary single-mode fiber (SMF) transmission are further distorted. This is mainly due to the different losses and transmission speeds experienced by the two polarization directions during fiber transmission. Ideally, the fiber core is perfectly circular, and the refractive indices of each layer are uniformly distributed radially. In this case, the X and Y polarization modes have the same complex propagation coefficient (the propagation coefficient is a complex number; the real part determines the propagation speed, and the imaginary part determines the transmission loss), meaning the two polarization modes have the same transmission loss and transmission rate. However, in actual optical fibers, due to manufacturing deviations, material inhomogeneity, and the influence of external temperature, pressure, and stress, the complex propagation coefficients of the X and Y polarization modes differ. The difference in the real part causes polarization mode dispersion (PMD), while the difference in the imaginary part leads to power imbalance between the X and Y polarization components, introducing a relative time delay between the signals carried in the X and Y polarization directions. This increases the difficulty of signal recovery and codeword alignment in digital signals. PMD can also be caused by the nonlinear characteristics of optical fibers, coupling between two polarization modes, and energy conversion. PMD is sometimes characterized by differential group delay. The PMD characteristics of an optical fiber link are affected by the environment in which the fiber is located, mainly by changes in temperature and stress, which are usually relatively slow changes.

[0178] It's important to note that ordinary SMFs (Self-Polarizing Fibers) do not possess polarization-preserving properties. This means that an optical signal X-I+j*XQ input into the fiber with X-polarization will typically change its polarization state after passing through an SMF of a certain length, resulting in an optical signal containing electromagnetic field components in both the X and Y polarization directions. The same phenomenon occurs with optical signals Y-I+j*YQ input into the fiber with Y-polarization. Current mainstream coherent receivers also utilize photonic chips, which separate the optical signal from the fiber into an X-polarized signal (Rx signal) and a Y-polarized signal (Ry signal). However, both the Rx and Ry signals are composed of X-I+j*XQ and Y-I+j*YQ components. A crucial function of coherent receivers and DSPs is to recover the X-polarized signal through signal processing. I Component, X Q Components, Y I Components, Y Q The components are then aligned with their symbols or codewords. The aforementioned imbalances and skews increase the difficulty of this signal processing, therefore, it is necessary to minimize the imbalances and skews perceived by the final receiver. It should be understood that distortions caused by imperfections in coherent components can be compensated for in the factory calibration, but drift during operation and distortions introduced by fiber optic transmission cannot be compensated for in the factory calibration. In coherent transmission scenarios of 400 gigabits per second (Gbps) and 800 Gbps, these distortions are mitigated by the margin of the optical signal-to-noise ratio (OSNR) tolerance of the coherent link relative to the actual OSNR cost of transmission. As the rate increases to 1.6 terabit per second (Tbps), the OSNR margin decreases, and the cost of the same degree of distortion becomes more significant.

[0179] To address the aforementioned problems of coherent optical signal impairment or distortion, this application provides several solutions. For devices 1 and 2 located at opposite ends of an optical fiber, device 1 receives the coherent optical signal from device 2. Device 1 obtains control information through detection and other processing of the coherent optical signal. This control information serves as reference information for device 2 in impairment compensation. Device 1 feeds back the control information to device 2, and device 2 adjusts the configuration parameters of the coherent transmitter based on the control information, thereby compensating for impairment in subsequent coherent optical signals emitted by the coherent transmitter, reducing the impact of signal impairment on system performance. Essentially, in a real-world scenario, this feedback adjustment mechanism can dynamically compensate for impairment based on the actual impairment of the coherent optical signal, providing better suppression of signal impairment caused by various factors. Furthermore, this application uses in-band transmission to feed back the control information, meaning that the control information and service data can be transmitted through the same optical signal, eliminating the need for additional transmission bandwidth and reducing implementation costs.

[0180] It should be noted that the coherent optical module in this application embodiment can be of various types, which will be described below.

[0181] For example, an optical digital signal processor (oDSP) chip is located inside a coherent optical module, which can be called a digital coherent optical (DCO) module.

[0182] For example, the oDSP chip is located outside the coherent optical module and is not located inside the host. That is, the oDSP chip is placed independently of the coherent optical module and the host. This coherent optical module can be called an analog coherent optical (ACO) module.

[0183] For example, a coherent optical module can be a linear-drive pluggable optics (LPO) module, a near package optics (NPO) module, a co-packaged optics (CPO) module, a half-retimed optics (HRO) module, a linear receive optics (LRO) module, and a transmitter retimed optics (TRO) module, etc. In the embodiments of this application, the LPO module, NPO module, CPO module, HRO module, LRO module, and TRO module can also be referred to as an LPO optical module, NPO optical module, CPO optical module, HRO optical module, LRO optical module, and TRO optical module.

[0184] 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 (OE). 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.

[0185] 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 optical 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. Furthermore, the optical signal is further degraded by defects in the fiber optic link during transmission. At the optical receiver of the peer LPO optical module, the optical signal is converted into an electrical signal. This electrical signal, without digital signal processing (e.g., retiming), reaches the peer host directly. Degradation of the optical signal via the fiber optic link and impairment caused by the passive electrical link in the peer host accumulate and are carried to the peer host's SERDEs. In practical applications, the local host performs certain preprocessing on the transmitted electrical signal (pre-emphasis, equalization, etc.) to pre-compensate for the impairment caused by the host's passive electrical link and the signal degradation introduced during the photoelectric conversion of the optical transmitter. The peer host's compensation and equalization capabilities are mainly used to address the degradation of the optical signal via the fiber optic link, the signal degradation introduced during the photoelectric conversion of the optical receiver, and the impairment caused by the peer host's passive electrical link. Such complex signal processing requirements place high demands on the host's SERDEs, and may even lead to insufficient signal processing capabilities and problems.

[0186] 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).

[0187] Figure 4 is a schematic diagram of a protocol stack layer model architecture applicable to an embodiment of this application. This protocol stack layer model is the Ethernet protocol stack layer. Ethernet is a set of standards defined by the Institute of Electrical and Electronics Engineers (IEEE) 802 standards organization, involving network, interface, and physical layer technologies. The Ethernet physical layer is relevant to this embodiment, and its protocol stack layer can be seen in Figure 4. As shown in Figure 4, this model architecture is a network interconnection model, defining a seven-layer framework for network interconnection, from bottom to top: physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer.

[0188] Ethernet resides in the data link layer and physical layer of the Open System Interconnection (OSI) reference model. As shown in Figure 4, the data link layer comprises two sublayers: the logical link control (LLC) sublayer and the medium access control (MAC) sublayer, which is responsible for parsing and assembling Ethernet frames.

[0189] As shown in Figure 4, the physical layer can include a Physical Medium Dependent (PMD) sublayer, a Physical Medium Attachment (PMA) sublayer, and a Physical Coding (PCS) sublayer. A reconciliation sublayer (RS) is also included between the PCS and the MAC sublayer. The RS and PCS share a gigabit media independent interface (GMII), such as XGMII, 25GMII, or 50GMII. The PMD sublayer connects to the medium via a Medium Dependent Interface (MDI), which can be a cable or optical fiber.

[0190] Figure 5 is a flowchart illustrating a configuration parameter adjustment method according to an embodiment of this application. As shown in Figure 5, in this embodiment, the two ends of the communication system are referred to as device A and device B, respectively. For example, device A and device B are located at opposite ends of an optical fiber. The following description uses the example of device A sending a coherent optical signal to device B. The scenario of device B sending a coherent optical signal to device A follows a similar procedure and will not be elaborated further. Specifically, after receiving the coherent optical signal from device B, device A performs detection and other processing on the coherent optical signal to obtain control information. Device A then sends the control information to device B via in-band transmission. Device B adjusts the configuration parameters of the coherent transmitter according to the control information to compensate for the impairment of the coherent optical signal.

[0191] It should be noted that, regarding the configuration parameter adjustment method provided in this application embodiment, device B is mainly used to acquire and transmit control information, while device A is mainly used to read the control information and adjust the configuration parameters of the coherent transmitter according to the control information. The operation of device A can be implemented by host A and / or optical module A, and the operation of device B can be implemented by host B and / or optical module B. Some possible scenarios are described below.

[0192] In one possible scenario (Scenario 1), all operations related to the configuration parameter adjustment method are implemented through optical modules. That is, in Scenario 1, device A is optical module A, device B is optical module B, and both optical modules A and B include an oDSP chip. For example, optical module B is used to acquire and transmit control information, while optical module A is used to read the control information and adjust the configuration parameters of the coherent transmitter based on it.

[0193] In one possible scenario 2, all aspects of the configuration parameter adjustment method are implemented through the host. That is, in this scenario 2, device A is host A, device B is host B, and both host A and host B include an oDSP chip. For example, host B is used to acquire and transmit control information, while host A is used to read the control information and adjust the configuration parameters of the coherent transmitter based on it.

[0194] In one possible scenario (3), some operations in the configuration parameter adjustment method are implemented by the optical module, while others are implemented by the host. That is, in scenario 3, device A is a communication device including host A and optical module A, and device B is a communication device including host B and optical module B. For example, optical module B is used to acquire control information and send it to host B; host B is used to send back control information; host A is used to read control information and send it to optical module A; and optical module A is used to adjust the configuration parameters of the coherent transmitter according to the control information.

[0195] It should be noted that, for the configuration parameter adjustment method provided in the embodiments of this application, the above-described scenarios 1, 2 and 3 describe devices at both ends of the optical fiber that use the same structure. The following will be described in detail with reference to specific embodiments.

[0196] In other possible scenarios, the devices at both ends of the optical fiber can also employ different structures. For example, device A is optical module A, and device B is host B. Alternatively, device A is optical module A, and device B includes host B and optical module B. Another example: device A is host A, and device B is optical module B. Yet another example: device A is host A, and device B includes host B and optical module B. Finally, device A includes host A and optical module A, and device B is host B. Finally, device A includes host A and optical module A, and device B is optical module B.

[0197] 101. Device A sends a coherent optical signal to device B.

[0198] It should be noted that the transmission and reception of coherent optical signals are achieved by optical modules at both ends of the optical fiber. Specifically, optical module A is used to transmit coherent optical signals, which are transmitted through the optical fiber, and optical module B is used to receive coherent optical signals.

[0199] 102. Device B detects the coherent optical signal to obtain control information.

[0200] In this embodiment, the coherent optical signal can be detected using an oDSP chip to obtain control information. For example, detecting the coherent optical signal to obtain control information includes the following steps: optical module B first converts the coherent optical signal into an analog electrical signal, then converts the analog electrical signal into a digital signal, and the digital signal is sent to the oDSP chip for detection to obtain control information. For example, if the oDSP chip is integrated into optical module B, then optical module B performs the detection to obtain the control information. Alternatively, if the oDSP chip is integrated into host B, then host B performs the detection to obtain the control information. This application does not limit the specific method by which the oDSP chip obtains control information; for example, the oDSP chip can calculate the control information using an algorithm.

[0201] It should be noted that the coherent optical signal transmitted by device A may be damaged or distorted due to various reasons. Control information can be understood as reference information provided by device B to device A for adjusting the configuration parameters of the coherent transmitter; in other words, control information can be understood as reference information provided by device B to device A for damage compensation. This application does not limit the specific naming of "control information," for example, "control information" can also be called "damage information," "reference information," or "feedback information," etc. Specifically, control information can provide effective reference for device A to adjust the configuration parameters of the coherent transmitter from one or more aspects. This application does not limit the specific content of the control information; some possible examples are provided below.

[0202] Aspect 1: Control information can indicate that the coherent optical signal transmitted by device A has been impaired or distorted. For example, control information includes bit error rate (BER) degrade. If device B detects that the BER of the coherent optical signal is higher than a threshold, it receives BER degrade control information. Device A can adjust the configuration parameters of the coherent transmitter according to the control information to reduce the BER of the coherent optical signal.

[0203] Aspect 2: Control information can indicate a deviation between the parameter values ​​of the coherent optical signal transmitted by device A and the expected values. In other words, control information is the deviation information between the parameter values ​​of the coherent optical signal actually detected by device B and the expected values ​​of the coherent optical signal. Device A can adjust the configuration parameters of the coherent transmitter according to the control information to compensate for the aforementioned deviation. For example, control information includes at least one of the following: skew in two polarization directions, skew in IQ direction, power imbalance in two polarization directions, or power imbalance in IQ direction. Skew in two polarization directions, often referred to as XY skew, refers to the offset or timing error between the data streams in the X-polarization direction and the Y-polarization direction. Skew in IQ direction, often referred to as IQ skew, refers to the offset or timing error between the I-channel data stream and the Q-channel data stream. It should be understood that the IQ skew in the X-polarization direction and the IQ skew in the Y-polarization direction can be the same or different. Power imbalance in two polarization directions refers to the power difference between the data streams in the two polarization directions. The power imbalance between I and Q refers to the power difference between the I-channel and Q-channel data streams. It should be understood that the IQ power imbalance in the X-polarization direction can be the same as or different from the IQ power imbalance in the Y-polarization direction.

[0204] In aspect 3, the control information can indicate the configuration parameters of the coherent transmitter. This is equivalent to device B having already calculated the required configuration parameters (i.e., control information) for device A's coherent transmitter. Device A adjusts the configuration parameters of the coherent transmitter according to the control information; that is, device A reconfigures the coherent transmitter according to the configuration parameters indicated by the control information to achieve impairment compensation. For example, the control information includes at least one of equalizer coefficients, precoding switches, or filter coefficients. Another example is that the control information includes at least one of two polarization direction skew compensation values ​​or IQ skew compensation values. The two polarization direction skew compensation values ​​are different from the two polarization direction skew amounts. In aspect 2, device A can calculate the two polarization direction skew compensation values ​​based on the two polarization direction skew amounts. In aspect 3, device B directly calculates the two polarization direction skew compensation values. The two polarization direction skew compensation values ​​can be understood as configuration parameters that compensate for XY skew. Similarly, the skew compensation value of IQ is different from the skew amount of IQ. In aspect 2, device A can calculate the skew compensation value of IQ based on the skew amount of IQ. In aspect 3, device B directly calculates the skew compensation value of IQ. The skew compensation value of IQ can be understood as a configuration parameter that compensates for the skew of IQ.

[0205] 103. Device B sends a signal carrying control information to device A.

[0206] In this embodiment, device B transmits a signal carrying control information to device A using in-band transmission. This means device B sends both data and control information to device A via the same signal path. In other words, device B uses the same modulation scheme for both the data and control information to be transmitted. For example, the modulation scheme could be quadrature phase shift keying (QPSK) modulation or 16-ary quadrature amplitude modulation (16QAM). It should be understood that if out-of-band transmission were used to send control information, it would be equivalent to superimposing an additional signal onto the signal used for transmitting the service. This would increase the modulation scheme and transmission bandwidth, requiring device A to add additional signal demodulation processing logic to obtain the control information, thus making the processing more complex. Therefore, using in-band transmission to send control information eliminates the need for additional transmission bandwidth and superimposed signals, resulting in lower implementation costs.

[0207] It should be noted that this application provides various in-band transmission methods for transmitting control information, which will be described in detail below with reference to specific embodiments. In one possible scenario, device B is host B, which inserts control information into the data stream to be transmitted. In this case, the signal carrying the control information sent by device B is an electrical signal, which is converted into a coherent optical signal by optical module B and sent to device A. In another possible scenario, device B is optical module B, which inserts control information into the data stream to be transmitted. In this case, the signal carrying the control information sent by device B is a coherent optical signal, which is transmitted to device A via optical fiber.

[0208] 104. Device A adjusts the configuration parameters of the coherent transmitter according to the control information.

[0209] After receiving the control information, device A can selectively adjust the configuration parameters of the coherent transmitter to perform impairment compensation, thereby reducing the impairment or distortion of the coherent optical signal subsequently transmitted by the coherent transmitter. The process of adjusting the configuration parameters of the coherent transmitter can be completed automatically by the device or software, or manually; this is not limited here. In some possible scenarios, after receiving the control information, device A can first determine whether the conditions for impairment compensation have been met. If so, it further adjusts the configuration parameters of the coherent transmitter according to the control information. For example, impairment compensation may not be necessary in scenarios with good link quality; the specific conditions for impairment compensation are not limited here. It should be noted that the embodiments of this application do not limit the specific configuration parameters of the coherent transmitter to be adjusted. For example, impairment compensation can be achieved by adjusting the digital or analog domain of the coherent transmitter. For instance, for IQ skew, IQ skew can be reduced by adjusting the delay of the I-channel or Q-channel.

[0210] In one possible implementation, the configuration parameters of the coherent transmitter can be adjusted using an oDSP chip. For example, the oDSP chip first determines how to adjust the configuration parameters of the coherent transmitter based on control information, and then controls the coherent transmitter to adjust the configuration parameters. The coherent transmitter is located in optical module A, and the oDSP chip can be located in optical module A or host A.

[0211] Figure 6 is a schematic diagram of a system scenario for a configuration parameter adjustment method according to an embodiment of this application. As shown in Figure 6, the method is described using an example where both optical module A and optical module B integrate oDSP chips. A similar method is used for scenarios where host A or host B integrates oDSP chips, the main difference being the deployment location of the oDSP chip. No further diagrams or descriptions are provided for this scenario here. Specifically, as shown in Figure 6, both optical module A and optical module B include an oDSP chip, a coherent transmitter, a coherent receiver, and a controller. The coherent transmitter includes a laser and a modulator, the coherent receiver includes a mixer and a photodetector (PD), and the controller can specifically be a microcontroller unit (MCU). Both host A and host B 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 coherent transmitter / receiver; this second side can be referred to as the media side. This application does not limit the devices included in the hostside and mediaside. The first side is used to communicate with host A via a telecommunication channel. For example, the SERDS located on the first side of the oDSP chip communicates with the SERDS located on the PHY chip (SERDS not shown in Figure 6) via a telecommunication channel. The second side is used to communicate with the coherent transmitter / receiver via a telecommunication channel. In one implementation, the coherent transmitter in optical module A and the coherent receiver in optical module B are connected via an optical channel, and the coherent transmitter in optical module B and the coherent receiver in optical module A are connected via an optical channel. The controller and the device controller are connected via a management interface. For example, this management interface can be an inter-integrated circuit (IIC, I2C) interface, and the management protocol based on this management interface can be a common management interface specification (CMIS).

[0212] This section uses the scenario of optical module A sending an optical signal to optical module B as an example. The PHY chip of host A sends an electrical signal to the oDSP chip of optical module A. This signal can be a non-return-to-zero (NRZ) modulation signal or a pulse amplitude modulation 4-level (PAM4) signal. The oDSP chip of optical module A 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 A. The coherent transmitter of optical module A modulates the electrical signal from the oDSP chip onto an optical carrier to obtain coherent optical signal 1, and then transmits coherent optical signal 1 through the channel transmission medium. The coherent receiver of optical module B receives coherent optical signal 1 through the channel transmission medium. Based on the local oscillator (LO) optical signal, it performs mixing and other processing on coherent optical signal 1, converting it into an electrical signal. The oDSP chip of optical module B then detects this electrical signal to obtain control information. The PHY chip of host B sends an electrical signal to the oDSP chip of optical module B. The oDSP chip of optical module B generates an electrical signal carrying control information based on the electrical signal from host B. The coherent transmitter of optical module B generates coherent optical signal 2 based on the electrical signal carrying control information and transmits coherent optical signal 2 through the channel transmission medium. The coherent receiver of optical module A receives coherent optical signal 2 through the channel transmission medium and performs mixing and other processing on coherent optical signal 2 based on the LO optical signal, converting it into an electrical signal. The oDSP chip of optical module A demodulates and processes electrical signals to identify control information, and adjusts the configuration parameters of the coherent transmitter according to the control information to achieve impairment compensation, thereby reducing the impairment of the coherent optical signals subsequently transmitted by the coherent transmitter of optical module A.

[0213] The following describes specific implementation methods for transmitting control information using in-band transmission, using several different examples.

[0214] Example 1: Control information is carried through alignment marker (AM) information.

[0215] Figure 7 illustrates the operation flow of a PCS (Programmable Logic Controller). As shown in Figure 7, for the transmitted data stream, the PCS specifically includes the following operations: encoding and rate matching, transcoding, scrambling, AM (alignment insertion), forward error correction (FEC) pre-distribution, FEC encoding, and distribution and interleave. For the received data stream, the PCS specifically includes the following operations: AM locking and lane deskew, lane reordering and de-interleave, FEC decoding, post-FEC interleave, AM removal, descrambling, reverse transcoding, and decoding and rate matching. It can be seen that the PCS operations for the transmitted data stream and the operations for the received data stream are inverse operations of each other.

[0216] It should be noted that the AM insertion operation described above is used to periodically insert AM information into the data stream to be transmitted, and the data receiving end can perform synchronization alignment based on the AM information. In Example 1, control information is inserted into the data stream to be transmitted as part of the AM information, that is, the AM information carries control information.

[0217] AM information can specifically be an AM group, which is a fixed-length bit sequence that appears periodically in the effective data at fixed bit-length intervals. During transmission, an AM group is split across multiple channel data streams for alignment at the receiver. Specifically, an AM group includes n AMs, a padding field, and a status field. Each AM includes multiple common marker (CM) fields, multiple unique marker (UM) fields, and multiple unique padding (UP) fields; for example, each AM includes CM0 to CM5, UM0 to UM5, and UP0 to UP2.

[0218] Specifically, in Embodiment 1, at least one field from UP0, UP1, UP2, and pad can be used to carry control information. The bits filled in the pad field do not have fixed values ​​and can be used to carry control information. The data receiving end does not need to extract UP0, UP1, and UP2 for synchronization alignment; the bit values ​​in these three fields can be redefined to carry control information. For example, one field from UP0, UP1, UP2, and pad can be selected to carry control information. Another example is that two fields from UP0, UP1, UP2, and pad can be selected to carry control information. Yet another example is that three fields from UP0, UP1, UP2, and pad can be selected to carry control information. Still another example is that all fields from UP0, UP1, UP2, and pad can be used to carry control information.

[0219] It should be noted that the number of bits in the pad field of the AM group can vary in different scenarios. For example, in a 400Gbps transmission scenario, the pad field of the AM group includes 65 bits, while in an 800Gbps transmission scenario, the pad field of the AM group includes 133 bits. The number n of AM fields in the AM group depends on the number n of channel data streams in the actual scenario, that is, n AMs are located in n channel data streams. The distribution of AM groups is described below using an 800Gbps transmission scenario as an example.

[0220] Figure 8 illustrates the distribution of AM groups across multiple channel data streams. As shown in Figure 8, after the aforementioned PCS insertion process, 16 channel data streams are obtained for the transmitted data stream. These 16 channel data streams can also be referred to as 16 PCS lane data streams. The AM group comprises 16 AMs (AM0 to AM15), located in the 16 channel data streams respectively. Specifically, AM0 is located in PCS channel data stream 0, AM1 in PCS channel data stream 1, ..., and AM15 in PCS channel data stream 15. The padding field comprises 133 bits. Each PCS channel data stream from PCS channel data stream 0 to PCS channel data stream 12 includes 10 bits in the padding field, totaling 130 bits. PCS channel data stream 13 includes 3 bits in the padding field and also includes 3 bits in the status field.

[0221] It should be noted that the number of bits in the AM group used to carry control information depends on the size of the control information and the specific application location; no limit is made here. Several possible implementation methods for carrying control information via the AM group are provided below.

[0222] Implementation Method 1-1: Utilize the pad field in the AM group to carry control information. The pad field has a large number of usable bits, sufficient to support carrying control information. Furthermore, using the pad field to centrally carry control information makes the encapsulation and parsing of the control information easier to implement.

[0223] Implementation Methods 1-2: Based on Implementation Method 1-1, multiple identical control information messages can be repeatedly carried. The data receiving end parses multiple control information messages from the received data stream and makes a judgment based on these multiple control information messages to determine whether the correct control information has been received. In other words, multiple identical control information messages can verify each other, thereby improving the reliability of the transmitted control information.

[0224] Optionally, the pad field in one AM group is sufficient to carry multiple copies of the same control information.

[0225] Optionally, if the pad field in one AM group is insufficient to carry multiple copies of the same control information, then multiple copies of the same control information can be carried through the pad fields of multiple AM ​​groups. For example, in an 800Gbps transmission scenario, two 400G data streams undergo the aforementioned PCS operation process, including AM insertion. These two 400G data streams are denoted as data stream 0 and data stream 1, respectively. AM group 0 is inserted into data stream 0, and AM group 1 is inserted into data stream 1. The control information carried by the pad field in AM group 0 is the same as the control information carried by the pad field in AM group 1, which is equivalent to carrying two copies of the same control information.

[0226] Implementation methods 1-3 utilize UP0, UP1, and UP2 from one of the PCS channel data streams (e.g., PCS channel data stream 0) to carry control information. The number of usable bits in UP0, UP1, and UP2 within a single PCS channel data stream is sufficient to support carrying control information. Furthermore, concentrating control information within a single PCS channel data stream simplifies the encapsulation and parsing of the control information.

[0227] Implementation methods 1-4: Based on implementation methods 1-3, multiple identical control information can be repeatedly carried. The data receiving end parses multiple control information from the received data stream and makes a judgment based on these multiple control information to determine whether the correct control information has been received. In other words, multiple identical control information can verify each other, thereby improving the reliability of transmitted control information.

[0228] Optionally, UP0, UP1, and UP2 in a single PCS channel data stream are sufficient to carry multiple copies of the same control information.

[0229] Optionally, if UP0, UP1, and UP2 in one PCS channel data stream are insufficient to carry multiple copies of the same control information, then multiple copies of the same control information can be carried by UP0, UP1, and UP2 in multiple PCS channel data streams. For example, the control information carried by UP0, UP1, and UP2 in PCS channel data stream 0 is the same as the control information carried by UP0, UP1, and UP2 in PCS channel data stream 1, which is equivalent to carrying two copies of the same control information.

[0230] Implementation methods 1-5 utilize the UP0 of each PCS channel data stream in multiple PCS channel data streams to carry control information. For example, in the scenario shown in Figure 8 above, 16 UP0s from 16 PCS channel data streams are used to carry control information. The number of usable bits in UP0 across multiple PCS channel data streams is sufficient to support carrying control information. Furthermore, multiple PCS channel data streams can be processed synchronously. During the AM group parsing process at the data receiver, UP0 is processed before UP1 and UP2, eliminating the need to wait for the processing delays of UP1 and UP2, thus facilitating rapid reading of control information.

[0231] Implementation methods 1-6: Based on implementation methods 1-5, multiple identical control information messages can be repeatedly carried. The data receiving end parses multiple control information messages from the received data stream and makes a judgment based on these multiple control information messages to determine whether the correct control information has been received. In other words, multiple identical control information messages can verify each other, thereby improving the reliability of the transmitted control information.

[0232] Optionally, the UP0 of multiple PCS channel data streams is sufficient to carry multiple copies of the same control information.

[0233] Optionally, if the UP0 values ​​of multiple PCS channel data streams are insufficient to carry multiple copies of the same control information, then the UP1 and / or UP2 values ​​of multiple PCS channel data streams can also carry multiple copies of the same control information. For example, in the scenario shown in Figure 8 above, the control information carried by the 16 UP0 values ​​in the 16 PCS channel data streams is the same as the control information carried by the 16 UP1 values ​​in the 16 PCS channel data streams, which is equivalent to carrying two copies of the same control information.

[0234] It should be noted that the operations of the aforementioned PCS can be implemented in the host or in the optical module. Several possible implementation scenarios are described below. It should be understood that the chip in the host can be called the host chip. If the PCS operations are implemented in the host, they can be executed by the host chip. The optical module may include an oDSP chip. If the PCS operations are implemented in the optical module, they can be executed by the oDSP chip. The oDSP chip can also be integrated into the host.

[0235] For ease of demonstration, the accompanying diagrams for each implementation scenario below mainly use FEC1 encoding in PCS as an example. Other operations of PCS besides FEC1 encoding can be referred to the introduction in Figure 7 above, and will not be shown one by one below.

[0236] Figure 9(a) is a schematic diagram of an application scenario of the configuration parameter adjustment method in this application embodiment. As shown in Figure 9(a), both optical module A and optical module B can perform PCS operations, and both optical module A and optical module B have oDSP chips. Specifically, the oDSP chip of optical module B obtains control information based on the coherent optical signal from optical module A. After host B performs a PCS operation including FEC1 encoding on the data stream to be transmitted, it sends the data stream to optical module B. Optical module B first performs the PCS inverse operation including FEC1 decoding, and then performs the PCS operation including FEC1 encoding. Among them, optical module B also performs an AM insertion operation before performing FEC1 encoding to insert the AM group carrying control information into the data stream to be transmitted. The data stream and control information are transmitted to optical module A through the same coherent optical signal. The operation of optical module A is specifically the inverse operation of optical module B. After optical module A performs FEC1 decoding on the received data stream, it also performs an AM removal operation. Through the AM removal operation, the control information in the AM group can be read, and then the configuration parameters of the coherent transmitter of optical module A can be adjusted according to the control information. As can be seen, in the scenario shown in Figure 9(a), the processing flow of the configuration parameter adjustment method provided in this application embodiment can be realized through optical module A and optical module B.

[0237] Figure 9(b) illustrates another application scenario of the configuration parameter adjustment method in this embodiment. As shown in Figure 9(b), host A and host B perform PCS operations, and both optical modules A and B have oDSP chips. Specifically, the oDSP chip of optical module B obtains control information based on the coherent optical signal from optical module A and sends the control information to host B. Optical module B can send the control information to host B via out-of-band transmission. For example, optical module B can send the control information to host B via the I2C interface, or it can send the control information to host B based on corresponding registers defined in CMIS. Host B performs PCS operations including FEC1 encoding on the data stream to be transmitted. Before performing FEC1 encoding, host B also performs AM insertion to insert an AM group carrying control information into the data stream to be transmitted. Then, host B sends the data stream and control information after PCS operation to optical module B, and optical module B transmits the data stream and control information to optical module A via the same coherent optical signal. Optical module A converts the received coherent optical signal into an electrical signal and sends it to host A. Host A's operation is the inverse of host B's operation. After FEC1 decoding of the received data stream, host A performs AM removal, which allows the reading of control information from the AM group. Host A then sends the read control information to optical module A, which adjusts the configuration parameters of its coherent transmitter based on the control information. Host A can send the control information to optical module A via out-of-band transmission, for example, through an I2C interface or by defining corresponding registers based on CMIS. It can be seen that in the scenario shown in Figure 9(b), a portion of the configuration parameter adjustment method provided in this embodiment is implemented in optical modules A and B, while another portion is implemented in host A and host B.

[0238] Figure 9(c) is a schematic diagram of another application scenario of the configuration parameter adjustment method in this application embodiment. As shown in Figure 9(b), host A and host B perform PCS operation, and both host A and host B integrate oDSP chips, while optical modules A and B do not have oDSP chips. That is, optical modules A and B can be LPO optical modules, NPO modules, CPO modules, etc. Specifically, optical module B converts the coherent optical signal from optical module A into an electrical signal and sends it to host B. The oDSP chip of host B obtains control information based on the electrical signal from optical module B. Host B performs PCS operation including FEC1 encoding on the data stream to be transmitted. Before performing FEC1 encoding, host B also performs AM insertion operation to insert the AM group carrying control information into the data stream to be transmitted. Then, host B sends the data stream and control information after PCS operation to optical module B, and optical module B transmits the data stream and control information to optical module A through the same coherent optical signal. Optical module A converts the received coherent optical signal into an electrical signal and sends it to host A. Host A's operation is the inverse of host B's operation. After FEC1 decoding of the received data stream, host A performs AM removal. This AM removal operation allows the reading of control information from the AM group. Host A then adjusts the configuration parameters of the coherent transmitter of optical module A based on this control information. It can be seen that, in the scenario shown in Figure 9(c), the processing flow of the configuration parameter adjustment method provided in this embodiment can be implemented using only host A and host B.

[0239] It should be noted that the devices at both ends of the optical fiber in the scenarios shown in Figures 9(a) to 9(c) above use the same structure. In other possible scenarios, the devices at both ends of the optical fiber may use different structures. For example, one end of the optical fiber may use the structure shown in Figure 9(a), and the other end may use the structure shown in Figure 9(b). Another example: one end of the optical fiber may use the structure shown in Figure 9(a), and the other end may use the structure shown in Figure 9(c). Yet another example: one end of the optical fiber may use the structure shown in Figure 9(b), and the other end may use the structure shown in Figure 9(c).

[0240] In some possible implementations, as shown in Figures 9(a) to 9(c), after performing FEC1 encoding on the data stream and control information to be transmitted, FEC2 encoding can be further performed on the data stream and control information to be transmitted, which is beneficial to further improve the reliability of data and control information transmission. For example, FEC2 encoding is performed by the oDSP chip, and FEC2 encoding can be specifically implemented in the FEC sublayer of the PMA.

[0241] It should be noted that FEC1 encoding can also be called external code encoding, and FEC2 encoding can also be called internal code encoding. The distinction between "internal" and "external" in internal and external codes is based on the distance between the FEC encoding operation and the transmission medium (such as optical fiber). Internal code encoding operates closer to the transmission medium, while external code encoding operates further away. In one possible implementation, both internal and external code encoding employ FEC encoding, forming a cascaded FEC transmission scheme. For example, Reed-Solomon (RS) codes can be used for external code encoding, and Hamming codes for internal code encoding. Another example is using RS codes for external code encoding and Bose-Chaudhuri-Hocquenghem (BCH) codes for internal code encoding. A BCH code correcting a single error is equivalent to a Hamming code. For example, RS code can be used for external code encoding, and Polar code for internal code encoding. In some specific applications, RS(544,514) code, also known as KP4 code, can be used for external code encoding.

[0242] Example 2: Control information is carried through digital signal processing (DSP) frames.

[0243] In Example 2, the FEC-encoded data stream is further framed to obtain DSP frames, and then a coherent optical signal carrying the DSP frames is transmitted. Control information can be inserted during the framing process, so that the DSP frames carry both data and control information simultaneously. The data receiver can read the control information by parsing the DSP frames. It should be understood that the FEC-encoded data stream can be a data stream that has only undergone external code encoding (FEC1 encoding), or a data stream that has undergone both external code encoding (FEC1 encoding) and internal code encoding (FEC2 encoding). The above-mentioned framing can also be called DSP framing; for example, framing can be implemented in an oDSP chip. Several possible implementation methods of framing are described below.

[0244] Figure 10(a) is a schematic diagram of one implementation of framing in an embodiment of this application. As shown in Figure 10(a), in one possible implementation, dual-polarization symbol mapping is performed on the received data sequence. Typically, the received data sequence is information and a check sequence obtained through FEC encoding. Dual-polarization symbol mapping includes symbol mapping and polarization distribution. The symbol mapping method is quadrature amplitude modulation (QAM). Typically, QAM modulation (also called symbol mapping) involves symbol mapping multiple input bits to obtain multiple QAM symbols, and polarization distribution of the multiple QAM symbols to obtain multiple dual-polarization (DP) symbols, i.e., DP-QAM symbols, such as DP-16QAM, DP-32QAM, and DP-64QAM. For ease of explanation, the two polarization directions will be uniformly referred to as the X-polarization direction and the Y-polarization direction, respectively, wherein the X-polarization direction and the Y-polarization direction are orthogonal to each other. It should be understood that the X-polarization direction and the Y-polarization direction are not two specified polarization directions, but rather two arbitrarily orthogonal polarization directions. Then, a certain number of dual-polarization symbols are subjected to the following framing process: specifically, a pre-framing dual-polarization symbol sequence containing multiple dual-polarization symbols is obtained, and multiple pilot symbols are inserted in the X-polarization direction and the Y-polarization direction respectively to obtain a post-framing dual-polarization symbol sequence. The sequence containing multiple pilot symbols is also called a pilot symbol sequence or pilot sequence.

[0245] In some specific applications, the framed dual-polarization symbol sequence is referred to as a frame, data frame, or DSP frame. For ease of explanation, this application embodiment will uniformly refer to the framed dual-polarization symbol sequence as a DSP frame.

[0246] It should be understood that a dual-polarization symbol can be represented by two symbols, one located in the X-polarization direction and the other in the Y-polarization direction. Each symbol can be represented by a complex number. For example, a symbol obtained using 16QAM modulation can be represented by any one of the following 16 complex numbers: ±1±1j, ±1±3j, ±3±1j, and ±3±3j, where ± indicates a positive or negative value, such as ±3 representing 3 or -3. Here, j represents the imaginary unit. In some scenarios, the imaginary unit may also be represented by other symbols such as i, which is not limited here. In the embodiments of this application, the imaginary unit is uniformly represented by j. In some specific applications, the real and imaginary parts may be normalized, but the essence remains unchanged. It should also be understood that the symbol sequence is obtained by the data stream through a symbol map. Taking 16QAM modulation as an example, every 4 bits in the data stream are modulated by 16QAM to obtain one symbol represented by a complex number. That is, the data stream is composed of bits, not complex number symbols.

[0247] It should be noted that a sequence containing L dual-polarization symbols can be represented by two complex sequences of length L, where one sequence represents the symbol in the X-polarization direction and the other represents the symbol in the Y-polarization direction, and L is an integer greater than 1. Each complex sequence of length L consists of a real part sequence of length L and an imaginary part sequence of length L. For example, a real part sequence of length L is an I-path sequence, and an imaginary part sequence of length L is a Q-path sequence; or, for another example, a real part sequence of length L is a Q-path sequence, and an imaginary part sequence of length L is an I-path sequence. Therefore, there are four different types of sequences: X-polarization direction I-path (in-phase component) sequence, X-polarization direction Q-path (quadrature-phase component) sequence, Y-polarization direction I-path sequence, and Y-polarization direction Q-path sequence. The X-polarization direction I-path sequence is also called X... I The component, the Q-path sequence in the X polarization direction, is also called X. Q The component, the Y-polarization direction I-path sequence, is also called the Y component. I The component, the Q-path sequence in the Y-polarization direction, is also called the Y-axis. Q Quantity.

[0248] It should be noted that after dual-polarization symbol mapping and framing operations, a dual-polarization symbol data stream to be transmitted is obtained. This stream can be represented by two symbol data streams: the first is the symbol data stream in the X-polarization direction, and the second is the symbol data stream in the Y-polarization direction. Alternatively, a dual-polarization symbol data stream can also be represented by four data streams, where the first is the data stream corresponding to the I-path component in the X-polarization direction (referred to as X...). I The second data stream is the data stream of the Q-path component in the X-polarization direction corresponding to the dual-polarization symbol stream (abbreviated as X). Q The third data stream is the data stream of the I-path component in the Y-polarization direction corresponding to the dual-polarization symbol stream (abbreviated as Y). I The fourth data stream is the data stream of the Q-path component in the Y-polarization direction corresponding to the dual-polarization symbol stream (abbreviated as Y). Q (Data flow).

[0249] It should be understood that in the dual-polarization symbol mapping and framing operation shown in Figure 10(a), framing (also known as DSP framing) is performed after dual-polarization symbol mapping, that is, framing is performed on the symbol level. Below are schematic diagrams of several other possible implementations, where framing is performed before dual-polarization symbol mapping, that is, framing is performed on the bit level.

[0250] Figure 10(b) is a schematic diagram of another implementation of framing in this application. As shown in Figure 10(b), framing is performed before dual-polarization symbol mapping. Specifically, a pre-framing bit sequence containing multiple bits is obtained, a target bit sequence is inserted, and dual-polarization symbol mapping is performed to obtain a post-framing dual-polarization symbol sequence. The target bit sequence is then mapped using dual-polarization symbol mapping to obtain a pilot symbol sequence; the target bit sequence is also referred to as the bits corresponding to the pilot sequence. It should be understood that the post-framing dual-polarization symbol sequence obtained using the implementation shown in Figure 10(b) is the same as the post-framing dual-polarization symbol sequence obtained using the implementation shown in Figure 10(a).

[0251] Figure 10(c) is a schematic diagram of another embodiment of framing in this application. As shown in Figure 10(c), framing is performed before dual-polarization symbol mapping. Specifically, two pre-framing bit sequences containing multiple bits are obtained respectively. A first target bit sequence and a second target bit sequence are inserted into the first and second pre-framing bit sequences respectively, and dual-polarization symbol mapping is performed to obtain a post-framing dual-polarization symbol sequence. The first target bit sequence is symbol mapped to obtain a pilot symbol sequence in the X-polarization direction, and the second target bit sequence is symbol mapped to obtain a pilot symbol sequence in the Y-polarization direction. The first target bit sequence is also called the bit corresponding to the pilot sequence in the X-polarization direction, and the second target bit sequence is also called the bit corresponding to the pilot sequence in the Y-polarization direction. It should be understood that the post-framing dual-polarization symbol sequence obtained by the pre-framing bit sequence using the embodiment shown in Figure 10(c) is the same as the post-framing dual-polarization symbol sequence obtained by the embodiment shown in Figure 10(a).

[0252] Figure 10(d) is a schematic diagram of another embodiment of framing in this application. As shown in Figure 10(d), framing is performed before dual-polarization symbol mapping. Specifically, four pre-framing bit sequences containing multiple bits are obtained respectively. A first target bit sequence, a second target bit sequence, a third target bit sequence, and a fourth target bit sequence are inserted into the first, second, third, and fourth pre-framing bit sequences, respectively, and dual-polarization symbol mapping is performed to obtain the framed dual-polarization symbol sequence. The first target bit sequence is symbol mapped to obtain the I-path component of the pilot symbol sequence in the X-polarization direction, the second target bit sequence is symbol mapped to obtain the Q-path component of the pilot symbol sequence in the X-polarization direction, the third target bit sequence is symbol mapped to obtain the I-path component of the pilot symbol sequence in the Y-polarization direction, and the fourth target bit sequence is symbol mapped to obtain the Q-path component of the pilot symbol sequence in the Y-polarization direction. The first target bit sequence is also called the pilot sequence in the X-polarization direction. I The bits corresponding to the components, the second target bit sequence, also known as the pilot sequence, are in X. Q The bits corresponding to the components, the third target bit sequence, also known as the pilot sequence, are in Y. I The bits corresponding to the components, the fourth target bit sequence, also known as the pilot sequence, are in Y. Q The bits corresponding to the components. It should be understood that the framed dual-polarization symbol sequence obtained by using the implementation shown in Figure 10(d) before framing is the same as the framed dual-polarization symbol sequence obtained by using the implementation shown in Figure 10(a).

[0253] It should be noted that the embodiments of this application are not limited to the specific framing method. In addition to the framing methods described in Figures 10(a), 10(b), 10(c), and 10(d), other similar framing methods are also applicable to this solution, and will not be described one by one here.

[0254] The structure of the DSP frame obtained after framing is described below. It should be understood that a DSP frame includes symbols in two polarization directions. The structure of the DSP frame is similar in both polarization directions. For example, a DSP frame includes N symbols in the X polarization direction and N symbols in the Y polarization direction. The structure of the DSP frame will be described below using one of the polarization directions as an example.

[0255] Figure 11 is a schematic diagram of a DSP frame structure in an embodiment of this application. As shown in Figure 11, a DSP frame in one polarization direction includes N symbols. Every M consecutive symbols in the N symbols include one pilot symbol and M-1 payload symbols located at a fixed position, where N = M × Q, and Q and M are both integers greater than 1. That is, every M consecutive symbols in the N symbols can be regarded as a group, and the N symbols include a total of Q groups of symbols. For example, N = 6144, M = 64, Q = 96, symbols 1-64 are the first group of 64 consecutive symbols, symbols 65-128 are the second group of 64 consecutive symbols, ..., symbols 6081-6144 are the 96th group of 64 consecutive symbols. It should be understood that the payload symbols can also be called pre-framing symbols, which include FEC-encoded information symbols and check symbols. At the receiving end, the pilot symbols can be used to assist in carrier phase recovery and can also be used to distinguish between two polarization directions. It should be understood that the embodiments of this application do not limit the specific position of the pilot symbol in each group of M symbols. As an example, each pilot symbol is located at the starting position of the consecutive M symbols. For example, the first symbol in the DSP frame shown in Figure 11 is the first pilot symbol.

[0256] It should be noted that the Q pilot symbols in a DSP frame are generated by a generator polynomial and a seed. Each pilot symbol is one of -A-Aj, -A+Aj, A-Aj, and A+Aj, where A is a real number. The value of A is determined by the modulation format used when generating the symbol. In some practical applications, -A-Aj, -A+Aj, A-Aj, and A+Aj are symbols on the constellation diagram of the modulation format used. For example, using QPSK, there are only four symbols, in which case A = ±1, and each pilot symbol can be represented by one of -1-1j, -1+1j, 1-1j, and 1+1j. In a frame, all four complex number representations of the frame symbols will exist. Using 16QAM, there are 16 symbols on the constellation diagram, in which case A = ±1 or ±3.

[0257] Figure 12 is a schematic diagram of symbols on a constellation diagram according to an embodiment of this application. As shown in Figure 12, when A = 3 or -3, each pilot symbol can be represented by one of -3-3j, -3+3j, 3-3j, and 3+3j, as shown by the hollow symbol in Figure 12. Similarly, when using 64QAM, A = ±1, ±3, ±5, or ±7. It should be noted that higher-order modulation formats can also be used, which will not be elaborated upon in this application. In actual transmission, using the four outermost symbols on the constellation diagram for pilot symbols can reduce the probability of symbol errors.

[0258] It should be noted that the symbols on the constellation diagram may also be compressed, and correspondingly, the value of A will also be compressed. Taking 16QAM as an example, after power normalization of the 16 symbols on the 16QAM constellation diagram, the values ​​of the 16 symbols on the 16QAM constellation diagram become... The value of A is or Other normalization methods may also be used, and this application does not limit them.

[0259] It should be understood that when the pilot symbols -A-Aj, -A+Aj, A-Aj, and A+Aj use the outermost four symbols of the constellation diagram, the pilot symbols have higher sensitivity but a larger peak-to-average power ratio; when the pilot symbols -A-Aj, -A+Aj, A-Aj, and A+Aj use the innermost four symbols of the constellation diagram, the pilot noise is lower, but its sensitivity is lower.

[0260] It should be noted that in some practical applications, the pilot symbols -A-Aj, -A+Aj, A-Aj, and A+Aj may not be symbols on the constellation diagram of the modulation format used. Instead, they can be four symbols from the area between the outermost four symbols and the innermost four symbols of the constellation diagram. In this case, the pilot symbol noise and sensitivity are generally low, but the peak-to-average power ratio is relatively low. Taking 16QAM as an example, the 16 symbols on the 16QAM constellation diagram take values ​​of {±1±1j, ±1±3j, ±3±1j, ±3±3j}, and the real number A satisfies 1≤A≤3. For example, the real number A...

[0261] It should be noted that an algebraic expression composed of the addition (or subtraction) of several monomials is called a polynomial. Each monomial in a polynomial is called a term of the polynomial, and the degree of the highest term among these monomials is the degree of the polynomial. The number of terms in a polynomial refers to the number of the monomials whose coefficients are not zero. Taking a 10th-order polynomial as an example, its number of terms is equal to the number of non-zero terms in a9…a1 plus 2. For example, when the generator polynomial is a 10th-order polynomial, this 10th-order polynomial can be expressed as:

[0262] x 10 +a9×x 9 +a8×x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1. Where a9…a1 can take the values ​​0 or 1.

[0263] Figure 13 is a schematic diagram of a pilot symbol generation structure in an embodiment of this application. As shown in Figure 13, each block can be regarded as a storage unit. The number of storage units is the same as the number of bits in the preloaded seed, that is, each storage unit is used to input the corresponding bit in the seed. For example, if the seed length is 10 bits, it can be represented in binary as m9, m8, m7, m6, m5, m4, m3, m2, m1, m0, then 10 corresponding storage units are used. Of course, the seed can also be represented in hexadecimal or decimal. When it is used in operation with the target polynomial, it needs to be converted to binary form, such as: 0110111000 is represented as 0x1B8 in hexadecimal and 440 in decimal.

[0264] It should be noted that the polynomial x 10 +a9×x 9 +a8×x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1 can sometimes be written as x^10+a9×(x^9)+a8×(x^8)+a7×(x^7)+a6×(x^6)+a5×(x^5)+a4×(x^4)+a3×(x^3)+a2×(x^2)+a1×x+1.

[0265] In one possible implementation, control information is carried using at least one pilot symbol in the DSP frame, which is equivalent to inserting control information into at least one pilot symbol during the framing process. The specific number of pilot symbols used to carry control information depends on the actual size of the control information and is not limited here. Several possible implementations of carrying control information using pilot symbols are provided below.

[0266] Implementation Method 2-1: Control information is carried by multiple consecutive pilot symbols in the DSP frame, so that the data receiving end can quickly read the control information from the DSP frame and save parsing time. For example, multiple consecutive pilot symbols, including the first pilot symbol in the DSP frame, can be selected to carry the control information. As another example, multiple consecutive pilot symbols, including the last pilot symbol in the DSP frame, can be selected to carry the control information.

[0267] Implementation Method 2-2: Periodically select multiple pilot symbols from the DSP frame to carry control information. In other words, select multiple pilot symbols at equal intervals from the DSP frame to carry control information. For example, if the 96 pilot symbols in the DSP frame are denoted as P0, P1, P2, ..., P95, 48 pilot symbols (P0, P2, P4, ..., P94) can be selected to carry control information. This is equivalent to inserting control information starting from the first pilot symbol and continuing to insert control information in the next pilot symbol after a one-symbol interval. It should be understood that the specific interval of how many pilot symbols to insert control information depends on the actual application scenario and is not limited here. It can be seen that by periodically selecting multiple pilot symbols from the DSP frame to carry control information, the remaining pilot symbols in the DSP frame that do not carry control information still have a periodicity, thus not affecting the original function of the pilot symbols. For example, this helps to ensure the stability of the synchronization and training functions.

[0268] In another possible implementation, the DSP frame includes padding symbols in addition to pilot symbols and payload symbols. Control information can be carried using at least one padding symbol in the DSP frame, which is equivalent to inserting control information into at least one padding symbol during framing. The specific number of padding symbols used to carry control information depends on the actual size of the control information and is not limited here. It should be understood that carrying control information using at least one padding symbol does not affect the original function of the pilot symbols, thus ensuring the transmission of control information while maintaining the original functionality.

[0269] This application does not limit the distribution of padding symbols in the DSP frame. For example, without changing the length of the original DSP frame, reducing the number of W payload symbols in the DSP frame and correspondingly increasing the number of W padding symbols is equivalent to replacing the W payload symbols with W padding symbols, where W is an integer greater than or equal to 1. Another example is adding at least one padding symbol while maintaining the original pilot and payload symbols in the DSP frame, which is equivalent to increasing the length of the DSP frame. If there are multiple padding symbols in the DSP frame, these multiple padding symbols can be arranged continuously and concentratedly in the DSP frame, or they can be distributed completely discontinuously in the DSP frame, or they can be distributed partially continuously and partially discontinuously in the DSP frame. A specific distribution method of padding symbols in a DSP frame is provided below.

[0270] Figure 14 is a schematic diagram of another structure of the DSP frame in an embodiment of this application. As shown in Figure 14, based on the DSP frame structure shown in Figure 11, the DSP frame also includes padding symbols. Specifically, the padding symbols in the DSP frame include Q subsets of padding symbols, each subset including W padding symbols, where W is an integer greater than or equal to 1. The Q subsets of padding symbols and the Q pilot symbols adopt the same periodic distribution. For example, in one polarization direction, the DSP frame includes V symbols, and each consecutive R symbols in the V symbols include 1 pilot symbol, W padding symbols (1 subset of padding symbols), and RW-1 payload symbols, where V = R × Q, and Q and R are both integers greater than 1. For example, if the length of the original DSP frame is not changed, comparing Figure 11 and Figure 14, R = M, V = N. For another example, if the original pilot symbols and payload symbols in the DSP frame are maintained, comparing Figure 11 and Figure 14, R = M + W.

[0271] The following uses Figure 14 as an example to provide several possible implementations of carrying control information through fill symbols.

[0272] Implementation methods 2-3 involve carrying control information using multiple consecutive subsets of padding symbols in the DSP frame. This allows the data receiver to quickly read the control information from the DSP frame, saving parsing time. For example, multiple consecutive subsets of padding symbols, including the first subset of padding symbols in the DSP frame, can be selected to carry the control information. Alternatively, multiple consecutive subsets of padding symbols, including the last subset of padding symbols in the DSP frame, can be selected to carry the control information.

[0273] Implementation Method 2-4: Periodically select multiple subsets of padding symbols from the DSP frame to carry control information. In other words, select multiple subsets of padding symbols at equal intervals from the DSP frame to carry control information. For example, if the 96 subsets of padding symbols in the DSP frame are denoted as T0, T1, T2, ..., T95, 48 subsets of padding symbols (T0, T2, T4, ..., T94) can be selected to carry control information. This is equivalent to inserting control information starting from the first subset of padding symbols and continuing to insert control information in the next subset of padding symbols after a one-component interval. It should be understood that the specific interval between inserting control information depends on the actual application scenario and is not limited here. It can be seen that while periodically selecting multiple subsets of padding symbols from the DSP frame to carry control information, the remaining subsets of padding symbols in the DSP frame that do not carry control information still have a periodicity, so that some functions can be implemented as needed using the remaining subsets of padding symbols that do not carry control information.

[0274] It should be noted that, for scenarios where the DSP frame includes padding symbols, control information can also be carried by combining at least one pilot symbol and at least one padding symbol. In other words, any of the embodiments in Implementation 2-1 and Implementation 2-2 can be combined with any of the embodiments in Implementation 2-3 and Implementation 2-4.

[0275] It should be understood that the above example illustrates how a DSP frame carries control information, using one polarization direction as an example. In some possible scenarios, the DSP frame carries control information in both polarization directions, which improves the transmission efficiency and reliability of the control information. The control information can be inserted at the same position in both polarization directions of the DSP frame, or it can be inserted at different positions; this is not limited here. For example, the DSP frame can carry one set of control information in both polarization directions.

[0276] Optionally, multiple identical control information sets can be repeatedly carried within the same DSP frame. The data receiver parses these multiple sets of control information from the received DSP frame and uses them to determine whether the correct control information has been received. In other words, multiple identical control information sets can mutually verify each other, thereby improving the reliability of the transmitted control information. For example, each of the two polarization directions of the DSP frame carries one set of control information, and the control information carried in each of the two polarization directions is identical; these two sets of identical control information can mutually verify each other. Alternatively, if there is sufficient space in one polarization direction of the DSP frame to carry multiple identical control information sets, these sets can also be carried in that single polarization direction.

[0277] In some possible scenarios, considering that control information is dynamically acquired in real time, if new control information is acquired after the current DSP frame carrying control information has been transmitted, the newly acquired control information can be inserted into subsequent DSP frames for transmission. Specifically, different DSP frames can be selected periodically to carry control information, which helps ensure the implementation of the synchronization alignment function. For example, control information can be inserted starting from the first selected DSP frame, and then inserted again in the next DSP frame after every one DSP frame interval, i.e., DSP frames are selected at equal intervals to carry control information.

[0278] Optionally, multiple identical control information can be repeatedly carried across multiple DSP frames. The data receiver parses multiple control information from the received multiple DSP frames and uses these multiple control information to determine whether the correct control information has been received. In other words, multiple identical control information can mutually verify each other, thereby improving the reliability of the transmitted control information. As an example, multiple DSP frames can be periodically selected, each carrying one piece of control information; that is, multiple DSP frames can be selected at equal intervals, each carrying one piece of control information, and the control information carried by these multiple DSP frames is the same. For example, the first piece of control information is inserted starting from the first selected DSP frame, and the same control information is inserted in the next DSP frame after every interval of one DSP frame.

[0279] Optionally, based on the above-mentioned repeated carrying of multiple identical control information in the same DSP frame, multiple identical control information can be further carried repeatedly in multiple DSP frames. This is equivalent to combining repeated carrying of the same control information within a DSP frame and repeated carrying of the same control information between multiple DSP frames, which is more conducive to improving the transmission reliability of control information.

[0280] It should be noted that the framing operation described above can be implemented either in the host computer or in the optical module. For example, if the oDSP chip is integrated in the host computer but the optical module does not include an oDSP chip, then the framing operation is performed by the host computer's oDSP chip. Conversely, if the optical module includes an oDSP chip, then the framing operation is performed by the optical module's oDSP chip.

[0281] Based on the above description of Embodiments 1 and 2, in some possible scenarios, the control information can also be transmitted back using the methods provided in Embodiments 1 and 2. That is, the signal sent by device B to device A includes both control information inserted into the AM group and control information inserted into the DSP frame, thereby improving the transmission efficiency and reliability of the control information. Besides Embodiments 1 and 2 described above, other methods can also be used to transmit control information back, which will not be described in detail here. For example, LT frames used in the link training (LT) phase can be used to carry control information, making traditional LT frames extended LT frames. Another example is that negotiation frames used in the negotiation phase can be used to carry control information. These negotiation frames can be Differential Manchester Encoded (DME) frames, carrying control information through one or more bits in the base page or next page of the DME frame.

[0282] Figure 15 is a schematic diagram of a communication device according to an embodiment of this application. As shown in Figure 15, the communication device includes a processing unit 201 and a transceiver unit 202. The communication device can be device A or device B as described in the above embodiments. In one possible implementation, the communication device is used to perform the operations of device A in the above embodiments. Specifically, the transceiver unit 202 is used to perform signal transmission and reception operations, and the processing unit 201 is used for other operations besides signal transmission and reception. For example, the transceiver unit 202 is used to perform steps 101 and 103 shown in Figure 5, and the processing unit 201 is used to perform step 104 shown in Figure 5. In another possible implementation, the communication device is used to perform the operations of device B in the above embodiments. Specifically, the transceiver unit 202 is used to perform signal transmission and reception operations, and the processing unit 201 is used for other operations besides signal transmission and reception. For example, the transceiver unit 202 is used to perform steps 101 and 103 shown in Figure 5, and the processing unit 201 is used to perform step 102 shown in Figure 5.

[0283] Figure 16 is a schematic diagram of another structure of the communication device in an embodiment of this application. As shown in Figure 16, the communication device includes a control circuit 301 and an interface circuit 302. It should be understood that the interface circuit 302 can be a transceiver or an input / output interface. The interface circuit 302 is used to receive signals from other devices outside the communication device and transmit them to the control circuit 301, or to send signals from the control circuit 301 to other devices outside the communication device. In one possible implementation, the communication device is used to perform the operation of device A in the above embodiments. Specifically, the interface circuit 302 is used to perform signal transmission and reception operations, and the control circuit 301 is used for other operations besides signal transmission and reception. For example, the interface circuit 302 is used to perform steps 101 and 103 shown in Figure 5, and the control circuit 301 is used to perform step 104 shown in Figure 5. In another possible implementation, the communication device is used to perform the operations of device B in the above embodiments. Specifically, the interface circuit 302 is used to perform signal transmission and reception operations, and the control circuit 301 is used to perform other operations besides signal transmission and reception. For example, the interface circuit 302 is used to perform steps 101 and 103 shown in FIG. 5, and the control circuit 301 is used to perform step 102 shown in FIG. 5. Optionally, the communication device may further include a memory 303, wherein the memory 303 is used to store program instructions and data.

[0284] In one possible scenario, the communication device shown in Figures 15 and 16 above can specifically be an optical module, wherein the optical module integrates an oDSP chip, and the operations performed by the processing unit 201 or the control circuit 301 can be implemented through the oDSP chip.

[0285] This application also provides a chip. This chip integrates circuitry for implementing the functions of the processing unit 201 or control circuit 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. This 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 data processing device in the foregoing embodiments based on program code stored in the memory.

[0286] As an example, the chip in the embodiments of this application can be a CPU, or other general-purpose processors, DSPs, 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.

[0287] 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.

[0288] It should be understood that the control circuit mentioned in the embodiments of this application can be implemented in hardware or software. When implemented in hardware, the control circuit can be a logic circuit, integrated circuit, etc. When implemented in software, the control circuit can be a general-purpose processor that reads software code stored in memory. The memory can exist independently and be connected to the control circuit, or the memory can be integrated with the control circuit.

[0289] As an example, the control circuit in the embodiments of this application can be a CPU, or other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, any conventional processor, or a processing circuit that implements a specific function.

[0290] 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.

[0291] In the above embodiments, it can be implemented entirely or partially by software, hardware, firmware, or any combination thereof.

[0292] When implemented in hardware, the data processing 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.

[0293] 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).

[0294] 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 method for adjusting configuration parameters in optical communication, characterized in that, include: The first device acquires control information, which is obtained based on a coherent optical signal from the second device, and the control information is used to adjust the configuration parameters of the coherent transmitter of the second device. The first device sends a signal to the second device, the signal including alignment flag (AM) information, the AM information carrying the control information.

2. The method according to claim 1, characterized in that, The AM information includes at least one of the uniquely filled UP0, UP1, and UP2 fields that carries the control information.

3. The method according to claim 1 or 2, characterized in that, The AM information includes a padding field that carries the control information.

4. The method according to claim 3, characterized in that, The signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried by the pad field in the first AM information is the same as the control information carried by the pad field in the second AM information.

5. The method according to claim 2, characterized in that, The signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field. The UP0 field, UP1 field, and UP2 field of any one of the multiple channel data streams carry the control information.

6. The method according to claim 5, characterized in that, The multiple channel data streams include a first channel data stream and a second channel data stream. The control information carried by the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried by the UP0, UP1, and UP2 fields of the second channel data stream.

7. The method according to claim 2, characterized in that, The signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field. The UP0 field of the multiple channel data streams carries the control information.

8. The method according to claim 7, characterized in that, The control information carried in the UP0 field of the multiple channel data streams is the same as the control information carried in the UP1 field of the multiple channel data streams.

9. The method according to any one of claims 1 to 8, characterized in that, The signal includes data, and the modulation method of the data is the same as the modulation method of the control information.

10. The method according to any one of claims 1 to 9, characterized in that, The first device is an optical module, and the control information acquired by the first device includes: The first device detects the coherent optical signal from the second device to obtain the control information.

11. The method according to any one of claims 1 to 9, characterized in that, The first device is a host, and the control information acquired by the first device includes: The first device receives an electrical signal sent by the optical module, which is obtained by the optical module through photoelectric conversion of a coherent optical signal from the second device; The first device detects the electrical signal to obtain the control information.

12. The method according to claim 10 or 11, characterized in that, After the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further encoded by the first forward error correction (FEC) in the first device.

13. The method according to claim 12, characterized in that, The AM information and the data to be transmitted, after being encoded by the first FEC, are further encoded by the second FEC in the first device.

14. The method according to any one of claims 1 to 9, characterized in that, The first device is a host, and the control information acquired by the first device includes: The first device receives the control information sent by the optical module, which is obtained by the optical module detecting the coherent optical signal from the second device.

15. The method according to claim 14, characterized in that, After the AM information is inserted into the data to be transmitted in the signal, the AM information and the data to be transmitted are further encoded by the first FEC in the first device.

16. The method according to claim 15, characterized in that, The signal is transmitted to the second device through the optical module, and the AM information and the data to be transmitted, after being encoded by the first FEC, are further encoded by the second FEC in the optical module.

17. The method according to any one of claims 1 to 16, characterized in that, The control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, offsets in in-phase and quadrature components IQ, offset compensation values ​​for IQ, power imbalance in two polarization directions, power imbalance in IQ, bit error rate (BER) degradation, equalizer coefficients, and precoding switch or filter coefficients.

18. A method for adjusting configuration parameters in optical communication, characterized in that, include: The first device acquires control information, which is obtained based on a coherent optical signal from the second device, and the control information is used to adjust the configuration parameters of the coherent transmitter of the second device. The first device sends a signal to the second device, the signal including a digital signal processing (DSP) frame, the DSP frame carrying the control information.

19. The method according to claim 18, characterized in that, The DSP frame includes pilot symbols, which carry the control information.

20. The method according to claim 18 or 19, characterized in that, The DSP frame in one polarization direction includes N symbols, and each consecutive M symbols in the N symbols includes one pilot symbol and at least one payload symbol, N = M × Q, where Q and M are both integers greater than 1, and at least one pilot symbol in the Q pilot symbols carries the control information.

21. The method according to claim 20, characterized in that, The control information is carried by k consecutive pilot symbols out of the Q pilot symbols, where k is an integer greater than 1.

22. The method according to claim 20, characterized in that, Among the Q pilot symbols, at least a first pilot symbol, a second pilot symbol, and a third pilot symbol carry the control information, and the number of pilot symbols between the first pilot symbol and the second pilot symbol is the same as the number of pilot symbols between the second pilot symbol and the third pilot symbol.

23. The method according to any one of claims 20 to 22, characterized in that, M = 64, Q = 96; or, M = 64, Q = 114; or, M = 32, Q = 116.

24. The method according to any one of claims 18 to 23, characterized in that, The DSP frame includes padding symbols that carry the control information.

25. The method according to claim 24, characterized in that, The filling symbols in one polarization direction include multiple filling symbol subsets, wherein the number of symbols in each pair of adjacent filling symbol subsets is the same, and at least one filling symbol subset carries the control information.

26. The method according to claim 25, characterized in that, The control information is carried by k consecutive subsets of padding symbols in the plurality of padding symbol subsets, where k is an integer greater than 1.

27. The method according to claim 25, characterized in that, At least three of the plurality of fill symbol subsets—a first fill symbol subset, a second fill symbol subset, and a third fill symbol subset—carry the control information, wherein the number of symbols between the first fill symbol subset and the number of symbols between the second fill symbol subset and the third fill symbol subset are the same.

28. The method according to any one of claims 18 to 27, characterized in that, The DSP frame carries the control information in two polarization directions, which are orthogonal to each other.

29. The method according to any one of claims 18 to 28, characterized in that, The DSP frame carries multiple identical control information.

30. The method according to any one of claims 18 to 29, characterized in that, The multiple DSP frames in the signal each carry the same control information.

31. The method according to any one of claims 18 to 30, characterized in that, The signal contains at least a first DSP frame, a second DSP frame, and a third DSP frame carrying the control information. The number of DSP frames between the first DSP frame and the second DSP frame is the same as the number of DSP frames between the second DSP frame and the third DSP frame.

32. The method according to any one of claims 18 to 31, characterized in that, The first device is a host or an optical module.

33. The method according to any one of claims 18 to 32, characterized in that, The control information includes at least one of the following: offsets in two polarization directions, offset compensation values ​​in two polarization directions, offsets in in-phase and quadrature components IQ, offset compensation values ​​for IQ, power imbalance in two polarization directions, power imbalance in IQ, bit error rate (BER) degradation, equalizer coefficients, and precoding switch or filter coefficients.

34. A method for adjusting configuration parameters in optical communication, characterized in that, include: The second device sends a coherent optical signal to the first device; The second device receives a signal sent by the first device, the signal including alignment flag AM information, the AM information carrying control information, the control information being obtained based on the coherent optical signal; The second device adjusts the configuration parameters of the coherent transmitter according to the control information.

35. The method according to claim 34, characterized in that, The AM information includes at least one of the uniquely filled UP0, UP1, and UP2 fields that carries the control information.

36. The method according to claim 34 or 35, characterized in that, The AM information includes a padding field that carries the control information.

37. The method according to claim 36, characterized in that, The signal includes a first data stream and a second data stream. The first data stream includes first AM information, and the second data stream includes second AM information. The control information carried by the pad field in the first AM information is the same as the control information carried by the pad field in the second AM information.

38. The method according to claim 35, characterized in that, The signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field. The UP0 field, UP1 field, and UP2 field of any one of the multiple channel data streams carry the control information.

39. The method according to claim 38, characterized in that, The multiple channel data streams include a first channel data stream and a second channel data stream. The control information carried by the UP0, UP1, and UP2 fields of the first channel data stream is the same as the control information carried by the UP0, UP1, and UP2 fields of the second channel data stream.

40. The method according to claim 35, characterized in that, The signal includes multiple channel data streams, each of which includes a UP0 field, a UP1 field, and a UP2 field. The UP0 field of the multiple channel data streams carries the control information.

41. A method for adjusting configuration parameters in optical communication, characterized in that, include: The second device sends a coherent optical signal to the first device; The second device receives a signal sent by the first device, the signal including a digital signal processing (DSP) frame, the DSP frame carrying the control information, the control information being obtained based on the coherent optical signal; The second device adjusts the configuration parameters of the coherent transmitter according to the control information.

42. The method according to claim 41, characterized in that, The DSP frame includes pilot symbols, which carry the control information.

43. The method according to claim 41 or 42, characterized in that, The DSP frame in one polarization direction includes N symbols, and each consecutive M symbols in the N symbols includes one pilot symbol and at least one payload symbol, N = M × Q, where Q and M are both integers greater than 1, and at least one pilot symbol in the Q pilot symbols carries the control information.

44. The method according to claim 43, characterized in that, The control information is carried by k consecutive pilot symbols out of the Q pilot symbols, where k is an integer greater than 1.

45. The method according to claim 43, characterized in that, Among the Q pilot symbols, at least a first pilot symbol, a second pilot symbol, and a third pilot symbol carry the control information, and the number of pilot symbols between the first pilot symbol and the second pilot symbol is the same as the number of pilot symbols between the second pilot symbol and the third pilot symbol.

46. ​​A chip, characterized in that, The chip includes a processor for performing the method as described in any one of claims 1 to 45.

47. A communication device, characterized in that, The communication device is used to perform the method as described in any one of claims 1 to 17, or the communication device is used to perform the method as described in any one of claims 34 to 40.

48. A communication device, characterized in that, The communication device is used to perform the method as described in any one of claims 18 to 33, or the communication device is used to perform the method as described in any one of claims 41 to 45.

49. A communication system, characterized in that, The communication system includes a first device and a second device; The first device is used to perform the method as described in any one of claims 1 to 17, and the second device is used to perform the method as described in any one of claims 34 to 40; or, the first device is used to perform the method as described in any one of claims 18 to 33, and the second device is used to perform the method as described in any one of claims 41 to 45.

50. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed by a computer, cause the method as described in any one of claims 1 to 45 to be implemented.

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