An information transmission method, device and system

Abstract

The embodiment of the application discloses an information transmission method, which is equivalent to designing a link training mode between optical modules in a coherent optical communication scene, and ensures that formal data transmission is started on the premise that the transmission quality of the coherent optical signal is good, so as to improve the reliability of data transmission. The first optical module receives a first frame sent by the second optical module, and the first frame indicates that the first optical module is converted from a training mode to a data mode, which is equivalent to that the second optical module is ready to send and receive data. Moreover, the first optical module acquires local first state information, and the first state information indicates that a first interface of the first optical module can send and receive data, and the first interface is an interface for communication with the second optical module. Furthermore, the first optical module can determine that the optical modules at both ends of the optical fiber link are ready to send and receive data by combining the first frame and the first state information, and it is determined that the transmission path of the data has been established, and the transmission path can be used for transmitting the coherent optical signal.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to an information transmission method, apparatus and system. Background Technology

[0002] 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 to transmit data, coherent optical signals use both phase and amplitude information to transmit data. The transmission channel includes the local device, the local optical module, the fiber optic link, the peer optical module, and the peer device. The transmission channel supports bidirectional transmission. Taking one transmission direction as an example, the local optical module transmits data from the local device to the peer optical module in the form of a coherent optical signal, and then the peer optical module sends the data carried by the coherent optical signal to the peer device.

[0003] The transmission channel comprises three links: the link between the local device and the local optical module, the link between the local optical module and the peer optical module, and the link between the peer device and the peer optical module. Data communication requires link-up for each link, meaning all devices on each link must enter data mode. Link-up between the local device and the local optical module, and between the peer device and the peer optical module, can be achieved through inter-sublayer link training (ILT). This effectively optimizes the transmission performance of the transmitters (TX) connected to the link. However, ILT is currently not suitable for coherent optical interfaces. Transmission between coherent optical modules relies on the receiver (RX) of the coherent optical module to ensure signal recovery quality. In scenarios with poor fiber optic link quality, this significantly impacts data transmission reliability. Therefore, there is an urgent need for an ILT method applied between coherent optical modules to improve the transmission quality of coherent optical signals. Summary of the Invention

[0004] This application provides an information transmission method, which is equivalent to designing a link training method between optical modules in a coherent optical communication scenario. This ensures that formal data transmission only begins under the premise that the transmission quality of the coherent optical signal is good, thereby improving the reliability of data transmission.

[0005] Firstly, this application provides an information transmission method. For the optical modules at both ends of an optical fiber link, a decision can be made based on the coherent optical signal from the other end to determine whether the optical module at the other end should continue training. Specifically, the optical modules at both ends can instruct each other to continue training by sending frames. Specifically, the first optical module receives a first frame sent by the second optical module. The first frame indicates that the first optical module has switched from training mode to data mode, meaning the second optical module is ready to send and receive data, and the first optical module no longer needs to continue training. Furthermore, the first optical module obtains local first state information, which indicates that its first interface can send and receive data. The first interface is the interface through which the transmission path communicates with the second optical module. Then, the first optical module, combining the first frame and the first state information, can determine whether to switch from training mode to data mode. If the second optical module also switches from training mode to data mode, both optical modules at both ends of the optical fiber link are ready to send and receive data, thus establishing data communication on the transmission path, which can then be used to transmit coherent optical signals.

[0006] As can be seen, this application designs a link training method between optical modules in a coherent optical communication scenario. Before formal data transmission, each optical module must determine whether a data transmission path can be established based on whether it is ready to send and receive data locally and whether the other end is ready to send and receive data. If the transmission quality of the coherent optical signal is poor, training needs to continue, thus ensuring that formal data transmission only begins under the premise that the transmission quality of the coherent optical signal is good, thereby improving the reliability of data transmission.

[0007] In some possible implementations, the method further includes: the first optical module determining second status information based on the first frame, the second status information indicating that the second interface of the second optical module can send and receive data, the second interface being the interface on the transmission path that communicates with the first optical module. In other words, the first optical module can determine from the first frame that the second interface of the second optical module can send and receive data, and combined with the fact that the first interface of the first optical module can send and receive data, this indicates that the transmission path between the first and second optical modules has good quality, ensuring the reliability of data transmission.

[0008] In some possible implementations, the first frame includes the second state information, which makes it easier for the first optical module to directly determine the second state information by parsing the first frame, thus simplifying the implementation.

[0009] In some possible implementations, the first status information is further used to indicate that the third interface of the first optical module can send and receive data. The third interface is the interface on the transmission path that communicates with the first device. The first frame is also used to indicate that the interface on the transmission path that communicates with the second device can send and receive data. The transmission path is the path between the first device and the second device. That is, based on the first frame, the first optical module can also determine that the link training between the second optical module and the second device has been completed. Combined with the first status information indicating that the link training between the first optical module and the first device has been completed, it can be determined that all three links between the first device and the second device have good transmission quality, further ensuring the reliability of data transmission between the first device and the second device.

[0010] In some possible implementations, the method further includes: the first optical module determining local locking based on the coherent optical signal from the second optical module; when local locking is achieved, the first status information is used to indicate that the first interface can receive data. Specifically, when digital signal processing (DSP) is determined to be locked in both polarization directions, it is equivalent to detecting the position of the pilot symbol in the frame in both polarization directions, indicating local locking and good data reception quality. This method can accurately reflect the quality of the received data.

[0011] In some possible implementations, the feasibility of a signal is determined based on the locally locked state, which is used for transmission from the physical medium dependent (PMD) sublayer to the physical medium attachment (PMA) sublayer. In this implementation, instead of determining signal feasibility solely based on the optical power of the received coherent optical signal, determining feasibility based on local locking allows for a more accurate determination, resulting in more precise information transmission from the PMA sublayer to the PMD sublayer.

[0012] In some possible implementations, the method further includes: the first optical module determining that the DSP is locked in two polarization directions based on the coherent optical signal from the second optical module; when the DSP is locked in the two polarization directions, the first status information is used to indicate that the first interface can receive data. This method can accurately reflect the quality of the received data, thus facilitating the determination of whether the first interface can receive data.

[0013] In some possible implementations, the feasibility of the signal is determined based on the locking of the DSP in the two polarization directions, and this feasibility is used for transmission from the PMD sublayer to the PMA sublayer. In this implementation, instead of determining signal feasibility solely based on the optical power of the received coherent optical signal, determining signal feasibility based on the locking of the DSP in the two polarization directions allows for a more accurate determination of signal feasibility, resulting in more accurate information transmission from the PMA sublayer to the PMD sublayer.

[0014] In some possible implementations, the method further includes: the first optical module acquiring a first coherent optical signal from the second optical module, the acquisition including at least one operation among frequency offset convergence, equalization, and forward error correction (FEC) decoding, wherein the first interface indicated by the first state information is capable of receiving data is determined based on the acquisition result. This provides multiple methods for determining the quality of received data, enriching the implementation possibilities of this application.

[0015] In some possible implementations, the feasibility of a signal is determined based on the acquisition results, and this feasibility is used for transmission from the PMD sublayer to the PMA sublayer. In this implementation, instead of determining signal feasibility solely based on the optical power of the received coherent optical signal, using the acquisition results allows for a more accurate determination of signal feasibility, resulting in more accurate information transmission from the PMA sublayer to the PMD sublayer.

[0016] In some possible implementations, when the first optical module has prepared the transmitter clock, the first status information is used to indicate that the first interface can send data. By determining that the data can be sent normally, bidirectional data transmission is guaranteed.

[0017] In some possible implementations, before the first optical module receives the first frame sent by the second optical module, the method further includes: the first optical module receiving a second frame sent by the second optical module, the second frame indicating that the second optical module is ready to receive data. Combining this information that the second optical module is ready to receive data, the first optical module can also determine that the first interface can send data. In other words, the first optical module can verify the accuracy of the information fed back by the second optical module based on the received second and first frames, which helps to more accurately determine whether link training has been completed.

[0018] In some possible implementations, before the first optical module receives the first frame sent by the second optical module, the method further includes: the first optical module receiving a third frame sent by the second optical module, the third frame being used to instruct the first optical module to continue training mode. This is equivalent to maintaining training mode until link training is complete, in order to optimize transmitter parameters and thus improve transmission quality.

[0019] In some possible implementations, the method further includes: the first optical module sending a fourth frame to the second optical module, the fourth frame indicating that the second optical module switches from training mode to data mode. Since the first status information indicates that the first interface of the first optical module can send and receive data, the first optical module can send the fourth frame to the second optical module to indicate that the second optical module switches from training mode to data mode, enabling both the first and second optical modules to switch to data mode and thus promptly begin transmitting data to each other.

[0020] In some possible implementations, the fourth frame includes the first state information, which makes it easier for the second optical module to directly determine the first state information by parsing the fourth frame, thus simplifying the implementation.

[0021] In some possible implementations, when the link training is complete, the first frame is used to indicate that the first optical module is switching from training mode to data mode.

[0022] In some possible implementations, the first frame is a DSP frame. In one polarization direction, every M consecutive symbols in the DSP frame include one pilot symbol and M-1 payload symbols. The DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode. That is, the indication information is transmitted using in-band transmission, which does not require additional transmission bandwidth or superimposed signals, resulting in lower implementation costs. Furthermore, it does not require occupying the payload symbols of the DSP frame used for data transmission to carry the indication information, and does not change the original structure of the DSP frame.

[0023] In some possible implementations, the Q pilot symbols in the DSP frame are generated based on a generator polynomial and a seed. Different seedings can yield different pilot sequences, which in turn can convey different information without requiring additional design and thus reducing implementation costs.

[0024] In some possible implementations, M = 32, 64, 96, or 128.

[0025] Secondly, this application provides an information transmission method. Specifically, a second optical module generates a first frame, which instructs the first optical module to switch from training mode to data mode, meaning the second optical module is ready to send and receive data, and the first optical module no longer needs to continue training. Then, the second optical module sends the first frame to the first optical module to trigger the first optical module to switch from training mode to data mode. The first and second optical modules are used to transmit coherent optical signals through a transmission path in data mode.

[0026] As can be seen, this application designs a link training method between optical modules in a coherent optical communication scenario. Before formal data transmission, the optical module at either end must determine whether to switch from training mode to data mode based on the frames sent by the other end. If the transmission quality of the coherent optical signal is poor, training needs to continue, thus ensuring that formal data transmission only begins under the premise that the transmission quality of the coherent optical signal is good, thereby improving the reliability of data transmission.

[0027] In some possible implementations, the second optical module generating the first frame includes: the second optical module generating the first frame based on status information, wherein the status information is used to indicate that the interface of the second optical module for communicating with the first optical module on the transmission path can send and receive data. That is, the second optical module is locally ready to send and receive data, indicating that the signal quality received by the second optical module is good. Instructing the first optical module to switch from training mode to data mode at this time helps ensure the reliability of data transmission in data mode.

[0028] In some possible implementations, the first frame includes the state information, which makes it easier for the first optical module to directly determine the state information by parsing the first frame, thus simplifying the implementation.

[0029] In some possible implementations, the first frame is also used to indicate that the interface of the second optical module on the transmission path for communicating with the second device can send and receive data.

[0030] In some possible implementations, before the second optical module sends the first frame to the first optical module, the method further includes: the second optical module sending a second frame to the first optical module, the second frame being used to indicate that the second optical module is ready to receive data.

[0031] In some possible implementations, before the second optical module sends the first frame to the first optical module, the method further includes: the second optical module sending a third frame to the first optical module, the third frame being used to instruct the first optical module to continue training mode.

[0032] In some possible implementations, the method further includes: the second optical module receiving a fourth frame sent by the first optical module, the fourth frame being used to indicate that the second optical module switches from training mode to data mode.

[0033] In some possible implementations, the first frame is a DSP frame, in which every M consecutive symbols in a polarization direction include 1 pilot symbol and M-1 payload symbols, and the DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode.

[0034] In some possible implementations, the Q pilot symbols in the DSP frame are generated according to a generator polynomial and a seed.

[0035] In some possible implementations, M = 32, 64, 96, or 128.

[0036] Thirdly, embodiments of this application provide an optical module including a processing unit and a transceiver unit, which may be referred to as a first optical module. The transceiver unit is used to receive a first frame transmitted by a second optical module, the first frame indicating that the first optical module switches from training mode to data mode. The processing unit is used to switch from training mode to data mode based on the first frame and first state information, the first state information indicating that a first interface of the first optical module can send and receive data, the first interface being an interface on the transmission path that communicates with the second optical module, the transmission path being used to transmit coherent optical signals between the first optical module and the second optical module in the data mode.

[0037] In some possible implementations, the processing unit is further configured to determine second status information based on the first frame, the second status information being used to indicate that the second interface of the second optical module can send and receive data, the second interface being the interface on the transmission path that communicates with the first optical module.

[0038] In some possible implementations, the first frame includes the second state information.

[0039] In some possible implementations, the first status information is also used to indicate that the third interface of the first optical module can send and receive data, the third interface being the interface on the transmission path that communicates with the first device. The first frame is also used to indicate that the interface on the transmission path that communicates with the second device is able to send and receive data, the transmission path being the path between the first device and the second device.

[0040] In some possible implementations, the processing unit is further configured to determine that the local area is locked based on the coherent optical signal from the second optical module, and when the local area is locked, the first status information is used to indicate that the first interface can receive data.

[0041] In some possible implementations, the signal-feasible state is determined based on the locally locked state, which is used for transmission from the PMD sublayer to the PMA sublayer.

[0042] In some possible implementations, the processing unit is further configured to determine that the DSP is locked in two polarization directions based on the coherent optical signal from the second optical module. When the DSP is locked in the two polarization directions, the first status information is used to indicate that the first interface can receive data.

[0043] In some possible implementations, the signal viability state is determined based on the DSP being locked in the two polarization directions, and the signal viability state is used for transmission from the PMD sublayer to the PMA sublayer.

[0044] In some possible implementations, the processing unit is further configured to acquire a first coherent optical signal from the second optical module, the acquisition including at least one of frequency offset convergence, equalization, and forward error correction (FEC) decoding, wherein the first interface indicated by the first state information is capable of receiving data is determined based on the acquisition result.

[0045] In some possible implementations, the signal feasibility state is determined based on the acquisition results, and the signal feasibility state is used for transmission from the PMD sublayer to the PMA sublayer.

[0046] In some possible implementations, when the first optical module has prepared the transmitter clock, the first status information is used to indicate that the first interface can send data.

[0047] In some possible implementations, before the first optical module receives the first frame sent by the second optical module, the transceiver unit is also configured to receive a second frame sent by the second optical module, the second frame being used to indicate that the second optical module is ready to receive data.

[0048] In some possible implementations, before the first optical module receives the first frame sent by the second optical module, the transceiver unit is also configured to receive a third frame sent by the second optical module, the third frame being used to instruct the first optical module to continue training mode.

[0049] In some possible implementations, the transceiver unit is further configured to send a fourth frame to the second optical module, the fourth frame being used to instruct the second optical module to switch from training mode to data mode.

[0050] In some possible implementations, the fourth frame includes the first state information.

[0051] In some possible implementations, when the link training is complete, the first frame is used to indicate that the first optical module is switching from training mode to data mode.

[0052] In some possible implementations, the first frame is a DSP frame, in which every M consecutive symbols in a polarization direction include 1 pilot symbol and M-1 payload symbols, and the DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode.

[0053] In some possible implementations, the Q pilot symbols in the DSP frame are generated according to a generator polynomial and a seed.

[0054] In some possible implementations, M = 32, 64, 96, or 128.

[0055] Fourthly, embodiments of this application provide an optical module including a processing unit and a transceiver unit, which may be referred to as a second optical module. The processing unit generates a first frame, which instructs the first optical module to switch from training mode to data mode. The transceiver unit sends the first frame to the first optical module, which triggers the first optical module to switch from training mode to data mode. The first optical module and the second optical module are used to transmit coherent optical signals through a transmission path in the data mode.

[0056] In some possible implementations, the processing unit is specifically configured to generate the first frame based on status information, the status information being used to indicate that the interface of the second optical module on the transmission path for communicating with the first optical module can send and receive data.

[0057] In some possible implementations, the first frame includes the status information.

[0058] In some possible implementations, the first frame is also used to indicate that the interface of the second optical module on the transmission path for communicating with the second device can send and receive data.

[0059] In some possible implementations, before the second optical module sends the first frame to the first optical module, the transceiver unit is also configured to send a second frame to the first optical module, the second frame being used to indicate that the second optical module is ready to receive data.

[0060] In some possible implementations, before the second optical module sends the first frame to the first optical module, the transceiver unit is also configured to send a third frame to the first optical module, the third frame being used to instruct the first optical module to continue training mode.

[0061] In some possible implementations, the transceiver unit is further configured to receive a fourth frame sent by the first optical module, the fourth frame being used to indicate that the second optical module is switching from training mode to data mode.

[0062] In some possible implementations, the first frame is a DSP frame, in which every M consecutive symbols in a polarization direction include 1 pilot symbol and M-1 payload symbols, and the DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode.

[0063] In some possible implementations, the Q pilot symbols in the DSP frame are generated according to a generator polynomial and a seed.

[0064] In some possible implementations, M = 32, 64, 96, or 128.

[0065] Fifthly, embodiments of this application provide a chip, which includes a processor for performing the method described in either the first or second aspect.

[0066] In a sixth aspect, embodiments of this application provide an optical module for performing the method as described in any embodiment of the first aspect.

[0067] In a seventh aspect, embodiments of this application provide an optical module for performing the method as described in any embodiment of the second aspect.

[0068] Eighthly, embodiments of this application provide an optical module, 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 aspect.

[0069] In a ninth aspect, embodiments of this application provide an optical module, 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 second aspect.

[0070] In a tenth aspect, embodiments of this application provide a communication system including a first optical module and a second optical module. The first optical module is used to perform the method described in any embodiment of the first aspect, and the second optical module is used to perform the method described in any embodiment of the second aspect.

[0071] In one 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 or second aspect to be implemented.

[0072] In a twelfth aspect, this application provides a computer program product including program instructions that, when executed, implement the method described in any of the embodiments of the first or second aspect above. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of a communication system used in an embodiment of this application;

[0074] Figure 2 This is a schematic diagram of a method for generating coherent optical signals.

[0075] Figure 3 This is a schematic diagram illustrating another method for generating coherent optical signals.

[0076] Figure 4 This is a schematic diagram of a system scenario for coherent optical communication according to an embodiment of this application;

[0077] Figure 5 This is a flowchart illustrating an information transmission method in an embodiment of this application.

[0078] Figure 6 This is a schematic diagram illustrating one implementation of the local state machine of the optical module in this application.

[0079] Figure 7 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application.

[0080] Figure 8 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application.

[0081] Figure 9 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application.

[0082] Figure 10(a) is a schematic diagram of one implementation method of framing in an embodiment of this application;

[0083] Figure 10(b) is a schematic diagram of another implementation of framing in the embodiments of this application;

[0084] Figure 10(c) is a schematic diagram of another embodiment of framing in this application.

[0085] Figure 10(d) is a schematic diagram of another embodiment of framing in this application;

[0086] Figure 11 This is a schematic diagram of a DSP frame structure in an embodiment of this application;

[0087] Figure 12 This is a schematic diagram of a symbol on a constellation diagram according to an embodiment of this application;

[0088] Figure 13 This is a schematic diagram of a pilot symbol generation structure in an embodiment of this application;

[0089] Figure 14 This is a schematic diagram of another structure of the DSP frame in the embodiments of this application;

[0090] Figure 15 This is a schematic diagram of the structure of an optical module in an embodiment of this application;

[0091] Figure 16 This is a schematic diagram of another structure of the optical module in an embodiment of this application. Detailed Implementation

[0092] This application provides an information transmission method, which is equivalent to designing a link training method between optical modules in a coherent optical communication scenario. This ensures that formal data transmission only begins under the premise that the transmission quality of the coherent optical signal is good, thereby improving the reliability of data transmission.

[0093] To facilitate understanding of the embodiments of this application, the following points are made:

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] Sixth, regarding some states or parameters defined in the embodiments of this application (such as local_rx_ready, local_rts, remote_rts, etc.), the logical "yes" or "no" can be represented by "state or parameter = 0 or 1". For example, "state or parameter = 0" means "no" and "state or parameter = 1" means "yes".

[0100] Figure 1 This is a schematic diagram of a communication system used in an embodiment of this application. Figure 1As shown, 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 called 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. This channel can also be called an electrical link, which may include an electrical channel and an electrical interface. For example, the electrical link can be an attachment unit interface (AUI), which includes an AUI channel and an AUI electrical interface component. Alternatively, it can be a common electrical interface (or common electrical I / O, CEI). Exemplarily, 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; the specifics are not limited here.

[0101] In coherent optical communication scenarios, both the transmitting end processing module 02 and the receiving end processing module 04 can be optical modules used to transmit coherent optical signals. These optical modules can also be called coherent optical modules. 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 modulators, and the ICR includes mixers.

[0102] It should be understood that 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. Receiving and demodulating coherent optical signals requires mixing a local oscillator (LO) optical signal with the coherent optical signal to obtain phase information. In a coherent optical module, the LO optical signal is provided by a continuous wave light source. The LO and coherent optical signals are mixed by an optical mixer and then converted into an electrical signal by a balanced detector. The oDSP chip performs clock data recovery (CDR) on the electrical signal and then performs digital signal processing (DSP) to compensate for link impairments, etc. For example, a coherent optical module can specifically be an 800LR module or a 1600LR module, etc.

[0103] Figure 2 This is a schematic diagram illustrating one method of generating coherent optical signals. For example... Figure 2As shown, 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 at 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 then combined using a 2:1 power divider. At this point, 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 μm-level 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.

[0104] Figure 3 This is a schematic diagram illustrating another method for generating coherent optical signals. (For example...) Figure 3As shown, coherent optical transmission systems also widely utilize the two orthogonal polarization modes supported by the fiber optic channel to further double the spectral efficiency. Two polarization modes 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. Polarization multiplexed coherent optical modulators 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 an integrated chip's polarization splitting rotator (PSR). 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.

[0105] It should be noted that the coherent optical module in this application embodiment can be of various types, which will be described below.

[0106] For example, an optical digital signal processor (oDSP) chip is located inside a coherent optical module, which can be called a digital coherent optics (DCO) module.

[0107] 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.

[0108] For example, a coherent optical module can be a near package optics (NPO) module or a co-packaged optics (CPO) module. NPO modules can also be called NPO optical modules, and CPO modules can also be called CPO optical modules. NPO and CPO modules do not have a pluggable physical package form and are closer to the host. NPO and CPO modules can also be called optical engines (OE). NPO or CPO technology is a technology that "packages" the host and the optical engine. When NPO technology is used to package the host and the optical engine, the optical engine can be called an NPO module. When CPO technology is used to package the host and the optical engine, the optical engine can be called a CPO module.

[0109] Figure 4 This is a schematic diagram of a system scenario for coherent optical communication according to an embodiment of this application. For example... Figure 4 As shown, this example uses optical module 1 and optical module 2, both of which integrate oDSP chips. Specifically, optical module 1 and optical module 2 each 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 be a microcontroller unit (MCU). Host 1 and host 2 each include a PHY chip and a device controller, which can 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 host side. The oDSP chip and the PHY chip can use an AUI interface. The second side of the oDSP chip is used to connect to the coherent transmitter / receiver; this second side can be called the media side. This embodiment does not limit the devices included in the host side and media side. The first side is used to communicate with host 1 via a telecommunications channel, for example, the serdes located on the first side of the oDSP chip and the serdes located on the PHY chip. Figure 4The optical module (not shown) communicates via a telecommunications channel. The second side communicates with the coherent transmitter / receiver via the telecommunications channel. For example, the second side transmits analog electrical signals via the telecommunications channel. The modulator of the coherent transmitter can modulate the optical signal based on the received electrical signal to enable the optical signal to carry data. The oDSP chip can perform analog-to-digital conversion and digital signal processing based on the received electrical signal. In one implementation, the coherent transmitter in optical module 1 and the coherent receiver in optical module 2 are connected via an optical channel, and the coherent transmitter in optical module 2 and the coherent receiver in optical module 1 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).

[0110] This section uses the scenario of optical module 1 sending an optical signal to optical module 2 as an example. The PHY chip of host 1 sends an electrical signal to the oDSP chip of optical module 1. 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 1 can generate a quadrature phase shift keying (QPSK) signal or a 16-ary quadrature amplitude modulation (16QAM) signal based on the electrical signal sent by the PHY chip of host 1. The coherent transmitter of optical module 1 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 2 receives coherent optical signal 1 through the channel transmission medium, and performs mixing and other processing on coherent optical signal 1 according to the local oscillator (LO) optical signal to convert coherent optical signal 1 into an electrical signal. The oDSP chip of optical module 2 then performs CDR and DSP processing on the electrical signal and sends it to the PHY chip.

[0111] The information transmission method provided in the embodiments of this application will be described below.

[0112] Figure 5 This is a flowchart illustrating one method for information transmission in an embodiment of this application. Figure 5 As shown in the embodiment of this application, the two ends of the optical fiber link are referred to as optical module 1 and optical module 2, respectively.

[0113] 101. Optical module 1 sends coherent optical signal 1 to optical module 2.

[0114] 102. Optical module 2 sends coherent optical signal 2 to optical module 1.

[0115] The coherent optical signals transmitted between optical module 1 and optical module 2 are transmitted via an optical fiber link. The transmission modes of optical module 1 and optical module 2 include, but are not limited to, training mode and data mode. For example, the transmission mode may also include a local pattern mode. This application mainly describes the training mode and data mode. In training mode, optical module 1 and optical module 2 are performing link training, also known as inter-sublayer link training (ILT). In this mode, coherent optical signal 1 and coherent optical signal 2 carry information about the link training used by optical module 1 and optical module 2 to communicate with each other. In data mode, after link training is completed, the system can switch to data mode. In this mode, coherent optical signal 1 carries data sent from optical module 1 to optical module 2, and coherent optical signal 2 carries data sent from optical module 2 to optical module 1. When both optical module 1 and optical module 2 are in data mode, it is equivalent to linking up the optical fiber link between them. It should be understood that the embodiments of this application are introduced with both optical module 1 and optical module 2 starting from the training mode.

[0116] 103. Optical module 1 determines status information 1 based on coherent optical signal 2.

[0117] Optical module 1 can determine state information 1 based on coherent optical signal 2 from optical module 2, wherein state information 1 is local state information related to link training recorded by optical module 1.

[0118] For example, status information 1 includes the status of the local receiver, i.e., whether the local receiver is ready to receive data. This status can be denoted as local_rx_ready. For instance, local_rx_ready = 0 indicates that the local receiver is not ready to receive data, equivalent to the interface between the local receiver and optical module 2 not being ready to receive data; local_rx_ready = 1 indicates that the local receiver is ready to receive data, equivalent to the interface between the local receiver and optical module 2 being ready to receive data.

[0119] The following describes several possible implementation methods for determining the local_rx_ready state.

[0120] In one possible implementation, optical module 1 processes the received coherent optical signal 2 to obtain parameters for forward error correction (FEC) decoding. These FEC decoding parameters can also be considered as parameters of the local FEC state machine of optical module 1. Taking the 800GBASE-LR1 Inner FEC defined by IEEE 802.3dj as an example, the FEC decoding parameters include dsp_lock. <x>This is used to indicate whether the DSP is locked in two polarization directions. For example, dsp_lock <0> =0 indicates that the DSP is not locked in the X-polarization direction, dsp_lock <0> =1 indicates that the DSP is locked in the X-polarization direction; dsp_lock <1> =0 indicates that the DSP is not locked in the Y-polarization direction, dsp_lock <1> =1 is used to indicate that the DSP is locked in the Y polarization direction.

[0121] In one example, the frame carried by the coherent optical signal 2 received by optical module 1 includes pilot symbols. Optical module 1 can determine dsp_lock based on whether the position of the pilot symbols in the frame is detected. <x>For example, in the X-polarization direction, if optical module 1 can detect the position of the pilot symbol in the frame, then dsp_lock <0> =1; otherwise, dsp_lock <0> =0. For example, in the Y-polarization direction, if optical module 1 can detect the position of the pilot symbol in the frame, then dsp_lock <1> =1; otherwise, dsp_lock <1> =0.

[0122] In one example, if dsp_lock <0> =1 and dsp_lock <1> =1 indicates that coherent optical signals in both polarization directions are locked, equivalent to optical module 1 being ready to receive data, thus confirming local_rx_ready = 1. Conversely, if dsp_lock = 1, then... <0> and dsp_lock <1> If at least one of the states is not "1", it means that optical module 1 is not ready to receive data, and thus local_rx_ready = 0 can be determined.

[0123] Optionally, optical module 1 can be configured according to dsp_lock <0> and dsp_lock <1> The parameter determining whether a signal is feasible can be denoted as `signal_ok`. `signal_ok` is used for transmission from the Physical Medium Dependent (PMD) sublayer to the Physical Medium Attachment (PMA) sublayer. For example, if `dsp_lock`... <0> =1 and dsp_lock <1> If dsp_lock = 1, then signal_ok = 1, indicating that the signal is feasible (ok), i.e., signal_ok = ok. Conversely, if dsp_lock = 1, then signal_ok = 1. <0> and dsp_lock <1> If at least one state is not "1", then signal_ok = 0, indicating that the signal is not feasible (fail), and signal_ok = fail. That is to say, in this embodiment, the value of signal_ok is no longer determined solely by the optical power of the received coherent optical signal. Determining the value of signal_ok more accurately based on whether the DSPs in the two polarization directions are locked helps to make the information transmitted from the PMA sublayer to the PMD sublayer more accurate.

[0124] In one example, the local_rx_ready state can also be determined based on a parameter indicating whether the local system is locked. This parameter can be denoted as local_lock or all_locked, and local_lock can also be considered a parameter of the local link training state machine of optical module 1. Specifically, local_lock depends on dsp_lock. <0> and dsp_lock <1> For example, dsp_lock <0> =1 and dsp_lock <1> If dsp_lock = 1, then local_lock = 1, which confirms local_rx_ready = 1. Conversely, if dsp_lock = 1, then local_lock = 1. <0> and dsp_lock <1> If at least one of the states is not "1", then local_lock = 0, which determines that local_rx_ready = 0.

[0125] Optionally, optical module 1 can determine the feasibility parameter of the signal based on local_lock. This feasibility parameter can be denoted as signal_ok, which is used for transmission from the PMD sublayer to the PMA sublayer. For example, if local_lock = 1, then signal_ok = 1, indicating that the signal is feasible (ok). Conversely, if local_lock = 0, it indicates that the signal is not feasible (fail). In other words, in this embodiment, the value of signal_ok is no longer determined solely by the optical power of the received coherent optical signal; determining the value based on local locking is beneficial for a more accurate determination of signal_ok, making the information transmitted from the PMA sublayer to the PMD sublayer more accurate.

[0126] In another possible implementation, optical module 1 acquires the received coherent optical signal 2, and optical module 1 can determine the local_rx_ready state based on the acquisition results. For example, the acquisition includes at least one operation among frequency offset convergence, equalization, and FEC decoding. Several possible examples of determining the local_rx_ready state based on the acquisition results are described below. If at least one of the following examples is satisfied, local_rx_ready = 1 can be determined.

[0127] In one example, optical module 1 determines that the coherent optical signal 2 uses a modulation format such as DP-16QAM or DP-QPSK.

[0128] In one example, optical module 1 determines that the optical power of coherent optical signal 2 is greater than a threshold, for example, the threshold could be the minimum average receiver power (min) defined in IEEE 802.3dj 800GBASE-LR1.

[0129] In one example, the frequency deviation between the local oscillator wavelength of optical module 1 and the wavelength of coherent optical signal 2 is within a preset range, for example, less than 2.5 GHz or 5 GHz, so that the DSP of optical module 1 can realize clock recovery and data recovery.

[0130] In one example, the DSP of optical module 1 can perform signal processing on coherent optical signal 2, such as equalization, polarization demodulation, IQ demodulation, dispersion compensation, etc.

[0131] In one example, optical module 1 is able to perform FEC decoding on frames carried by coherent optical signal 2.

[0132] Optionally, optical module 1 can determine the feasibility parameter of the signal based on the acquisition results. This feasibility parameter can be denoted as `signal_ok`, which is used for transmission from the PMD sublayer to the PMA sublayer. For example, if `local_lock = 1`, then `signal_ok = 1`, indicating that the signal is feasible (ok). Conversely, if `local_lock = 0`, it indicates that the signal is not feasible (fail). In other words, in this embodiment, the value of `signal_ok` is no longer determined solely by the optical power of the received coherent optical signal. Using the acquisition results allows for a more accurate determination of the `signal_ok` value, resulting in more accurate information transmission from the PMA sublayer to the PMD sublayer.

[0133] For example, status information 1 includes the status of the local transmitter, i.e., whether the local transmitter is ready to send data. This status can be denoted as local_tx_ready. For instance, local_tx_ready = 0 indicates that the local transmitter is not ready to send data, which is equivalent to the local interface communicating with optical module 2 not being ready to send data; local_tx_ready = 1 indicates that the local transmitter is ready to send data, which is equivalent to the local interface communicating with optical module 2 being ready to send data.

[0134] In one example, local_tx_ready = 1 when the transmitter clock of optical module 1 is ready; otherwise, local_tx_ready = 0. For example, if the transmitter of optical module 1 uses the local clock, then local_tx_ready = 1. As another example, if the interface between optical module 1 and host 1 is ready to transmit and receive data, and the transmitter of optical module 1 uses the recovered clock, then local_tx_ready = 1. For details, please refer to Figure 178B-7 in the IEEE 802.3dj standard; it will not be elaborated upon here.

[0135] For example, status information 1 can also indicate whether the local interface of optical module 1 used to communicate with optical module 2 can send and receive data. This status can be denoted as local_rts, and local_rts can be a Boolean variable.

[0136] In one example, `local_rts` is determined by the state of the local receiver of optical module 1, the state of the local transmitter of optical module 1, and the state of the local receiver of optical module 2. Optical module 1 can record the state of the local receiver of optical module 2 as `remote_rx_ready`. For example, `local_rx_ready = 1` and `remote_rx_ready = 1` indicate that the receivers of both optical module 1 and optical module 2 are ready to receive data, equivalent to `ISL_ready = 1`. Combined with `local_tx_ready = 1`, then `local_rts = 1`, which means that the local interface of optical module 1 used for communication with optical module 2 can send and receive data. In other words, `local_rx_ready = 1` indicates that the local interface of optical module 1 used for communication with optical module 2 can receive data, and `local_tx_ready = 1` and `remote_rx_ready = 1` indicate that the local interface of optical module 1 used for communication with optical module 2 can send data. Conversely, if at least one of the states of local_tx_ready, local_rx_ready, and remote_rx_ready is not "1", then local_rts = 0, which means that the local interface of optical module 1 used to communicate with optical module 2 cannot send and / or receive data.

[0137] In one example, `local_rts` is determined by the states of the local receivers of optical module 1 and optical module 2. Optical module 1 can record the state of the local receiver of optical module 2 as `remote_rx_ready`. For example, `local_rx_ready = 1` and `remote_rx_ready = 1` indicate that both the receivers of optical module 1 and optical module 2 are ready to receive data, equivalent to `ISL_ready = 1`. Therefore, it can be further determined that `local_rts = 1`, meaning that the interface of optical module 1 used for communication with optical module 2 can send and receive data. In other words, `local_rx_ready = 1` indicates that the interface of optical module 1 used for communication with optical module 2 can receive data, and `remote_rx_ready = 1` indicates that the interface of optical module 1 used for communication with optical module 2 can send data. Conversely, if at least one of the states of local_rx_ready and remote_rx_ready is not "1", then local_rts = 0, which means that the local interface of optical module 1 used to communicate with optical module 2 cannot send and / or receive data.

[0138] For example, status information 1 can also indicate whether the interface of optical module 1 used locally for communication with host 1 can send and receive data. For instance, it can be determined whether the interface between optical module 1 and host 1 can send and receive data according to the ILT between optical module and host as defined in IEEE 802.3dj. This includes whether the interface of optical module 1 used locally for communication with host 1 can send and receive data and whether the interface of host 1 used locally for communication with optical module 1 can send and receive data. The specifics will not be elaborated here.

[0139] 104. Optical module 2 determines status information 2 based on coherent optical signal 1.

[0140] Optical module 2 can determine state information 2 based on the coherent optical signal 1 from optical module 1. State information 2 is the local state information related to link training recorded by optical module 2. It should be understood that state information 2 is similar to state information 1 mentioned above. For details, please refer to the relevant introduction of state information 1 in step 103 above, which will not be repeated here.

[0141] 105. Optical module 1 sends frame 1 to optical module 2 according to status information 1.

[0142] Optical module 1 generates frame 1 based on state information 1 and sends frame 1 to optical module 2. For example, optical module 1 can send a coherent optical signal carrying frame 1 to optical module 2.

[0143] In one example, status information 1 indicates that the local interface of optical module 1 used for communication with optical module 2 cannot send and / or receive data, i.e., local_rts = 0, and frame 1 is used to indicate that optical module 2 continues in training mode. Alternatively, status information 1 indicates that the local interface of optical module 1 used for communication with optical module 2 can send and receive data, i.e., local_rts = 1, and frame 1 is used to indicate that optical module 2 switches from training mode to data mode.

[0144] For example, optical module 2 can determine state information 1 based on frame 1. For instance, if frame 1 indicates that optical module 2 should continue in training mode, optical module 2 can determine based on frame 1 that the local interface of optical module 1 used for communication with optical module 2 cannot send and / or receive data; if frame 1 indicates that optical module 2 should switch from training mode to data mode, optical module 2 can determine based on frame 1 that the local interface of optical module 1 used for communication with optical module 2 can send and receive data.

[0145] For example, frame 1 may carry state information 1 so that optical module 2 can obtain state information 1 based on frame 1.

[0146] In one example, before determining local_rts, optical module 1 can first determine local_rx_ready and / or local_tx_ready. Then, before sending frame 1 indicating local_rts to optical module 2, optical module 1 can also send frame 1 indicating local_rx_ready and / or local_tx_ready to optical module 2, so that optical module 2 can verify the accuracy of optical module 1's status information 1 based on multiple received frames 1.

[0147] In one example, the status information 1 carried in frame 1 can also indicate whether the interface between optical module 1 and host 1 can send and receive data. This status can be denoted as `adjacent_ISL_ready`, which means that the inter-sublayer link (ISL) between optical module 1 and host 1 is ready to transmit data. For optical module 2, the `adjacent_ISL_ready` of optical module 1 can be denoted as `adjacent_remote_rts`, which means that optical module 2 uses `adjacent_remote_rts` to record whether the interface between optical module 1 and host 1 can send and receive data.

[0148] For example, optical module 1 can send multiple frames 1 to optical module 2 to indicate multiple pieces of information such as local_rx_ready, local_tx_ready, local_rts, and adjacent_ISL_ready respectively. Alternatively, optical module 1 can send one frame 1 to optical module 2 to indicate multiple or all of the information in local_rx_ready, local_tx_ready, local_rts, and adjacent_ISL_ready at once.

[0149] 106. Optical module 2 sends frame 2 to optical module 1 according to status information 2.

[0150] Optical module 2 generates frame 2 based on state information 2 and sends frame 2 to optical module 1. For example, optical module 2 can send a coherent optical signal carrying frame 2 to optical module 1. For example, frame 2 is used to instruct optical module 1 to continue training mode or switch from training mode to data mode. It should be understood that the information indicated by frame 2 is similar to the information indicated by frame 1, the only difference being the object of the instruction. For details, please refer to the relevant introduction of frame 1 in step 103 above, which will not be repeated here.

[0151] 107. Optical module 1 determines the transmission mode based on status information 1 and frame 2.

[0152] 108. Optical module 2 determines the transmission mode based on status information 2 and frame 1.

[0153] Optical module 1 can determine its local status information 2 based on frame 2 sent by optical module 2. Combined with its local status information 1, optical module 1 can determine whether its transmission mode is training mode or data mode. Similarly, optical module 2 can determine its local status information 1 based on frame 1 sent by optical module 1. Combined with its local status information 2, optical module 2 can determine whether its transmission mode is training mode or data mode.

[0154] In one example, optical module 1 can determine the local_rts of optical module 2 based on frame 2. For optical module 1, the local_rts of optical module 2 can be denoted as remote_rts. For example, if the local_rts of optical module 2 is 0, the remote_rts of optical module 1 is also 0; if the local_rts of optical module 2 is 1, the remote_rts of optical module 1 is also 1. If at least one of the local_rts and remote_rts of optical module 1 is not "1", the transmission mode of optical module 1 is training mode. If both the local_rts and remote_rts of optical module 1 are 1, the transmission mode of optical module 1 is data mode.

[0155] In one example, optical module 2 can determine the local_rts of optical module 1 based on frame 1. For optical module 2, the local_rts of optical module 1 can be denoted as remote_rts. For example, if the local_rts of optical module 1 is 0, the remote_rts of optical module 2 is also 0; if the local_rts of optical module 1 is 1, the remote_rts of optical module 2 is also 1. If at least one of the local_rts and remote_rts of optical module 2 is not "1", the transmission mode of optical module 2 is training mode. If both the local_rts and remote_rts of optical module 2 are 1, the transmission mode of optical module 1 is data mode.

[0156] It should be noted that if both optical module 1 and optical module 2 are in data mode, it means that the link between optical module 1 and optical module 2 has been established or started (link up), or it can also be said that the path between optical module 1 and optical module 2 has been established or started (path up).

[0157] In one possible scenario, such as Figure 4 As shown, the coherent optical communication system includes host 1, optical module 1, optical module 2, and host 2. The link between host 1 and optical module 1 can be determined by the ILT (Integrated Link Time), and the link between host 2 and optical module 2 can also be determined by the ILT. For details, please refer to the ILT definition between optical modules and hosts in IEEE 802.3dj; it will not be elaborated here.

[0158] In one example, optical module 1 can determine its `adjacent_ISL_ready` value based on frame 2, which is equivalent to determining whether the interface between optical module 2 and host 2 can send and receive data. For example, for optical module 1, optical module 2's `adjacent_ISL_ready` can be denoted as `adjacent_remote_rts`. If optical module 1's `adjacent_ISL_ready` = 1 and `adjacent_remote_rts` = 1, optical module 1 can determine that the link between optical module 1 and host 1 has been established or started, and that the link between optical module 2 and host 2 has also been established or started.

[0159] In one example, optical module 2 can determine the `adjacent_ISL_ready` of optical module 1 based on frame 1. This is equivalent to determining whether the interface between optical module 1 and host 1 can send and receive data. For example, for optical module 2, the `adjacent_ISL_ready` of optical module 1 can be denoted as `adjacent_remote_rts`. If `adjacent_ISL_ready` = 1 and `adjacent_remote_rts` = 1 for optical module 2, optical module 2 can determine that the link between optical module 2 and host 2 has been established or started, and that the link between optical module 1 and host 1 has also been established or started.

[0160] It should be noted that if the links between optical module 1 and optical module 2, between optical module 1 and host 1, and between optical module 2 and host 2 have all been established or started, it is equivalent to host 1, optical module 1, optical module 2 and host 2 all being in data mode. In this case, the path between host 1 and host 2, including the three links, has been established or started.

[0161] The following describes several ways the local state machine of an optical module changes state from training mode to data mode. It should be understood that for the following... Figures 6 to 9 A schematic diagram of any state machine. The condition marked by the arrow above any "box" in the state machine is the condition for entering that state, and the condition marked by the arrow below any "box" in the state machine is the condition for leaving that state.

[0162] Figure 6 This is a schematic diagram illustrating one implementation of the local state machine of the optical module in this application. For example... Figure 6 As shown, in the "Start Training" state, the transmission mode is training mode, and the local transmitter is ready to send data. Entering the "Local Training" state is determined by `local_lock`; for example, `local_lock = 1` confirms entry into the "Local Training" state. If `local_rx_ready = 1` is determined through "Local Training", then the transmitter can leave the "Local Training" state and enter the "Remote Training" state. At this point, a frame carrying "receiver ready = 1" can be sent to the remote optical module. "Receiver ready = 1" indicates that `local_rx_ready = 1`. Based on the frame carrying "receiver ready = 1" sent by the remote optical module, it can be determined that the remote optical module's `local_rx_ready = 1`, which can be recorded locally as `remote_rx_ready = 1`, thus confirming the "Remote Training" state. Since both `local_rx_ready = 1` and `remote_rx_ready = 1`, the transmitter can enter the "ISL Ready to Transmit Data (ISL_ready)" state. After confirming that local_rts = 1, a frame carrying "continuetraining = 0" can be sent to the remote optical module. This is equivalent to instructing the remote optical module not to continue training, indicating that the local optical module's local_rts = 1. "Not continuing training" means ending or stopping the current training. Furthermore, a frame carrying "continue training = 0" sent by the remote optical module can be received, thus confirming that the remote optical module's local_rts = 1, which can be recorded locally as remote_rts = 1. Since both local_rts = 1 and remote_rts = 1, the system can enter the "path ready for data transmission (path_ready)" state. At this time, a timer can be started, which can be called the "propagation_timer". After waiting for a period of time, the timer completes, and the system can enter the "path up (path up)" state, at which point the transmission mode switches to data mode.

[0163] Figure 7 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application. For example... Figure 7 As shown, in the "Start Training" state, the transmission mode is training mode, and the local transmitter is ready to send data. Entering the "Local Training" state is determined by `local_lock`; for example, `local_lock = 1` confirms entry into the "Local Training" state. If `local_rx_ready = 1` is determined through "Local Training", then the transmitter can leave the "Local Training" state and enter the "Remote Training" state. At this point, a frame carrying "receiver ready = 1 or continue training = 0" can be sent to the remote optical module. "Receiver ready = 1 or continue training = 0" indicates that `local_rx_ready = 1` and `local_rts = 1`. Based on the frame carrying "receiver ready = 1 or continue training = 0" sent by the remote optical module, it can be determined that the remote optical module's `local_rx_ready = 1` and `local_rts = 1`, which can be recorded locally as `remote_rx_ready = 1` and `remote_rts = 1`, thus confirming the "Remote Training" state. Since both `local_rx_ready` and `remote_rx_ready` are 1, the system can enter the "ISL ready to transmit data (ISL_ready)" state. Since both `local_rts` and `remote_rts` are 1, the system can enter the "path ready to transmit data (path_ready)" state, at which point a timer, which can be called the "propagation_timer," can be started. After a period of time, the timer completes, and the system can enter the "path up" state, at which point the transmission mode switches to data mode.

[0164] Figure 8 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application. For example... Figure 8 As shown, in the "Start Training" state, the transmission mode is training mode, and the local transmitter is ready to send data. For example, the decision to enter the "Local Training" state is based on the acquisition results. Taking the determination that local_rx_ready = 1 based on the acquisition results as an example, the "Local Training" state can be entered. At this time, a frame carrying "receiverready = 1" can be sent to the remote optical module. "receiver ready = 1" indicates that local_rx_ready = 1. Based on the frame carrying "receiver ready = 1" sent by the remote optical module, it can be determined that the remote optical module's local_rx_ready = 1, which can be recorded locally as remote_rx_ready = 1, thus determining the "Remote Training" state. Since local_rx_ready = 1 and remote_rx_ready = 1, the "ISL Ready to Transmit Data (ISL_ready)" state can be entered. After confirming that local_rts = 1, a frame carrying "continue training = 0" can be sent to the remote optical module. This is equivalent to instructing the remote optical module not to continue training, indicating that the local optical module's local_rts = 1. "Not continuing training" means ending or stopping the current training. Furthermore, frames carrying "continue training = 0" sent by the remote optical module can be received, thus confirming that the remote optical module's local_rts = 1, which can be recorded locally as remote_rts = 1. Since both local_rts = 1 and remote_rts = 1, the system can enter the "path ready to transmit data (path_ready)" state. At this time, a timer can be started, which can be called the "propagation_timer". After waiting for a period of time, the timer completes, and the system can enter the "path up (path up)" state, at which point the transmission mode switches to data mode.

[0165] Figure 9 This is a schematic diagram illustrating another implementation of the local state machine of the optical module in this application. For example... Figure 9 As shown, in the "Start Training" state, the transmission mode is training mode, and the local transmitter is ready to send data. For example, the decision to enter the "Local Training" state is based on the acquisition results. Taking the determination that local_rx_ready = 1 based on the acquisition results as an example, the "Local Training" state can be entered. At this time, a frame carrying "receiverready = 1 or continue training = 0" can be sent to the remote optical module. "receiver ready = 1 or continue training = 0" indicates that local_rx_ready = 1 and local_rts = 1. Based on the frame carrying "receiverready = 1 or continue training = 0" sent by the remote optical module, it can be determined that the remote optical module's local_rx_ready = 1 and local_rts = 1. Locally, this can be recorded as remote_rx_ready = 1 and remote_rts = 1, thus determining the "Remote Training" state. Since both `local_rx_ready` and `remote_rx_ready` are 1, the system can enter the "ISL ready to transmit data (ISL_ready)" state. Since both `local_rts` and `remote_rts` are 1, the system can enter the "path ready to transmit data (path_ready)" state, at which point a timer, which can be called the "propagation_timer," can be started. After a period of time, the timer completes, and the system can enter the "path up" state, at which point the transmission mode switches to data mode.

[0166] It should be noted that, regarding the above Figures 6 to 9 The implementation of the local state machine for the optical module described in this application uses "yes" states such as local_lock=1, local_rx_ready=1, remote_rx_ready=1, local_rts=1, and remote_rts=1 to advance the state machine. If a "no" state appears in the above states, such as local_lock=0 or local_rx_ready=0, the recovery branch will be entered. For details, please refer to the recovery branch defined in Figure 178B-8 of the standard IEEE 802.3dj, which will not be elaborated here.

[0167] In one possible implementation, the above Figure 5 In the illustrated embodiment, the frames 1 and 2 transmitted between optical module 1 and optical module 2 can specifically be DSP frames. The following describes several possible implementations of framing, which can also be called DSP framing. For example, framing can be implemented in an oDSP chip.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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).

[0173] 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.

[0174] 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).

[0175] 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).

[0176] 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).

[0177] 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.

[0178] 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.

[0179] Figure 11 This is a schematic diagram of a DSP frame structure in an embodiment of this application. For example... Figure 11 As shown, a DSP frame in one polarization direction includes N symbols. Every M consecutive symbols within the N symbols includes one pilot symbol at a fixed position and M-1 payload symbols, where N = M × Q, and both Q and M are integers greater than 1. That is, every M consecutive symbols within the N symbols can be considered a group, and the N symbols comprise Q groups of symbols. For example, with N = 6144, M = 64, and Q = 96, symbols 1-64 constitute the first group of 64 consecutive symbols, symbols 65-128 constitute the second group of 64 consecutive symbols, and so on, until symbols 6081-6144 constitute the 96th group of 64 consecutive symbols. It should be understood that the payload symbols, also known as pre-framing symbols, include FEC-encoded information symbols and check symbols. At the receiver, pilot symbols can be used to assist in carrier phase recovery and to distinguish between the two polarization directions. It should be understood that the embodiments of this application do not limit the specific location of the pilot symbols in each group of M symbols. As an example, each pilot symbol is located at the starting position of its consecutive M symbols, for example... Figure 11 The first symbol in the DSP frame shown is the first pilot symbol. This application does not limit the value of M; for example, M = 32, 64, 96, or 128, etc.

[0180] 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.

[0181] Figure 12 This is a schematic diagram of a symbol on a constellation diagram according to an embodiment of this application. For example... Figure 12 As shown, when A = 3 or -3, each pilot symbol can be represented by one of -3-3j, -3+3j, 3-3j, and 3+3j, as follows: Figure 12 The hollow symbol is shown. Similarly, using 64QAM, A = ±1, ±3, ±5, or ±7. It should be noted that higher-order modulation formats can also be used, but this application will not elaborate further. In actual transmission, using the four outermost symbols on the constellation diagram for pilot symbols can reduce the probability of symbol errors.

[0182] 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.

[0183] 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.

[0184] 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...

[0185] 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:

[0186] 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.

[0187] Figure 13 This is a schematic diagram of a pilot symbol generation structure according to an embodiment of this application. Figure 13 As shown, each box can be considered a storage unit, and 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, and thus uses 10 corresponding storage units. Of course, the seed can also be represented in hexadecimal or decimal. When it is used in operations with the target polynomial, it needs to be converted to binary form. For example, 0110111000 is represented as 0x1B8 in hexadecimal and 440 in decimal.

[0188] 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.

[0189] In one possible scenario, the local optical module can use Q pilot symbols in the DSP frame to transmit information to the remote optical module. For example, the Q pilot symbols in the DSP frame can indicate whether the remote optical module should continue in training mode or switch from training mode to data mode. The pilot sequence composed of the Q pilot symbols in the DSP frame is determined by the generator polynomial and the seed. Different seeds result in different pilot sequences, which in turn transmit different information. It should be understood that since the DSP frame includes pilot sequences in two polarization directions, different seeds must be used to distinguish between the two polarization directions. Some possible examples are described below.

[0190] In one example, the correspondence between the seed used in the pilot sequence and the information indicated by the pilot sequence can be shown in Table 1 below. For example, Table 1 corresponds to the above... Figure 6 or Figure 8 The scenario is shown below. The pilot sequence obtained using "Seed A" in the X-polarization direction indicates "continue training = 0", the pilot sequence obtained using "Seed B" in the X-polarization direction indicates "continue training = 1", the pilot sequence obtained using "Seed C" in the Y-polarization direction indicates "continue training = 0", and the pilot sequence obtained using "Seed D" in the Y-polarization direction indicates "continue training = 1". The pilot sequence obtained using "Seed E" in the X-polarization direction indicates "receiver ready = 0", the pilot sequence obtained using "Seed F" in the X-polarization direction indicates "receiver ready = 1", the pilot sequence obtained using "Seed G" in the Y-polarization direction indicates "receiver ready = 0", and the pilot sequence obtained using "Seed H" in the Y-polarization direction indicates "receiver ready = 1".

[0191] Table 1

[0192]

[0193]

[0194] In one example, the correspondence between the seed used in the pilot sequence and the information indicated by the pilot sequence can be shown in Table 2 below. For example, Table 2 corresponds to the above... Figure 6 or Figure 8 The scenario is shown. The pilot sequence in the X-polarization direction obtained using "Seed A" is used to indicate "continue training = 0", and the pilot sequence in the Y-polarization direction obtained using "Seed B" is used to indicate "continue training = 0". The pilot sequence in the X-polarization direction obtained using "Seed C" is used to indicate "receiver ready = 0", the pilot sequence in the X-polarization direction obtained using "Seed D" is used to indicate "receiver ready = 1", the pilot sequence in the Y-polarization direction obtained using "Seed E" is used to indicate "receiver ready = 0", and the pilot sequence in the Y-polarization direction obtained using "Seed F" is used to indicate "receiver ready = 1". It should be understood that... Figure 6 or Figure 8 In the scenario shown, since "continuetraining=0" will only be sent if "receiver ready=1" is sent, sending "receiver ready=0" means "continue training=1", and there is no need to set the corresponding seed for "continue training=1".

[0195] Table 2

[0196]

[0197] In one example, the correspondence between the seed used in the pilot sequence and the information indicated by the pilot sequence can be shown in Table 3 below. For example, Table 3 corresponds to the above... Figure 7 or Figure 9 The scenario shown is as follows. The pilot sequence in the X-polarization direction obtained using "Seed A" is used to indicate "continue training = 0", the pilot sequence in the X-polarization direction obtained using "Seed B" is used to indicate "continue training = 1", the pilot sequence in the Y-polarization direction obtained using "Seed C" is used to indicate "continue training = 0", and the pilot sequence in the Y-polarization direction obtained using "Seed D" is used to indicate "continue training = 1".

[0198] Table 3

[0199]

[0200] In one example, the correspondence between the seed used in the pilot sequence and the information indicated by the pilot sequence can be shown in Table 4 below. For example, Table 4 corresponds to the above... Figure 7 or Figure 9 The scenario shown is as follows: The pilot sequence in the X-polarization direction obtained using "Seed A" is used to indicate "receiver ready = 0", the pilot sequence in the X-polarization direction obtained using "Seed B" is used to indicate "receiver ready = 1", the pilot sequence in the Y-polarization direction obtained using "Seed C" is used to indicate "receiver ready = 0", and the pilot sequence in the Y-polarization direction obtained using "Seed D" is used to indicate "receiver ready = 1".

[0201] Table 4

[0202]

[0203] For example, consider the relationship between "continue training" and "receiver ready". "continue training = 0" is equivalent to "receiver ready = 1", and "continue training = 1" is equivalent to "receiver ready = 0".

[0204] In one example, "continue training" or "receiver ready" can also be used to indicate adjacent_ISL_ready. For example, if "continue training=0" ("receiver ready=1"), then adjacent_ISL_ready=1, and the remote optical module can be recorded as adjacent_remote_rts=1; conversely, if "continue training=1" ("receiver ready=0"), then adjacent_ISL_ready=0, and the remote optical module can be recorded as adjacent_remote_rts=0.

[0205] Figure 14 This is a schematic diagram of another structure of the DSP frame in an embodiment of this application. For example... Figure 14 As shown above, in the above Figure 11 Based on the DSP frame structure shown, 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. Every R consecutive 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, compared to... Figure 11 and Figure 14 R=M, V=N. For example, if the original pilot symbols and payload symbols in the DSP frame are preserved, compared... Figure 11 and Figure 14 R = M + W.

[0206] In one possible scenario, the local optical module can use the padding symbols in the DSP frame to transmit information to the peer optical module. For example, the padding symbols in the DSP frame can indicate whether the peer optical module should continue in training mode or switch from training mode to data mode.

[0207] In one example, different information described in any of the tables in Tables 1 to 4 above can be conveyed by using different values ​​of one or more padding symbols in the DSP frame.

[0208] In one example, in addition to using one part of the padding symbols of the DSP frame to convey the information described in any of the tables 1 to 4 above, another part of the padding symbols of the DSP frame can be used to convey other information, such as adjacent_ISL_ready.

[0209] In one example, for Figure 14 The DSP frame shown can utilize the pilot sequence within the DSP frame to transmit the information described in any of the tables 1 to 4 above. Furthermore, one or more padding symbols within the DSP frame can be used to transmit other information; for example, information such as adjacent_ISL_ready can also be transmitted.

[0210] It should be noted that, for Figure 11 As shown in Figure 14, multiple identical information can be repeatedly transmitted through multiple DSP frames. The receiving optical module parses multiple pieces of information from the received multiple DSP frames and makes a judgment based on these multiple pieces of information to determine whether the correct information has been received. In other words, multiple identical pieces of information can verify each other, thereby improving the reliability of transmitted information.

[0211] Figure 15 This is a schematic diagram of one structure of the optical module in an embodiment of this application. Figure 15 As shown, the optical module includes a processing unit 201 and a transceiver unit 202. The optical module can be either optical module 1 or optical module 2 in the above embodiments. In one possible implementation, the optical module is used to perform the operations of optical module 1 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... Figure 5 Steps 101, 102, 105, and 106 shown are executed by the processing unit 201. Figure 5 Steps 103 and 107 are shown. In another possible implementation, the optical module is used to perform the operations of the optical module 2 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... Figure 5 Steps 101, 102, 105, and 106 shown are executed by the processing unit 201. Figure 5 Steps 104 and 108 are shown.

[0212] Figure 16 This is a schematic diagram of another structure of the optical module in an embodiment of this application. For example... Figure 16 As shown, the optical module 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 optical module and transmit them to the control circuit 301, or to send signals from the control circuit 301 to other devices outside the optical module. Optionally, the optical module may also include a memory 303, wherein the memory 303 is used to store program instructions and data.

[0213] In one possible implementation, the optical module is used to perform the operations of the optical module 1 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... Figure 5 Steps 101, 102, 105, and 106 shown are executed by control circuit 301. Figure 5 Steps 103 and 107 are shown. In another possible implementation, the optical module is used to perform the operations of the optical module 2 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... Figure 5 Steps 101, 102, 105, and 106 shown are executed by control circuit 301. Figure 5 Steps 104 and 108 are shown.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof.

[0221] 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.

[0222] 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 integrating 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).

[0223] 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.< / x> < / x>

Claims

1. An information transmission method, characterized in that, include: The first optical module receives a first frame sent by the second optical module, the first frame being used to indicate that the first optical module switches from training mode to data mode; The first optical module switches from the training mode to the data mode based on the first frame and the first state information. The first state information is used to indicate that the first interface of the first optical module can send and receive data. The first interface is an interface on the transmission path that communicates with the second optical module. The transmission path is used to transmit coherent optical signals between the first optical module and the second optical module in the data mode.

2. The method according to claim 1, characterized in that, The method further includes: The first optical module determines second status information based on the first frame. The second status information is used to indicate that the second interface of the second optical module can send and receive data. The second interface is the interface on the transmission path that communicates with the first optical module.

3. The method according to claim 2, characterized in that, The first frame includes the second status information.

4. The method according to any one of claims 1 to 3, characterized in that, The first status information is also used to indicate that the third interface of the first optical module can send and receive data, the third interface being the interface on the transmission path that communicates with the first device. The first frame is also used to indicate that the interface on the transmission path that communicates with the second device can send and receive data, the transmission path being the path between the first device and the second device.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: The first optical module determines that it is locally locked based on the coherent optical signal from the second optical module. When the local lock is established, the first status information is used to indicate that the first interface can receive data.

6. The method according to claim 5, characterized in that, The signal is feasible state determined based on the local lock, which is used for transmission from the Physical Medium Dependent (PMD) sublayer to the Physical Medium Additional (PMA) sublayer.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: The first optical module determines that the digital signal processing DSP in the two polarization directions is locked based on the coherent optical signal from the second optical module. When the DSP in the two polarization directions is locked, the first status information is used to indicate that the first interface can receive data.

8. The method according to claim 7, characterized in that, The feasible state of the signal is determined based on the fact that the DPS is locked in the two polarization directions, and the feasible state of the signal is used for transmission from the PMD sublayer to the PMA sublayer.

9. The method according to any one of claims 1 to 8, characterized in that, The method further includes: The first optical module acquires a first coherent optical signal from the second optical module. The acquisition includes at least one operation among frequency offset convergence, equalization, and forward error correction (FEC) decoding. The first interface indicated by the first status information is capable of receiving data, which is determined based on the acquisition results.

10. The method according to claim 9, characterized in that, The feasible state of the signal is determined based on the acquisition results, and the feasible state of the signal is used for transmission from the PMD sublayer to the PMA sublayer.

11. The method according to any one of claims 1 to 10, characterized in that, When the first optical module has prepared the transmitter clock, the first status information is used to indicate that the first interface can send data.

12. The method according to any one of claims 1 to 11, characterized in that, Before the first optical module receives the first frame sent by the second optical module, the method further includes: The first optical module receives a second frame sent by the second optical module, the second frame being used to indicate that the second optical module is ready to receive data.

13. The method according to any one of claims 1 to 12, characterized in that, Before the first optical module receives the first frame sent by the second optical module, the method further includes: The first optical module receives a third frame sent by the second optical module. The third frame is used to instruct the first optical module to continue training mode.

14. The method according to any one of claims 1 to 13, characterized in that, The method further includes: The first optical module sends a fourth frame to the second optical module, the fourth frame being used to instruct the second optical module to switch from training mode to data mode.

15. The method according to claim 14, characterized in that, The fourth frame includes the first status information.

16. The method according to any one of claims 1 to 15, characterized in that, When the link training is complete, the first frame is used to indicate that the first optical module is switched from training mode to data mode.

17. The method according to any one of claims 1 to 16, characterized in that, The first frame is a DSP frame. In one polarization direction, every M consecutive symbols in the DSP frame include 1 pilot symbol and M-1 payload symbols. The DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode.

18. The method according to claim 17, characterized in that, The Q pilot symbols in the DSP frame are generated according to the generator polynomial and the seed.

19. The method according to claim 17 or 18, characterized in that, M = 32, 64, 96 or 128.

20. An information transmission method, characterized in that, include: The second optical module generates the first frame, which is used to indicate that the first optical module switches from training mode to data mode. The second optical module sends the first frame to the first optical module. The first frame is used to trigger the first optical module to switch from the training mode to the data mode. The first optical module and the second optical module are used to transmit coherent optical signals through the transmission path in the data mode.

21. The method according to claim 20, characterized in that, The second optical module generates the first frame including: The second optical module generates the first frame based on the status information, which indicates that the interface of the second optical module on the transmission path for communicating with the first optical module can send and receive data.

22. The method according to claim 21, characterized in that, The first frame includes the status information.

23. The method according to any one of claims 20 to 22, characterized in that, The first frame is also used to indicate that the interface of the second optical module on the transmission path for communicating with the second device can send and receive data.

24. The method according to any one of claims 20 to 23, characterized in that, Before the second optical module sends the first frame to the first optical module, the method further includes: The second optical module sends a second frame to the first optical module, the second frame being used to indicate that the second optical module is ready to receive data.

25. The method according to any one of claims 20 to 24, characterized in that, Before the second optical module sends the first frame to the first optical module, the method further includes: The second optical module sends a third frame to the first optical module, which is used to instruct the first optical module to continue training mode.

26. The method according to any one of claims 20 to 25, characterized in that, The method further includes: The second optical module receives a fourth frame sent by the first optical module, the fourth frame being used to indicate that the second optical module switches from training mode to data mode.

27. The method according to any one of claims 20 to 26, characterized in that, The first frame is a DSP frame. In one polarization direction, every M consecutive symbols in the DSP frame include 1 pilot symbol and M-1 payload symbols. The DSP frame includes Q pilot symbols, where M and Q are both integers greater than 1. The Q pilot symbols in the first frame are used to indicate that the first optical module is switching from training mode to data mode.

28. The method according to any one of claims 20 to 27, characterized in that, The Q pilot symbols in the DSP frame are generated according to the generator polynomial and the seed.

29. The method according to any one of claims 20 to 28, characterized in that, M = 32, 64, 96 or 128.

30. A chip, characterized in that, The chip includes a processor for performing the method as described in any one of claims 1 to 29.

31. An optical module, characterized in that, The optical module is used to perform the method as described in any one of claims 1 to 19.

32. An optical module, characterized in that, The optical module is used to perform the method as described in any one of claims 20 to 29.

33. A communication system, characterized in that, The communication system includes a first optical module and a second optical module, wherein the first optical module is used to perform the method as described in any one of claims 1 to 19, and the second optical module is used to perform the method as described in any one of claims 20 to 29.

34. 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 29 to be implemented.

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