Data processing method and data processing apparatus

Abstract

Embodiments of the present application disclose a data processing method and a data processing apparatus. The data processing method is applied to a receiving end in the field of optical transmission, and is mainly used for implementing frame synchronization. In the present application, a differential processing operation is introduced into a frame synchronization process performed at the receiving end. Specifically, the receiving end performs differential processing on received data transmitted by means of a channel to obtain differential data, and performs differential processing on an acquired pilot sequence to obtain a differential pilot sequence. Further, the receiving end performs cross-correlation calculation on the differential data and the differential pilot sequence, and on the basis of the cross-correlation calculation result, determines a frame start position in the received data, so as to complete frame synchronization. This configuration reduces the impact of laser frequency offsets on frame synchronization at the receiving end, and improves the effectiveness of frame synchronization.

Description

Data processing method and data processing device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on August 31, 2023, with application number 202311130829.9 and invention name “A Data Processing Method and Data Processing Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of optical communications, and in particular to a data processing method and a data processing device. Background Art

[0003] Driven by 5G, cloud computing, big data, and artificial intelligence, high-speed optical transmission networks are developing towards high capacity, packetization, and intelligence. Coherent optical communication systems utilize the amplitude, phase, polarization, and frequency of light waves to carry information. To combat optical signal distortion caused by dispersion, polarization-related impairments, noise, nonlinear effects, and other factors during transmission and maintain long-distance transmission, coherent optical communication systems typically incorporate a number of designed fixed symbol sequences into the transmitted symbol sequence to facilitate recovery of the transmitted symbols at the receiving end.

[0004] The frame formats used in 400ZR and 800ZR scenarios include continuous training sequences, whose correlation is highly tolerant to laser frequency deviation. However, the 800LR scenario uses a minimalist frame structure, including a pilot sequence consisting of periodically inserted pilot symbols. This pilot sequence lasts for a long symbol period, and its correlation is very sensitive to laser frequency deviation. The phase noise introduced by laser frequency deviation can significantly reduce the correlation of the pilot sequence, thereby affecting the effectiveness of frame synchronization at the receiver.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a data processing method and a data processing device, which reduce the impact of laser frequency deviation on frame synchronization of a receiving end and improve the effect of frame synchronization.

[0007] In a first aspect, embodiments of the present application provide a data processing method, which is applied to a receiving end. Multiple consecutive data frames sent by a transmitting end are transmitted to a receiving end via a channel. It should be understood that the received data transmitted via the channel can be considered a symbol set comprising multiple symbols. Furthermore, the symbol set includes R symbol subsets, each of which includes W symbols. R is an integer greater than 1, and W is an integer greater than or equal to 1. Specifically, the receiving end performs differential processing on each symbol subset to obtain a corresponding differential symbol subset, thereby obtaining a total of R differential symbol subsets. The receiving end obtains a pilot sequence and performs differential processing on the pilot sequence to obtain a differential pilot sequence, wherein the pilot sequence includes Z pilot symbols, 2≤Z≤Q, the Z pilot symbols in the pilot sequence correspond one-to-one to the Z pilot symbols in the data frame, and any pilot symbol in the pilot sequence is c times the corresponding pilot symbol in the data frame, where c is not equal to 0. Furthermore, the receiving end determines the frame start position in the symbol set according to the R differential symbol subsets and the differential pilot sequence.

[0008] It should be noted that each data frame sent by the transmitter meets the following characteristics: In one polarization direction, the data frame includes N symbols, and each consecutive M symbols of the N symbols include a pilot symbol at a fixed position and M-1 payload symbols, N = M × Q, where Q is an even number and M is an integer greater than or equal to 1. The Q pilot symbols are generated by a target polynomial and a seed. Each pilot symbol is one of -A-Aj, -A+Aj, A-Aj, and A+Aj, and A is a real number.

[0009] In this embodiment, the frequency difference between the transmitting laser and the receiving laser, namely the laser frequency deviation, is considered, which can affect the receiving end's frame synchronization performance. This application introduces differential processing during the receiving end's frame synchronization process, reducing the impact of the laser frequency deviation on the receiving end's frame synchronization performance and improving the frame synchronization performance. Furthermore, the pilot symbols generated by the transmitting end using this method have good autocorrelation and cross-correlation characteristics and meet DC balance, which facilitates signal quality recovery at the receiving end.

[0010] In some possible implementations, the Z pilot symbols in the pilot sequence correspond one-to-one to the Z consecutive pilot symbols in the data frame, so that the complexity of differential processing is lower.

[0011] In some possible implementations, performing differential processing on a symbol subset to obtain a differential symbol subset includes: the receiving end obtaining K symbols adjacent to the starting position or the ending position of the symbol subset, where K = a × M, and 1 ≤ a ≤ Z. The receiving end performs differential processing on a symbol sequence including the symbol subset and the K symbols to obtain the differential symbol subset. In this implementation, the transmitting end inserts pilot symbols into the data frame every M symbols. Therefore, the receiving end performs differential processing on each symbol subset every K = a × M symbols, ensuring the effectiveness of differential processing.

[0012] In some possible implementations, performing differential processing on a symbol sequence including a symbol subset and K symbols to obtain a differential symbol subset includes: a receiving end first performing a conjugate calculation on the vth symbol in the symbol sequence, and then multiplying the result of the conjugate calculation by the v+Kth symbol in the symbol sequence to obtain the vth symbol in the sth differential symbol subset. Where 0 ≤ v ≤ W-1. This implementation provides a specific implementation method for differential processing received data, which has good feasibility.

[0013] In some possible implementations, performing differential processing on a symbol sequence including a symbol subset and K symbols to obtain a differential symbol subset includes: a receiving end first performing a conjugate calculation on the v+Kth symbol in the symbol sequence, and then multiplying the result of the conjugate calculation by the vth symbol in the symbol sequence to obtain the vth symbol in the sth differential symbol subset. Where 0 ≤ v ≤ W-1. This implementation provides another specific implementation of differential processing for received data, enhancing the flexibility of the present solution.

[0014] In some possible implementations, performing differential processing on the pilot sequence to obtain a differential pilot sequence includes: the receiving end cyclically shifting the pilot sequence right by a symbols, where 1≤a≤Z. The receiving end performs a conjugate calculation on the pilot sequence after the cyclic shift right by a symbols to obtain a conjugate sequence, and multiplies the Z symbols in the conjugate sequence with the Z pilot symbols in the pilot sequence one by one to obtain the differential pilot sequence. This embodiment provides a specific implementation method for performing differential processing on the pilot sequence, performing differential processing on pilot symbols every a=K / M symbols, ensuring the effectiveness of differential processing.

[0015] In some possible implementations, performing differential processing on the pilot sequence to obtain the differential pilot sequence includes: the receiving end cyclically shifting the pilot sequence left by a symbols, where 1≤a≤Z. The receiving end performs conjugation calculation on the pilot sequence after the cyclic shift left by a symbols to obtain a conjugate sequence, and multiplies the Z symbols in the conjugate sequence with the Z pilot symbols in the pilot sequence one by one to obtain the differential pilot sequence. This embodiment provides another specific implementation of differential processing on the pilot sequence, enhancing the flexibility of the present solution.

[0016] In some possible implementations, It should be understood that effects such as polarization rotation and phase noise in the transmission channel will deteriorate the correlation of the sequence, and as a increases, the impact of these effects becomes greater. Therefore, the smaller the value of a, the better.

[0017] In some possible implementations, the pilot sequence includes Q pilot symbols, and the Q pilot symbols in the pilot sequence are the same as the Q pilot symbols in the data frame.

[0018] In some possible implementations, determining a frame start position in the symbol set based on the R differential symbol subsets and the differential pilot sequence includes: performing a cross-correlation calculation on the R differential symbol subsets and the differential pilot sequence, and determining the frame start position in the symbol set based on a result of the cross-correlation calculation.

[0019] In a second aspect, an embodiment of the present application provides a chip comprising a processor and a memory, the memory and the processor being interconnected via lines, instructions being stored in the memory, and the processor being used to execute the method described in any embodiment of the first aspect.

[0020] In a third aspect, an embodiment of the present application provides a data processing device. The data processing device includes: a receiving unit, a first differential processing unit, a second differential processing unit, and an identification unit. The receiving unit is configured to receive a symbol set after multiple data frames sent by a transmitting end are transmitted through a channel. The symbol set includes R symbol subsets, each symbol subset includes W symbols, R is an integer greater than 1, and W is an integer greater than or equal to 1. The first differential processing unit is configured to perform differential processing on each symbol subset to obtain a corresponding differential symbol subset, so as to obtain a total of R differential symbol subsets. The second differential processing unit is configured to obtain a pilot sequence and perform differential processing on the pilot sequence to obtain a differential pilot sequence, wherein the pilot sequence includes Z pilot symbols, 1≤Z≤Q, the Z pilot symbols in the pilot sequence correspond one-to-one to the Z pilot symbols in the data frame, and any pilot symbol in the pilot sequence is c times the corresponding pilot symbol in the data frame, where c is not equal to 0. The identification unit is configured to determine a frame start position in the symbol set according to the R differential symbol subsets and the differential pilot sequence.

[0021] It should be noted that each data frame sent by the transmitter meets the following characteristics: In one polarization direction, the data frame includes N symbols, and each consecutive M symbols of the N symbols include a pilot symbol at a fixed position and M-1 payload symbols, N = M × Q, where Q is an even number and M is an integer greater than or equal to 1. The Q pilot symbols are generated by a target polynomial and a seed. Each pilot symbol is one of -A-Aj, -A+Aj, A-Aj, and A+Aj, and A is a real number.

[0022] In some possible implementations, the Z pilot symbols in the pilot sequence correspond one-to-one to Z consecutive pilot symbols in the data frame.

[0023] In some possible implementations, the first differential processing unit is specifically configured to: obtain K symbols adjacent to a starting position or an ending position of the symbol subset, where K = a×M, 1≤a≤Z, and perform differential processing on a symbol sequence including the symbol subset and the K symbols to obtain a differential symbol subset.

[0024] In some possible implementations, the first differential processing unit is specifically configured to: perform a conjugate calculation on the vth symbol in the symbol sequence, and multiply the result of the conjugate calculation by the v+Kth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, where 0≤v≤W-1.

[0025] In some possible implementations, the first differential processing unit is specifically configured to: perform a conjugate calculation on the v+Kth symbol in the symbol sequence, and multiply the result of the conjugate calculation by the vth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, where 0≤v≤W-1.

[0026] In some possible implementations, the second differential processing unit is specifically configured to: cyclically shift the pilot sequence right by a symbols, where 1≤a≤Z; perform conjugation calculation on the pilot sequence after the cyclic shift right by a symbols to obtain a conjugated sequence; and multiply the Z symbols in the conjugated sequence by the Z pilot symbols in the pilot sequence one by one to obtain a differential pilot sequence.

[0027] In some possible implementations, the second differential processing unit is specifically configured to: cyclically shift the pilot sequence left by a symbols, where 1≤a≤Z; perform conjugation calculation on the pilot sequence after the cyclic shift left by a symbols to obtain a conjugated sequence; and multiply the Z symbols in the conjugated sequence by the Z pilot symbols in the pilot sequence one by one to obtain a differential pilot sequence.

[0028] In some possible implementations, Indicates rounding down the positive real number b.

[0029] In some possible implementations, the pilot sequence includes Q pilot symbols, and the Q pilot symbols in the pilot sequence are the same as the Q pilot symbols in the data frame.

[0030] In some possible implementations, the identification unit is specifically configured to: perform cross-correlation calculation on the R differential symbol subsets and the differential pilot sequence; and determine a frame start position in the symbol set according to a result of the cross-correlation calculation.

[0031] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0032] Considering the frequency difference between the laser at the transmitting end and the laser at the receiving end, that is, the laser frequency deviation, it will affect the effect of the frame synchronization of the receiving end. Therefore, the present application introduces the operation of differential processing in the process of frame synchronization of the receiving end. Specifically, the receiving end performs differential processing on the received data transmitted through the channel to obtain differential data, and performs differential processing on the locally stored pilot sequence to obtain a differential pilot sequence. Furthermore, the receiving end performs cross-correlation calculation on the differential data and the differential pilot sequence, and determines the frame starting position in the received data based on the result of the cross-correlation calculation, thereby completing frame synchronization. In this way, the influence of the laser frequency deviation on the frame synchronization of the receiving end is reduced, and the effect of frame synchronization is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of a communication system used in an embodiment of the present application;

[0034] FIG2 is a schematic diagram of an implementation of a DSP processor at a transmitting end according to an embodiment of the present application;

[0035] FIG3 is a schematic diagram of the structure of a data frame according to an embodiment of the present application;

[0036] FIG4 is a schematic diagram of a first pilot symbol generation structure according to an embodiment of the present application;

[0037] FIG5 is a schematic diagram of a second pilot symbol generation structure according to an embodiment of the present application;

[0038] FIG6 is a flow chart of a data processing method according to an embodiment of the present application;

[0039] FIG7 is a schematic diagram of a symbol sequence for differential processing in an embodiment of the present application;

[0040] FIG8 is a schematic diagram of differential processing performed every K symbols in an embodiment of the present application;

[0041] FIG9 is a schematic diagram of a pilot sequence cyclically shifted by a symbols in an embodiment of the present application;

[0042] FIG10 is a schematic diagram of a first cross-correlation result between received data and a pilot sequence;

[0043] FIG11 is a schematic diagram of a second cross-correlation result between received data and pilot sequences;

[0044] FIG12 is a schematic diagram of the structure of another data frame according to an embodiment of the present application;

[0045] FIG13 is a schematic diagram of a third pilot symbol generation structure according to an embodiment of the present application;

[0046] FIG14 is a schematic diagram of correlation characteristics and cross-correlation characteristics corresponding to pilot symbols in an embodiment of the present application;

[0047] FIG15 is a schematic diagram showing autocorrelation characteristics and cross-correlation characteristics in an embodiment of the present application;

[0048] FIG16 is a schematic diagram of a fourth pilot symbol generation structure according to an embodiment of the present application;

[0049] FIG17 is another schematic diagram of correlation characteristics and cross-correlation characteristics corresponding to pilot symbols in an embodiment of the present application;

[0050] FIG18 is another schematic diagram showing the autocorrelation characteristics and cross-correlation characteristics in an embodiment of the present application;

[0051] FIG19 is a schematic structural diagram of a data processing device applied to a receiving end in an embodiment of the present application;

[0052] FIG20 is another structural diagram of the data processing device in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The embodiments of the present application provide a data processing method and a data processing device, which reduce the impact of laser frequency deviation on frame synchronization of a receiving end and improve the effect of frame synchronization.

[0054] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, rather than to limit a specific order or precedence. It should be understood that the above terms are interchangeable where appropriate so that the embodiments described in this application can be implemented in a sequence other than that described in this application. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0055] Figure 1 is a schematic diagram of a communication system used in an embodiment of the present application. As shown in Figure 1, at the transmitting end, the information source provides a data stream to be sent. The encoder receives the data stream and encodes it. The codeword information obtained by encoding the parity bits and information bits is sent to the transmitting end digital signal processing (DSP) processor for framing. After being transmitted through the channel, it reaches the receiving end. After the receiving end receives the distorted signal caused by noise or other damage in the channel, it is sent to the receiving end DSP processor for dispersion compensation, synchronization, phase recovery and other operations. The decoder then decodes the signal to restore the original data and sends it to the destination.

[0056] FIG2 is a schematic diagram of an implementation method of the transmitting DSP processor in an embodiment of the present application. As shown in FIG2 , in a possible implementation, the transmitting DSP processor performs symbol mapping on the received data sequence. Typically, the received data sequence is information and a check sequence obtained by a forward error correction code (FEC). The symbol mapping method includes but is not limited to quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM). The transmitting DSP processor also performs polarization symbol division on the data sequence to obtain dual-polarization (DP) symbols, such as DP-QPSK, DP-8QAM, DP-16QAM, DP-32QAM, and DP-64QAM. For ease of introduction, the two polarization directions are uniformly referred to as the X polarization direction and the Y polarization direction, respectively, where the X polarization direction and the Y polarization direction are mutually orthogonal. It should be understood that the X polarization direction and the Y polarization direction are not two specified polarization directions, but two arbitrary mutually orthogonal polarization directions.

[0057] Furthermore, the transmitting DSP processor performs the following framing process on a certain number of dual-polarization symbols. Specifically, pilot symbols are inserted in the X and Y polarization directions to obtain a sequence of dual-polarization symbols to be transmitted, called a frame. In this embodiment, this is called a data frame, which can also be called a DSP frame.

[0058] It should be noted that after symbol mapping, the symbols can also be interleaved, and the interleaved symbols can be subjected to the above-mentioned framing process. It should be understood that a dual-polarization symbol can be represented by two symbols, one of which is located in the X polarization direction and the other is located in the Y polarization direction. Each symbol can be represented by a complex number. For example, the symbol obtained by 16QAM modulation can be represented by any one of the following 16 complex numbers, ±1±1j, ±1±3j, ±3±1j and ±3±3j, where ± represents a positive or negative value, such as ±3 represents 3 or -3. Among them, j represents an imaginary unit. In some scenarios, the imaginary unit may also be represented by other symbols such as i, which is not limited here. In some cases, the real part and the imaginary part are normalized, but the essence does not change. Furthermore, a sequence with L dual-polarization symbols can be completely represented by two complex sequences of length L, where one complex sequence represents the symbol in the X polarization direction and the other complex sequence represents the symbol in the Y polarization direction. Each complex sequence of length L is represented by a real sequence of length L (also called an I-path sequence) and an imaginary sequence of length L (also called a Q-path sequence), where L is an integer greater than 1. Therefore, there are four different types of sequences: X-polarization I-path sequence, X-polarization Q-path sequence, Y-polarization I-path sequence, and Y-polarization Q-path sequence.

[0059] The following first details the structure of the data frame generated by the transmitter. It should be understood that a data frame includes symbols in two polarization directions, and the data frame structure is similar in both polarization directions. For example, a data frame includes N symbols in the X polarization direction and N symbols in the Y polarization direction. The following describes the data frame structure using one polarization direction as an example.

[0060] Figure 3 is a schematic diagram of the structure of a data frame in an embodiment of the present application. As shown in Figure 3, a data frame includes N symbols in one polarization direction, and each consecutive M symbols of the N symbols include a pilot symbol located at a fixed position and M-1 payload symbols, where N = M × Q, Q is an even number, and M is an integer greater than or equal to 1. That is, each consecutive M symbols of the N symbols can be regarded as a group, and the N symbols include a total of Q groups of symbols. For example, N = 6144, M = 64, Q = 96, symbol 1-symbol 64 is the first group of 64 consecutive symbols, symbol 65-symbol 128 is the second group of 64 consecutive symbols, ..., symbol 6081-symbol 6144 is the 96th group of 64 consecutive symbols. It should be understood that the payload symbol can also be called a pre-framing symbol, which includes an information symbol and a check symbol that have been FEC-encoded. At the receiving end, the pilot symbol can be used to assist in carrier phase recovery and can also be used to distinguish between two polarization directions.

[0061] It should be understood that the present application does not limit the specific position of the pilot symbol in each group of M symbols. As an example, each pilot symbol is located at the starting position of the consecutive M symbols. For example, the first symbol in the data frame shown in Figure 3 is the first pilot symbol.

[0062] It should be noted that the Q pilot symbols in the data frame are generated by a target 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 degree of the target polynomial is less than or equal to 10, and the number of terms of the target polynomial is greater than or equal to 2 and less than or equal to 8, so that the hardware implementation complexity is relatively low. In addition, the Q pilot symbols satisfy the Direct Current Balanced condition, that is, the sum of the Q pilot symbols is 0, that is, the sum of the real parts of the complex numbers corresponding to the Q pilot symbols is 0, and the sum of the imaginary parts is also 0, which can achieve direct current balance and facilitate the recovery of signal quality at the receiving end.

[0063] In addition, the two polarization directions are orthogonal to each other, that is, when one of the polarization directions is X polarization, the other polarization direction is Y polarization; when one of the polarization directions is Y polarization, the other polarization direction is X polarization.

[0064] In a data frame, the sequence of Q pilot symbols in the X polarization direction is different from the sequence of Q pilot symbols in the Y polarization direction. For example, if the sequence of pilot symbols in the X polarization direction is -A-Aj, -A-Aj, A+Aj, and A-Aj, then the sequence of pilot symbols in the Y polarization direction can be different and can be -A-Aj, -A-Aj, A+Aj, and A+Aj. This difference prevents the receiver from being unable to distinguish between the two polarization directions during actual transmission.

[0065] In the embodiment of the present application, when the target polynomial adopts a 10th-order polynomial, the 10th-order polynomial can be expressed as:

[0066] 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; wherein, a9…a1 can take the value of 0 or 1. Figure 4 is a schematic diagram of the first pilot symbol generation structure in an embodiment of the present application. As shown in Figure 4, each box can be regarded as 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, the seed length is 10 bits, which can be expressed in binary form as m9, m8, m7, m6, m5, m4, m3, m2, m1, m0, and the corresponding 10 storage units are used. Of course, the seed can also be expressed in hexadecimal or decimal, and it needs to be converted to binary form when operating with the target polynomial, such as: 0110111000 is expressed as 0x1B8 in hexadecimal and 440 in decimal.

[0067] Figure 5 is a schematic diagram of the second pilot symbol generation structure in an embodiment of the present application. As shown in Figure 5, the seed length is 9 bits and can be represented in binary form as m8, m7, m6, m5, m4, m3, m2, m1, and m0. Of course, the seed can also be represented in hexadecimal or decimal, and needs to be converted to binary form when operating with the target polynomial.

[0068] In the embodiment of the present application, the target polynomial and seed can be determined by designing the values ​​of the coefficients a9…a1 in the 10th-order polynomial or the values ​​of the coefficients a8…a1 in the 9th-order polynomial, so that the generated pilot symbol sequence has good autocorrelation characteristics in the X polarization direction or the Y polarization direction, and good cross-correlation characteristics in the two polarization directions. In addition, by selecting an appropriate target polynomial and seed, the Q pilot symbols are DC balanced, which is beneficial for the quality of the signal recovered by the receiving end.

[0069] It should be noted that the data frame considered in the embodiment of the present invention only contains pilot symbols and payload symbols (also called pre-framing symbols). This DSP frame structure is different from other existing DSP superframe structures, in which DSP superframes usually contain multiple types of symbols, such as frame synchronization symbols used for frame synchronization and distinguishing between two polarization directions, training symbols used for link training, and pilot symbols used for carrier phase recovery. Therefore, in the receiving end processing corresponding to the DSP frame considered by the present invention, the pilot symbols are not only used to assist in carrier phase recovery, but also need to be used to distinguish between the two polarization directions and for frame synchronization. The receiving end obtains 4 data streams, namely the real part sequence data stream in the X polarization direction, the imaginary part sequence data stream in the X polarization direction, the real part sequence data stream in the Y polarization direction, and the imaginary part sequence data stream in the Y polarization direction; the pilot symbols are needed to distinguish the real or imaginary part sequence in the X polarization direction or the Y polarization direction corresponding to each data stream. In the embodiments of the present invention, the target polynomial and seed are determined by designing the values ​​of the coefficients a9…a1 in a 10th-order polynomial or the values ​​of the coefficients a8…a1 in a 9th-order polynomial, so that the real sequence (also known as the I path) and the imaginary sequence (also known as the Q path) of the generated pilot symbol sequences in the two polarization directions have good autocorrelation and cross-correlation characteristics. More specifically, the designed real sequence of the pilot symbol sequence in the X polarization direction, the imaginary sequence of the pilot symbol sequence in the X polarization direction, the real sequence of the pilot symbol sequence in the Y polarization direction, and the imaginary sequence of the pilot symbol sequence in the Y polarization direction, a total of four sequences with a length of Q bits, have good autocorrelation characteristics and good cross-correlation characteristics.

[0070] It should be noted that the data frames sent by the transmitter will be transmitted through the channel to reach the receiver. Considering the frequency difference between the laser at the transmitter and the laser at the receiver, that is, the laser frequency deviation, it will affect the effect of the frame synchronization performed by the receiver. Therefore, the present application introduces a differential processing operation in the process of frame synchronization performed by the receiver, so that the correlation between the received data and the known pilot sequence is no longer sensitive to the laser frequency deviation, thereby ensuring the effect of frame synchronization. It should be understood that what the receiver receives is data after channel transmission, which can be understood as a distorted signal affected by noise or other damage in the channel. The data received by the receiver includes multiple data frames generated by the transmitter, but the data received by the receiver is not aligned with the data sent by the transmitter. Therefore, the receiver needs to perform digital signal processing on the received data to achieve frame synchronization, so as to determine the frame starting position in the received data. In some possible implementations, each data frame sent by the transmitter includes a pilot symbol, and the receiver can use the pilot symbol to perform digital signal processing to determine the frame starting position.

[0071] The following describes the frame synchronization process of the receiving end in this application.

[0072] FIG6 is a flow chart of a data processing method according to an embodiment of the present application. It should be understood that the data processing method is applied to the receiving end, and can be implemented, for example, by the receiving end DSP processor shown in FIG1.

[0073] It should be noted that the transmitting end frames a certain number of dual-polarization symbols. Specifically, pilot symbols are inserted in the X polarization direction and the Y polarization direction, respectively, to obtain a dual-polarization symbol sequence to be transmitted, which is called a frame. This is referred to as a data frame in this application, and may also be referred to as a DSP frame. It should be understood that the X polarization direction and the Y polarization direction are not two specified polarization directions, but rather two arbitrary mutually orthogonal polarization directions. In other words, the transmitting end sends a symbol sequence in two polarization directions, so the data received by the receiving end includes symbols in both polarization directions. The data processing method performed by the receiving end on the symbols in the two polarization directions is similar. For ease of explanation, the data processing method of the receiving end is described below using one polarization direction as an example.

[0074] Specifically, as shown in step 101, the receiving end performs differential processing on the received data transmitted through the channel to obtain differential data. As shown in step 102, the receiving end performs differential processing on the obtained pilot sequence to obtain a differential pilot sequence. As shown in step 103, the receiving end performs a cross-correlation calculation on the differential data and the differential pilot sequence. As shown in step 104, the receiving end determines the frame start position in the received data based on the result of the cross-correlation calculation, thereby achieving frame synchronization.

[0075] It should be noted that the pilot sequence obtained by the receiving end includes Z pilot symbols, where 2≤Z≤Q. As an example, the receiving end pre-stores the pilot sequence and can read the pilot sequence when differential processing is required. As another example, the receiving end can also generate a pilot sequence including Z pilot symbols based on the target polynomial and the seed. The specific method of generating the pilot symbols is similar to that of the transmitting end and will not be repeated here. It should be understood that the Q pilot symbols in each data frame sent by the transmitting end are the same. The receiving end only needs to obtain one pilot sequence and does not need to obtain a corresponding number of pilot sequences for multiple received data frames.

[0076] It should be understood that the data frame generated by the transmitter includes Q pilot symbols, and the Z pilot symbols in the pilot sequence obtained by the receiver correspond one-to-one with the Z pilot symbols in the data frame. Furthermore, any pilot symbol in the pilot sequence is c times the corresponding pilot symbol in the data frame, where c is not equal to 0. For example, if one of the pilot symbols in the data frame is A+Aj, the corresponding pilot symbol in the pilot sequence can be A+Aj or 2A+2Aj, etc. In the first possible scenario, the Z pilot symbols in the pilot sequence correspond one-to-one with the Z consecutive pilot symbols in the data frame. Taking Q=96 and Z=48 as an example, the pilot sequence can be any 48 consecutive pilot symbols in the data frame. In the second possible scenario, the pilot sequence includes Q pilot symbols, and the Q pilot symbols in the pilot sequence are the same as the Q pilot symbols in the data frame. In the third possible scenario, the pilot sequence can also be Z non-consecutive pilot symbols in the data frame.

[0077] The following first describes in detail the operation of differential processing during the frame synchronization process by taking the first possible scenario and the second possible scenario as examples.

[0078] For step 101, taking one of the polarization directions as an example, the received data transmitted through the channel can be regarded as a symbol set including multiple symbols, wherein the symbol set includes a symbol sequence of multiple data frames generated by the transmitter in one polarization direction. Further, the symbol set includes R symbol subsets, and each symbol subset includes W symbols. Wherein, R is an integer greater than 1, and W is an integer greater than or equal to 1. It should be understood that the division method of the symbol subset is independent of the size of the data frame, that is, the number of symbols in the symbol subset and the number of symbols in the data frame can be the same or different, and the specific limitation is not made here. It should also be understood that the symbol subset here is a concept introduced only for the convenience of introduction. In practice, the data received by the receiving end is a whole and there may be no division.

[0079] FIG7 is a schematic diagram of a symbol sequence for differential processing in an embodiment of the present application. Specifically, the receiving end performs differential processing on each symbol subset every K symbols, that is, each symbol sequence for differential processing includes a symbol subset and K symbols adjacent to it. As shown in FIG7 , taking the sth symbol subset as an example, 0≤s≤R-1, first obtain the K symbols adjacent to the sth symbol subset, which can be the K symbols at the end of the s-1th symbol subset or the K symbols starting from the s+1th symbol subset. It should be understood that for the 0th symbol subset, only the K symbols starting from the 1st symbol subset can be obtained. Then, the sth symbol sequence including the sth symbol subset and the K symbols adjacent to it is differentially processed to obtain the sth differential symbol subset, thereby obtaining differential data including R differential symbol subsets. Wherein, K=a×M, 1≤a≤Z.

[0080] FIG8 is a schematic diagram of differential processing performed every K symbols in an embodiment of the present application. As shown in FIG8 , taking differential processing of the s-th symbol sequence as an example, specifically, differential processing is to conjugate multiply the v-th symbol in the s-th symbol sequence by the v+K-th symbol, where 0≤v≤W-1. In one possible implementation, a conjugate calculation is first performed on the v-th symbol in the s-th symbol sequence, and then the result of the conjugate calculation is multiplied by the v+K symbols in the s-th symbol sequence to obtain the v-th symbol in the s-th differential symbol subset. In this manner, differential processing is performed to obtain the s-th differential symbol subset. In another possible implementation, a conjugate calculation is first performed on the v+K-th symbol in the s-th symbol sequence, and then the result of the conjugate calculation is multiplied by the v symbols in the s-th symbol sequence to obtain the v-th symbol in the s-th differential symbol subset. In this manner, differential processing is performed to obtain the s-th differential symbol subset.

[0081] In step 102, the receiving end first cyclically shifts the locally stored pilot sequence, and then performs differential processing on the original pilot sequence and the cyclically shifted pilot sequence to obtain a differential pilot sequence. It should be understood that the length of the pilot sequence remains unchanged after the cyclic shift; only the position of each pilot symbol in the pilot sequence is shifted one by one in one direction. Cyclic shifting includes two methods: left cyclic shifting and right cyclic shifting. The following uses a cyclic shift of a symbols as an example. It should be noted that in this application, pilot symbols are inserted into the transmitted data frame every M symbols. Therefore, when differential processing is performed on the received data every K = a × M symbols, the corresponding pilot symbols are differentially processed every a = K / M symbols.

[0082] Figure 9 is a schematic diagram of a pilot sequence cyclically shifted by a symbols in an embodiment of the present application. Figure 9(a) shows the original pilot sequence before the cyclic shift. Figure 9(b) shows the pilot sequence after a cyclic shift to the right by a symbols. Figure 9(c) shows the pilot sequence after a cyclic shift to the left by a symbols. Where 1≤a≤Z.

[0083] In one possible implementation, the receiving end performs a conjugate calculation on the pilot sequence that has been cyclically shifted right by a symbols to obtain a conjugate sequence, and multiplies the Z symbols in the conjugate sequence with the Z pilot symbols in the original pilot sequence one by one to obtain a differential pilot sequence. In another possible implementation, the receiving end performs a conjugate calculation on the pilot sequence that has been cyclically shifted left by a symbols to obtain a conjugate sequence, and multiplies the Z symbols in the conjugate sequence with the Z pilot symbols in the original pilot sequence one by one to obtain a differential pilot sequence.

[0084] It should be noted that the value range of a is preferably It should be understood that effects such as polarization rotation and phase noise in the transmission channel will deteriorate the correlation of the sequence, and as a increases, the impact of these effects becomes greater. Therefore, the smaller the value of a, the better.

[0085] It should be noted that, in addition to performing differential processing on the pilot sequence by cyclic shift as described above, the pilot sequence may also be differentially processed by other methods, and cyclic shift is only a relatively simple implementation method.

[0086] In the third possible scenario described above, the pilot sequence may also be Z discontinuous pilot symbols in the data frame. The following example briefly introduces this scenario.

[0087] In one possible implementation, pilot symbols are extracted from the pilot symbol sequence of the data frame at intervals of G symbols as the receiving-end pilot sequence, where G is a positive even number divisible by Q, and 2 ≤ G. In this case, the value of K for the differential processing is K = G × a × M. Based on this, the differential processing operation is similar to the processing methods described in the first and second possible scenarios above, that is, the receiving end performs differential processing on each symbol subset every K symbols, and performs differential processing on the pilot sequence every a symbols.

[0088] In step 103, the receiving end performs cross-correlation calculations on the R differential symbol subsets obtained in step 101 and the differential pilot sequence obtained in step 102. As an example, the R differential symbol subsets can be cross-correlated with the differential pilot sequence separately, and then the results of the R cross-correlation calculations can be combined. As another example, the R differential symbol subsets can be cross-correlated with the differential pilot sequence as a whole. It should be understood that the cross-correlation calculation results obtained in the above two examples are the same.

[0089] Specifically, the implementation of cross-correlation can be expressed by the following formula:

[0090] or,

[0091] Where D represents R differential symbol subsets, T represents the differential pilot sequence, S represents the offset, -N≤S≤N-1 or 0≤S≤N-1, T * (n) represents the conjugate of the symbols in the differential pilot sequence. The definition of cross-correlation shows that when the offset S equals S0, the differential data and the differential pilot sequence are aligned, and the cross-correlation value is maximized. This position corresponds to the start of the frame. Alternatively, to simplify computational complexity, a partial sequence can be extracted from the differential pilot sequence. This partial differential pilot sequence is then cross-correlated with the differential data. The length of the partial differential pilot sequence is greater than 0 and less than or equal to Z.

[0092] Regarding step 104, when the positions of the received data and the pilot sequence are aligned, the cross-correlation value is maximum. However, when there is a certain offset between the two positions, the cross-correlation value is smaller. Therefore, the peak value of the cross-correlation sequence can be used to find the starting position of the frame, thereby achieving frame synchronization at the receiving end. It should be noted that the above describes the processing method for one polarization direction, and the processing method for the other polarization direction is similar. By comprehensively considering the cross-correlation results of the two polarization directions, a cross-correlation peak value can be obtained to determine the common starting position of the received data in the two polarization directions, thereby achieving frame synchronization.

[0093] Figure 10 is a schematic diagram of the first cross-correlation result between the received data and the pilot sequence. Figure 11 is a schematic diagram of the second cross-correlation result between the received data and the pilot sequence. As shown in Figures 10 and 11, the horizontal axis represents the offset (the unit is the number of symbols) and the vertical axis represents the normalized amplitude. It should be understood that Figure 10 shows the cross-correlation result when neither the received data nor the pilot sequence is subjected to differential processing, and Figure 11 shows the cross-correlation result after both the received data and the pilot sequence are subjected to differential processing. By comparison, it can be seen that the peak in Figure 10 is not obvious, making it difficult to identify the starting position of the frame. The peak in Figure 11 is obvious, the cross-correlation is better, and it is easier to identify the starting position of the frame. Therefore, introducing differential processing in the process of frame synchronization is more conducive to achieving frame synchronization and can improve the tolerance to laser frequency deviation.

[0094] In summary of the above introduction, the present application introduces a differential processing operation in the process of frame synchronization at the receiving end. Specifically, the receiving end performs differential processing on the received data transmitted through the channel to obtain differential data, and performs differential processing on the locally stored pilot sequence to obtain a differential pilot sequence. Furthermore, the receiving end performs a cross-correlation calculation on the differential data and the differential pilot sequence, and determines the frame start position in the received data based on the result of the cross-correlation calculation, thereby completing frame synchronization. In this way, the influence of the laser frequency deviation on the frame synchronization of the receiving end is reduced, and the effect of frame synchronization is improved. In addition, the pilot symbols generated by the transmitting end in the above manner have good autocorrelation and cross-correlation characteristics and meet DC balance, which is beneficial for the receiving end to recover the signal quality.

[0095] It should be noted that in order to achieve better differential correlation, the target polynomial and seed for generating the pilot sequence at the transmitting end need to be specifically designed.

[0096] Several specific embodiments are described below taking N=6144, M=64, and Q=96 as an example.

[0097] Example 1: The target polynomial is x^10+x^9+x^6+x+1, the seed in the X polarization direction is 0x0B4, and the seed in the Y polarization direction is 0x2D1.

[0098] Figure 12 is a schematic diagram of the structure of another data frame in an embodiment of the present application. Considering dual-polarization DP-16QAM modulation, 96×63=6048 dual-polarization payload symbols are obtained through BCH (126,110) encoding and DP-16QAM dual-polarization modulation. One pilot symbol is inserted before every 63 symbols in the 6048 payload symbols, and a total of 96 pilot symbols are inserted, resulting in a data frame (also called a DSP frame) structure as shown in Figure 14, that is, N=6144, M=64, Q=96. In the X polarization direction or the Y polarization direction, 96 pilot symbols are generated based on the target polynomial and the seed.

[0099] Figure 13 is a schematic diagram of the third pilot symbol generation structure in an embodiment of the present application. If the target polynomial is x^10+x^9+x^6+x+1, the seed for the X polarization direction is 0x0B4, and the seed for the Y polarization direction is 0x2D1, the generation process of 96 pilot symbols in each polarization direction is shown in Figure 13.

[0100] In the X-polarization direction, the input seed is 0x0B4, which converts to a binary sequence of 0010110100, representing the values ​​from m9 to m0. If the two consecutive bits output are 1 and 0, the pilot symbol in the X-polarization direction is A-Aj. If the two consecutive bits output are 0 and 0, the pilot symbol in the X-polarization direction is -A-Aj. If the two consecutive bits output are 1 and 1, the pilot symbol in the X-polarization direction is A+Aj. If the two consecutive bits output are 0 and 1, the pilot symbol in the X-polarization direction is -A+Aj. Similarly, 96 pilot symbols in the X-polarization direction are obtained.

[0101] In the Y polarization direction, the input seed is 0x2D1, which converts to the binary sequence 1011010001, representing the values ​​from m9 to m0. If the two bits are 1 and 0, the pilot symbol in the Y polarization direction is A-Aj. If the two bits are 0 and 0, the pilot symbol in the Y polarization direction is -A-Aj. If the two bits are 1 and 1, the pilot symbol in the Y polarization direction is A+Aj. If the two bits are 0 and 1, the pilot symbol in the Y polarization direction is -A+Aj. Similarly, 96 pilot symbols in the Y polarization direction are obtained.

[0102] Figure 14 is a schematic diagram of the correlation characteristics and cross-correlation characteristics corresponding to the pilot symbols in an embodiment of the present application. As shown in Figure 14, the horizontal axis represents the offset (the unit is the number of symbols), and the vertical axis represents the normalized amplitude. (a) in Figure 14 shows the periodic autocorrelation results of the pilot symbol sequence separated by two symbols in the X and Y polarization directions, and (b) in Figure 14 shows the periodic differential cross-correlation results of the pilot symbol sequence in the X and Y polarization directions. The normalized amplitude of the sidelobe value of the periodic differential autocorrelation function of the symbol sequence in the two polarization directions is not greater than 0.179, and the normalized amplitude of the sidelobe value of the periodic differential cross-correlation function of the symbol sequence in the two polarization directions is not greater than 0.222.

[0103] Figure 15 is a schematic diagram reflecting the autocorrelation characteristics and cross-correlation characteristics in an embodiment of the present application. As shown in Figure 15, the abscissa represents the offset (the unit is the number of symbols), and the ordinate represents the normalized amplitude. Among them, the real part sequence of the pilot symbol sequence in the X polarization direction is recorded as (X_I), the imaginary part sequence of the pilot symbol sequence in the X polarization direction is recorded as (X_Q), the real part sequence of the pilot symbol sequence in the Y polarization direction is recorded as (Y_I), and the imaginary part sequence of the pilot symbol sequence in the Y polarization direction is recorded as (Y_Q). Figure 15 shows the autocorrelation characteristics and cross-correlation characteristics of the four sequences of length Q bits, X_I, X_Q, Y_I, and Y_Q. Figure 15(a) shows the periodic differential autocorrelation results for the real sequence in the X-polarization direction (X_I), the imaginary sequence in the X-polarization direction (X_Q), the real sequence in the Y-polarization direction (Y_I), and the imaginary sequence in the Y-polarization direction (Y_Q). Figure 15(b) shows the periodic differential cross-correlation results for the real sequence in the X-polarization direction and the real sequence in the Y-polarization direction (X_I & Y_I), the real sequence in the X-polarization direction and the imaginary sequence in the X-polarization direction (X_I & X_Q), the real sequence in the X-polarization direction and the imaginary sequence in the Y-polarization direction (X_I & Y_Q), the imaginary sequence in the X-polarization direction and the real sequence in the Y-polarization direction (X_Q & Y_I), the real sequence in the Y-polarization direction and the imaginary sequence in the Y-polarization direction (Y_I & Y_Q), and the imaginary sequence in the X-polarization direction and the imaginary sequence in the Y-polarization direction (X_Q & Y_Q). The sidelobe values ​​of the periodic differential autocorrelation function and the normalized amplitude of the periodic differential cross-correlation function are both less than 0.2709.

[0104] The receiver uses the PS pilot sequence to perform DSP recovery based on the received signals in both polarization directions. For example, by calculating the differential correlation between the received signal and the PS pilot sequence symbols in the X and Y polarization directions, polarization direction can be distinguished and frame synchronization can be performed. The PS pilot signal is also used for carrier phase recovery. The designed pilot symbol sequence has good differential autocorrelation and differential cross-correlation characteristics, ensuring DC balance, which helps improve the quality of the recovered signal at the receiver.

[0105] Example 2: The target polynomial is x^10+x^9+x^4+x+1, the seed in the X polarization direction is 0x128, and the seed in the Y polarization direction is 0x12A.

[0106] Figure 16 is a schematic diagram of the fourth pilot symbol generation structure in an embodiment of the present application. If the target polynomial is x^10+x^9+x^4+x+1, the seed in the X polarization direction is 0x128, and the seed in the Y polarization direction is 0x12A, the generation process of 96 pilot symbols in each polarization direction is shown in Figure 16.

[0107] In the X-polarization direction, the input seed is 0x128, which, after conversion to the binary sequence, is 0100101000, which is the value from m9 to m0. If the two bits are output sequentially, 1 and 0, the pilot symbol in the X-polarization direction is A-Aj. If the two bits are output sequentially, 0 and 0, the pilot symbol in the X-polarization direction is -A-Aj. If the two bits are output sequentially, 1 and 1, the pilot symbol in the X-polarization direction is A+Aj. If the two bits are output sequentially, 0 and 1, the pilot symbol in the X-polarization direction is -A+Aj. Similarly, 96 pilot symbols in the X-polarization direction are obtained.

[0108] In the Y polarization direction, the input seed is 0x12A, which converts to the binary sequence 0100101010, representing the values ​​from m9 to m0. If the two bits are 1 and 0, the pilot symbol in the Y polarization direction is A-Aj. If the two bits are 0 and 0, the pilot symbol in the Y polarization direction is -A-Aj. If the two bits are 1 and 1, the pilot symbol in the Y polarization direction is A+Aj. If the two bits are 0 and 1, the pilot symbol in the Y polarization direction is -A+Aj. Similarly, 96 pilot symbols in the Y polarization direction are obtained.

[0109] Figure 17 is another schematic diagram of the correlation characteristics and cross-correlation characteristics corresponding to the pilot symbols in an embodiment of the present application. As shown in Figure 17, the horizontal axis represents the offset (the unit is the number of symbols), and the vertical axis represents the normalized amplitude. (a) in Figure 17 shows the periodic autocorrelation results of the pilot symbol sequence separated by two symbols in the X and Y polarization directions, and (b) in Figure 17 shows the periodic differential cross-correlation results of the pilot symbol sequence in the X and Y polarization directions. The normalized amplitude of the sidelobe value of the periodic differential autocorrelation function of the symbol sequence in the two polarization directions is not greater than 0.178, and the normalized amplitude of the sidelobe value of the periodic differential cross-correlation function of the symbol sequence in the two polarization directions is not greater than 0.222.

[0110] Figure 18 is another schematic diagram reflecting the autocorrelation characteristics and cross-correlation characteristics in the embodiment of the present application. As shown in Figure 18, the abscissa represents the offset (unit is the number of symbols), and the ordinate represents the normalized amplitude. Wherein, the real sequence of the pilot symbol sequence in the X polarization direction is recorded as (X_I), the imaginary sequence of the pilot symbol sequence in the X polarization direction is recorded as (X_Q), the real sequence of the pilot symbol sequence in the Y polarization direction is recorded as (Y_I), and the imaginary sequence of the pilot symbol sequence in the Y polarization direction is recorded as (Y_Q). Figure 18 shows the autocorrelation characteristics and cross-correlation characteristics of the four sequences of Q bits, X_I, X_Q, Y_I, and Y_Q. (a) in Figure 18 shows the periodic differential autocorrelation results of the real sequence in the X polarization direction (X_I), the imaginary sequence in the X polarization direction (X_Q), the real sequence in the Y polarization direction (Y_I) and the imaginary sequence in the Y polarization direction (Y_Q). Figure 18(b) shows the periodic difference cross-correlation results between the real sequence in the X-polarization direction and the real sequence in the Y-polarization direction (X_I & Y_I), the real sequence in the X-polarization direction and the imaginary sequence in the X-polarization direction (X_I & X_Q), the real sequence in the X-polarization direction and the imaginary sequence in the Y-polarization direction (X_I & Y_Q), the imaginary sequence in the X-polarization direction and the real sequence in the Y-polarization direction (X_Q & Y_I), the real sequence in the Y-polarization direction and the imaginary sequence in the Y-polarization direction (Y_I & Y_Q), and the imaginary sequence in the X-polarization direction and the imaginary sequence in the Y-polarization direction (X_Q & Y_Q). The sidelobe values ​​of the periodic difference autocorrelation function and the normalized amplitude of the periodic difference cross-correlation function are both less than 0.2709.

[0111] The receiver uses the PS pilot sequence to perform DSP recovery based on the received signals in both polarization directions. For example, by calculating the differential correlation between the received signal and the PS pilot sequence symbols in the X and Y polarization directions, polarization direction can be distinguished and frame synchronization can be performed. The PS pilot signal is also used for carrier phase recovery. The designed pilot symbol sequence has good differential autocorrelation and differential cross-correlation characteristics, ensuring DC balance, which helps improve the quality of the recovered signal at the receiver.

[0112] The following describes a data processing device provided in an embodiment of the present application.

[0113] Figure 19 is a schematic diagram of the structure of a data processing device applied to a receiving end in an embodiment of the present application. As shown in Figure 19, the data processing device includes a receiving unit 201, a first differential processing unit 202, a second differential processing unit 203, and an identification unit 204. The receiving unit 201 is used to receive data transmitted from the transmitting end via a channel. The first differential processing unit 202 is used to perform the operations of step 101 above. The second differential processing unit 203 is used to perform the operations of step 102 above. The identification unit 204 is used to perform the operations of steps 103 and 104 above.

[0114] It should be understood that the data processing device provided in this application can also be implemented in other ways. For example, the unit division in the above-mentioned device is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system. In addition, the functional units in the various embodiments of the present application can be integrated into one processing unit, or they can be independent physical units, or two or more functional units can be integrated into one processing unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0115] Figure 20 is another structural diagram of the data processing device in an embodiment of the present application. As shown in Figure 20, the data processing device includes a processor 301 and a transceiver 302. The processor 301 and the transceiver 302 are interconnected via a line. Specifically, the transceiver 302 is used to perform data transmission and reception operations, and the processor 301 is used to perform other operations besides data transmission and reception. In one possible embodiment, the processor 301 may include the first differential processing unit 202, the second differential processing unit 203 and the identification unit 204 shown in Figure 19 above, and the transceiver 302 includes the receiving unit 201 shown in Figure 19 above. Optionally, the data processing device may further include a memory 303, wherein the memory 303 is used to store program instructions and data.

[0116] The present application also provides a chip. This chip integrates circuitry and one or more interfaces for implementing the functions of the processor 301 described above. When the chip integrates memory, it can perform the method steps of any one or more of the aforementioned embodiments. When the chip does not integrate memory, it can be connected to an external memory via an interface. The chip implements the actions performed by the transmitting device or receiving device in the aforementioned embodiments based on program code stored in the external memory.

[0117] It should be noted that the processor shown in Figure 20 above can adopt a general central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The memory shown in Figure 20 above can store an operating system and other application programs. When the technical solution provided by the embodiment of the present application is implemented by software or firmware, the program code for implementing the technical solution provided by the embodiment of the present application is stored in the memory and executed by the processor. In one embodiment, the processor may include a memory inside. In another embodiment, the processor and the memory are two independent structures.

[0118] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0119] Those skilled in the art will appreciate that all or part of the steps in the above embodiments can be implemented by hardware or by programs instructing the relevant hardware to perform the steps. The programs can be stored in a computer-readable storage medium, which can be a read-only memory, a random access memory, or the like. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0120] When software is used for implementation, the method steps described in the above embodiment can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0121] Finally, it should be noted that the above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A data processing method, characterized in that: include: A symbol set of multiple data frames sent by a receiving end after being transmitted through a channel, wherein in one polarization direction, each of the data frames includes N symbols, each of the N symbols includes 1 pilot symbol located at a fixed position and M-1 payload symbols, N=M×Q, Q is an even number, M is an integer greater than or equal to 1, the symbol set includes R symbol subsets, each of the symbol subsets includes W symbols, R is an integer greater than 1, and W is an integer greater than or equal to 1; Performing differential processing on each symbol subset to obtain a corresponding differential symbol subset, so as to obtain a total of R differential symbol subsets; Acquire a pilot sequence, and perform differential processing on the pilot sequence to obtain a differential pilot sequence, wherein the pilot sequence includes Z pilot symbols, 2≤Z≤Q, the Z pilot symbols in the pilot sequence correspond one-to-one to the Z pilot symbols in the data frame, and any pilot symbol in the pilot sequence is c times the corresponding pilot symbol in the data frame, and c is not equal to 0; A frame start position in the symbol set is determined according to the R differential symbol subsets and the differential pilot sequence.

2. The method according to claim 1, characterized in that The Z pilot symbols in the pilot sequence correspond one-to-one to the consecutive Z pilot symbols in the data frame.

3. The method according to claim 2, characterized in that The differential symbol subset obtained by performing differential processing on the symbol subset includes: Obtain K symbols adjacent to the starting position or the ending position of the symbol subset, K=a×M, 1≤a≤Z; A differential symbol subset is obtained by performing differential processing on a symbol sequence including the symbol subset and the K symbols.

4. The method according to claim 3, characterized in that The differential symbol subset obtained by performing differential processing on the symbol sequence including the symbol subset and the K symbols includes: Performing conjugate calculation on the vth symbol in the symbol sequence; The result of the conjugate calculation is multiplied by the v+Kth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, 0≤v≤W-1.

5. The method according to claim 3, characterized in that: The differential symbol subset obtained by performing differential processing on the symbol sequence including the symbol subset and the K symbols includes: Performing conjugate calculation on the v+Kth symbol in the symbol sequence; The result of the conjugate calculation is multiplied by the vth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, 0≤v≤W-1.

6. The method according to any one of claims 2 to 5, characterized in that Performing differential processing on the pilot sequence to obtain a differential pilot sequence includes: Circularly shift the pilot sequence rightward by a symbols, 1≤a≤Z; Performing conjugate calculation on the pilot sequence after the rightward cyclic shift by a symbols to obtain a conjugate sequence; The Z symbols in the conjugate sequence are multiplied one by one with the Z pilot symbols in the pilot sequence to obtain the differential pilot sequence.

7. The method according to any one of claims 2 to 5, characterized in that Performing differential processing on the pilot sequence to obtain a differential pilot sequence includes: Circularly shift the pilot sequence to the left by a symbols, 1≤a≤Z; Performing conjugate calculation on the pilot sequence after the pilot sequence is cyclically shifted to the left by a symbols to obtain a conjugate sequence; The Z symbols in the conjugate sequence are multiplied one by one with the Z pilot symbols in the pilot sequence to obtain the differential pilot sequence.

8. The method according to any one of claims 3 to 7, characterized in that Indicates that the positive real number b is rounded down.

9. The method according to any one of claims 1 to 8, characterized in that The pilot sequence includes Q pilot symbols, and the Q pilot symbols in the pilot sequence are the same as the Q pilot symbols in the data frame.

10. The method according to any one of claims 1 to 9, characterized in that Determining a frame start position in the symbol set according to the R differential symbol subsets and the differential pilot sequence includes: Performing cross-correlation calculation on the R differential symbol subsets and the differential pilot sequence; A frame start position in the symbol set is determined according to the result of the cross-correlation calculation.

11. A chip, characterized in that: The chip includes a processor and a memory, wherein the memory and the processor are connected to each other via a line, instructions are stored in the memory, and the processor is used to execute the method according to any one of claims 1 to 10.

12. A data processing device, characterized in that: include: A receiving unit, a first differential processing unit, a second differential processing unit and an identification unit; The receiving unit is used to: receive a symbol set of multiple data frames sent by a transmitting end after being transmitted through a channel, wherein in one polarization direction, the data frame includes N symbols, each of the N symbols includes 1 pilot symbol located at a fixed position and M-1 payload symbols, N=M×Q, Q is an even number, M is an integer greater than or equal to 1, the symbol set includes R symbol subsets, each of the symbol subsets includes W symbols, R is an integer greater than 1, and W is an integer greater than or equal to 1; The first differential processing unit is used to: perform differential processing on each symbol subset to obtain a corresponding differential symbol subset, so as to obtain a total of R differential symbol subsets; The second differential processing unit is used to: obtain a pilot sequence, and perform differential processing on the pilot sequence to obtain a differential pilot sequence, wherein the pilot sequence includes Z pilot symbols, 1≤Z≤Q, the Z pilot symbols in the pilot sequence correspond one-to-one to the Z pilot symbols in the data frame, and any pilot symbol in the pilot sequence is c times the corresponding pilot symbol in the data frame, and c is not equal to 0; The identification unit is used to determine a frame start position in the symbol set according to the R differential symbol subsets and the differential pilot sequence.

13. The data processing device according to claim 12, characterized in that: The Z pilot symbols in the pilot sequence correspond one-to-one to the consecutive Z pilot symbols in the data frame.

14. The data processing device according to claim 13, characterized in that: The first differential processing unit is specifically used for: Obtain K symbols adjacent to the starting position or the ending position of the symbol subset, K=a×M, 1≤a≤Z; A differential symbol subset is obtained by performing differential processing on a symbol sequence including the symbol subset and the K symbols.

15. The data processing device according to claim 14, characterized in that: The first differential processing unit is specifically used for: Performing conjugate calculation on the vth symbol in the symbol sequence; The result of the conjugate calculation is multiplied by the v+Kth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, 0≤v≤W-1.

16. The data processing device according to claim 14, characterized in that: The first differential processing unit is specifically used for: Performing conjugate calculation on the v+Kth symbol in the symbol sequence; The result of the conjugate calculation is multiplied by the vth symbol in the symbol sequence to obtain the vth symbol in the differential symbol subset, 0≤v≤W-1.

17. The data processing device according to any one of claims 13 to 16, characterized in that: The second difference processing unit is specifically used for: Circularly shift the pilot sequence rightward by a symbols, 1≤a≤Z; Performing conjugate calculation on the pilot sequence after the rightward cyclic shift by a symbols to obtain a conjugate sequence; The Z symbols in the conjugate sequence are multiplied one by one with the Z pilot symbols in the pilot sequence to obtain the differential pilot sequence.

18. The data processing device according to any one of claims 13 to 16, characterized in that: The second difference processing unit is specifically used for: Circularly shift the pilot sequence to the left by a symbols, 1≤a≤Z; Performing conjugate calculation on the pilot sequence after the pilot sequence is cyclically shifted to the left by a symbols to obtain a conjugate sequence; The Z symbols in the conjugate sequence are multiplied one by one with the Z pilot symbols in the pilot sequence to obtain the differential pilot sequence.

19. The data processing device according to any one of claims 14 to 18, characterized in that: Indicates that the positive real number b is rounded down.

20. The data processing device according to any one of claims 12 to 19, characterized in that: The pilot sequence includes Q pilot symbols, and the Q pilot symbols in the pilot sequence are the same as the Q pilot symbols in the data frame.

21. The data processing device according to any one of claims 12 to 20, characterized in that: The identification unit is specifically used for: Performing cross-correlation calculation on the R differential symbol subsets and the differential pilot sequence; A frame start position in the symbol set is determined according to the result of the cross-correlation calculation.

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