Data transmission method, apparatus and system

Abstract

Disclosed in embodiments of the present application are a data transmission method, apparatus and system. A data frame acquired by a transmitting end comprises multiple subframes, and each subframe comprises training symbols and pilot symbols. In one polarization direction, within each subframe, every consecutive Ng symbols include a pilot symbol, Ng being an integer greater than 1; among a total of NTP symbols in the subframe including all the training symbols and all the pilot symbols, at least one symbol takes the value of one of -A1-A1j, -A1+A1j, A1-A1j, and A1+A1j; and among the NTP symbols in the subframe, at least one symbol takes the value of one of -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, A1 and A2 are both real numbers not equal to 0, A1<A2, and j represents the imaginary unit. Hence, in one polarization direction, the values of the NTP symbols in the subframe are distributed in both the inner and outer rings of a constellation diagram, enabling the peak-to-average power ratio and transmission performance penalty of the NTP symbols to be relatively low.

Description

A data transmission method, apparatus and system

[0001] This application claims priority to Chinese Patent Application No. 202410786073.1, filed with the State Intellectual Property Office of China on June 17, 2024, entitled "A Data Transmission Method, Apparatus and System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a data transmission method, apparatus and system. Background Technology

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

[0004] In existing coherent optical transmission systems, the fixed symbol sequences used are mainly applied to scenarios with speeds of 400 gigabits per second (Gbps) and 800 Gbps, which cannot adapt to future scenarios with speeds of 1.2 terabit per second (Tbps) and above (including 1.2 Tbps and 1.6 Tbps). For example, in existing 800ZR or 800LR transmissions using dual-polarization 16-ary Quadrature Amplitude Modulation (DP-16QAM), the pilot sequence used comes from the outermost four symbols of the constellation diagram. While the pilot symbols have high sensitivity, they also have a high peak-to-average power ratio and high noise, resulting in a significant cost to actual transmission performance. This is a problem that urgently needs to be solved in the future. Summary of the Invention

[0005] This application provides a data transmission method, apparatus, and system that have a low cost in terms of actual transmission performance and are beneficial for improving the quality of signal recovery at the receiving end, and can be well applied to various coherent transmission scenarios.

[0006] In a first aspect, an embodiment of the present application provides a data transmission method, which is applied to a sending end. Specifically, the sending end obtains a data frame including a plurality of sub-frames, and the sub-frames include training symbols and pilot symbols. Among them, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, and the N g is an integer greater than 1. Among the N TP symbols including all the training symbols and all the pilot symbols in the sub-frame, at least one symbol takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j. Among the N TP symbols of the sub-frame, at least one symbol takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j. Both A1 and A2 are real numbers not equal to 0, and A1 < A2, where j represents the imaginary unit. Furthermore, the sending end transmits the data frame. It should be noted that this method can also be applied to a specific module in the sending end. For example, the signal processor of the sending end. It should be understood that the module obtaining the data frame can be understood as the data frame generated by the module itself, or it can be understood as the data frame received by the module from its previous module. It should also be understood that the module transmitting the data frame can be understood as the module transmitting the data frame to the receiving end through the channel, or it can be understood as the module transmitting the data frame to its subsequent module.

[0007] In this embodiment, the complex numbers -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j are the constellation points corresponding to the symbol mapping adopted. It can be seen that in one polarization direction, the values of the N TP symbols in the sub-frame are some in the inner circle of the constellation diagram (such as taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, or A1 + A1j), and some in the outer circle of the constellation diagram (such as taking values of -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j), making the peak-to-average power ratio and the cost of transmission performance of the N TP symbols relatively low.

[0008] In some possible embodiments, in one polarization direction, the number of the training symbols in the sub-frame is T, the number of the pilot symbols in the sub-frame is M, both T and M are integers greater than 0, and there is one symbol in the sub-frame that is both a training symbol and a pilot symbol, and N TP = T + M - 1. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols. Calculate the N TPWhen determining the number of symbols for a given symbol, it is necessary to consider that one symbol in a subframe may be both a pilot symbol and a training symbol.

[0009] In some possible implementations, T is even and M is odd, or T is odd and M is even.

[0010] In some possible implementations, in one polarization direction, the number of training symbols in the subframe is T, the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0, and N... TP =T+M. It should be understood that N... TP The symbol is obtained by combining the T training symbols and the M pilot symbols.

[0011] In some possible implementations, T is even and M is even, or T is odd and M is odd.

[0012] In some possible implementations, the N TP The sum of all the symbols is 0. That is to say, N TP The sum of the real parts of the complex numbers corresponding to each symbol is 0, and the sum of the imaginary parts is also 0, which satisfies DC balance and helps improve the quality of the recovered signal at the receiving end.

[0013] In some possible implementations, the N TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0014] In some possible implementations, the N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, where N... TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where N is the number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. TP = N1 + N2, where N1 and N2 are both integers greater than 0. That is, in this implementation, N... TP Each symbol takes one of eight complex numbers: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, which better suits the DP-16QAM scenario.

[0015] In some possible implementations, the sum of the N1 symbols is 0, the sum of the N2 symbols is 0, and both N1 and N2 are even numbers. That is, the N1 symbols corresponding to the inner circle of the constellation diagram satisfy DC balance, and the N2 symbols corresponding to the outer circle of the constellation diagram also satisfy DC balance, such that all N... TPEach symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0016] In some possible implementations, among the N1 symbols, the number of symbols with the value -A1-A1j is d1, the number of symbols with the value -A1+A1j is d2, the number of symbols with the value A1-A1j is d3, and the number of symbols with the value A1+A1j is d4, where d1 = d4, d2 = d3, and N1 = d1 + d2 + d3 + d4. Among the N2 symbols, the number of symbols with the value -A2-A2j is d5, the number of symbols with the value -A2+A2j is d6, the number of symbols with the value A2-A2j is d7, and the number of symbols with the value A2+A2j is d8, where d5 = d8, d6 = d7, and N2 = d5 + d6 + d7 + d8. This ensures that the sum of the N1 symbols is 0, and the sum of the N2 symbols is 0, such that N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0017] In some possible implementations, N1 ≥ N2. As an example, Probabilistic Constellation Shaping (PCS) is employed to change the probability of constellation points appearing while keeping their positions constant, resulting in a non-uniform distribution and thus improving system transmission performance. Typically, before framing, the probability of a symbol being on the inner circle of a constellation point is greater than the probability of it being on the outer circle. In this case, consider the N... TP The number of constellation points in the inner circle of the constellation diagram among the symbols is greater than N. TP The number of constellation points in the outer ring of the constellation diagram among the symbols, i.e., N1 > N2, such that N TP The transmission performance cost caused by each symbol is relatively low. As another example, using traditional Quadrature Amplitude Modulation (QAM), the probability of a symbol being a constellation point symbol is the same before framing. In this case, consider N1 = N2 = N... TP / 2.

[0018] In some possible implementations, the subframe includes a total of 2×N training symbols and pilot symbols in both polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​-A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all N. TP / 4. This effectively ensures that the number of symbols for each value approaches balance, and also ensures that the sequence composed of all training symbols and all pilot symbols achieves DC balance, which is beneficial to improving the quality of the recovered signal at the receiving end.

[0019] In some possible implementations, in one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0. The T training symbols included in the subframe in the first polarization direction are different from the T training symbols included in the subframe in the second polarization direction, and the M pilot symbols included in the subframe in the first polarization direction are different from the M pilot symbols included in the subframe in the second polarization direction. This facilitates the receiving end in distinguishing the two polarization directions of the data frame.

[0020] In some possible implementations, the data frame employs a symbol mapping scheme of Dual-polarization 16-ary Quadrature Amplitude Modulation (DP-16QAM), where A1 / A2 = 1 / 3. Alternatively, the data frame employs a symbol mapping scheme of Dual-polarization 64-ary Quadrature Amplitude Modulation (DP-64QAM), where A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7.

[0021] In some possible implementations, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all M pilot symbols, H = M. Alternatively, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all T training symbols and all M pilot symbols, H = N. TP .

[0022] In some possible implementations, the order of the target polynomial is less than or equal to 11, and the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8. When selecting a polynomial, the order and the number of non-zero terms should be minimized to reduce the complexity and power consumption of the pilot symbol generation structure. Given a target polynomial, there may not be a seed that results in good autocorrelation and cross-correlation between the target polynomial and the pilot symbol sequence determined by the seed. Therefore, the selection of the target polynomial is not merely about minimizing the order and the number of non-zero terms; it also requires considering whether a corresponding seed can be selected that results in good autocorrelation and cross-correlation characteristics of the generated pilot symbol sequence, including its real and imaginary parts, to improve the quality of the recovered signal at the receiving end.

[0023] In some possible implementations, the target polynomial is one of the following: 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; 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; x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1; x 11 +a 10 ×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.

[0024] In some possible embodiments, in one polarization direction, a first bit sequence including 3×H bits is generated by the target polynomial and the seed, and every consecutive 3 bits in the first bit sequence correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing. It should be understood that there are a total of 8 combinations of the values of 3 bits, which can exactly correspond to the 8 values of N TP symbols, improving the feasibility of the present solution.

[0025] In some possible embodiments, every consecutive 3 bits in the first bit sequence are respectively b 3t 、b 3t+1 、b 3t+2 , 0 ≤ t < H, and every consecutive 3 bits in the first bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables.

[0026] Table 1-1a

[0027] Table 1-2a

[0028] Table 1-3a

[0029] Table 1-4a

[0030] Table 1-5a

[0031] Table 1-6a

[0032] Table 1-7a

[0033] Table 1-8a

[0034] Table 1-9a

[0035] Table 1-10a

[0036] Table 1-11a

[0037] Table 1-12a

[0038] In some possible embodiments, in one polarization direction, a first bit sequence including 3×H bits is generated by the target polynomial and the seed. Each consecutive 3 bits in the first bit sequence correspond to 4 bits, and the 4 bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to scenarios where framing is performed first and then dual-polarization symbol mapping is performed.

[0039] In some possible embodiments, each consecutive 3 bits in the first bit sequence are respectively b 3t , b 3t+1 , b 3t+2 , where 0 ≤ t < H. Each consecutive 3 bits in the first bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0040] Table 1-1b

[0041] Table 1-2b

[0042] Table 1-3b

[0043] Table 1-4b

[0044] Table 1-5b

[0045] Table 1-6b

[0046] Table 1-7b

[0047] Table 1-8b

[0048] Table 1-9b

[0049] Table 1-10b

[0050] Table 1-11b

[0051] Table 1-12b

[0052] In some possible embodiments, H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and H target symbols in the second polarization direction are generated by the target polynomial, the third seed, and the fourth seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction. The target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the fourth seed are used to obtain the amplitude of each target symbol in the second polarization direction.

[0053] In some possible embodiments, in the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. In the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence, a total of 3 bits, correspond to a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing.

[0054] In some possible embodiments, every consecutive 2 bits in the second bit sequence or the fourth bit sequence are b 2t and b 2t+1 , and 1 bit in the third bit sequence or the fifth bit sequence is s t , 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables.

[0055] Table 2-1a

[0056] Table 2-2a

[0057] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0058] In some possible embodiments, every consecutive 2 bits in the second bit sequence or the fourth bit sequence are respectively b 2t and b 2t+1 , and 1 bit in the third bit sequence or the fifth bit sequence is s t , where 0≤t<H. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0059] Table 2-1b

[0060] Table 2-2b

[0061] In some possible embodiments, H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and H target symbols in the second polarization direction are generated by the target polynomial, the second seed, and the third seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, the target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction and the amplitude of each target symbol in the second polarization direction.

[0062] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing.

[0063] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol.

[0064] Table 3-1a

[0065] Table 3-2a

[0066] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0067] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , where 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0068] Table 3-1b

[0069] Table 3-2b

[0070] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a pre-framing symbol and at least one of two symbols: a frame synchronization symbol and a reserved symbol. In the first type of subframe, the training symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which also includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0071] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a frame synchronization symbol, a reserved symbol, and a pre-framing symbol. In the first type of subframe, the training symbol is located before the frame synchronization symbol, the frame synchronization symbol is located before the reserved symbol, and the reserved symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which further includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0072] In some possible implementations, N g The values ​​are 32, 64, 96, or 128.

[0073] In some possible implementations, each of the T training symbols takes the value -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. It should be understood that all the values ​​of the training symbols are within the outer ring of the constellation diagram. In this case, the training symbols have better sensitivity, which is beneficial for link training, makes the receiver signal processing more robust, and helps improve the quality of the recovered signal at the receiver.

[0074] In some possible implementations, T = 11, M = 114.

[0075] In some possible implementations, in the first polarization direction, the values ​​of the 11 training symbols are: -A2+A2j, A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, A2+A2j, -A2-A2j, -A2-A2j, A2+A2j, A2-A2j, A2-A2j; and in the second polarization direction, the values ​​of the 11 training symbols are: -A2-A2j, -A2-A2j, A2-A2j, -A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j, A2-A2j.

[0076] In some possible implementations, A1 = 1 and A2 = 3; or and

[0077] In some possible embodiments, each of the pilot symbols is located at the starting position within the consecutive N g symbols where it is located.

[0078] In a second aspect, embodiments of the present application provide a data transmission method, which is applied to a receiving end. Specifically, the receiving end receives a second data frame transmitted through a channel from a first data frame. It should be understood that the second data frame received by the receiving end is different from the first data frame transmitted by the sending end, and the second data frame can be understood as a distorted signal affected by noise or other impairments in the channel. For the first data frame, the first data frame includes multiple sub-frames, and the sub-frame includes training symbols and pilot symbols. Among them, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, and the N g is an integer greater than 1. Among the total N TP symbols including all the training symbols and all the pilot symbols in the sub-frame, at least one symbol takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j. Among the N TP symbols of the sub-frame, at least one symbol takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j. Both A1 and A2 are non-zero real numbers, and A1 < A2, where j represents the imaginary unit.

[0079] In some possible embodiments, after the receiving end receives the second data frame, the receiving end performs signal processing on the second data frame.

[0080] In some possible embodiments, in one polarization direction, the number of training symbols in the sub-frame is T, and the number of pilot symbols in the sub-frame is M. Both T and M are integers greater than 0. There is one symbol in the sub-frame that is both a training symbol and a pilot symbol, and N TP = T + M - 1. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols. When calculating the number of symbols of the N TP symbols, it is necessary to consider that there is one symbol in the sub-frame that is both a pilot symbol and a training symbol.

[0081] In some possible embodiments, T is an even number and M is an odd number, or T is an odd number and M is an even number.

[0082] In some possible embodiments, in one polarization direction, the number of training symbols in the sub-frame is T, and the number of pilot symbols in the sub-frame is M. Both T and M are integers greater than 0, and N TP = T + M. It should be understood that the N TPThe symbol is obtained by combining the T training symbols and the M pilot symbols.

[0083] In some possible implementations, T is even and M is even, or T is odd and M is odd.

[0084] In some possible implementations, the N TP The sum of all the symbols is 0. That is to say, N TP The sum of the real parts of the complex numbers corresponding to each symbol is 0, and the sum of the imaginary parts is also 0, which satisfies DC balance and helps improve the quality of the recovered signal at the receiving end.

[0085] In some possible implementations, the N TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0086] In some possible implementations, the N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, where N... TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where N is the number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. TP = N1 + N2, where N1 and N2 are both integers greater than 0. That is, in this implementation, N... TP Each symbol takes one of eight complex numbers: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, which better suits the DP-16QAM scenario.

[0087] In some possible implementations, the sum of the N1 symbols is 0, the sum of the N2 symbols is 0, and both N1 and N2 are even numbers. That is, the N1 symbols corresponding to the inner circle of the constellation diagram satisfy DC balance, and the N2 symbols corresponding to the outer circle of the constellation diagram also satisfy DC balance, such that all N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0088] In some possible implementations, among the N1 symbols, the number of symbols with the value -A1-A1j is d1, the number of symbols with the value -A1+A1j is d2, the number of symbols with the value A1-A1j is d3, and the number of symbols with the value A1+A1j is d4, where d1 = d4, d2 = d3, and N1 = d1 + d2 + d3 + d4. Among the N2 symbols, the number of symbols with the value -A2-A2j is d5, the number of symbols with the value -A2+A2j is d6, the number of symbols with the value A2-A2j is d7, and the number of symbols with the value A2+A2j is d8, where d5 = d8, d6 = d7, and N2 = d5 + d6 + d7 + d8. This ensures that the sum of the N1 symbols is 0, and the sum of the N2 symbols is 0, such that N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0089] In some possible implementations, N1 ≥ N2. As an example, Probabilistic Constellation Shaping (PCS) is employed to change the probability of constellation points appearing while keeping their positions constant, resulting in a non-uniform distribution and thus improving system transmission performance. Typically, before framing, the probability of a symbol being on the inner circle of a constellation point is greater than the probability of it being on the outer circle. In this case, consider the N... TP The number of constellation points in the inner circle of the constellation diagram among the symbols is greater than N. TP The number of constellation points in the outer ring of the constellation diagram among the symbols, i.e., N1 > N2, such that N TP The transmission performance cost caused by each symbol is relatively low. As another example, using traditional Quadrature Amplitude Modulation (QAM), the probability of a symbol being a constellation point symbol is the same before framing. In this case, consider N1 = N2 = N... TP / 2.

[0090] In some possible implementations, the subframe includes a total of 2×N training symbols and pilot symbols in both polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​-A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all N. TP / 4. This effectively ensures that the number of symbols for each value approaches balance, and also ensures that the sequence composed of all training symbols and all pilot symbols achieves DC balance, which is beneficial to improving the quality of the recovered signal at the receiving end.

[0091] In some possible implementations, in one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0. The T training symbols included in the subframe in the first polarization direction are different from the T training symbols included in the subframe in the second polarization direction, and the M pilot symbols included in the subframe in the first polarization direction are different from the M pilot symbols included in the subframe in the second polarization direction. This facilitates the receiving end in distinguishing the two polarization directions of the first data frame.

[0092] In some possible implementations, the first data frame uses a symbol mapping scheme of dual-polarization 16-ary Quadrature Amplitude Modulation (DP-16QAM), where A1 / A2 = 1 / 3. Alternatively, the first data frame uses a symbol mapping scheme of dual-polarization 64-ary Quadrature Amplitude Modulation (DP-64QAM), where A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7.

[0093] In some possible implementations, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all M pilot symbols, H = M. Alternatively, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all T training symbols and all M pilot symbols, H = N. TP .

[0094] In some possible implementations, the order of the target polynomial is less than or equal to 11, and the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8. When selecting a polynomial, the order and the number of non-zero terms should be minimized to reduce the complexity and power consumption of the pilot symbol generation structure. Given a target polynomial, there may not be a seed that results in good autocorrelation and cross-correlation between the target polynomial and the pilot symbol sequence determined by the seed. Therefore, the selection of the target polynomial is not merely about minimizing the order and the number of non-zero terms; it also requires considering whether a corresponding seed can be selected that results in good autocorrelation and cross-correlation characteristics of the generated pilot symbol sequence, including its real and imaginary parts, to improve the quality of the recovered signal at the receiving end.

[0095] In some possible implementations, the target polynomial is one of the following: 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; 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; x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1; x 11 +a 10 ×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.

[0096] In some possible implementations, in one polarization direction, a first bit sequence comprising 3×H bits is generated by the target polynomial and the seed. Each consecutive three bits in the first bit sequence correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. This implementation is suitable for scenarios where dual polarization symbol mapping is performed before framing. It should be understood that there are a total of 8 combinations of the 3 bits, which can correspond to N... TP The eight possible values ​​for each symbol improve the feasibility of this solution.

[0097] In some possible implementations, every three consecutive bits in the first bit sequence are b 3t b3t+1 , b 3t+2 , where \(0\leq t < H\), and each consecutive 3 bits in the first bit sequence satisfy the relationship shown in one of the following tables corresponding to the target symbol.

[0098] Table 1 - 1a

[0099] Table 1 - 2a

[0100] Table 1 - 3a

[0101] Table 1 - 4a

[0102] Table 1 - 5a

[0103] Table 1 - 6a

[0104] Table 1 - 7a

[0105] Table 1 - 8a

[0106] Table 1 - 9a

[0107] Table 1 - 10a

[0108] Table 1 - 11a

[0109] Table 1 - 12a

[0110] In some possible implementation manners, in one polarization direction, the first bit sequence including \(3\times H\) bits is generated by the target polynomial and the seed. Each consecutive 3 bits in the first bit sequence correspond to 4 bits, and the 4 bits are symbol - mapped to obtain a target symbol with values of \(-A1 - A1j\), \(-A1+A1j\), \(A1 - A1j\), \(A1+A1j\), \(-A2 - A2j\), \(-A2+A2j\), \(A2 - A2j\), or \(A2+A2j\). This implementation manner is applicable to the scenario where framing is performed first and then dual - polarization symbol mapping.

[0111] In some possible implementation manners, each consecutive 3 bits in the first bit sequence are respectively b 3t , b 3t+1 , b 3t+2, where \(0\leq t < H\), each consecutive 3 bits in the first bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0112] Table 1-1b

[0113] Table 1-2b

[0114] Table 1-3b

[0115] Table 1-4b

[0116] Table 1-5b

[0117] Table 1-6b

[0118] Table 1-7b

[0119] Table 1-8b

[0120] Table 1-9b

[0121] Table 1-10b

[0122] Table 1-11b

[0123] Table 1-12b

[0124] In some possible embodiments, the \(H\) target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and the \(H\) target symbols in the second polarization direction are generated by the target polynomial, the third seed, and the fourth seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction. The target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the fourth seed are used to obtain the amplitude of each target symbol in the second polarization direction.

[0125] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Each consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Each consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing is performed.

[0126] In some possible embodiments, each consecutive 2 bits in the second bit sequence or the fourth bit sequence are respectively b 2t and b 2t+1 , and 1 bit in the third bit sequence or the fifth bit sequence is s t , 0 ≤ t < H. Each consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables, and each consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables.

[0127] Table 2-1a

[0128] Table 2-2a

[0129] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every two consecutive bits in the second bit sequence and one bit in the third bit sequence, a total of three bits, correspond to four first bits. The four first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence, a total of three bits, correspond to four second bits. The four second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0130] In some possible embodiments, every two consecutive bits in the second bit sequence or the fourth bit sequence are respectively b 2t and b 2t+1 , and one bit in the third bit sequence or the fifth bit sequence is s t , 0 ≤ t < H. Every two consecutive bits in the second bit sequence and one bit in the third bit sequence and the corresponding four bits satisfy the relationship shown in one of the following tables, and every two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence and the corresponding four bits satisfy the relationship shown in one of the following tables.

[0131] Table 2-1 b

[0132] Table 2-2 b

[0133] In some possible embodiments, H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and H target symbols in the second polarization direction are generated by the target polynomial, the second seed, and the third seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, the target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction and the amplitude of each target symbol in the second polarization direction.

[0134] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing.

[0135] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol.

[0136] Table 3-1a

[0137] Table 3-2a

[0138] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0139] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , where 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0140] Table 3-1b

[0141] Table 3-2b

[0142] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a pre-framing symbol and at least one of two symbols: a frame synchronization symbol and a reserved symbol. In the first type of subframe, the training symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which also includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0143] In some possible implementations, the subframe arranged in the first position in the first data frame is a first type of subframe. The first type of subframe further includes a frame synchronization symbol, a reserved symbol, and a pre-framing symbol. In the first type of subframe, the training symbol is located before the frame synchronization symbol, the frame synchronization symbol is located before the reserved symbol, and the reserved symbol is located before the pre-framing symbol. The first data frame includes at least one second type of subframe, and the second type of subframe further includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0144] In some possible implementations, N g The values ​​are 32, 64, 96, or 128.

[0145] In some possible implementations, each of the T training symbols takes the value -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. It should be understood that all the values ​​of the training symbols are within the outer ring of the constellation diagram. In this case, the training symbols have better sensitivity, which is beneficial for link training, makes the receiver signal processing more robust, and helps improve the quality of the recovered signal at the receiver.

[0146] In some possible implementations, T = 11, M = 114.

[0147] In some possible implementations, in the first polarization direction, the values ​​of the 11 training symbols are: -A2+A2j, A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, A2+A2j, -A2-A2j, -A2-A2j, A2+A2j, A2-A2j, A2-A2j; and in the second polarization direction, the values ​​of the 11 training symbols are: -A2-A2j, -A2-A2j, A2-A2j, -A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j, A2-A2j.

[0148] In some possible implementations, A1 = 1 and A2 = 3; or and

[0149] In some possible embodiments, each of the pilot symbols is located at the starting position among the consecutive N g symbols where it is located.

[0150] In a third aspect, an embodiment of the present application provides a data transmission device, including a processing unit and a sending unit. The processing unit is configured to: obtain a data frame including a plurality of sub-frames, and the sub-frame includes training symbols and pilot symbols. Among them, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, and the N g is an integer greater than 1. Among the N TP symbols including all the training symbols and all the pilot symbols in the sub-frame, at least one symbol takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j. Among the N TP symbols in the sub-frame, at least one symbol takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j. Both A1 and A2 are non-zero real numbers, and A1 < A2, and j represents the imaginary unit. The sending unit is configured to: send the data frame.

[0151] In some possible embodiments, in one polarization direction, the number of the training symbols in the sub-frame is T, the number of the pilot symbols in the sub-frame is M, both T and M are integers greater than 0, and there is one symbol in the sub-frame that is both a training symbol and a pilot symbol. N TP = T + M - 1. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols together. When calculating the number of the N TP symbols, it is necessary to consider that there is one symbol in the sub-frame that is both a pilot symbol and a training symbol.

[0152] In some possible embodiments, T is an even number and M is an odd number, or T is an odd number and M is an even number.

[0153] In some possible embodiments, in one polarization direction, the number of the training symbols in the sub-frame is T, the number of the pilot symbols in the sub-frame is M, both T and M are integers greater than 0, and N TP = T + M. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols together.

[0154] In some possible embodiments, T is an even number and M is an even number, or T is an odd number and M is an odd number.

[0155] In some possible embodiments, the N TPThe sum of all the symbols is 0. That is to say, N TP The sum of the real parts of the complex numbers corresponding to each symbol is 0, and the sum of the imaginary parts is also 0, which satisfies DC balance and helps improve the quality of the recovered signal at the receiving end.

[0156] In some possible implementations, the N TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0157] In some possible implementations, the N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, where N... TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where N is the number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. TP = N1 + N2, where N1 and N2 are both integers greater than 0. That is, in this implementation, N... TP Each symbol takes one of eight complex numbers: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, which better suits the DP-16QAM scenario.

[0158] In some possible implementations, the sum of the N1 symbols is 0, the sum of the N2 symbols is 0, and both N1 and N2 are even numbers. That is, the N1 symbols corresponding to the inner circle of the constellation diagram satisfy DC balance, and the N2 symbols corresponding to the outer circle of the constellation diagram also satisfy DC balance, such that all N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0159] In some possible implementations, among the N1 symbols, the number of symbols with the value -A1-A1j is d1, the number of symbols with the value -A1+A1j is d2, the number of symbols with the value A1-A1j is d3, and the number of symbols with the value A1+A1j is d4, where d1 = d4, d2 = d3, and N1 = d1 + d2 + d3 + d4. Among the N2 symbols, the number of symbols with the value -A2-A2j is d5, the number of symbols with the value -A2+A2j is d6, the number of symbols with the value A2-A2j is d7, and the number of symbols with the value A2+A2j is d8, where d5 = d8, d6 = d7, and N2 = d5 + d6 + d7 + d8. This ensures that the sum of the N1 symbols is 0, and the sum of the N2 symbols is 0, such that N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0160] In some possible implementations, N1 ≥ N2. As an example, Probabilistic Constellation Shaping (PCS) is employed to change the probability of constellation points appearing while keeping their positions constant, resulting in a non-uniform distribution and thus improving system transmission performance. Typically, before framing, the probability of a symbol being on the inner circle of a constellation point is greater than the probability of it being on the outer circle. In this case, consider the N... TP The number of constellation points in the inner circle of the constellation diagram among the symbols is greater than N. TP The number of constellation points in the outer ring of the constellation diagram among the symbols, i.e., N1 > N2, such that N TP The transmission performance cost caused by each symbol is relatively low. As another example, using traditional Quadrature Amplitude Modulation (QAM), the probability of a symbol being a constellation point symbol is the same before framing. In this case, consider N1 = N2 = N... TP / 2.

[0161] In some possible implementations, the subframe includes a total of 2×N training symbols and pilot symbols in both polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​-A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all N. TP / 4. This effectively ensures that the number of symbols for each value approaches balance, and also ensures that the sequence composed of all training symbols and all pilot symbols achieves DC balance, which is beneficial to improving the quality of the recovered signal at the receiving end.

[0162] In some possible implementations, in one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0. The T training symbols included in the subframe in the first polarization direction are different from the T training symbols included in the subframe in the second polarization direction, and the M pilot symbols included in the subframe in the first polarization direction are different from the M pilot symbols included in the subframe in the second polarization direction. This facilitates the receiving end in distinguishing the two polarization directions of the data frame.

[0163] In some possible implementations, the data frame employs a symbol mapping scheme of Dual-polarization 16-ary Quadrature Amplitude Modulation (DP-16QAM), where A1 / A2 = 1 / 3. Alternatively, the data frame employs a symbol mapping scheme of Dual-polarization 64-ary Quadrature Amplitude Modulation (DP-64QAM), where A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7.

[0164] In some possible implementations, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all M pilot symbols, H = M. Alternatively, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all T training symbols and all M pilot symbols, H = N. TP .

[0165] In some possible implementations, the order of the target polynomial is less than or equal to 11, and the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8. When selecting a polynomial, the order and the number of non-zero terms should be minimized to reduce the complexity and power consumption of the pilot symbol generation structure. Given a target polynomial, there may not be a seed that results in good autocorrelation and cross-correlation between the target polynomial and the pilot symbol sequence determined by the seed. Therefore, the selection of the target polynomial is not merely about minimizing the order and the number of non-zero terms; it also requires considering whether a corresponding seed can be selected that results in good autocorrelation and cross-correlation characteristics of the generated pilot symbol sequence, including its real and imaginary parts, to improve the quality of the recovered signal at the receiving end.

[0166] In some possible implementations, the target polynomial is one of the following: 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; 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; x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x + 1; x 11 +a 10 ×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。

[0167] In some possible embodiments, in one polarization direction, a first bit sequence including 3×H bits is generated by the target polynomial and the seed, and each consecutive 3 bits in the first bit sequence corresponds to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing. It should be understood that there are a total of 8 combinations of the values of 3 bits, which can just correspond to the 8 values of N TP symbols respectively, improving the feasibility of the present solution.

[0168] In some possible embodiments, each consecutive 3 bits in the first bit sequence are respectively b 3t 、b 3t+1 、b 3t+2 , 0 ≤ t < H, and each consecutive 3 bits in the first bit sequence and the corresponding target symbol satisfy the relationship shown in one of the following tables.

[0169] Table 1-1a

[0170] Table 1-2a

[0171] Table 1-3a

[0172] Table 1-4a

[0173] Table 1-5a

[0174] Table 1-6a

[0175] Table 1-7a

[0176] Table 1-8a

[0177] Table 1-9a

[0178] Table 1-10a

[0179] Table 1-11a

[0180] Table 1-12a

[0181] In some possible embodiments, in one polarization direction, a first bit sequence including 3×H bits is generated by the target polynomial and the seed. Each consecutive 3 bits in the first bit sequence correspond to 4 bits, and the 4 bits are symbol-mapped to obtain a target symbol with values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0182] In some possible embodiments, each consecutive 3 bits in the first bit sequence are respectively b 3t , b 3t+1 , b 3t+2 , where 0 ≤ t < H, and each consecutive 3 bits in the first bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0183] Table 1-1b

[0184] Table 1-2b

[0185] Table 1-3b

[0186] Table 1-4b

[0187] Table 1-5b

[0188] Table 1-6b

[0189] Table 1-7b

[0190] Table 1-8b

[0191] Table 1-9b

[0192] Table 1-10b

[0193] Table 1-11b

[0194] Table 1-12b

[0195] In some possible implementations, the H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and the H target symbols in the second polarization direction are generated by the target polynomial, the third seed, and the fourth seed. The target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, and the target polynomial and the second seed are used to obtain the magnitude of each target symbol in the first polarization direction. Similarly, the target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the fourth seed are used to obtain the magnitude of each target symbol in the second polarization direction.

[0196] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every three bits, which are two consecutive bits in the second bit sequence and one bit in the third bit sequence, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every three bits, which are two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing is carried out.

[0197] In some possible embodiments, every two consecutive bits in the second bit sequence or the fourth bit sequence are b 2t and b 2t+1 , and one bit in the third bit sequence or the fifth bit sequence is s t , where 0 ≤ t < H. The relationship between every two consecutive bits in the second bit sequence and one bit in the third bit sequence and the corresponding target symbol satisfies one of the relationships shown in the following tables, and the relationship between every two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence and the corresponding target symbol satisfies one of the relationships shown in the following tables.

[0198] Table 2-1a

[0199] Table 2-2a

[0200] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0201] In some possible embodiments, every consecutive 2 bits in the second bit sequence or the fourth bit sequence are respectively b 2t and b 2t+1 , and 1 bit in the third bit sequence or the fifth bit sequence is s t , where 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0202] Table 2-1b

[0203] Table 2-2b

[0204] In some possible embodiments, H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and H target symbols in the second polarization direction are generated by the target polynomial, the second seed, and the third seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, the target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction and the amplitude of each target symbol in the second polarization direction.

[0205] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing.

[0206] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol.

[0207] Table 3-1a

[0208] Table 3-2a

[0209] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0210] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , where 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and one bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and the other bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0211] Table 3-1b

[0212] Table 3-2b

[0213] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a pre-framing symbol and at least one of two symbols: a frame synchronization symbol and a reserved symbol. In the first type of subframe, the training symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which also includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0214] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a frame synchronization symbol, a reserved symbol, and a pre-framing symbol. In the first type of subframe, the training symbol is located before the frame synchronization symbol, the frame synchronization symbol is located before the reserved symbol, and the reserved symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which further includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0215] In some possible implementations, N g The values ​​are 32, 64, 96, or 128.

[0216] In some possible implementations, each of the T training symbols takes the value -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. It should be understood that all the values ​​of the training symbols are within the outer ring of the constellation diagram. In this case, the training symbols have better sensitivity, which is beneficial for link training, makes the receiver signal processing more robust, and helps improve the quality of the recovered signal at the receiver.

[0217] In some possible implementations, T = 11, M = 114.

[0218] In some possible implementations, in the first polarization direction, the values ​​of the 11 training symbols are: -A2+A2j, A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, A2+A2j, -A2-A2j, -A2-A2j, A2+A2j, A2-A2j, A2-A2j; and in the second polarization direction, the values ​​of the 11 training symbols are: -A2-A2j, -A2-A2j, A2-A2j, -A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j, A2-A2j.

[0219] In some possible implementations, A1 = 1 and A2 = 3; or and

[0220] In some possible embodiments, each of the pilot symbols is located at the starting position within the consecutive N g symbols where it is located.

[0221] In a fourth aspect, an embodiment of the present application provides a data transmission device, including a receiving unit. The receiving unit is configured to: receive a second data frame transmitted through a channel from a first data frame, the first data frame including a plurality of sub-frames, the sub-frame including training symbols and pilot symbols, wherein, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, the N g is an integer greater than 1, among the total N TP symbols including all the training symbols and all the pilot symbols in the sub-frame, at least one symbol takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j, and among the N TP symbols of the sub-frame, at least one symbol takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j, where A1 and A2 are both non-zero real numbers and A1 < A2, and j represents the imaginary unit.

[0222] In some possible embodiments, the data transmission device further includes a processing unit, and the processing unit is configured to: perform signal processing on the second data frame.

[0223] In some possible embodiments, in one polarization direction, the number of training symbols in the sub-frame is T, the number of pilot symbols in the sub-frame is M, both T and M are integers greater than 0, and there is one symbol in the sub-frame that is both a training symbol and a pilot symbol, and N TP = T + M - 1. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols. When calculating the number of symbols of the N TP symbols, it is necessary to consider that there is one symbol in the sub-frame that is both a pilot symbol and a training symbol.

[0224] In some possible embodiments, T is an even number and M is an odd number, or T is an odd number and M is an even number.

[0225] In some possible embodiments, in one polarization direction, the number of training symbols in the sub-frame is T, the number of pilot symbols in the sub-frame is M, both T and M are integers greater than 0, and N TP = T + M. It should be understood that the N TP symbols are obtained by combining the T training symbols and the M pilot symbols.

[0226] In some possible implementations, T is even and M is even, or T is odd and M is odd.

[0227] In some possible implementations, the N TP The sum of all the symbols is 0. That is to say, N TP The sum of the real parts of the complex numbers corresponding to each symbol is 0, and the sum of the imaginary parts is also 0, which satisfies DC balance and helps improve the quality of the recovered signal at the receiving end.

[0228] In some possible implementations, the N TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0229] In some possible implementations, the N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, where N... TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where N is the number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. TP = N1 + N2, where N1 and N2 are both integers greater than 0. That is, in this implementation, N... TP Each symbol takes one of eight complex numbers: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, which better suits the DP-16QAM scenario.

[0230] In some possible implementations, the sum of the N1 symbols is 0, the sum of the N2 symbols is 0, and both N1 and N2 are even numbers. That is, the N1 symbols corresponding to the inner circle of the constellation diagram satisfy DC balance, and the N2 symbols corresponding to the outer circle of the constellation diagram also satisfy DC balance, such that all N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0231] In some possible implementations, among the N1 symbols, the number of symbols with the value -A1-A1j is d1, the number of symbols with the value -A1+A1j is d2, the number of symbols with the value A1-A1j is d3, and the number of symbols with the value A1+A1j is d4, where d1 = d4, d2 = d3, and N1 = d1 + d2 + d3 + d4. Among the N2 symbols, the number of symbols with the value -A2-A2j is d5, the number of symbols with the value -A2+A2j is d6, the number of symbols with the value A2-A2j is d7, and the number of symbols with the value A2+A2j is d8, where d5 = d8, d6 = d7, and N2 = d5 + d6 + d7 + d8. This ensures that the sum of the N1 symbols is 0, and the sum of the N2 symbols is 0, such that N... TP Each symbol satisfies DC balance, which helps improve the quality of the recovered signal at the receiving end.

[0232] In some possible implementations, N1 ≥ N2. As an example, Probabilistic Constellation Shaping (PCS) is employed to change the probability of constellation points appearing while keeping their positions constant, resulting in a non-uniform distribution and thus improving system transmission performance. Typically, before framing, the probability of a symbol being on the inner circle of a constellation point is greater than the probability of it being on the outer circle. In this case, consider the N... TP The number of constellation points in the inner circle of the constellation diagram among the symbols is greater than N. TP The number of constellation points in the outer ring of the constellation diagram among the symbols, i.e., N1 > N2, such that N TP The transmission performance cost caused by each symbol is relatively low. As another example, using traditional Quadrature Amplitude Modulation (QAM), the probability of a symbol being a constellation point symbol is the same before framing. In this case, consider N1 = N2 = N... TP / 2.

[0233] In some possible implementations, the subframe includes a total of 2×N training symbols and pilot symbols in both polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​-A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all N. TP / 4. This effectively ensures that the number of symbols for each value approaches balance, and also ensures that the sequence composed of all training symbols and all pilot symbols achieves DC balance, which is beneficial to improving the quality of the recovered signal at the receiving end.

[0234] In some possible implementations, in one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0. The T training symbols included in the subframe in the first polarization direction are different from the T training symbols included in the subframe in the second polarization direction, and the M pilot symbols included in the subframe in the first polarization direction are different from the M pilot symbols included in the subframe in the second polarization direction. This facilitates the receiving end in distinguishing the two polarization directions of the first data frame.

[0235] In some possible implementations, the first data frame uses a symbol mapping scheme of dual-polarization 16-ary Quadrature Amplitude Modulation (DP-16QAM), where A1 / A2 = 1 / 3. Alternatively, the first data frame uses a symbol mapping scheme of dual-polarization 64-ary Quadrature Amplitude Modulation (DP-64QAM), where A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7.

[0236] In some possible implementations, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all M pilot symbols, H = M. Alternatively, in one polarization direction, H target symbols are generated from a target polynomial and a seed, the H target symbols comprising all T training symbols and all M pilot symbols, H = N. TP .

[0237] In some possible implementations, the order of the target polynomial is less than or equal to 11, and the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8. When selecting a polynomial, the order and the number of non-zero terms should be minimized to reduce the complexity and power consumption of the pilot symbol generation structure. Given a target polynomial, there may not be a seed that results in good autocorrelation and cross-correlation between the target polynomial and the pilot symbol sequence determined by the seed. Therefore, the selection of the target polynomial is not merely about minimizing the order and the number of non-zero terms; it also requires considering whether a corresponding seed can be selected that results in good autocorrelation and cross-correlation characteristics of the generated pilot symbol sequence, including its real and imaginary parts, to improve the quality of the recovered signal at the receiving end.

[0238] In some possible implementations, the target polynomial is one of the following: 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; 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; x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1; x 11 +a 10 ×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.

[0239] In some possible implementations, in one polarization direction, a first bit sequence comprising 3×H bits is generated by the target polynomial and the seed. Each consecutive three bits in the first bit sequence correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. This implementation is suitable for scenarios where dual polarization symbol mapping is performed before framing. It should be understood that there are a total of 8 combinations of the 3 bits, which can correspond to N... TP The eight possible values ​​for each symbol improve the feasibility of this solution.

[0240] In some possible implementations, every three consecutive bits in the first bit sequence are b 3t b3t+1 and b 3t+2 where 0 ≤ t < H, and each consecutive 3 bits in the first bit sequence satisfy the relationship shown in one of the following tables with the corresponding target symbol.

[0241] Table 1-1a

[0242] Table 1-2a

[0243] Table 1-3a

[0244] Table 1-4a

[0245] Table 1-5a

[0246] Table 1-6a

[0247] Table 1-7a

[0248] Table 1-8a

[0249] Table 1-9a

[0250] Table 1-10a

[0251] Table 1-11a

[0252] Table 1-12a

[0253] In some possible embodiments, in one polarization direction, the first bit sequence including 3×H bits is generated by the target polynomial and the seed, and each consecutive 3 bits in the first bit sequence correspond to 4 bits, and the 4 bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping.

[0254] In some possible embodiments, each consecutive 3 bits in the first bit sequence are respectively b 3t and b 3t+1 and b 3t+2, where \(0\leq t < H\), each consecutive 3 bits in the first bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0255] Table 1-1b

[0256] Table 1-2b

[0257] Table 1-3b

[0258] Table 1-4b

[0259] Table 1-5b

[0260] Table 1-6b

[0261] Table 1-7b

[0262] Table 1-8b

[0263] Table 1-9b

[0264] Table 1-10b

[0265] Table 1-11b

[0266] Table 1-12b

[0267] In some possible embodiments, the \(H\) target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and the \(H\) target symbols in the second polarization direction are generated by the target polynomial, the third seed, and the fourth seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction. The target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the fourth seed are used to obtain the amplitude of each target symbol in the second polarization direction.

[0268] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every three bits, which are two consecutive bits in the second bit sequence and one bit in the third bit sequence, correspond to a target symbol with values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every three bits, which are two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence, correspond to a target symbol with values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing is carried out.

[0269] In some possible embodiments, every two consecutive bits in the second bit sequence or the fourth bit sequence are b 2t and b 2t+1 , and one bit in the third bit sequence or the fifth bit sequence is s t , where 0 ≤ t < H. The relationship between every two consecutive bits in the second bit sequence, one bit in the third bit sequence and the corresponding target symbol satisfies one of the relationships shown in the following tables, and the relationship between every two consecutive bits in the fourth bit sequence, one bit in the fifth bit sequence and the corresponding target symbol satisfies one of the relationships shown in the following tables.

[0270] Table 2-1a

[0271] Table 2-2a

[0272] In some possible embodiments, on the first polarization direction, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence including H bits is generated by the target polynomial and the second seed. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits. The 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. On the second polarization direction, a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence including H bits is generated by the target polynomial and the fourth seed. Every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence, a total of 3 bits, correspond to 4 second bits. The 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0273] In some possible embodiments, every consecutive 2 bits in the second bit sequence or the fourth bit sequence are respectively b 2t and b 2t+1 , and 1 bit in the third bit sequence or the fifth bit sequence is s t , where 0 ≤ t < H. Every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every consecutive 2 bits in the fourth bit sequence and 1 bit in the fifth bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0274] Table 2-1b

[0275] Table 2-2b

[0276] In some possible embodiments, H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and H target symbols in the second polarization direction are generated by the target polynomial, the second seed, and the third seed. Among them, the target polynomial and the first seed are used to obtain the quadrant of each target symbol in the first polarization direction, the target polynomial and the third seed are used to obtain the quadrant of each target symbol in the second polarization direction, and the target polynomial and the second seed are used to obtain the amplitude of each target symbol in the first polarization direction and the amplitude of each target symbol in the second polarization direction.

[0277] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every consecutive 2 bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j; in the second polarization direction, every consecutive 2 bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to a target symbol taking values of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where dual-polarization symbol mapping is performed first and then framing.

[0278] In some possible embodiments, every consecutive 2 bits in the second bit sequence are respectively and Every consecutive 2 bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , 0 ≤ t < H. The relationship between every consecutive 2 bits in the second bit sequence, one bit in the third bit sequence, and the corresponding target symbol satisfies one of the relationships shown in the following tables, and the relationship between every consecutive 2 bits in the fourth bit sequence, the other bit in the third bit sequence, and the corresponding target symbol satisfies one of the relationships shown in the following tables.

[0279] Table 3-1a

[0280] Table 3-2a

[0281] In some possible embodiments, a second bit sequence including 2×H bits is generated by the target polynomial and the first seed, a third bit sequence including 2×H bits is generated by the target polynomial and the second seed, and a fourth bit sequence including 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every 2 consecutive bits in the second bit sequence and 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 first bits, and the 4 first bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j; in the second polarization direction, every 2 consecutive bits in the fourth bit sequence and the other 1 bit in the third bit sequence, a total of 3 bits, correspond to 4 second bits, and the 4 second bits are symbol-mapped to obtain a target symbol with a value of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, or A2 + A2j. This embodiment is applicable to the scenario where framing is performed first and then dual-polarization symbol mapping is performed.

[0282] In some possible embodiments, every 2 consecutive bits in the second bit sequence are respectively and Every 2 consecutive bits in the fourth bit sequence are respectively and One bit in the third bit sequence is s 2t , and the other bit in the third bit sequence is s 2t+1 , where 0 ≤ t < H. Every 2 consecutive bits in the second bit sequence and one bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables, and every 2 consecutive bits in the fourth bit sequence and the other bit in the third bit sequence and the corresponding 4 bits satisfy the relationship shown in one of the following tables.

[0283] Table 3-1b

[0284] Table 3-2b

[0285] In some possible implementations, the subframe arranged in the first position in the data frame is a first type of subframe. The first type of subframe further includes a pre-framing symbol and at least one of two symbols: a frame synchronization symbol and a reserved symbol. In the first type of subframe, the training symbol is located before the pre-framing symbol. The data frame includes at least one second type of subframe, which also includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0286] In some possible implementations, the subframe arranged in the first position in the first data frame is a first type of subframe. The first type of subframe further includes a frame synchronization symbol, a reserved symbol, and a pre-framing symbol. In the first type of subframe, the training symbol is located before the frame synchronization symbol, the frame synchronization symbol is located before the reserved symbol, and the reserved symbol is located before the pre-framing symbol. The first data frame includes at least one second type of subframe, and the second type of subframe further includes a pre-framing symbol. In the second type of subframe, the training symbol is located before the pre-framing symbol.

[0287] In some possible implementations, N g The values ​​are 32, 64, 96, or 128.

[0288] In some possible implementations, each of the T training symbols takes the value -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. It should be understood that all the values ​​of the training symbols are within the outer ring of the constellation diagram. In this case, the training symbols have better sensitivity, which is beneficial for link training, makes the receiver signal processing more robust, and helps improve the quality of the recovered signal at the receiver.

[0289] In some possible implementations, T = 11, M = 114.

[0290] In some possible implementations, in the first polarization direction, the values ​​of the 11 training symbols are: -A2+A2j, A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, A2+A2j, -A2-A2j, -A2-A2j, A2+A2j, A2-A2j, A2-A2j; and in the second polarization direction, the values ​​of the 11 training symbols are: -A2-A2j, -A2-A2j, A2-A2j, -A2+A2j, -A2+A2j, A2+A2j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j, A2-A2j.

[0291] In some possible implementations, A1 = 1 and A2 = 3; or and

[0292] In some possible implementations, each pilot symbol is located in a consecutive N... g The starting position of each symbol.

[0293] Fifthly, embodiments of this application provide a chip for performing the methods described in any of the first or second aspects.

[0294] In a sixth aspect, embodiments of this application provide an optical module, which includes a processor and an interface. The interface is used to transmit and receive signals, and the processor is used to execute the methods described in any embodiment of the first aspect. For example, the interface is used to transmit signals from the processor or to transmit received signals to the processor.

[0295] In a seventh aspect, embodiments of this application provide a transmitting device. The transmitting device includes a host-side device and an optical module as described in the sixth aspect, the optical module being used to convert electrical signals from the host-side device into optical signals and to transmit the optical signals.

[0296] Eighthly, embodiments of this application provide an optical module including a processor and an interface. The interface is used for transmitting and receiving signals, and the processor is used to execute the methods described in any embodiment of the second aspect. For example, the interface is used to transmit signals from the processor or to transmit received signals to the processor.

[0297] Ninthly, embodiments of this application provide a receiving device. The receiving device includes a host-side device and an optical module as described in the eighth aspect, the optical module being used to convert a received optical signal into an electrical signal and transmit the electrical signal to the host-side device.

[0298] In a tenth aspect, embodiments of this application provide a communication system including a transmitting device as described in the seventh aspect and a receiving device as described in the ninth aspect, wherein the transmitting device is used to transmit an optical signal to the receiving device.

[0299] 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 embodiment of the first or second aspect to be implemented.

[0300] 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

[0301] Figure 1 is a schematic diagram of a communication system applied in an embodiment of this application;

[0302] Figure 2(a) is a schematic diagram of one implementation of the starting DSP processor in an embodiment of this application;

[0303] Figure 2(b) is a schematic diagram of another implementation of the DSP processor in this application;

[0304] Figure 2(c) is a schematic diagram of another embodiment of the DSP processor in this application;

[0305] Figure 2(d) is a schematic diagram of another embodiment of the DSP processor in this application.

[0306] Figure 3 is a schematic diagram of a data transmission method in an embodiment of this application;

[0307] Figure 4 is a schematic diagram of a data frame structure in an embodiment of this application;

[0308] Figure 5 is a schematic diagram of a subframe structure in a data frame according to an embodiment of this application;

[0309] Figure 6 is a schematic diagram of another structure of a subframe in a data frame in an embodiment of this application;

[0310] Figure 7 is a schematic diagram of a constellation diagram according to an embodiment of this application;

[0311] Figure 8(a) is a schematic diagram of the first target symbol generation structure in the embodiments of this application;

[0312] Figure 8(b) is a schematic diagram of the second target symbol generation structure in the embodiments of this application;

[0313] Figure 8(c) is a schematic diagram of the third target symbol generation structure in the embodiments of this application;

[0314] Figure 8(d) is a schematic diagram of the fourth target symbol generation structure in the embodiments of this application;

[0315] Figure 9(a) is a schematic diagram of the fifth target symbol generation structure in the embodiments of this application;

[0316] Figure 9(b) is a schematic diagram of the sixth target symbol generation structure in the embodiments of this application;

[0317] Figure 10(a) is a schematic diagram of the seventh target symbol generation structure in the embodiments of this application;

[0318] Figure 10(b) is a schematic diagram of the eighth target symbol generation structure in the embodiments of this application;

[0319] Figure 11 is a schematic diagram of the specific structure of a data frame in an embodiment of this application;

[0320] Figure 12 is a schematic diagram of a data transmission device in an embodiment of this application;

[0321] Figure 13 is a schematic diagram of another structure of the data transmission device in an embodiment of this application;

[0322] Figure 14 is a schematic diagram of a structure of an optical module in an embodiment of this application;

[0323] Figure 15 is a schematic diagram of a transmitting device in an embodiment of this application;

[0324] Figure 16 is a schematic diagram of a receiving device in an embodiment of this application. Detailed Implementation

[0325] This application provides a data transmission method, apparatus, and system that have a low cost in terms of actual transmission performance and are beneficial for improving the quality of signal recovery at the receiving end, and can be well applied to various coherent transmission scenarios.

[0326] It should be noted that the terms "first," "second," etc., in this application specification, claims, and the accompanying drawings are used to distinguish similar objects, not to limit a specific order or sequence. It should be understood that the above terms can be used interchangeably where appropriate so that the embodiments described in this application can be implemented in a sequence other than that described in this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0327] Figure 1 is a schematic diagram of a communication system applied in an embodiment of this application. As shown in Figure 1, at the transmitting end, the source provides a data stream to be transmitted. A forward error correction (FEC) encoder receives the data stream and performs FEC encoding on it. The codeword information obtained by combining the parity bits and information bits is sent to the transmitting end digital signal processing (DSP) processor for framing, and then transmitted through the channel to the receiving end. After receiving the distorted signal caused by noise or other impairments in the channel, the receiving end sends it to the receiving end DSP processor for dispersion compensation, synchronization, phase recovery, and other operations. Then, it is decoded by the FEC decoder to recover the original data and send it to the destination. The above-mentioned framing can also be called DSP framing.

[0328] Figure 2(a) is a schematic diagram of one implementation of the transmitting DSP processor in this application. As shown in Figure 2(a), in one possible implementation, the transmitting DSP processor performs dual-polarization symbol mapping 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. Therefore, the sending DSP processor performs framing processing on a certain number of dual-polarization symbols as follows: specifically, it obtains a pre-framing dual-polarization symbol sequence containing multiple dual-polarization symbols, and inserts multiple preset symbols in both the X-polarization direction and the Y-polarization direction to obtain a post-framing dual-polarization symbol sequence. It should be understood that the preset symbols are the symbols added during the framing operation.

[0329] In this embodiment, the pre-framing dual-polarization symbols are also called payload symbols, which include FEC-encoded information and parity bits, and are obtained by symbol mapping (called information symbols and parity symbols). The post-framing dual-polarization symbol sequence is called a data frame, also known as a frame or DSP frame. For ease of introduction, this embodiment of the application uniformly refers to the post-framing dual-polarization symbol sequence as a data frame. Multiple preset symbols include multiple training symbols and multiple pilot symbols. Multiple preset symbols are also called preset symbol sequences or preset sequences. Multiple training symbols are also called training symbol sequences or training sequences. Multiple pilot symbols are also called pilot symbol sequences or pilot sequences. Typically, the preset symbols are not completely identical in the X-polarization direction and the Y-polarization direction. That is, at at least one position, the values ​​of the preset symbols in the X-polarization direction and the Y-polarization direction are different.

[0330] 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.

[0331] It should be noted that a sequence with N0 dual-polarization symbols can be completely represented by two complex sequences of length N0, one representing the symbol in the X-polarization direction and the other representing the symbol in the Y-polarization direction. Each complex sequence of length N0 is represented by a sequence of N0 real parts (also called the I-path sequence) and a sequence of N0 imaginary parts (also called the Q-path sequence), where N0 is an integer greater than 1. Therefore, there are four different types of sequences, including the X-polarization I-path (in-phase component) sequence, the X-polarization Q-path (quadrature-phase component) sequence, the Y-polarization I-path sequence, and the Y-polarization Q-path sequence. The X-polarization I-path sequence is also called the X... IThe 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.

[0332] 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).

[0333] It should be understood that in the dual-polarization symbol mapping and framing operation shown in Figure 2(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 of the originating DSP processor, where framing is performed before dual-polarization symbol mapping, that is, framing is performed on the bit level.

[0334] Figure 2(b) is a schematic diagram of another implementation of the sending DSP processor in this application. As shown in Figure 2(b), framing is performed before dual-polarization symbol mapping. Specifically, a pre-framing bit sequence containing multiple bits is obtained, a preset bit sequence is inserted, and dual-polarization symbol mapping is performed to obtain a post-framing dual-polarization symbol sequence. The preset bit sequence is then processed by dual-polarization symbol mapping to obtain a preset symbol sequence, which is also referred to as the bits corresponding to the preset sequence. It should be understood that the post-framing dual-polarization symbol sequence obtained by using the implementation shown in Figure 2(b) is the same as the post-framing dual-polarization symbol sequence obtained by using the implementation shown in Figure 2(a).

[0335] Figure 2(c) is a schematic diagram of another embodiment of the transmitting DSP processor in this application. As shown in Figure 2(c), framing is performed before dual-polarization symbol mapping. Specifically, two pre-framing bit sequences containing multiple bits are obtained respectively. A first preset bit sequence and a second preset 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 preset bit sequence is symbol mapped to obtain a preset symbol sequence in the X-polarization direction, and the second preset bit sequence is symbol mapped to obtain a preset symbol sequence in the Y-polarization direction. The first preset bit sequence is also called the bit corresponding to the preset sequence in the X-polarization direction, and the second preset bit sequence is also called the bit corresponding to the preset 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 2(c) is the same as the post-framing dual-polarization symbol sequence obtained by the embodiment shown in Figure 2(a).

[0336] Figure 2(d) is a schematic diagram of another embodiment of the originating DSP processor in this application. As shown in Figure 2(d), framing is performed before dual-polarization symbol mapping. Specifically, four pre-framing bit sequences containing multiple bits are obtained respectively. A first preset bit sequence, a second preset bit sequence, a third preset bit sequence, and a fourth preset 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 post-framing dual-polarization symbol sequence. The first preset bit sequence is symbol mapped to obtain the I-path component of the preset symbol sequence in the X-polarization direction; the second preset bit sequence is symbol mapped to obtain the Q-path component of the preset symbol sequence in the X-polarization direction; the third preset bit sequence is symbol mapped to obtain the I-path component of the preset symbol sequence in the Y-polarization direction; and the fourth preset bit sequence is symbol mapped to obtain the Q-path component of the preset symbol sequence in the Y-polarization direction. The first preset bit sequence is also called the preset sequence in the X-polarization direction. I The bits corresponding to the components, the second preset bit sequence, also known as the preset sequence in X Q The bits corresponding to the components, the third preset bit sequence, also known as the preset sequence in Y I The bits corresponding to the components, the fourth preset bit sequence, also known as the preset sequence 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 2(d) before framing is the same as the framed dual-polarization symbol sequence obtained by using the implementation shown in Figure 2(a).

[0337] It should be noted that this application does not limit the specific framing method adopted by the sending DSP processor. In addition to the framing methods described in Figures 2(a), 2(b), 2(c), and 2(d), other similar framing methods are also applicable to this scheme, and will not be described in detail here.

[0338] In some specific applications, the aforementioned multiple preset symbols, in addition to including multiple training symbols and multiple pilot symbols, may also include at least one of a Frame Alignment Word Sequence (FAW Sequence) and a Reserved Symbol Sequence. In this case, the data frame is also called a multi-frame or super-frame, or simply a frame. Optionally, the reserved symbols may also be called fixed stuff (FS), and the frame alignment symbols may also be called a multi-frame alignment signal (MFAS). Typically, in the first type of subframe, the training symbols are located before the pre-framing symbols. In the second type of subframe, the training symbols are located before the pre-framing symbols.

[0339] In some specific applications, the subframe positioned first in the first data frame is a first-type subframe. This first-type subframe further includes a frame synchronization symbol, a reserved symbol, and a pre-framing symbol. In this first-type subframe, the training symbol precedes the frame synchronization symbol, the frame synchronization symbol precedes the reserved symbol, and the reserved symbol precedes the pre-framing symbol. The first data frame includes at least one second-type subframe, which also includes a pre-framing symbol. In this second-type subframe, the training symbol precedes the pre-framing symbol.

[0340] Figure 3 is a schematic diagram of a data transmission method according to an embodiment of this application. As shown in Figure 3, the data transmission method includes the following steps.

[0341] 101. The sending end obtains the data frame.

[0342] It should be noted that this application does not limit the specific implementation method of generating data frames. For example, the dual-polarization symbol mapping and framing method described in Figures 2(a), 2(b), 2(c), or 2(d) can be used. Of course, other similar dual-polarization symbol mapping and framing methods are also applicable to this scheme, and will not be described in detail here. It should be understood that a data frame includes symbols in two polarization directions. The structure of the data frame is similar in both polarization directions. For example, a data frame includes a symbol sequence in the X polarization direction and a symbol sequence in the Y polarization direction. The structure of the data frame will be described below using one polarization direction as an example.

[0343] Figure 4 is a schematic diagram of a data frame structure in an embodiment of this application. As shown in Figure 4, the data frame contains multiple subframes, each subframe containing T training symbols and M pilot symbols, where T and M are both integers greater than 0. The subframes mainly include two types: one type of subframe includes frame synchronization symbols, which is usually the first subframe, and the other subframes are the second type of subframes.

[0344] Figure 5 is a schematic diagram of a subframe structure in a data frame according to an embodiment of this application. As shown in example (a) of Figure 5, the first type of subframe contains T training symbols and M pilot symbols, one of which is both a training symbol and a pilot symbol. The first T symbols in the first type of subframe are training symbols, which can be used for link training and subframe synchronization. Typically, the first symbol of the subframe (the symbol at the starting position) is both a training symbol and a pilot symbol. Of course, it is also possible that any one of the first T symbols is both a training symbol and a pilot symbol; this application does not limit this. Furthermore, in the first type of subframe, every N g The symbols at fixed positions within the symbol set are pilot symbols used for carrier phase recovery. For example, the example in Figure 5(a) shows a set of symbols for each N... g The first symbol in the set of symbols is the pilot symbol. In some specific applications, the integer N... g The values ​​are 32, 64, 96, or 128. After T training symbols, N is the number of symbols. FAW A frame synchronization symbol is used for synchronization between superframes (also known as multiple frames). Furthermore, in N... FAW After the frame synchronization symbol, there are usually multiple reserved symbols, which can be reserved for other future uses. The reserved symbols can also be located in one of the multiple second-type subframes, and this application does not limit them.

[0345] As shown in example (b) of Figure 5, the second type of subframe contains T training symbols and M pilot symbols, where one symbol is both a training symbol and a pilot symbol. In the second type of subframe, the first T symbols are training symbols, and every N... g The symbol at a fixed position among the symbols is the pilot symbol. Typically, in the second type of subframe, apart from the training symbols and pilot symbols, the remaining symbols are pre-frame (payload) symbols.

[0346] Figure 6 is a schematic diagram of another structure of a subframe in a data frame according to an embodiment of this application. As shown in example (a) of Figure 6, the first type of subframe contains T training symbols and M pilot symbols. In the first type of subframe, each N g The symbols at fixed positions within a set of symbols are pilot symbols used for carrier phase recovery. For example, as shown in example (a) of Figure 6, with each N... gThe first symbol among the symbols is a pilot symbol. In the first type of subframe, starting from the second symbol, consecutive T symbols are training symbols, which can be used for link training and subframe synchronization. In some specific applications, the integer N g is 32, 64, 96 or 128. After the T training symbols are N FAW frame synchronization symbols, which are used for synchronization between superframes (also called multi-frames). In addition, after the N FAW frame synchronization symbols, there are usually multiple reserved symbols, which can be reserved for future other uses. The reserved symbols can also be located in one of the multiple second type of subframes, and this application does not make any limitations. It should be noted that compared with the data frame structure shown in FIG. 5, in the data frame structure shown in FIG. 6, there is no symbol that is both a training symbol and a pilot symbol.

[0347] It should be noted that in the embodiments of this application, specific schemes for T training symbols and M pilot symbols are mainly given, and no specific constraints are imposed on the frame synchronization symbols.

[0348] In the embodiments of this application, in one polarization direction, the subframe includes T training symbols and M pilot symbols, where T and M are integers greater than 0. Each of the training symbols and each of the pilot symbols takes a value of one of the 8 complex numbers: -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, A2 + A2j, where A1 and A2 are non-zero real numbers, and A1 < A2, and j represents the imaginary unit. And, the T training symbols and M pilot symbols together satisfy direct current balance.

[0349] It should be noted that for the data frame structure shown in FIG. 5, the first symbol in the subframe is both a training symbol and a pilot symbol, and the T training symbols and M pilot symbols together have a total of N TP = T + M - 1 symbols that satisfy direct current balance. That is, the sum of the N TP = T + M - 1 symbols is 0. More specifically, the sum of the real parts of the complex numbers corresponding to the N TP = T + M - 1 symbols is 0, and the sum of the imaginary parts is also 0, which can achieve direct current balance and is beneficial to improving the quality of the signal recovered by the receiving end. Here, A1j can also be written as A1 × j, and A2j can also be written as A2 × j. Considering that N TP is an even number to make the N TP=T+M-1 symbols may satisfy DC balance, therefore T is even and M is odd, or T is odd and M is even. It should be understood that, in the data frame structure shown in Figure 5, the total number of symbols combining the T training symbols and M pilot symbols is not T+M. It is necessary to consider that the first symbol is both a pilot symbol and a training symbol, so the total number of symbols needs to be subtracted by 1, meaning the total number of symbols is N. TP = T + M - 1 symbols.

[0350] It should be noted that, for the data frame structure shown in Figure 6, the T training symbols and M pilot symbols combined total N TP =T+M symbols satisfy DC balance. That is, the N TP =The sum of T+M symbols is 0. More specifically, the N... TP =The sum of the real parts of the complex numbers corresponding to T+M symbols is 0, and the sum of their imaginary parts is also 0, which achieves DC balance and helps improve the quality of the recovered signal at the receiving end. Here, A1j can also be written as A1×j, and A2j can also be written as A2×j. Consider N as N TP Only when N is an even number can the stated N be true. TP = T+M symbols may satisfy DC balance, therefore T is even and M is even, or T is odd and M is odd.

[0351] It should be understood that the real part of a complex number is also called the I-way component, and the imaginary part of a complex number is also called the Q-way component.

[0352] In this embodiment of the application, the T training symbols and M pilot symbols are combined to form a total of N. TP A symbol, which can be called N TP N training symbols and pilot symbols, where N TP =T+M-1 or N TP =T+M. For ease of explanation, N will be referred to as T+M below. TP The training symbols and pilot symbols are referred to as "N". TP "a symbol".

[0353] In some specific applications, the complex numbers -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, A2 + A2j are the constellation points corresponding to the adopted symbol mapping. It should be noted that -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j can be expressed as (-1 - 1j)×A1, (-1 + 1j)×A1, (1 - 1j)×A1, (1 + 1j)×A1, and -A2 - A2j, -A2 + A2j, A2 - A2j, A2 + A2j can be expressed as (-1 - 1j)×A2, (-1 + 1j)×A2, (1 - 1j)×A2, (1 + 1j)×A2. Considering A1 < A2, it should be understood that the 4 constellation points corresponding to -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j are the points in the inner ring of the constellation diagram, and the 4 constellation points corresponding to -A2 - A2j, -A2 + A2j, A2 - A2j, A2 + A2j are the points in the outer ring of the constellation diagram.

[0354] FIG. 7 is a schematic diagram of a constellation diagram in an embodiment of the present application. As shown in FIG. 7, the constellation diagram can be divided into four regions according to the horizontal axis and the vertical axis, and each region is called a quadrant. Among them, A1 + A1j and A2 + A2j are located in the first quadrant, -A1 + A1j and -A2 + A2j are located in the second quadrant, -A1 - A1j and -A2 - A2j are located in the third quadrant, and A1 - A1j and A2 - A2j are located in the fourth quadrant.

[0355] In some specific applications, taking the 16QAM symbol mapping as an example, A2 = 3×A1. The values of the 16 constellation points (also called symbols) on the 16QAM constellation diagram adopted are {±1 ± 1j, ±1 ± 3j, ±3 ± 1j, ±3 ± 3j}, with A1 = 1 and A2 = 3. As shown in the example of FIG. 7(a), hollow circles are used to represent the 4 outermost constellation points in the constellation diagram, that is, the symbols -3 - 3j, -3 + 3j, 3 - 3j, 3 + 3j; circles filled with vertical lines are used to represent the 4 innermost constellation points in the constellation diagram, that is, the symbols -1 - 1j, -1 + 1j, 1 - 1j, 1 + 1j.

[0356] It should be noted that, as shown in the example of (b) in FIG. 7, a 16QAM symbol mapping method is also given. A 16QAM symbol in the X polarization direction or the Y polarization direction is obtained by mapping 4 bits. For example, 0000 is mapped to -3 - 3j, 0101 is mapped to -1 - 1j, 0010 is mapped to -3 + 3j, 0111 is mapped to -1 + 1j, 1010 is mapped to 3 + 3j, 1111 is mapped to 1 + 1j, 1000 is mapped to 3 - 3j, and 1101 is mapped to 1 - 1j. In some other specific applications, taking 64QAM symbol mapping as an example. The values of the 64 symbols on the 64QAM constellation diagram used are one of {±1 ± 1j, ±1 ± 3j, ±1 ± 5j, ±1 ± 7j, ±3 ± 1j, ±5 ± 1j, ±7 ± 1j, ±3 ± 3j, ±3 ± 5j, ±3 ± 7j, ±5 ± 3j, ±7 ± 3j, ±5 ± 5j, ±5 ± 7j, ±7 ± 5j, ±7 ± 7j}, where A1 = 1 or 3 or 5, A2 = 3 or 5 or 7, and A1 < A2. That is, A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7. Typically, A1 = 3 and A2 = 5 are selected, so that the sensitivity of the training symbol or pilot symbol is better and the transmission performance cost is relatively low.

[0357] It should be understood that in some possible scenarios, in addition to the above 8 complex numbers of -A1 - A1j, -A1 + A1j, A1 - A1j, A1 + A1j, -A2 - A2j, -A2 + A2j, A2 - A2j, A2 + A2j, the training symbol or pilot symbol may also have more other values, and the specific number of possible values of the training symbol or pilot symbol is not limited here. Taking 64QAM symbol mapping as an example, the value of the training symbol or pilot symbol can also be -A3 - A3j, -A3 + A3j, A3 - A3j or A3 + A3j, where A3 is a real number not equal to 0, and A1 < A2 < A3. For example, A1 = 1, A2 = 3, A3 = 5. Another example is A1 = 3, A2 = 5, A3 = 7.

[0358] It should be noted that it is also possible to compress the symbols on the constellation diagram. Correspondingly, the values of A1 and A2 will also be compressed accordingly. For example, power normalization is performed on the 16 symbols on the 16QAM constellation diagram. At this time, the values of the 16 symbols on the 16QAM constellation diagram become There is and For example, when power normalization is performed on the 64 symbols on the 64QAM constellation diagram, there is or or or or And A1 <A2。

[0359] In this embodiment of the application, the N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, N TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where integer N1>0, integer N2>0, and N1+N2=N. TP It should be understood that the N mentioned above... TP The values ​​of the symbols are sometimes in the inner circle and sometimes in the outer circle of the constellation diagram, resulting in generally low noise and sensitivity for both training and pilot symbols, but with relatively low peak-to-average power ratio and transmission performance costs. Typically, N1 ≥ N2. It should also be understood that each of the N1 symbols can take the values ​​-A1-A1j, -A1+A1j, A1-A1j, or A1+A1j, but not all of these four values ​​may exist in the N1 symbols; for example, only two of the values ​​may be present. Similarly, each of the N2 symbols can take the values ​​-A2-A2j, -A2+A2j, A2-A2j, or A2+A2j, but not all of these four values ​​may be present in the N2 symbols; for example, only two of the values ​​may be present.

[0360] In some possible scenarios, for pilot symbols, some pilot symbols are among the aforementioned N1 symbols, and some are among the aforementioned N2 symbols; that is, some pilot symbol values ​​are in the inner circle of the constellation diagram, and some are in the outer circle. For training symbols, all training symbols are among the aforementioned N1 symbols, meaning all training symbol values ​​are in the inner circle of the constellation diagram; or, all training symbols are among the aforementioned N2 symbols, meaning all training symbol values ​​are in the outer circle of the constellation diagram. In this case, the training symbols have better sensitivity, which is beneficial for link training, making the receiver signal processing more robust and improving the quality of the recovered signal at the receiver; or, some training symbols are among the aforementioned N1 symbols, and some are among the aforementioned N2 symbols; that is, some training symbol values ​​are in the inner circle of the constellation diagram, and some are in the outer circle.

[0361] In some specific applications, probabilistic constellation shaping (PCS) is employed to alter the probability of constellation points appearing while keeping their positions constant, resulting in a non-uniform distribution and thus improving system transmission performance. Typically, before framing, the probability of a symbol being located within the inner circle of a constellation point is greater than the probability of it being located within the outer circle. In this case, considering the N... TPThe number of constellation points in the inner circle of the constellation diagram among the symbols is greater than N. TP The number of constellation points in the outer ring of the constellation diagram among the symbols, i.e., N1 > N2, such that N TP The transmission performance cost caused by each symbol is relatively low.

[0362] In other specific applications, traditional QAM modulation is used, where the probability of a symbol being a constellation point symbol is the same before framing. In this case, consider N1 = N2 = N TP / 2.

[0363] The following is an implementation of the N. TP A specific implementation method for achieving DC balance using N symbols. TP N1 symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j satisfy DC balance, meaning the sum of the N1 symbols in the inner circle is 0. The number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, and A1+A1j among the N1 symbols are d1, d2, d3, and d4 respectively, where d1 = d4, d2 = d3, and d1 + d2 + d3 + d4 = N1. On the other hand, the N... TP The N2 symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j also satisfy DC balance, meaning the sum of the N2 symbols on the outer ring is 0. The number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j among the N2 symbols are d5, d6, d7, and d8 respectively, where d5 = d8, d6 = d7, and d5 + d6 + d7 + d8 = N2. At this point, it can be guaranteed that the N... TP The symbol also achieves DC balance, which helps improve the quality of the recovered signal at the receiver. Here, N1 and N2 are both even numbers. In some specific applications, traditional QAM modulation is used, and considering N1 = N2 = N... TP / 2, at this time N TP The value of is a multiple of 4.

[0364] Furthermore, in one polarization direction, the N TP The number of each of the symbols -A1-A1j, -A1+A1j, A1-A1j, and A1+A1j differs from the number of each other by less than or equal to 2, and the N TP The number of symbols -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all less than or equal to 2. This effectively ensures that the number of symbols in each polarization direction is nearly balanced, which is beneficial to improving the quality of the recovered signal at the receiver.

[0365] It should also be noted that in some specific applications, the data frame includes a total of 2×N in both the X-polarization and Y-polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​that are -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j is N. TP / 4. At this point, the number of symbols is effectively balanced, which helps improve the quality of the signal recovered by the receiver.

[0366] In a data frame, the sequence of T training symbols in the X-polarization direction (also called the training sequence) is distinct from the sequence of T training symbols in the Y-polarization direction. Similarly, the sequence of M pilot symbols in the X-polarization direction (also called the pilot sequence) is distinct from the sequence of M pilot symbols in the Y-polarization direction. Specifically, the pilot sequence in the X-polarization direction and the training sequence in the Y-polarization direction differ in at least one training symbol, and the pilot sequence in the X-polarization direction and the pilot sequence in the Y-polarization direction differ in at least one pilot symbol. These two differences prevent the receiver from being unable to distinguish between the two polarization directions during actual transmission. For example, if the sequence of 8 training symbols in the X-polarization direction is -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j, then the sequence of 8 training symbols in the Y-polarization direction cannot be exactly the same, and can be -A1+A1j, -A1-A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, A2+A2j.

[0367] 102. The sending end sends a data frame to the receiving end.

[0368] The data frames sent by the transmitting end will be transmitted to the receiving end through the channel. In some possible scenarios, the dual-polarization symbols in the data frame will be converted from digital to analog (DAC) to obtain four analog signals, corresponding to the I component signal in the X polarization direction, the Q component signal in the X polarization direction, the I component signal in the Y polarization direction, and the Q component signal in the Y polarization direction, respectively, and then transmitted to the receiving end through optical fiber.

[0369] 103. The receiving end performs signal processing on the received data frames.

[0370] It should be understood that the data frame received by the receiving end is a data frame transmitted through the channel, which can be understood as a distorted signal affected by noise or other impairments in the channel. That is, the data frame received by the receiving end is different from the data frame sent by the sending end. For example, the data frame received by the receiving end is not aligned with the data frame sent by the sending end, and the receiving end needs to perform frame synchronization based on frame synchronization symbols or training symbols. The specific operations performed by the receiving end after receiving the data frame will not be described in detail in this application. For details, please refer to the system structure diagram shown in Figure 1. For example, the receiving end DSP processor performs signal processing on the received data frame, including operations such as dispersion compensation, synchronization, and phase recovery.

[0371] It should be noted that, in some specific applications, for the sake of hardware simplicity, the M pilot symbols of each subframe in the data frame are generated by a target polynomial and a seed. In other specific applications, the N pilot symbols of each subframe in the data frame... TP N symbols (including all T training symbols and all M pilot symbols, where N) TP =T+M-1 or N TP =T+M) is generated from the target polynomial and the seed. For simplicity, in one polarization direction, the multiple symbols generated from the target polynomial and the seed are referred to as the target symbol sequence, which contains H target symbols.

[0372] As an example, in the case where the M pilot symbols are generated by the target polynomial and the seed, the target symbol sequence consists of the M pilot symbols, and the total number of target symbols in each subframe is H = M.

[0373] As another example, for the N TP In the case where the symbols are generated from the target polynomial and the seed, the target symbol sequence consists of the T training symbols and M pilot symbols, and the total number of target symbols in each subframe is H = N. TP More specifically, for the data frame structure shown in Figure 5, the first symbol in the subframe is both the training symbol and the pilot symbol, where H = N. TP =T+M-1. For the data frame structure shown in Figure 6, there is no symbol in the subframe that is both a training symbol and a pilot symbol, so H=N TP =T+M.

[0374] The following section introduces several possible ways to generate H target symbols from multiple perspectives.

[0375] Firstly, the H target symbols in the X-polarization direction are generated by the target polynomial and the seed in the X-polarization direction; the H target symbols in the Y-polarization direction are generated by the target polynomial and the seed in the Y-polarization direction. In this embodiment, the same target generating polynomial (also called the target polynomial) can be used for target symbols in two orthogonal polarization directions. However, since the seeds used in the two polarization directions are different, the H target symbols obtained in the two polarization directions are not exactly the same.

[0376] Figure 8(a) is a schematic diagram of the first target symbol generation structure in the embodiment of this application. The target polynomial is a 10th-order polynomial, which can be expressed 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. Where a9…a1 can take the values ​​0 or 1.

[0377] 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 with non-zero coefficients; for example, the number of terms in the 10th-order polynomial mentioned above is equal to the number of non-zero terms in a9…a1 plus 2.

[0378] In some specific applications, the number of non-zero terms in a9…a1 is no greater than 6, meaning the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 8(a), 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 b9, b8, b7, b6, b5, b4, b3, b2, b1, b0, then 10 corresponding storage units are used. Of course, the seed can also be represented in hexadecimal or decimal. When it is used in operation with the target polynomial, it needs to be converted to binary form. For example, 0110111000 is represented as 0x1B8 in hexadecimal and 440 in decimal.

[0379] It should be noted that the polynomial x 10 +a9×x 9 +a8×x8 +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.

[0380] Figure 8(b) is a schematic diagram of the second target symbol generation structure in an embodiment of this application. The target polynomial is a 9th-order polynomial, which can be represented as: 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 a8…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a8…a1 is no greater than 6, meaning the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 8(b), the seed length is 9 bits, which can be represented in binary as b8, b7, b6, b5, b4, b3, b2, b1, b0. Of course, the seed can also be represented in hexadecimal or decimal, but it needs to be converted to binary form when operating with the target polynomial.

[0381] Figure 8(c) is a schematic diagram of the third target symbol generation structure in the embodiments of this application. The target polynomial is an 8th-order polynomial, which can be expressed as: x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2+a1×x+1. Where a7…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a7…a1 is no greater than 6, meaning the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 8(c), the seed length is 8 bits, which can be represented in binary as b7, b6, b5, b4, b3, b2, b1, b0. Of course, the seed can also be represented in hexadecimal or decimal, but it needs to be converted to binary form when operating with the target polynomial.

[0382] Figure 8(d) is a schematic diagram of the fourth target symbol generation structure in the embodiments of this application. The target polynomial is an 11th-order polynomial, which can be represented as: x 11 +a 10 ×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 a 10 …a1 can take the value 0 or 1. In some specific applications, a… 10 …The number of non-zero terms in a1 is no greater than 6, meaning the number of terms in the objective polynomial is greater than or equal to 2 and less than or equal to 8, resulting in low hardware implementation complexity. As shown in Figure 8(d), the seed length is 11 bits, which can be represented in binary as b. 10 b9, b8, b7, b6, b5, b4, b3, b2, b1, b0. Of course, the seed can also be represented in hexadecimal or decimal, but it needs to be converted to binary form when it is used in operation with the target polynomial.

[0383] In Figures 8(a), 8(b), 8(c), and 8(d), for a scenario requiring the generation of H target symbols in a polarization direction, a bit sequence b0, b1, b2, ... b, comprising 3 × H bits, is obtained based on the target polynomial and the seed. 3D-1 The aforementioned bit sequence is also called a pseudo-random binary sequence (PRBS). A bit sequence generated using an 8th-order polynomial is called PRBS8, a bit sequence generated using a 9th-order polynomial is called PRBS9, a bit sequence generated using a 10th-order polynomial is called PRBS10, and a bit sequence generated using an 11th-order polynomial is called PRBS11. Bit sequence b0, b1, b2, ... b 3D-1 In this context, every 3 consecutive bits are denoted as b.3t , b 3t+1 , b 3t+2 (0 ≤ t < D), the bit sequence b0, b1, b2, … b 3D-1 Among them, every 3 consecutive bits are used to map to one of the H target symbols. In some specific applications, b 3t and b 3t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, and b 3t+2 is used to obtain the amplitude corresponding to the target symbol; in some other specific applications, b 3t and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, and b 3t+1 is used to obtain the amplitude corresponding to the target symbol; in some other specific applications, b 3t+1 and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, and b 3t is used to obtain the amplitude corresponding to the target symbol.

[0384] In some specific applications, the framing operation is after the dual-polarization symbol mapping. For example, as shown in Figure 2(a), the above 3 consecutive bits b 3t , b 3t+1 , b 3t+2 are mapped to the target symbol where b 3t and b 3t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, and b 3t+2 is used to obtain the amplitude corresponding to the target symbol. The relationship between the values of the above 3 consecutive bits and the values of the target symbol is shown in Table 1-1a below.

[0385] Table 1-1a

[0386] In some specific embodiments, the framing operation is before the dual-polarization symbol mapping. For example, as shown in Figure 2(b), Figure 2(c) or Figure 2(d), the above 3 consecutive bits b 3t , b 3t+1 , b 3t+2The mapping is done using 4 bits. Table 1-1b below shows the correspondence between the values ​​of the three consecutive bits and the values ​​of the resulting 4 bits. These 4 bits are then symbolically mapped to obtain a target symbol: 0000 is symbolically mapped to -A2-A2j, 0101 to -A1-A1j, 0010 to -A2+A2j, 0111 to -A1+A1j, 1010 to A2+A2j, 1111 to A1+A1j, 1000 to A2-A2j, and 1101 to A1-A1j.

[0387] Table 1-1b

[0388] It should be noted that "symbol mapping" in the embodiments of this application refers to the operation of mapping bits to symbols, such as using symbol mapping methods like DP-16QAM or DP-64QAM. Taking DP-16QAM as an example, 8 bits undergo dual-polarization symbol mapping to obtain 1 DP-16QAM symbol, that is, 4 bits undergo symbol mapping to obtain 16QAM symbol in the polarization direction. The aforementioned "bit sequence b0, b1, b2, ... b 3D-1 Every three consecutive bits are used to map to one of the H target symbols, and the three consecutive bits b are used to map to one of the target symbols. 3t b 3t+1 b 3t+2 The "mapping" in "mapping to 4 bits" is a concept different from "symbol mapping." Specifically, taking the scenario shown in Figure 2(a) as an example, the mapping of 3 consecutive bits from the 3×H bits obtained by PRBS to obtain a target symbol can be understood as determining the value of the target symbol corresponding to the value of the 3 consecutive bits by looking up table 1-1a. This operation of looking up table 1-1a according to the correspondence is "mapping," or it can also be called "3 consecutive bits corresponding to 1 target symbol." Taking the scenarios shown in Figures 2(b)-2(d) as examples, the mapping of 3 consecutive bits from the 3×H bits obtained by PRBS to obtain 4 bits can be understood as determining the value of the 4 bits corresponding to the value of the 3 consecutive bits by looking up table 1-1b. This operation of looking up table 1-1b according to the correspondence is "mapping," or it can also be called "3 consecutive bits corresponding to 4 bits." Then, the 4 bits are symbol-mapped to obtain 1 target symbol. The "mapping" and "symbol mapping" appearing in similar embodiments below can be understood with reference to the description here.

[0389] It should be noted that the framing operation occurs before the dual polarization symbol mapping, as shown in Figure 2(b), Figure 2(c), or Figure 2(d), where the three consecutive bits b are... 3t b3t+1 b 3t+2 Four bits are obtained using the mapping rules shown in Table 1-1b. These four bits are then used for symbol mapping to obtain a target symbol. The obtained target symbol is mapped to the target symbol using the mapping rules shown in Table 1-1a. 3t b 3t+1 b 3t+2 The target symbols obtained by mapping are the same. Therefore, for simplicity, the embodiments of this application can combine Tables 1-1a and 1-1b as shown in Table 1-1 below. That is, Table 1-1 below is a complete correspondence table of 3 consecutive bits and their corresponding target symbols and 4 bits. For the schemes shown in Figures 2(a) to 2(d), they can all be implemented through Table 1-1. Therefore, Tables 1-2 to 3-2 provided later are complete correspondence tables similar to Table 1-1. Tables 1-2 to 3-2 can also be split into two tables in a similar way to Table 1-1a and Table 1-1b, to adapt to the scenarios shown in Figure 2(a) and Figures 2(b) to 2(d) respectively. They will not be described in detail below.

[0390] Table 1-1

[0391] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+2 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Table 1-2 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-2 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0392] Table 1-2

[0393] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b3t+1 and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-3 below. In some specific implementations, the framing operation is performed before dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-3 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0394] Table 1-3

[0395] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t+1 and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-4 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-4 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0396] Table 1-4

[0397] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+1The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-5 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-5 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0398] Table 1-5

[0399] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+1 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-6 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-6 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0400] Table 1-6

[0401] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+2 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-7 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-7 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0402] Table 1-7

[0403] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+2 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-8 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-8 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0404] Table 1-8

[0405] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t+1 and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Tables 1-9 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-9 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0406] Table 1-9

[0407] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t+1 and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Table 1-10 below. In some specific embodiments, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-10 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0408] Table 1-10

[0409] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b 3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+1 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Table 1-11 below. In some specific embodiments, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-11 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0410] Table 1-11

[0411] In other specific applications, the above three consecutive bits b 3t b 3t+1 b 3t+2 Mapped to target symbol Where b 3t and b3t+2 These two bits are used to obtain the quadrant corresponding to the target symbol, b 3t+1 The values ​​of the three consecutive bits used to obtain the amplitude corresponding to the target symbol are related to the values ​​of the target symbol as shown in Table 1-12 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the three consecutive bits b are used... 3t b 3t+1 b 3t+2 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 1-12 below shows the relationship between the values ​​of the above 3 consecutive bits and the values ​​of the 4 bits obtained by mapping.

[0412] Table 1-12

[0413] It should be noted that by designing the coefficients a in the 11th-order polynomial 10 The target polynomial and seed are determined by the values ​​of a1, or the coefficients a9…a1 in a 10th-order polynomial, or the coefficients a8…a1 in a 9th-order polynomial, or the coefficients a7…a1 in an 8th-order polynomial. This ensures that the real part sequence (also called the I-path) and imaginary part sequence (also called the Q-path) of the generated target symbol sequences in the two polarization directions have good autocorrelation and cross-correlation characteristics. More specifically, the designed target symbol sequence in the X-polarization direction, the real part sequence in the X-polarization direction, the imaginary part sequence in the Y-polarization direction, and the imaginary part sequence in the Y-polarization direction, a total of 4 D-bit sequences, have good autocorrelation and cross-correlation characteristics, which is beneficial to improving the quality of the recovered signal at the receiving end.

[0414] It should be noted that, as shown in Figures 8(a)-8(d), the order of the target polynomial and the number of non-zero terms in its coefficients affect the complexity of the target symbol generation structure. In this embodiment, when designing the target polynomial, the order of the polynomial must be constrained to be no greater than 11, and the number of non-zero terms must be no greater than 8. When selecting a polynomial, the order and number of non-zero terms of the target polynomial should be minimized to reduce the complexity and power consumption of the target symbol generation structure. It should also be noted that, given a target polynomial, there may not be a seed that ensures good autocorrelation and cross-correlation between the target polynomial and the target symbol sequence determined by the seed. Therefore, the selection of the target polynomial is not only about minimizing the order and the number of non-zero terms, but also about considering whether a corresponding seed can be selected that results in good autocorrelation and cross-correlation characteristics of the generated target symbol sequence, as well as its real and imaginary parts, to improve the quality of the recovered signal at the receiving end.

[0415] In this embodiment, polynomials of order less than or equal to 11, particularly 8th, 9th, 10th, or 11th order polynomials, and mainly higher-order polynomials, are considered. These do not significantly improve the sequence autocorrelation and cross-correlation properties of the generated target symbols. Lower-order polynomials, such as 6th and 7th order polynomials, while having lower implementation complexity, typically produce target symbols with insufficient sequence autocorrelation and cross-correlation properties. Furthermore, polynomials with no more than 8 terms are considered, as they have lower hardware implementation complexity.

[0416] Secondly, the H target symbols in the X-polarization direction are generated by the target polynomial, the first seed, and the second seed in the X-polarization direction; the H target symbols in the Y-polarization direction are generated by the target polynomial, the third seed, and the fourth seed in the Y-polarization direction.

[0417] The target polynomial and the first seed in the X-polarization direction are used to obtain the quadrant of each of the H target symbols, that is, to determine whether the i-th target symbol is A1+A1j or A2+A2j in the first quadrant, -A1+A1j or -A2+A2j in the second quadrant, -A1-A1j or -A2-A2j in the third quadrant, or A1-A1j or A2-A2j in the fourth quadrant.

[0418] The target polynomial and the second seed in the X-polarization direction are used to obtain the amplitude of each target symbol among the H target symbols, that is, to determine whether the i-th target symbol is located in the inner circle as -A1-A1j, -A1+A1j, A1-A1j or A1+A1j, or located in the outer circle as -A2-A2j, -A2+A2j, A2-A2j or A2+A2j.

[0419] The target polynomial in the Y-polarization direction and the third seed in the Y-polarization direction are used to obtain the quadrant of each of the H target symbols, that is, to determine whether the i-th target symbol is A1+A1j or A2+A2j in the first quadrant, -A1+A1j or -A2+A2j in the second quadrant, -A1-A1j or -A2-A2j in the third quadrant, or A1-A1j or A2-A2j in the fourth quadrant.

[0420] The target polynomial in the Y-polarization direction and the fourth seed in the Y-polarization direction are used to obtain the amplitude of each target symbol among the H target symbols, that is, to determine whether the i-th target symbol is located in the inner circle as -A1-A1j, -A1+A1j, A1-A1j or A1+A1j, or located in the outer circle as -A2-A2j, -A2+A2j, A2-A2j or A2+A2j.

[0421] In this embodiment of the application, the same target generating polynomial (also called target polynomial) can be used for target symbols in two orthogonal polarization directions. However, since the seeds used in the two polarization directions are different, the H target symbols obtained in the two polarization directions are not exactly the same.

[0422] Figure 9(a) is a schematic diagram of the fifth target symbol generation structure in the embodiments of this application. The target polynomial is a 10th-order 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. Where a9…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a9…a1 is no greater than 6, meaning the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 9(a), the length of the first seed used to obtain the quadrant of each symbol in the X-polarization direction is 10 bits, and the length of the third seed used to obtain the quadrant of each symbol in the Y-polarization direction is 10 bits. The first or third seed can be represented in binary form as b9, b8, b7, b6, b5, b4, b3, b2, b1, b0. Of course, the seeds can also be represented in hexadecimal or decimal, but need to be converted to binary form when operating with the target polynomial. The second seed used to obtain the amplitude of each symbol in the X-polarization direction has a length of 10 bits, and the fourth seed used to obtain the amplitude of each symbol in the Y-polarization direction has a length of 10 bits. The second seed or the fourth seed can be represented in binary form as s9, s8, s7, s6, s5, s4, s3, s2, s1, s0.

[0423] Figure 9(b) is a schematic diagram of the sixth target symbol generation structure in the embodiments of this application. The target polynomial is a 9th-order polynomial: 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 a8…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a8…a1 is no greater than 6, meaning the number of terms in the target polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 9(b), the length of the first seed used to obtain the quadrant of each symbol in the X-polarization direction is 9 bits, and the length of the third seed used to obtain the quadrant of each symbol in the Y-polarization direction is 9 bits. The first or third seed can be represented in binary as b8, b7, b6, b5, b4, b3, b2, b1, b0. Of course, the seeds can also be represented in hexadecimal or decimal, but need to be converted to binary form when operating with the target polynomial. The length of the second seed used to obtain the amplitude of each symbol in the X-polarization direction is 9 bits, and the length of the fourth seed used to obtain the amplitude of each symbol in the Y-polarization direction is 9 bits, which can be represented in binary as s8, s7, s6, s5, s4, s3, s2, s1, s0.

[0424] In Figures 9(a) and 9(b), for a scenario requiring the generation of H target symbols in a polarization direction, a bit sequence b0, b1, b2, ... b, comprising 2 × H bits, is obtained based on the target polynomial and the first seed. 2D-1 Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of H bits. D-1 The bit sequence b0, b1, b2, ... b 2D-1 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s D-1 1 bit s in t A total of 3 bits b 2t b 2t+1 s t It is mapped to one target symbol out of H target symbols. The b 2t and b 2t+1 These two bits are used to obtain the quadrant corresponding to the target symbol, s t Used to obtain the amplitude corresponding to the target symbol.

[0425] In some specific applications, the above three bits b 2t b 2t+1 s t Mapped to target symbol The relationship between the values ​​of the above three bits and the value of the target symbol is shown in Table 2-1 below. In some specific implementations, the framing operation is performed before dual polarization symbol mapping, and the above three bits b 2t b 2t+1 s tThe mapping is to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 2-1 below shows the relationship between the values ​​of the 3 bits and the values ​​of the 4 bits obtained from the mapping.

[0426] Table 2-1

[0427] In other specific applications, the above three bits b 2t b 2t+1 s t Mapped to target symbol The relationship between the values ​​of the above three bits and the value of the target symbol is shown in Table 2-2 below. In some specific implementations, the framing operation is performed before dual polarization symbol mapping, and the above three bits b 2t b 2t+1 s t The mapping is to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol. The rightmost column of Table 2-2 below shows the relationship between the values ​​of the 3 bits and the values ​​of the 4 bits obtained from the mapping.

[0428] Table 2-2

[0429] Thirdly, the H target symbols in the X-polarization direction are generated by the target polynomial, the first seed, and the second seed; the H target symbols in the Y-polarization direction are generated by the target polynomial, the second seed, and the third seed. Here, the same target polynomial is used for both the X-polarization and Y-polarization directions.

[0430] The target polynomial and the first seed are used to obtain the quadrant of each of the H target symbols in the X polarization direction, that is, to determine whether the i-th target symbol is A1+A1j or A2+A2j in the first quadrant, -A1+A1j or -A2+A2j in the second quadrant, -A1-A1j or -A2-A2j in the third quadrant, or A1-A1j or A2-A2j in the fourth quadrant.

[0431] The target polynomial and the third seed are used to obtain the quadrant of each of the H target symbols in the Y polarization direction, that is, to determine whether the i-th target symbol is A1+A1j or A2+A2j in the first quadrant, -A1+A1j or -A2+A2j in the second quadrant, -A1-A1j or -A2-A2j in the third quadrant, or A1-A1j or A2-A2j in the fourth quadrant.

[0432] The target polynomial and the second seed are used to obtain the amplitude of each of the H target symbols in the X-polarization direction, i.e., to determine whether the i-th target symbol in the X-polarization direction is located in the inner circle (-A1-A1j, -A1+A1j, A1-A1j, or A1+A1j) or in the outer circle (-A2-A2j, -A2+A2j, A2-A2j, or A2+A2j). The target polynomial and the second seed are also used to obtain the amplitude of each of the H target symbols in the Y-polarization direction, i.e., to determine whether the i-th target symbol in the Y-polarization direction is located in the inner circle (-A1-A1j, -A1+A1j, A1-A1j, or A1+A1j) or in the outer circle (-A2-A2j, -A2+A2j, A2-A2j, or A2+A2j).

[0433] Figure 10(a) is a schematic diagram of the seventh target symbol generation structure in the embodiments of this application. The target polynomial is a 10th-order 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. Where a9…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a9…a1 is no greater than 6, meaning the number of terms in the objective polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 10(a), the length of the first seed used to obtain the quadrant of each symbol in the X-polarization direction is 10 bits, which can be represented in binary form as: The third seed, used to obtain the quadrant of each symbol in the Y-polarization direction, is 10 bits long and can be represented in binary form as follows: Of course, the seed can also be represented in hexadecimal or decimal, but it needs to be converted to binary form when operating with the target polynomial. The second seed, used to obtain the amplitude of each symbol in the X-polarization direction and the Y-polarization direction, is 10 bits long and can be represented in binary as s9, s8, s7, s6, s5, s4, s3, s2, s1, s0.

[0434] Figure 10(b) is a schematic diagram of the eighth target symbol generation structure in the embodiments of this application. The target polynomial is a 9th-order polynomial: 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 a8…a1 can take values ​​of 0 or 1. In some specific applications, the number of non-zero terms in a8…a1 is no greater than 6, meaning the number of terms in the objective polynomial is greater than or equal to 2 and less than or equal to 8, resulting in lower hardware implementation complexity. As shown in Figure 10(b), the length of the first seed used to obtain the quadrant of each symbol in the X-polarization direction is 9 bits, which can be represented in binary form as: The third seed used to obtain the quadrant of each sign in the Y-polarization direction is 9 bits long, which can be represented in binary form as follows: Of course, the seed can also be represented in hexadecimal or decimal, but it needs to be converted to binary form when operating with the target polynomial. The second seed, used to obtain the amplitude of each symbol in the X-polarization direction and the Y-polarization direction, is 9 bits long and can be represented in binary as s8, s7, s6, s5, s4, s3, s2, s1, s0.

[0435] In Figures 10(a) and 10(b), for a scenario requiring the generation of H dual-polarization target symbols, a bit sequence comprising 2×H bits is obtained based on the target polynomial and the first seed. Obtain a bit sequence consisting of 2×H bits based on the objective polynomial and the third seed. Based on the objective polynomial and the second seed, obtain a bit sequence s0, s1, s2, ... s0 consisting of 2 × H bits. 2D-1 .

[0436] In the X-polarization direction, the bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 2D-1 One of the bits s in 2t A total of 3 bits s 2t It is mapped to one target symbol out of H target symbols. and These two bits are used to obtain the quadrant corresponding to the target symbol, s 2t Used to obtain the amplitude corresponding to the target symbol.

[0437] In the Y-polarization direction, the bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 2D-1 The other bit s in 2t+1 A total of 3 bits s 2t+1It is mapped to one target symbol out of H target symbols. and These two bits are used to obtain the quadrant corresponding to the target symbol, s 2t+1 Used to obtain the amplitude corresponding to the target symbol.

[0438] In some specific applications, the above 3 bits s 2t Mapped to target symbol The above 3 bits s 2t+1 Mapped to target symbol The relationship between the values ​​of the above three bits and the value of the target symbol is shown in Table 3-1 below. In some specific implementations, the framing operation is performed before dual polarization symbol mapping, and the above three bits... s 2t The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol in the X-polarization direction; the aforementioned 3 bits s 2t+1 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol in the Y-polarization direction. The rightmost column of Table 3-1 below shows the relationship between the values ​​of the 3 bits and the values ​​of the 4 bits obtained from the mapping.

[0439] Table 3-1

[0440] In other specific applications, the above three bits s 2t Mapped to target symbol The above 3 bits s 2t+1 Mapped to target symbol The relationship between the values ​​of the above three bits and the value of the target symbol is shown in Table 3-2 below. In some specific implementations, the framing operation is performed before the dual polarization symbol mapping, and the above three bits... s 2t The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol in the Y-polarization direction; the above 3 bits s 2t+1 The mapping is done to 4 bits, and these 4 bits are then symbol-mapped to obtain a target symbol in the Y-polarization direction. The rightmost column of Table 3-2 below shows the relationship between the values ​​of the 3 bits and the values ​​of the 4 bits obtained from the mapping.

[0441] Table 3-2

[0442] The following are some specific implementation examples.

[0443] Example 1: Figure 11 is a schematic diagram of the specific structure of a data frame in an embodiment of this application. Taking DP-16QAM modulation as an example, 172032 dual-polarization payload symbols (dual-polarization symbols before framing) are obtained by Open FEC (OFEC) encoding and DP-16QAM modulation. The data frame (also called a superframe or multiframe) includes 24 subframes. In one polarization direction, each subframe includes N s = 7296 symbols, and the first symbol in each subframe is both the pilot symbol and the training symbol. As shown in the example of Figure 11(a), the first subframe has T = 11 training symbols, N FAW Frame synchronization symbols, N RES N are reserved symbols, where N FAW +N RES =96. Here, the reserved symbol is also called fixed padding, and the frame synchronization symbol can also be called the multi-frame alignment signal. In some specific applications, the N RES =22, N RES =76. The reserved symbol is also called fixed fill.

[0444] As shown in example (b) of Figure 11, there are also T = 11 training symbols in subframes 2 to 24; and in each subframe, every N g = The first symbol in the 64 symbols is the pilot symbol, and each subframe contains M = 114 pilot symbols.

[0445] In either the X-polarization or Y-polarization direction, the T=11 training symbols and M=114 pilot symbols combined together constitute N. TP =T+M-1=11+114-1=124 symbols satisfy DC balance, which is beneficial to improving the quality of signal recovery at the receiving end. The N TP =Each of the 124 symbols takes one of the following values: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j. The N... TP =124 symbols are obtained through 16QAM symbol mapping, that is, the N TP = There are 124 symbols, all located on 16QAM constellation points, with A1 / A2 = 1 / 3. In some specific applications, A1 = 1 and A2 = 3; in other specific applications, and

[0446] In this embodiment, traditional 16QAM mapping is used as an example, without employing PCS technology. In this case, the probability of the pre-framing symbol being any of the 16 symbols in the 16QAM constellation is the same. In the X-polarization direction or the Y-polarization direction, N... TP = The total number of points located within the inner circle of the 16QAM constellation diagram out of 124 symbols, i.e., symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j, is 62. N TP = The total number of points located on the outer ring of the 16QAM constellation diagram out of the 124 symbols, that is, symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j, is 62. At this time, N TP =The average energy of 124 symbols is the same as the average energy of the symbols before framing, N TP = The transmission performance cost resulting from 124 symbols is relatively low.

[0447] Example 2:

[0448] Based on Example 1, consider the sequence of 11 training symbols as shown in Table 4 below.

[0449] Table 4

[0450] The first symbol in each subframe is both a pilot symbol and a training symbol. In the X-polarization direction, the first symbol of the 114 pilot symbols has a value of -A2+A2j; in the Y-polarization direction, the first symbol of the 114 pilot symbols has a value of -A2-A2j. These 114 pilot symbols are generated based on the target polynomial and its corresponding seed.

[0451] The quadrants of the 114 pilot symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the first seed. The amplitudes of the 114 pilot symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the second seed. A bit sequence b0, b1, b2, ... b, comprising 228 bits, is obtained based on the target polynomial and the first seed. 227 Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 114 bits. 113 The bit sequence b0, b1, b2, ... b 227 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 113 1 bit s in t A total of 3 bits b 2t b 2t+1 s tIt is mapped to one of the pilot symbols -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, serving as a pilot symbol in the X-polarization direction.

[0452] The quadrants of the 114 pilot symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the third seed, and the amplitudes of the 114 pilot symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the fourth seed. A bit sequence b0, b1, b2, ... b, comprising 228 bits, is obtained based on the target polynomial and the third seed. 227 Based on the objective polynomial and the fourth seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 114 bits. 113 The bit sequence b0, b1, b2, ... b 227 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 113 1 bit s in t A total of 3 bits b 2t b 2t+1 s t It is mapped to one of the pilot symbols -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, serving as a pilot symbol in the Y-polarization direction.

[0453] In this embodiment, the mapping method shown in Table 2-1 is used as an example, that is, s t When =0, the pilot symbol is located in the inner circle of the constellation diagram, s t When =1, the pilot symbol is located on the outer ring of the constellation diagram. The combination of the target polynomial, first seed, second seed, third seed, and fourth seed is shown in one row of the table below.

[0454] Table 5

[0455] Example 3:

[0456] Based on Example 1, consider N TP =124 symbols (including training symbols and pilot symbols, called target symbols) are generated based on the target polynomial and the corresponding seed.

[0457] The quadrants of the 124 target symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the first seed. The amplitudes of the 124 target symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the second seed. A bit sequence b0, b1, b2, ... b, comprising 248 bits, is obtained based on the target polynomial and the first seed. 247 Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 144 bits. 123 The bit sequence b0, b1, b2, ... b 247 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 143 1 bit s in t A total of 3 bits b 2t b 2t+1 s t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the X-polarization direction.

[0458] The quadrants of the 124 target symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the third seed, and the amplitudes of the 124 target symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the fourth seed. A bit sequence b0, b1, b2, ... b, comprising 248 bits, is obtained based on the target polynomial and the third seed. 247 Based on the objective polynomial and the fourth seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 124 bits. 123 The bit sequence b0, b1, b2, ... b 247 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 123 1 bit s in t A total of 3 bits b 2t b 2t+1 s t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the Y-polarization direction.

[0459] In this embodiment, the mapping method shown in Table 2-1 is used as an example, that is, s t When =0, the target symbol is located in the inner circle of the constellation diagram, s tWhen the target polynomial is 1, the target symbol is located on the outer ring of the constellation diagram. The combination of the target polynomial, the first seed, the second seed, the third seed, and the fourth seed is shown in one row of the table below.

[0460] Table 6

[0461] Example 4:

[0462] Based on Example 1, consider N TP =124 symbols are generated based on the objective polynomial and its corresponding seed.

[0463] The quadrants of the 124 target symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the first seed. The amplitudes of the 124 target symbols in the X-polarization direction on the constellation diagram are generated by the target polynomial and the second seed. A bit sequence b0, b1, b2, ... b, comprising 248 bits, is obtained based on the target polynomial and the first seed. 247 Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 144 bits. 123 The bit sequence b0, b1, b2, ... b 247 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 143 1 bit s in t A total of 3 bits b 2t b 2t+1 s t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the X-polarization direction.

[0464] The quadrants of the 124 target symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the third seed, and the amplitudes of the 124 target symbols in the Y-polarization direction on the constellation diagram are generated by the target polynomial and the fourth seed. A bit sequence b0, b1, b2, ... b, comprising 248 bits, is obtained based on the target polynomial and the third seed. 247 Based on the objective polynomial and the fourth seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 124 bits. 123 The bit sequence b0, b1, b2, ... b 247 In every 2 consecutive bits b 2t b 2t+1 And bit sequence s0, s1, s2, ... s 123 1 bit s in t A total of 3 bits b2t b 2t+1 s t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the Y-polarization direction.

[0465] In this embodiment, the mapping method shown in Table 2-2 is used as an example, that is, s t When =0, the target symbol is located on the outer circle of the constellation diagram, s t When the target polynomial is 1, the target symbol is located in the inner circle of the constellation diagram. The combination of the target polynomial, the first seed, the second seed, the third seed, and the fourth seed is shown in one row of the table below.

[0466] Table 7

[0467] Example 5:

[0468] Based on Example 1, consider N TP =124 symbols (called target symbols) are generated based on the target polynomial and the corresponding seed.

[0469] A bit sequence of 248 bits is obtained based on the objective polynomial and the first seed. A bit sequence of 248 bits is obtained based on the objective polynomial and the third seed. Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 248 bits. 247 .

[0470] bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 247 One of the bits s in 2t A total of 3 bits s 2t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the X-polarization direction.

[0471] bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 247 The other bit s in 2t+1 A total of 3 bits s 2t+1The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the Y-polarization direction.

[0472] In this embodiment, the mapping method shown in Table 3-1 is used as an example, that is, s 2t (or s) 2t+1 When ) is 0, the target symbol is located in the inner circle of the constellation diagram, s 2t (or s) 2t+1 When ), the target symbol is located on the outer ring of the constellation diagram. The combination of the target polynomial, the first seed, the second seed, and the third seed is shown in one row of the table below.

[0473] Table 8

[0474] Example 6:

[0475] Based on Example 1, consider N TP =124 symbols (called target symbols) are generated based on the target polynomial and the corresponding seed.

[0476] A bit sequence of 248 bits is obtained based on the objective polynomial and the first seed. A bit sequence of 248 bits is obtained based on the objective polynomial and the third seed. Based on the objective polynomial and the second seed, a bit sequence s0, s1, s2, ... s is obtained, consisting of 248 bits. 247 .

[0477] bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 247 One of the bits s in 2t A total of 3 bits s 2t The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the X-polarization direction.

[0478] bit sequence Every 2 consecutive bits And bit sequence s0, s1, s2, ... s 247 The other bit s in 2t+1 A total of 3 bits s 2t+1The target symbol is mapped to one of the following: -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j, and serves as a target symbol in the Y-polarization direction.

[0479] In this embodiment, the mapping method shown in Table 3-2 is used as an example, that is, s 2t (or s) 2t+1 When ) is 0, the target symbol is located on the outer ring of the constellation diagram, s 2t (or s) 2t+1 When ), the target symbol is located in the inner circle of the constellation diagram. The combination of the target polynomial, the first seed, the second seed, and the third seed is shown in one row of the table below.

[0480] Table 9

[0481] Figure 12 is a schematic diagram of a data transmission device according to an embodiment of this application. This data transmission device is applied at the transmitting end. As shown in Figure 12, the data transmission device includes a processing unit 201 and a transmitting unit 202. The processing unit 201 is used to execute the operation of step 101 in the above embodiment, and the transmitting unit 202 is used to execute the operation of step 102 in the above embodiment.

[0482] Figure 13 is a schematic diagram of another structure of the data transmission device in an embodiment of this application. This data transmission device is applied at the receiving end. As shown in Figure 13, the data transmission device includes a receiving unit 302, which is used to perform the operation of step 102 in the above embodiment. Optionally, the data transmission device further includes a processing unit 301, which is used to perform the operation of step 103 in the above embodiment.

[0483] It should be understood that the data transmission devices provided in Figures 12 and 13 can also be implemented in other ways. For example, the unit division in the above devices is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system. In addition, the functional units in the various embodiments of this application may be integrated into one processing unit, or they may be independent physical units, or two or more functional units may be integrated into one processing unit. The integrated units described above can be implemented in hardware or as software functional units.

[0484] Figure 14 is a schematic diagram of an optical module in an embodiment of this application. As shown in Figure 14, the optical module includes a processor 401 and an interface 402. The interface 402 can be a transceiver or an input / output interface, and is used to receive signals from other devices and transmit them to the processor 401 or to send signals from the processor 401 to other devices. Optionally, the optical module may also include a memory 403, wherein the memory 403 is used to store program instructions and data.

[0485] In one possible scenario, the optical module is used at the transmitting end, and the processor 401 is used to execute the operation of step 101 in the above embodiments. For example, the processor 401 includes the processing unit 201 shown in FIG12. As an example, the processor 401 executes the operation of step 101 in the above embodiments to obtain a first data frame and sends the first data frame through interface 402. In this example, interface 402 may specifically refer to an electrical interface. As another example, the processor 401 executes the operation of step 101 in the above embodiments to obtain a first data frame, and the modulator in the optical module performs signal processing such as electro-optic conversion according to the first data frame to obtain an optical signal, and then sends the optical signal through interface 402. In this example, interface 402 may specifically refer to an optical interface.

[0486] In another possible scenario, the optical module is applied at the receiving end, and the processor 401 is used to execute the operation of step 103 in the above embodiments. For example, the processor 401 includes the processing unit 301 shown in FIG13. As an example, the interface receives an optical signal transmitted through the channel, the demodulator in the optical module performs signal processing such as photoelectric conversion on the optical signal to obtain a second data frame, and the processor 401 executes the operation of step 103 in the above embodiments on the second data frame. In this example, the interface 402 may specifically refer to an optical interface. As another example, the demodulator in the optical module performs signal processing such as photoelectric conversion on the received optical signal to obtain a second data frame, and transmits the second data frame to the processor 401 through the interface 402. The processor 401 executes the operation of step 103 in the above embodiments on the second data frame. In this example, the interface 402 may specifically refer to an electrical interface.

[0487] Typically, an optical module consists of optoelectronic devices, a processor, and an interface. The optoelectronic devices include transmitting and receiving devices. The transmitting end of the optical module converts electrical signals into optical signals and transmits them through optical fibers. The receiving end of the optical module receives the optical signals and converts them back into electrical signals.

[0488] It should be noted that the types of optical modules in this application embodiment include, but are not limited to, normal optical modules, near package optics (NPO) modules, and co-packaged optics (CPO) modules. Normal optical modules can perform functions including, but not limited to, digital signal processing (DSP) and clock data recovery (CDR). For example, a normal optical module converts analog signals to digital signals, performs DSP on the digital signals, and then converts them back to analog signals before sending them to the host device. Because DSP requires retiming, a normal optical module can also be called a retimed module. Normal optical modules are connected to the host device via an attachment unit interface (AUI). NPO and CPO modules do not have pluggable physical packaging and are closer to the host device. NPO and CPO modules can also be called optical engines. NPO or CPO technology is a technology that "packages" the host device (or host chip) and the optical engine. When NPO technology is used to encapsulate the host-side device and the optical engine, the optical engine can be called an NPO module. When CPO technology is used to encapsulate the host-side device and the optical engine, the optical engine can be called a CPO module.

[0489] Figure 15 is a schematic diagram of a transmitting device according to an embodiment of this application. As shown in Figure 15, the transmitting device includes a host-side device 501 and an optical module 502. The host-side device 501 is used to send electrical signals to the optical module 502, and the optical module 502 converts the electrical signals into optical signals and transmits the optical signals through a channel. For example, the host-side device 501 may specifically be a switch, router, or server. This transmitting device can be a communication device including the host-side device 501 and the optical module 502. It should also be understood that the transmitting devices in this embodiment are named based on the data flow direction and do not limit the function of the device. For example, the transmitting device may also have a receiving function.

[0490] Figure 16 is a schematic diagram of a receiving device in an embodiment of this application. As shown in Figure 16, the receiving device includes a host-side device 601 and an optical module 602. The optical module 602 is used to convert the received optical signal into an electrical signal and send the electrical signal to the host-side device 601. For example, the host-side device 601 may specifically be a switch, router, or server. The receiving device can be a communication device including the host-side device 601 and the optical module 602. It should also be understood that the receiving device in the embodiments of this application is named based on the data flow direction and does not limit the function of the device. For example, the receiving device may also have a sending function.

[0491] This application also provides an Optical Transport Network (OTN) device, which includes line-side equipment and client-side equipment. The client-side equipment may also be referred to as a tributary-side equipment in some scenarios. The line-side equipment includes a processor and an interface. In one possible scenario, the OTN device is used at the transmitting end, and the processor is used to execute the operation of step 101 in the above embodiment. In another possible scenario, the OTN device is used at the receiving end, and the processor is used to execute the operation of step 103 in the above embodiment. The interface can be a transceiver or an input / output interface, used to receive signals from other devices besides the line-side equipment and transmit them to the processor, or to send signals from the processor to other devices besides the line-side equipment.

[0492] This application also provides a chip. The chip integrates circuitry for implementing the functions of the processor 401 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 an interface. The chip can perform the method steps of any one or more of the foregoing embodiments. Alternatively, the chip can implement the actions performed by the data processing device in the foregoing embodiments based on program code stored in the memory.

[0493] As an example, the chip in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor, any conventional processor, or a processing circuit that implements a specific function.

[0494] 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.

[0495] It should be understood that the processor mentioned in the embodiments of this application can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. The memory can exist independently and be connected to the processor, or the memory can be integrated with the processor.

[0496] As an example, the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor, any conventional processor, or a processing circuit that implements a specific function.

[0497] 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.

[0498] In the above embodiments, it can be implemented entirely or partially by software, hardware, firmware, or any combination thereof.

[0499] 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.

[0500] When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a terminal device, or other programmable device. The computer program or instructions can be stored in or transmitted through a computer-readable storage medium. The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a Digital Versatile Disc (DVD); or it can be a semiconductor medium, such as a solid-state disk (SSD).

[0501] Finally, it should be noted that the above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

A data transmission method, characterized in that, include: Obtain a data frame including multiple sub - frames, where the sub - frames include training symbols and pilot symbols. Among them, in one polarization direction, every consecutive N g symbols in the sub - frame include one pilot symbol, and N g is an integer greater than 1. Among the N TP symbols including all the training symbols and all the pilot symbols in the sub - frame, at least one symbol takes a value of one of - A1 - A1j, - A1 + A1j, A1 - A1j, and A1 + A1j. Among the N TP symbols in the sub - frame, at least one symbol takes a value of one of - A2 - A2j, - A2 + A2j, A2 - A2j, and A2 + A2j. Both A1 and A2 are real numbers not equal to 0, A1 < A2, and j represents the imaginary unit; Send the data frame. The method according to claim 1, characterized in that, In one polarization direction, the number of training symbols in the subframe is T, the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0, and one symbol in the subframe is both a training symbol and a pilot symbol, N. TP =T+M-1. The method according to claim 1, characterized in that, In one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0, and N... TP =T+M. The method according to any one of claims 1 to 3 is characterized in that, The N TP The sum of all the symbols is 0. The method according to any one of claims 1 to 4, characterized in that, The N TP Each symbol satisfies DC balance. The method according to any one of claims 1 to 5, characterized in that, The N TP The total number of symbols with values ​​of -A1-A1j, -A1+A1j, A1-A1j, or A1+A1j is N1, where N... TP The total number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j is N2, where N is the number of symbols with values ​​of -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. TP = N1 + N2, where N1 and N2 are both integers greater than 0. The method according to claim 6, characterized in that, The sum of the N1 symbols is 0, the sum of the N2 symbols is 0, and both N1 and N2 are even numbers. The method according to claim 6 or 7, characterized in that, N1≥N2. The method according to any one of claims 6 to 8, characterized in that, The number of symbols with values ​​-A1-A1j, -A1+A1j, A1-A1j, and A1+A1j in the N1 symbols are all less than or equal to 2. The number of symbols with values ​​-A2-A2j, -A2+A2j, A2-A2j, and A2+A2j in the N2 symbols are all less than or equal to 2. The method according to any one of claims 1 to 9, characterized in that, The subframe includes a total of 2×N training symbols and pilot symbols in both polarization directions. TP 1 symbol, in the 2×N TP Of the symbols, the number of values ​​-A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, and A2+A2j are all N. TP / 4. The method according to any one of claims 1 to 10, characterized in that, In one polarization direction, the number of training symbols in the subframe is T, and the number of pilot symbols in the subframe is M, where T and M are both integers greater than 0. The T training symbols included in the subframe in the first polarization direction are different from the T training symbols included in the subframe in the second polarization direction, and the M pilot symbols included in the subframe in the first polarization direction are different from the M pilot symbols included in the subframe in the second polarization direction. The method according to any one of claims 1 to 11, characterized in that, The data frame adopts a symbol mapping method of dual polarization hexadecimal quadrature amplitude modulation DP-16QAM, A1 / A2=1 / 3; or, The data frame adopts a symbol mapping method of dual polarization 64-ary orthogonal amplitude modulation DP-64QAM, where A1 / A2 = 1 / 3, or A1 / A2 = 1 / 5, or A1 / A2 = 1 / 7, or A1 / A2 = 3 / 5, or A1 / A2 = 3 / 7, or A1 / A2 = 5 / 7. The method according to any one of claims 1 to 12, characterized in that, In one polarization direction, H target symbols are generated from a target polynomial and a seed, wherein the H target symbols are pilot symbols; or, In one polarization direction, H target symbols are generated from a target polynomial and a seed, wherein the H target symbols include training symbols and pilot symbols, and H = N. TP . The method according to claim 13, characterized in that, The degree of the objective polynomial is less than or equal to 11, and the number of terms in the objective polynomial is greater than or equal to 2 and less than or equal to 8. The method according to claim 13 or 14 is characterized in that, The objective polynomial is one of the following: 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; 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; x 8 +a7×x 7 +a6×x 6 +a5×x 5 +a4×x 4 +a3×x 3 +a2×x 2 +a1×x+1; x 11 +a 10 ×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. The method according to any one of claims 13 to 15, characterized in that, In one polarization direction, a first bit sequence comprising 3×H bits is generated by the target polynomial and the seed, wherein every three consecutive bits in the first bit sequence correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to any one of claims 13 to 15, characterized in that, In one polarization direction, a first bit sequence comprising 3×H bits is generated by the target polynomial and the seed. In the first bit sequence, every three consecutive bits correspond to four bits, and the four bits are symbol-mapped to obtain a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to any one of claims 13 to 15, characterized in that, The H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and the H target symbols in the second polarization direction are generated by the target polynomial, the third seed, and the fourth seed. The method according to claim 18, characterized in that, In the first polarization direction, a second bit sequence comprising 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence comprising H bits is generated by the target polynomial and the second seed. Each two consecutive bits in the second bit sequence and one bit in the third bit sequence, for a total of three bits, correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. In the second polarization direction, a fourth bit sequence comprising 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence comprising H bits is generated by the target polynomial and the fourth seed. Each set of three bits—two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence—corresponds to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to claim 18, characterized in that, In the first polarization direction, a second bit sequence comprising 2×H bits is generated by the target polynomial and the first seed, and a third bit sequence comprising H bits is generated by the target polynomial and the second seed. Every two consecutive bits in the second bit sequence and one bit in the third bit sequence, a total of three bits, correspond to four first bits. The four first bits are symbol-mapped to obtain a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. In the second polarization direction, a fourth bit sequence comprising 2×H bits is generated by the target polynomial and the third seed, and a fifth bit sequence comprising H bits is generated by the target polynomial and the fourth seed. Every two consecutive bits in the fourth bit sequence and one bit in the fifth bit sequence, totaling three bits, correspond to four second bits. These four second bits are symbol-mapped to obtain a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to any one of claims 13 to 15, characterized in that, The H target symbols in the first polarization direction are generated by the target polynomial, the first seed, and the second seed, and the H target symbols in the second polarization direction are generated by the target polynomial, the second seed, and the third seed. The method according to claim 21, characterized in that, A second bit sequence comprising 2×H bits is generated by the target polynomial and the first seed; a third bit sequence comprising 2×H bits is generated by the target polynomial and the second seed; and a fourth bit sequence comprising 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every two consecutive bits in the second bit sequence and one bit in the third bit sequence, a total of three bits, correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j; in the second polarization direction, every two consecutive bits in the fourth bit sequence and the other bit in the third bit sequence, a total of three bits, correspond to a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to claim 21, characterized in that, A second bit sequence comprising 2×H bits is generated by the target polynomial and the first seed; a third bit sequence comprising 2×H bits is generated by the target polynomial and the second seed; and a fourth bit sequence comprising 2×H bits is generated by the target polynomial and the third seed. In the first polarization direction, every two consecutive bits in the second bit sequence and one bit in the third bit sequence, a total of three bits, correspond to four first bits. These four first bits are symbol-mapped to obtain a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. In the second polarization direction, every two consecutive bits in the fourth bit sequence and the other bit in the third bit sequence, a total of three bits, correspond to four second bits. These four second bits are symbol-mapped to obtain a target symbol with the value -A1-A1j, -A1+A1j, A1-A1j, A1+A1j, -A2-A2j, -A2+A2j, A2-A2j, or A2+A2j. The method according to any one of claims 1 to 23 is characterized in that, The subframe arranged in the first position in the data frame is the first type of subframe. The first type of subframe also includes frame synchronization symbols, reserved symbols and pre-frame symbols. In the first type of subframe, the training symbols are located before the frame synchronization symbols, the frame synchronization symbols are located before the reserved symbols, and the reserved symbols are located before the pre-frame symbols. The data frame includes at least one second type of subframe, which further includes pre-frame symbols, in which training symbols are located before pre-frame symbols. The method according to any one of claims 1 to 24, characterized in that, N g The values ​​are 32, 64, 96, or 128. The method according to any one of claims 1 to 25, characterized in that, The number of training symbols in the subframe is 11, and the number of pilot symbols in the subframe is 114. The method according to any one of claims 1 to 26, characterized in that, Each pilot symbol is located in its corresponding consecutive N. g The starting position of each symbol. A data transmission method, characterized in that, include: Receive a second data frame transmitted through a channel from a first data frame, the first data frame including a plurality of sub-frames, the sub-frames including training symbols and pilot symbols, wherein, in one polarization direction, every consecutive N g symbols in the sub-frame include a pilot symbol, the N g being an integer greater than 1, at least one of the N TP symbols including all the training symbols and all the pilot symbols in the sub-frame takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j, and at least one of the N TP symbols in the sub-frame takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j, where A1 and A2 are both real numbers not equal to 0, A1 < A2, and j represents the imaginary unit. A data processing device, characterized in that, include: Processing unit and sending unit; The processing unit is configured to: obtain a data frame including a plurality of sub-frames, where the sub-frames include training symbols and pilot symbols, and where, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, where N g is an integer greater than 1, and at least one symbol among a total of N TP symbols including all the training symbols and all the pilot symbols in the sub-frame takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j, and at least one symbol among the N TP symbols in the sub-frame takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j, where A1 and A2 are both non-zero real numbers, A1 < A2, and j represents the imaginary unit; The sending unit is used to send the data frame. A data processing device, characterized in that, Includes a receiving unit; The receiving unit is configured to: receive a second data frame transmitted through a channel by a first data frame, the first data frame including a plurality of sub-frames, the sub-frames including training symbols and pilot symbols, wherein, in one polarization direction, every consecutive N g symbols in the sub-frame include one pilot symbol, the N g being an integer greater than 1, and at least one symbol among the total N TP symbols including all the training symbols and all the pilot symbols in the sub-frame takes a value of one of -A1 - A1j, -A1 + A1j, A1 - A1j, and A1 + A1j, and at least one symbol among the N TP symbols in the sub-frame takes a value of one of -A2 - A2j, -A2 + A2j, A2 - A2j, and A2 + A2j, where A1 and A2 are both real numbers not equal to 0, A1 < A2, and j represents the imaginary unit. A chip characterized in that, The chip is used to perform the method as described in any one of claims 1 to 28. An optical module, characterized in that, The optical module includes a processor and an interface, the interface being used for transmitting and receiving signals, and the processor being used for performing the method as described in any one of claims 1 to 27. A transmitting device, characterized in that, The transmitting device includes a host-side device and an optical module as described in claim 32, wherein the optical module is used to convert electrical signals from the host-side device into optical signals and transmit the optical signals. An optical module, characterized in that, The optical module includes a processor and an interface, the interface being used for transmitting and receiving signals, and the processor being used for performing the method as described in claim 28. A receiving device, characterized in that, The receiving device includes a host-side device and an optical module as described in claim 34, wherein the optical module is used to convert the received optical signal into an electrical signal and send the electrical signal to the host-side device. A communication system, characterized in that, include: The transmitting device as claimed in claim 33 and the receiving device as claimed in claim 35, wherein the transmitting device is configured to transmit a signal to the receiving device.

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