Signal processing method and related apparatus

Abstract

Disclosed in embodiments of the present application are a signal processing method and a related apparatus. The signal processing method can be applied to optical communication scenarios. The method in the embodiments of the present application comprises: a sending end performs polarity inversion on some symbols in a first modulation signal to obtain a second modulation signal, such that the absolute value of the sum of the values of all symbols in the second modulation signal is smaller than the absolute value of the sum of the values of all symbols in the first modulation signal. Therefore, the power of a low-frequency part in the second modulation signal is suppressed, thereby facilitating a receiving end performing direct-current removal processing on the signal to resist the impact of low-frequency noise in a channel on transmission performance. Moreover, the receiving end performs inverse transformation of power spectrum adjustment on the received signal according to identification information, so that an original signal present before the power spectrum adjustment by the sending end is recovered.

Description

A signal processing method and related device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on August 15, 2023, with application number 202311034394.8 and invention name “A signal processing method and related device”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] In the actual deployment of optical communication systems, channel impairments can degrade signal quality, significantly increasing the bit error rate (BER), thereby limiting the transmission performance of optical communication systems. For short-haul optical interconnection applications, the main approach is to combine intensity-modulation direct detection (IMDD) with high-order modulation formats. However, high-order modulation signals are highly susceptible to low-frequency noise, such as baseline drift. Furthermore, signal distortion caused by chromatic dispersion (CD) can impose additional transmission costs, limiting the system's transmission bandwidth.

[0004] To reduce the impact of low-frequency noise and dispersion on optical transmission, existing technologies usually use equalization algorithms to perform channel compensation at the receiving end. However, processing only at the receiving end has problems such as high algorithm complexity and insufficient compensation capabilities in harsh environments.

[0005] Summary of the Invention

[0006] The embodiment of the present application provides a signal processing method and related devices. The transmitting end suppresses the power of the low-frequency part by flipping the polarity of some symbols in the modulated signal, which is beneficial to resisting the influence of low-frequency noise in the channel on the transmission performance.

[0007] In a first aspect, an embodiment of the present application provides a signal processing method, which is applied to a transmitting end. Specifically, the transmitting end obtains a first modulated signal, wherein the first modulated signal includes M first symbol sets, each first symbol set includes N symbols, and M and N are both integers greater than 1. For example, N is generally an integer multiple of 2. It should be understood that each first symbol set can also be referred to as a symbol block, and each symbol in a block can include multiple bits. Afterwards, the transmitting end flips the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal including M×N symbols. The absolute value of the sum of the values ​​of all symbols in the second modulated signal is less than the absolute value of the sum of the values ​​of all symbols in the first modulated signal. Furthermore, the transmitting end sends the second modulated signal.

[0008] Furthermore, the sum of the values ​​of all symbols in the second modulated signal is less than or equal to the maximum value that a single symbol in the second modulated signal can take.

[0009] In this embodiment, the transmitter generates a second modulated signal by flipping the polarity of some symbols in the first modulated signal, ensuring that the absolute value of the sum of all symbols in the second modulated signal is less than the absolute value of the sum of all symbols in the first modulated signal. This suppresses the power of the low-frequency portion of the second modulated signal, facilitating DC removal at the receiver to mitigate the effects of low-frequency channel noise on transmission performance. Compared to channel compensation at the receiver, this processing method at the transmitter is less complex.

[0010] In some possible implementations, flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal includes: determining the value j corresponding to when the sum of the values ​​of all symbols in the i-th second symbol set is the minimum value. min The i-th second symbol set is obtained by flipping the polarity of all symbols after the j-th symbol in the i-th first symbol set, where 0≤i≤M-1, 0≤j≤N-2. min In this embodiment, the polarity of all symbols after the ith symbol set is flipped. In this embodiment, the ith first symbol set uses N-1 different polarity flipping methods to obtain the ith second symbol set, and the polarity flipping method that minimizes the sum of all symbol values ​​in the ith second symbol set is selected, thereby improving the suppression effect of the second modulated signal power at low frequencies.

[0011] In some possible implementations, the method further includes: generating identification information, wherein the identification information is used to indicate the jth symbol in the i-th first symbol set. minIt should be understood that the transmitting end will also send identification information to the receiving end so that the receiving end can perform an inverse transformation of the power spectrum adjustment on the received signal according to the identification information, thereby restoring the original signal before the transmitting end performs the power spectrum adjustment.

[0012] In some possible implementations, the sum of the values ​​of all symbols in the second modulated signal is equal to 0, that is, the sum of the values ​​of all symbols in the second modulated signal is minimized, which is conducive to maximally suppressing the power of the second modulated signal at low frequencies and achieving better results.

[0013] In some possible implementations, flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal includes: obtaining the sum of the values ​​of all symbols in the i-th first symbol set, where 0≤i≤M-1. If the sum of the values ​​of all symbols in the i-th first symbol set is equal to 0, the polarity of all symbols in the i-th first symbol set remains unchanged. If the sum of the values ​​of all symbols in the i-th first symbol set is not equal to 0, flipping the polarity of at least one symbol in the i-th first symbol set to obtain the i-th second symbol set, and the sum of the values ​​of all symbols in the i-th second symbol set is equal to 0. In the above manner, the sum of the values ​​of each symbol set in the second modulated signal can be made 0, and the sum of the values ​​of all symbols in the second modulated signal is also equal to 0, which can maximize the compression of the power spectrum of the low-frequency part of the second modulated signal.

[0014] In some possible implementations, flipping the polarity of at least one symbol in the i-th first symbol set to obtain the i-th second symbol set includes flipping the polarity of all symbols after the j-th symbol in the i-th first symbol set to obtain the i-th second symbol set, where 0≤j≤N-2. This implementation provides a specific implementation of symbol polarity flipping, which has better practical effects.

[0015] In some possible implementations, the method further includes generating identification information, the identification information being used to indicate a position of the jth symbol in the i-th second symbol set. It should be understood that the transmitting end will also send the identification information to the receiving end, so that the receiving end can perform an inverse transform of the power spectrum adjustment on the received signal based on the identification information, thereby recovering the original signal before the power spectrum adjustment was performed by the transmitting end.

[0016] In some possible implementations, before transmitting the second modulated signal, the method further includes: interleaving symbols in the second modulated signal. For the interleaved second modulated signal, in addition to compressing the low-frequency portion of the power spectrum, other frequency points, such as the mid-frequency portion or the high-frequency portion of the power spectrum, may also be compressed.

[0017] In some possible implementations, the second modulated signal includes Nshape symbol groups, each symbol group includes K symbols, M×N=N shape ×K,N shape is an integer greater than 1, and K is an integer greater than 1. The second modulated signal after interleaving is represented as: {the 0th symbol in the 0th symbol group, the 0th symbol in the 1st symbol group, ..., the Nth symbol group} shape -The 0th symbol in the 1st symbol group, the 1st symbol in the 0th symbol group, the 1st symbol in the 1st symbol group, ..., the Nth symbol shape -1 symbol group, ..., the K-1th symbol in the 0th symbol group, the K-1th symbol in the 1st symbol group, ..., the Nth shape -1 symbol in a group of symbols}.

[0018] In some possible implementations, after obtaining the first modulated signal, before flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal including M×N symbols, the method further includes: interleaving the symbols of each first symbol set in the first modulated signal. After flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal including M×N symbols, before outputting the second modulated signal, the method further includes: deinterleaving the symbols in the second modulated signal according to the interleaving method. For the deinterleaved second modulated signal, in addition to compressing the low-frequency portion of the power spectrum, compression of other frequency points such as the mid-frequency portion or high-frequency portion of the power spectrum can also be achieved.

[0019] In some possible implementations, each first symbol set in the first modulated signal includes R consecutive symbol subsets, each symbol subset includes L symbols, N=R×L, R is an integer greater than 1, and L is an integer greater than 1. The first symbol set in the first modulated signal after interleaving is expressed as: {the 0th symbol in the 0th symbol subset, the 0th symbol in the 1st symbol subset, …, the 0th symbol in the R-1th symbol subset, the 1st symbol in the 0th symbol subset, the 1st symbol in the 1st symbol subset, …, the 1st symbol in the R-1th symbol subset, …, the L-1th symbol in the 0th symbol subset, the L-1th symbol in the 1st symbol subset, …, the L-1th symbol in the R-1th symbol subset}.

[0020] In the second aspect, an embodiment of the present application provides a signal processing method, which is applied to a receiving end. Specifically, the receiving end receives a first signal and identification information sent by the transmitting end through a channel. The first signal includes the signal sent by the transmitting end and the interference in the channel transmission. Afterwards, the first signal is subjected to DC removal processing to obtain a second signal, and the second signal can be regarded as a signal sent by the transmitting end. The second signal includes M symbol sets, each symbol set includes N symbols, M is an integer greater than 1, and N is an integer greater than 1. The identification information is used to indicate the polarity reversal of the symbols in each symbol set. Furthermore, the polarity of at least one symbol in at least one symbol set is reversed according to the identification information to obtain a third signal including M×N symbols to restore the original signal of the transmitting end.

[0021] In this embodiment, the receiving end performs DC removal processing on the signal to help resist low-frequency noise in the channel. In addition, the receiving end performs an inverse transform of the power spectrum adjustment on the received signal based on the identification information, thereby recovering the original signal before the power spectrum adjustment performed by the transmitting end.

[0022] In some possible implementations, flipping the polarity of at least one symbol in at least one second symbol set based on the identification information includes: determining the jth symbol in the ith second symbol set based on the identification information, where 0≤i≤M-1 and 0≤j≤N-2, and flipping the polarity of all symbols after the jth symbol in the ith second symbol set.

[0023] In a third aspect, an embodiment of the present application provides a chip comprising a processor and a memory, the memory and the processor being interconnected via lines, instructions being stored in the memory, and the processor being used to execute the method described in any one of the embodiments of the first and second aspects.

[0024] In a fourth aspect, an embodiment of the present application provides a transmitting end device, comprising: a processing unit and a transmitting unit. The processing unit is configured to: obtain a first modulated signal, the first modulated signal comprising M first symbol sets, each first symbol set comprising N symbols, where M is an integer greater than 1, and N is an integer greater than 1; and flip the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal comprising M×N symbols, wherein the absolute value of the sum of the values ​​of all symbols in the second modulated signal is less than the absolute value of the sum of the values ​​of all symbols in the first modulated signal. The transmitting unit is configured to: transmit the second modulated signal.

[0025] In some possible implementations, the processing unit is specifically configured to: determine the value j corresponding to when the sum of the values ​​of all symbols in the i-th second symbol set is the minimum value. min, wherein the i-th second symbol set is obtained by flipping the polarity of all symbols after the j-th symbol in the i-th first symbol set, wherein 0≤i≤M-1, 0≤j≤N-2. min The polarity of all symbols after the first symbol is flipped.

[0026] In some possible implementations, the processing unit is further configured to: generate identification information, the identification information being used to indicate the jth symbol in the i-th first symbol set. min The position of a symbol.

[0027] In some possible implementations, the sum of the values ​​of all symbols in the second modulated signal is equal to 0.

[0028] In some possible implementations, the processing unit is specifically configured to: obtain a sum of the values ​​of all symbols in the i-th first symbol set, where 0≤i≤M-1. If the sum of the values ​​of all symbols in the i-th first symbol set is equal to 0, then the polarities of all symbols in the i-th first symbol set remain unchanged. If the sum of the values ​​of all symbols in the i-th first symbol set is not equal to 0, then flip the polarity of at least one symbol in the i-th first symbol set to obtain an i-th second symbol set, where the sum of the values ​​of all symbols in the i-th second symbol set is equal to 0.

[0029] In some possible implementations, the processing unit is specifically configured to: flip the polarity of all symbols after the jth symbol in the i-th first symbol set to obtain the i-th second symbol set, where 0≤j≤N-2.

[0030] In some possible implementations, the processing unit is further configured to: generate identification information, where the identification information is used to indicate a position of the jth symbol in the i-th second symbol set.

[0031] In some possible implementations, before sending the second modulated signal, the processing unit is further configured to: interleave symbols in the second modulated signal.

[0032] In some possible implementations, the second modulated signal includes N shape symbol groups, each symbol group includes K symbols, M×N=N shape ×K,N shape is an integer greater than 1, and K is an integer greater than 1. The second modulated signal after interleaving is represented as: {the 0th symbol in the 0th symbol group, the 0th symbol in the 1st symbol group, ..., the Nth symbol group} shape -The 0th symbol in the 1st symbol group, the 1st symbol in the 0th symbol group, the 1st symbol in the 1st symbol group, ..., the Nth symbol shape-1 symbol group, ..., the K-1th symbol in the 0th symbol group, the K-1th symbol in the 1st symbol group, ..., the Nth shape -1 symbol in a group of symbols}.

[0033] In some possible implementations, after obtaining the first modulated signal, and before flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal comprising M×N symbols, the processing unit is further configured to: interleave the symbols of each first symbol set in the first modulated signal. After flipping the polarity of at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal comprising M×N symbols, and before transmitting the second modulated signal, the processing unit is further configured to: deinterleave the symbols in the second modulated signal according to the interleaving method.

[0034] In some possible implementations, each first symbol set in the first modulated signal includes R consecutive symbol subsets, each symbol subset includes L symbols, N=R×L, R is an integer greater than 1, and L is an integer greater than 1. The first symbol set in the first modulated signal after interleaving is expressed as: {the 0th symbol in the 0th symbol subset, the 0th symbol in the 1st symbol subset, …, the 0th symbol in the R-1th symbol subset, the 1st symbol in the 0th symbol subset, the 1st symbol in the 1st symbol subset, …, the 1st symbol in the R-1th symbol subset, …, the L-1th symbol in the 0th symbol subset, the L-1th symbol in the 1st symbol subset, …, the L-1th symbol in the R-1th symbol subset}.

[0035] In a fifth aspect, an embodiment of the present application provides a receiving end device, which includes: a receiving unit and a processing unit. The receiving unit is used to: receive a first signal and identification information sent by a transmitting end through a channel. The processing unit is used to: perform DC removal processing on the first signal to obtain a second signal, the second signal including M symbol sets, each symbol set including N symbols, M is an integer greater than 1, N is an integer greater than 1, and the identification information is used to indicate the polarity reversal of the symbols in each symbol set. The polarity of at least one symbol in at least one symbol set is reversed according to the identification information to obtain a third signal including M×N symbols.

[0036] In some possible implementations, the processing unit is specifically configured to: determine, based on the identification information, the jth symbol in the i-th second symbol set, where 0≤i≤M-1 and 0≤j≤N-2, and flip the polarity of all symbols following the jth symbol in the i-th second symbol set.

[0037] In a sixth aspect, an embodiment of the present application provides a communication system, which includes a transmitting device as described in any embodiment of the fourth aspect and a receiving device as described in any embodiment of the fifth aspect.

[0038] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0039] The transmitter generates a second modulated signal by flipping the polarity of some symbols in the first modulated signal, ensuring that the sum of the values ​​of all symbols in the second modulated signal is less than or equal to the maximum value a single symbol can take. This suppresses the power of the low-frequency portion of the second modulated signal, helping to mitigate the impact of low-frequency noise in the channel on transmission performance. Compared to channel compensation at the receiver, this processing method at the transmitter is less complex. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a schematic diagram of a communication system used in an embodiment of the present application;

[0041] FIG2( a ) is a schematic diagram of an implementation method of a transmitting end in an embodiment of the present application;

[0042] FIG2( b ) is a schematic diagram of two implementation methods of the transmitting end in an embodiment of the present application;

[0043] FIG3 is a schematic diagram of a first flow chart of a signal processing method according to an embodiment of the present application;

[0044] FIG4 is a schematic diagram of compressing the power spectrum of the low-frequency portion in an embodiment of the present application;

[0045] FIG5 is a schematic diagram showing the corresponding relationship between OH and compression bandwidth in an embodiment of the present application;

[0046] Figure 6 shows the locations of several possible compression frequencies in the power spectrum;

[0047] FIG7 is a schematic diagram of a second flow chart of a signal processing method according to an embodiment of the present application;

[0048] FIG8 is a schematic diagram of a DC removal process performed by a receiving end in an embodiment of the present application;

[0049] FIG9 is a schematic structural diagram of a transmitting end device in an embodiment of the present application;

[0050] FIG10 is another structural diagram of a transmitting end device according to an embodiment of the present application;

[0051] FIG11 is a schematic structural diagram of a receiving end device in an embodiment of the present application;

[0052] FIG12 is another structural diagram of a receiving end device in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The embodiment of the present application provides a signal processing method and related devices. The transmitting end suppresses the power of the low-frequency part by flipping the polarity of some symbols in the modulated signal, which is beneficial to resisting the influence of low-frequency noise in the channel on the transmission performance.

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

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

[0056] Figure 2(a) is a schematic diagram of one implementation method of a transmitter in an embodiment of the present application. As shown in Figure 2(a), in one possible implementation, the transmitter modulates the data stream to obtain a modulated signal. Furthermore, the transmitter performs power spectrum shaping encoding on the modulated signal to compress the power of the low-frequency portion of the modulated signal to counteract the effects of low-frequency noise. It should be understood that the transmitter can also interleave the modulated signal that has undergone power spectrum shaping encoding to achieve power spectrum compression at multiple frequency points to counteract the effects of power attenuation at multiple frequency points.

[0057] Figure 2(b) illustrates two possible implementations of the transmitter in an embodiment of the present application. As shown in Figure 2(b), in another possible implementation, the transmitter modulates the data stream to obtain a modulated signal. The transmitter then interleaves the modulated signal and then performs power spectrum shaping coding on the interleaved modulated signal. Furthermore, the transmitter deinterleaves the power spectrum shaping coded modulated signal based on the interleaving method to achieve power spectrum compression at multiple frequency points, thereby counteracting the effects of multi-frequency power attenuation.

[0058] It should be understood that the present application does not limit the specific modulation method of the modulation signal. For example, the modulation method includes but is not limited to non-return to zero (NRZ) modulation and multi-level pulse amplitude modulation (PAMn). Among them, PAMn modulation includes PAM2 modulation, PAM4 modulation, or higher-level PAM modulation.

[0059] It should be noted that the modulation and power spectrum shaping coding in Figures 2(a) and 2(b) are necessary operations for compressing the power of the low-frequency portion of the modulated signal. Interleaving in Figure 2(a) is an optional operation for achieving power spectrum compression at multiple frequencies. Interleaving and deinterleaving in Figure 2(b) are also optional operations for achieving power spectrum compression at multiple frequencies.

[0060] The necessary operations in FIG. 2( a ) and FIG. 2( b ) are first introduced in detail below.

[0061] Figure 3 is a schematic diagram of a first flow chart of a signal processing method in an embodiment of the present application. In this embodiment, the signal processing method is applied to a transmitting end, and the signal processing method includes the following steps.

[0062] 101. Obtain a first modulated signal.

[0063] In this embodiment, the transmitting end modulates the data stream to obtain a first modulated signal. The first modulated signal includes M first symbol sets, each of which includes N symbols, where M and N are both integers greater than 1. For example, N is typically an integer multiple of 2. It should be understood that each first symbol set can also be referred to as a symbol block, and each symbol in the block can include multiple bits.

[0064] 102. Perform power spectrum shaping encoding on the first modulated signal to obtain a second modulated signal.

[0065] Specifically, the transmitting end flips at least one symbol in at least one first symbol set of the first modulated signal to obtain a second modulated signal. It should be understood that the specific symbols in the first symbol set in the first modulated signal whose polarity needs to be flipped depends on the specific situation. Here, the first symbol set after the polarity of the symbols is flipped is referred to as the second symbol set. The second modulated signal still includes M×N symbols, that is, the second modulated signal includes both the second symbol set with the symbol polarity flipped and the first symbol set without the symbol polarity flipped.

[0066] It should be noted that the transmitter flips at least one symbol in at least one first symbol set so that the absolute value of the sum of the values ​​of all symbols in the second modulated signal is less than the absolute value of the sum of the values ​​of all symbols in the first modulated signal. Furthermore, the sum of the values ​​of all symbols in the second modulated signal is less than or equal to the maximum value that a single symbol in the second modulated signal can take. It should be understood that the maximum value that a single symbol can take depends on the modulation format. For example, the maximum value that a single symbol can take in PAM4 modulation is +3, and the maximum value that a single symbol can take in PAM8 modulation is +7. In other words, the sum of the values ​​of all symbols in the second modulated signal is less than the maximum level value of the second modulated signal. In this way, the power of the low-frequency portion of the second modulated signal is reduced, which facilitates processing at the receiver to resist the influence of low-frequency noise. In one possible embodiment, the sum of the values ​​of all symbols in the second modulated signal is equal to 0, so that the power spectrum of the low-frequency portion of the second modulated signal can be compressed to the greatest extent. In some possible scenarios, the value of each symbol can specifically correspond to the level value of the modulation of that symbol. As an example, take the symbol sequence {+1, +1, -1, -1, +1} obtained by NRZ modulation, that is, the values ​​of the five symbols in the symbol sequence are +1, +1, -1, -1, +1, respectively, then the sum of the values ​​of the symbol sequence is +1. As another example, take the symbol sequence {+3, +1, -1, -3, +3} obtained by PAM4 modulation, that is, the values ​​of the five symbols in the symbol sequence are +3, +1, -1, -3, +3, respectively, then the sum of the values ​​of the symbol sequence is +3. In other possible scenarios, the symbol values ​​are complex numbers, such as using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM). Taking QPSK as an example, the value of each symbol is 1+1j, 1-1j, -1+1j, -1-1j. Assuming that the symbol sequence is 1+1j, 1-1j, -1+1j, -1-1j, 1+1j, then the sum of the values ​​of the symbol sequence is 1+1j, that is, the sum of the values ​​of the complex number is the result of adding the real part and the imaginary part of the complex number respectively.

[0067] The specific implementation of power spectrum shaping coding is introduced below.

[0068] Take the i-th first symbol set as an example, where 0≤i≤M-1. The transmitter flips the polarity of all symbols after the j-th symbol in the i-th first symbol set to obtain the i-th second symbol set, where 0≤j≤N-2. That is, the transmitter determines the target symbol in the i-th first symbol set, recorded as the j-th symbol, and flips the polarity of all symbols after the target symbol. The target symbol can be any symbol from the 0th symbol to the N-2th symbol in the i-th first symbol set. Then, there are N-1 different symbol polarity flipping methods for the i-th first symbol set. Accordingly, the i-th first symbol set corresponds to N-1 second symbol sets with symbol polarity flipped. Furthermore, the sum of all symbol values ​​of each second symbol set in these N-1 second symbol sets is determined, and the second symbol set with the smallest sum of all symbol values ​​is selected. The target symbol corresponding to the second symbol set is recorded as j min Therefore, the final result is the jth in the i-th first symbol set. min The i-th second symbol set after the polarity of all symbols after the i-th symbol is reversed.

[0069] It should be noted that if there are actually multiple different target symbols in the i-th first symbol set that can minimize the sum of the values ​​of all symbols after polarity reversal, then one of the target symbols can be selected as the actual reversal point based on the way the identification information is carried. For example, if the identification information is interspersed at the beginning or end of each symbol set in the second modulated signal, then try to select a target symbol that is located in the middle of the symbol set and away from the beginning or end to avoid the appearance of long consecutive 0s or long consecutive 1s after the identification information is converted into a binary sequence. For another example, if the identification information is transmitted independently of the second modulated signal, then any one of the multiple target symbols can be selected.

[0070] In one possible scenario, in order to ensure that the sum of the values ​​of all symbols in the second modulated signal is equal to 0, it should be ensured that the sum of the values ​​of all symbols in each symbol set of the second modulated signal is equal to 0. Specifically, for the M first symbol sets in the first modulated signal, first determine whether the sum of the values ​​of each first symbol set is 0. Take the i-th first symbol set as an example, where 0≤i≤M-1. If the sum of the values ​​of all symbols in the i-th first symbol set is 0, then the polarity of all symbols in the i-th first symbol set is maintained. If the sum of the values ​​of all symbols in the i-th first symbol set is not 0, then the polarity of at least one symbol in the i-th first symbol set is flipped to obtain the i-th second symbol set, so that the sum of the values ​​of all symbols in the i-th second symbol set is 0. In this way, the sum of the values ​​of each symbol set in the second modulated signal is 0, and the sum of the values ​​of all symbols in the second modulated signal is also equal to 0, which can maximize the compression of the power spectrum of the low-frequency part of the second modulated signal.

[0071] As an example, the transmitter flips the polarity of all symbols after the jth symbol in the i-th first symbol set to obtain the i-th second symbol set, where 0≤j≤N-2. Specifically, the sum of the values ​​of all N symbols in the i-th first symbol set is first calculated and recorded as Then, find the jth symbol in the i-th first symbol set, and record it as the Nth symbol in the first symbol set. b Symbols. Among them, the 0th symbol to the Nth symbol in the i-th first symbol set b The sum of the values ​​of the symbols is equal to half of the sum of the values ​​of all N symbols in the i-th first symbol set, that is, Therefore, the sum of the values ​​of the i-th second symbol set obtained by flipping the polarity of all symbols after the target symbol in the i-th first symbol set is equal to 0. Taking NRZ modulation as an example, the i-th first symbol set is expressed as {+1,-1,-1,...,+1,+1,-1,+1,-1,-1,...}, and its corresponding i-th second symbol set is expressed as {+1,-1,-1,...,+1,+1,+1,-1,+1,+1,...}. It should be noted that the transmitter can also select some symbols in the i-th first symbol set that need to flip polarity by other methods, as long as the sum of the values ​​of all N symbols in the i-th second symbol set is guaranteed to be equal to 0. The specific implementation method is not limited here.

[0072] In another possible scenario, for the M first symbol sets in the first modulated signal, it is first determined whether the sum of the values ​​of each first symbol set is 0. If the sum of the values ​​of all symbols in a first symbol set is 0, the polarity of all symbols in the first symbol set is maintained. For other first symbol sets whose sum is not 0, it is not strictly required that the sum of the values ​​of each second symbol set after the symbol polarity flip is equal to 0. As long as the sum of the values ​​of this part of the second symbol set as a whole is equal to 0, the sum of the values ​​of all symbols in the second modulated signal can also be guaranteed to be equal to 0. It should be understood that this application does not limit the specific operation method. Several possible examples are described below. Taking the 10 second symbol sets obtained after the symbol polarity flip as an example, for example, each two second symbol sets are grouped together to achieve complete positive and negative cancellation of the two second symbol sets, that is, the sum of the overall values ​​of each two second symbol sets as a group is equal to 0. For another example, the sum of the overall values ​​of five of the second symbol sets is combined with the sum of the overall values ​​of the other five second symbol sets to achieve complete positive and negative cancellation.

[0073] Figure 4 is a schematic diagram of compressing the power spectrum of the low-frequency portion in an embodiment of the present application. As shown in Figure 4, the horizontal axis represents frequency (in MHz) and the vertical axis represents power spectrum density (in dB). Taking PAM4 modulation as an example, each block includes 256 symbols. It can be seen that the second modulated signal after power spectrum shaping encoding achieves compression of the power spectrum of the low-frequency portion, with a 3dB bandwidth of 80 MHz.

[0074] 103. Send a second modulated signal.

[0075] The second modulated signal sent by the transmitting end is transmitted to the receiving end through the channel.

[0076] It should be noted that in order for the receiving end to be able to recover the first modulated signal before the transmitting end performs power spectrum shaping encoding after removing DC, the transmitting end also needs to send identification information to the receiving end to indicate the polarity reversal of each symbol set in the second modulated signal. Then, the receiving end can flip the polarity of some symbols again according to the identification information, thereby obtaining the original modulated signal from the transmitting end. As an example, the transmitting end flips the polarity of all symbols after the target symbol in the i-th first symbol set, and the identification information is specifically used to indicate the position of the target symbol. It should be noted that the second modulated signal and the identification information can be sent to the receiving end together through the channel. Alternatively, the identification information can also be sent to the receiving end through other channels independently of the second modulated signal.

[0077] In one possible embodiment, the identification information includes M indicator bits corresponding one-to-one to the M symbol sets in the second modulated signal, each indicator bit being used to indicate a polarity flip of a symbol in the corresponding symbol set. The M indicator bits may be interspersed among the M symbol sets in the second modulated signal. For example, each indicator bit is adjacent to the beginning of its corresponding symbol set. For another example, each indicator bit is adjacent to the end of its corresponding symbol set. For another example, each indicator bit may also be inserted at any position in the corresponding symbol set, and the specifics are not limited here.

[0078] FIG5 is a schematic diagram of the corresponding relationship between OH and compression bandwidth in an embodiment of the present application. It should be noted that the above identification information can also be called overhead (OH). As shown in FIG5, the horizontal axis represents the proportion of OH in the block, and the vertical axis represents the compression bandwidth of the power spectrum (in MHz). Among them, OH is the same as the length N of the block. b The corresponding relationship is: OH = log2N b / (log2N b +N b ). It can be seen that as OH increases, the power spectrum compression bandwidth of the signal becomes larger, and the suppression effect on low frequencies is better, but the redundant information also increases accordingly.

[0079] The optional operations in FIG. 2( a ) and FIG. 2( b ) are first introduced in detail below.

[0080] In one possible scenario, as shown in FIG2(a), the transmitting end may further interleave the second modulated signal to reorder the symbols in the second modulated signal, thereby achieving power spectrum compression at multiple different frequency positions. That is, for the interleaved second modulated signal, in addition to compressing the low-frequency portion of the power spectrum, it is also possible to achieve compression of other frequency points such as the intermediate frequency portion or the high frequency portion of the power spectrum. The following describes a possible interleaving method. For example, the second modulated signal includes N shape symbol groups, each symbol group includes K symbols, M×N=N shape ×K,N shape is an integer greater than 1, and K is an integer greater than 1. It should be understood that the symbol group here is not equivalent to the block introduced above, and the N of the symbol group is shape The second modulated signal after the interleaving is represented as: {the 0th symbol in the 0th symbol group, the 0th symbol in the 1st symbol group, ..., the Nth symbol group, shape -The 0th symbol in the 1st symbol group, the 1st symbol in the 0th symbol group, the 1st symbol in the 1st symbol group, ..., the Nth symbol shape-1 symbol group, ..., the K-1th symbol in the 0th symbol group, the K-1th symbol in the 1st symbol group, ..., the Nth shape -1 symbol in a group of symbols}.

[0081] In another possible scenario, as shown in Figure 2(b), before performing power spectrum shaping encoding on the first modulated signal, the transmitter first interleaves the first modulated signal to reorder the symbols in the first modulated signal. Next, the transmitter performs power spectrum shaping encoding on the interleaved first modulated signal. The specific implementation of power spectrum shaping encoding can refer to the relevant introduction of step 102 and will not be repeated here. Furthermore, the transmitter deinterleaves the second modulated signal obtained after power spectrum shaping encoding. Deinterleaving can be regarded as the inverse processing operation of interleaving. Based on the rules of interleaving, the corresponding deinterleaving operation is performed to restore the original symbol order. It should be understood that for the deinterleaved second modulated signal, in addition to compressing the low-frequency portion of the power spectrum, compression of other frequency points such as the mid-frequency portion or high-frequency portion of the power spectrum can also be achieved. A possible interleaving method is described below. For example, each first symbol set in the first modulated signal includes R consecutive symbol subsets, each symbol subset includes L symbols, N = R × L, where R is an integer greater than 1 and L is an integer greater than 1. Then, the first symbol set in the first modulated signal after interleaving is expressed as: {the 0th symbol in the 0th symbol subset, the 0th symbol in the 1st symbol subset,…, the 0th symbol in the R-1th symbol subset, the 1st symbol in the 0th symbol subset, the 1st symbol in the 1st symbol subset,…, the 1st symbol in the R-1th symbol subset,…, the L-1th symbol in the 0th symbol subset, the L-1th symbol in the 1st symbol subset,…, the L-1th symbol in the R-1th symbol subset}.

[0082] It should be noted that, for the scenario shown in FIG2(a), the power spectrum compression frequency corresponding to the second modulated signal output by the transmitter depends on N shape The following table 1 gives the value of N shape The power spectrum compression frequency points corresponding to several typical values, namely N shape The values ​​of include but are not limited to 2, 4 and 8. Figure 6 shows the locations of several possible compression frequency points in the power spectrum. As shown in Figure 6, the horizontal axis represents the frequency (unit is MHz) and the vertical axis represents the power spectrum density (unit is dB). Figure 6 (a) shows N shape = 2, the position of the compression frequency in the power spectrum, Figure 6 (b) shows N shape =4, the position of the compression frequency in the power spectrum, Figure 6 (c) shows N shape=8. The compressed frequency points in the power spectrum in Table 1 represent the relative positions of the compressed frequency points within the frequency coverage range of the power spectrum. As shown in Figure 6, the frequency coverage range of the power spectrum is 0MHz to 4×104MHz. For example, a compressed frequency point of 1 / 2 indicates that the compressed frequency point is located in the middle position within the frequency coverage range of the power spectrum, that is, 2×104MHz. For another example, a compressed frequency point of 1 / 4 indicates that the compressed frequency point is located at the 1 / 4 position within the frequency coverage range of the power spectrum, that is, 1×104MHz. For another example, a compressed frequency point of 3 / 4 indicates that the compressed frequency point is located at the 3 / 4 position within the frequency coverage range of the power spectrum, that is, 3×104MHz.

[0083] For the scenario shown in Figure 2(b), the power spectrum compression frequency corresponding to the second modulated signal output by the transmitter depends on the value of L = N / R. That is, when the value of L is 2, 4, and 8, the compression frequency positions of the power spectrum are shown in (a), (b), and (c) in Figure 6.

[0084] Table 1

[0085] As can be seen from the above description, the transmitter generates the second modulated signal by flipping the polarity of some symbols in the first modulated signal, so that the sum of the values ​​of all symbols in the second modulated signal equals 0. This suppresses the power of the low-frequency portion of the second modulated signal, helping to mitigate the impact of low-frequency noise in the channel on transmission performance. Compared to channel compensation methods performed at the receiver, this processing method at the transmitter is less complex.

[0086] The following describes the processing flow at the receiving end.

[0087] Figure 7 is a second flow chart of the signal processing method in the embodiment of the present application. In this embodiment, the signal processing method is applied to the receiving end, and the signal processing method includes the following steps.

[0088] 201. Receive a first signal and identification information sent by a transmitting end and transmitted through a channel.

[0089] It should be noted that the first signal received by the receiving end includes the signal sent by the transmitting end and interference in the channel transmission. Because the transmitting end flips the polarity of some symbols in the original signal before transmitting the signal, the identification information is used to indicate the polarity flipping of the symbols in the signal sent by the transmitting end, so that the receiving end can recover the original signal from the transmitting end based on the identification information.

[0090] 202. Perform DC removal processing on the first signal to obtain a second signal.

[0091] FIG8 is a schematic diagram of a DC removal process performed by the receiving end in an embodiment of the present application. It should be understood that there is low-frequency interference in the channel, and the power of the signal sent by the transmitting end at the low frequency is suppressed, so that the transmitted signal and the interference do not overlap in frequency. The receiving end can remove interference by removing DC without causing damage to the signal from the transmitting end. In other words, the second signal obtained by the receiving end after removing DC can be regarded as the signal sent by the transmitting end. Based on the relevant introduction of the embodiment shown in FIG3 above, it can be seen that the second signal includes M symbol sets, each symbol set includes N symbols, M is an integer greater than 1, and N is an integer greater than 1.

[0092] 203. Reverse the polarity of at least one symbol in at least one symbol set according to the identification information to obtain a third signal.

[0093] The receiving end determines which symbols in the symbol set in the second signal require polarity flipping based on the identification information, and then flips the polarity of these symbols, thereby recovering the modulated signal before the transmitting end performed power spectrum shaping encoding. In other words, the operation of step 203 can also be considered the inverse operation of step 102 above. The third signal can be considered the original signal before the transmitting end performed power spectrum shaping encoding.

[0094] As an example, the transmitter uses PAM4 modulation. Each symbol set in the second signal includes 256 symbols, and a corresponding indicator bit is inserted at the end of each symbol set. The receiver determines the length of the indicator bit based on the size of the symbol set, that is, log2256 = 8. Taking the symbol sequence of the symbol set + indicator bit as […-3, 1, 3, -1, 3, 1, -3, 1, -3, 3, 1, -1…-3, 3, 3, -1, 3, -1, -3, 1] as an example, the indicator bit is represented by the last 8 symbols in the symbol sequence. The receiver converts the indicator bit [-3, 3, 3, -1, 3, -1-3, 1] into binary information [01101001], which is 105 in decimal. Therefore, the receiving end flips the polarity of the 106th to 256th symbols in the symbol set. The symbol set after the polarity flipping is expressed as […-3, 1, 3, -1, 3, 1, 3, -1, 3, -3, -1, 1…].

[0095] It should be noted that in some possible scenarios, as shown in Figure 2(a), if the transmitter outputs an interleaved modulated signal, the receiver needs to deinterleave the received modulated signal before performing DC removal processing.

[0096] Figure 9 is a schematic diagram of the structure of a transmitting device in an embodiment of the present application. As shown in Figure 9, the transmitting device includes: a processing unit 301 and a transmitting unit 302. Processing unit 301 is configured to perform the operations of steps 101 and 102 above, and transmitting unit 302 is configured to perform the operation of step 103 above. Optionally, processing unit 301 is also configured to perform the interleaving operation shown in Figure 2(a), or alternatively, processing unit 301 is also configured to perform the interleaving and deinterleaving operations shown in Figure 2(a).

[0097] It should be understood that the transmitting end device provided in this application can also be implemented in other ways. For example, the unit division in the above-mentioned device is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system. In addition, the functional units in the various embodiments of this application can be integrated into a processing unit, or can be independent physical units, or two or more functional units can be integrated into a processing unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0098] Figure 10 is another schematic diagram of the structure of the transmitting end device in an embodiment of the present application. As shown in Figure 10, the transmitting end device includes a processor 401 and a transceiver 402. The processor 401 and the transceiver 402 are interconnected via a line. Specifically, the transceiver 402 is used to perform signal transmission and reception operations, and the processor 401 is used to perform other operations besides signal transmission and reception. In one possible implementation, the processor 401 may include the processing unit 301 shown in Figure 9 above, and the transceiver 402 includes the transmitting unit 302 shown in Figure 9 above. Optionally, the transmitting end device may also include a memory 403, wherein the memory 403 is used to store program instructions and data.

[0099] Figure 11 is a schematic diagram of the structure of a receiving device in an embodiment of the present application. As shown in Figure 11, the receiving device includes: a receiving unit 501 and a processing unit 502. The receiving unit 501 is used to perform the operation of step 201 above, and the processing unit 502 is used to perform the operations of steps 202 and 203 above.

[0100] It should be understood that the receiving device provided in this application can also be implemented in other ways. For example, the unit division in the above-mentioned device is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system. In addition, the functional units in the various embodiments of this application can be integrated into a processing unit, or can be independent physical units, or two or more functional units can be integrated into a processing unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0101] Figure 12 is another schematic diagram of the structure of a receiving device in an embodiment of the present application. As shown in Figure 12, the receiving device includes a processor 601 and a transceiver 602. The processor 601 and the transceiver 602 are interconnected via a line. Specifically, the transceiver 602 is used to perform signal transmission and reception operations, and the processor 601 is used to perform other operations besides signal transmission and reception. In one possible embodiment, the processor 601 may include the processing unit 502 shown in Figure 11 above, and the transceiver 602 includes the receiving unit 501 shown in Figure 11 above. Optionally, the receiving device may also include a memory 603, wherein the memory 603 is used to store program instructions and data.

[0102] The present application also provides a chip. This chip integrates circuitry and one or more interfaces for implementing the functions of the aforementioned processor 401 or processor 601. When the chip integrates memory, it can perform the method steps of any one or more of the aforementioned embodiments. When the chip does not integrate memory, it can be connected to an external memory via an interface. The chip implements the actions performed by the transmitting device or receiving device in the aforementioned embodiments based on program code stored in the external memory.

[0103] Finally, it should be noted that the above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A signal processing method, characterized in that: include: Acquire a first modulated signal, where the first modulated signal includes M first symbol sets, each of the first symbol sets includes N symbols, where M is an integer greater than 1, and N is an integer greater than 1; Flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, wherein an absolute value of the sum of values ​​of all symbols in the second modulated signal is less than an absolute value of the sum of values ​​of all symbols in the first modulated signal; The second modulated signal is transmitted.

2. The method according to claim 1, characterized in that Flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal includes: Determine the value of j corresponding to the minimum value when the sum of the values ​​of all symbols in the i-th second symbol set is the minimum value min , wherein the i-th second symbol set is obtained by reversing the polarities of all symbols after the j-th symbol in the i-th first symbol set, wherein 0≤i≤M-1, 0≤j≤N-2; For the jth symbol in the i-th first symbol set min The polarity of all symbols after the first symbol is reversed.

3. The method according to claim 2, characterized in that The method further comprises: Generate identification information, the identification information is used to indicate the jth in the i-th first symbol set min The position of a symbol.

4. The method according to claim 1, characterized in that: The sum of values ​​of all symbols in the second modulated signal is equal to 0.

5. The method according to claim 4, characterized in that Flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal includes: Obtain the sum of the values ​​of all symbols in the i-th first symbol set, where 0≤i≤M-1; If the sum of the values ​​of all symbols in the i-th first symbol set is equal to 0, the polarities of all symbols in the i-th first symbol set remain unchanged; If the sum of the values ​​of all symbols in the i-th first symbol set is not equal to 0, the polarity of at least one symbol in the i-th first symbol set is flipped to obtain the i-th second symbol set, and the sum of the values ​​of all symbols in the i-th second symbol set is equal to 0.

6. The method according to claim 5, characterized in that Flipping the polarity of at least one symbol in the i-th first symbol set to obtain the i-th second symbol set includes: The polarities of all symbols after the jth symbol in the i-th first symbol set are reversed to obtain the i-th second symbol set, 0≤j≤N-2.

7. The method according to claim 6, characterized in that The method further comprises: Generate identification information, where the identification information is used to indicate a position of the jth symbol in the i-th second symbol set.

8. The method according to any one of claims 1 to 7, characterized in that Before sending the second modulated signal, the method further includes: The symbols in the second modulated signal are interleaved.

9. The method according to claim 8, characterized in that The second modulation signal includes N shape symbol groups, each of which includes K symbols, M×N=N shape × K, N shape is an integer greater than 1, K is an integer greater than 1, and the second modulated signal after the interleaving is expressed as: {the 0th symbol in the 0th symbol group, the 0th symbol in the 1st symbol group, ..., the Nth shape The 0th symbol in the -1st symbol group, the 1st symbol in the 0th symbol group, the 1st symbol in the 1st symbol group, ..., the Nth symbol shape -1 symbol in the 1st symbol group, ..., the K-1th symbol in the 0th symbol group, the K-1th symbol in the 1st symbol group, ..., the Nth shape -1 symbol group}.

10. The method according to any one of claims 1 to 7, characterized in that After acquiring the first modulated signal, before flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, the method further includes: interleaving each symbol of the first symbol set in the first modulated signal; After flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, and before sending the second modulated signal, the method further includes: The symbols in the second modulated signal are deinterleaved according to the interleaving method.

11. The method according to claim 10, characterized in that Each first symbol set in the first modulated signal includes R consecutive symbol subsets, each of the symbol subsets includes L symbols, N=R×L, R is an integer greater than 1, and L is an integer greater than 1. The first symbol set in the first modulated signal after the interleaving is expressed as: {the 0th symbol in the 0th symbol subset, the 0th symbol in the 1st symbol subset,…, the 0th symbol in the R-1th symbol subset, the 1st symbol in the 0th symbol subset, the 1st symbol in the 1st symbol subset,…, the 1st symbol in the R-1th symbol subset,…, the L-1th symbol in the 0th symbol subset, the L-1th symbol in the 1st symbol subset,…, the L-1th symbol in the R-1th symbol subset}.

12. A signal processing method, characterized in that: include: Receiving a first signal and identification information transmitted through a channel and sent by a transmitting end; Performing DC removal processing on the first signal to obtain a second signal, the second signal including M symbol sets, each of the symbol sets including N symbols, M is an integer greater than 1, N is an integer greater than 1, and the identification information is used to indicate the polarity reversal of the symbols in each of the symbol sets; The polarity of at least one symbol in at least one of the symbol sets is flipped according to the identification information to obtain a third signal including M×N symbols.

13. The method according to claim 12, characterized in that Flipping the polarity of at least one symbol in at least one of the second symbol sets according to the identification information includes: Determine the jth symbol in the i-th second symbol set according to the identification information, where 0≤i≤M-1, 0≤j≤N-2; The polarities of all symbols after the jth symbol in the i-th second symbol set are reversed.

14. A chip, characterized in that: The chip includes a processor and a memory, wherein the memory and the processor are connected to each other via a line, instructions are stored in the memory, and the processor is used to execute the method according to any one of claims 1 to 13.

15. A transmitting end device, characterized in that: include: A processing unit and a sending unit; The processing unit is used to: obtain a first modulated signal, the first modulated signal includes M first symbol sets, each of the first symbol sets includes N symbols, M is an integer greater than 1, and N is an integer greater than 1; Flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, wherein an absolute value of the sum of values ​​of all symbols in the second modulated signal is less than an absolute value of the sum of values ​​of all symbols in the first modulated signal; The sending unit is used to: send the second modulated signal.

16. The transmitting end device according to claim 15, characterized in that: The processing unit is specifically used for: Determine the value of j corresponding to the minimum value when the sum of the values ​​of all symbols in the i-th second symbol set is the minimum value min , wherein the i-th second symbol set is obtained by reversing the polarities of all symbols after the j-th symbol in the i-th first symbol set, wherein 0≤i≤M-1, 0≤j≤N-2; For the jth symbol in the i-th first symbol set min The polarity of all symbols after the first symbol is reversed.

17. The transmitting end device according to claim 16, characterized in that: The processing unit is also used for: Generate identification information, the identification information is used to indicate the jth in the i-th first symbol set min The position of a symbol.

18. The transmitting end device according to claim 15, characterized in that: The sum of values ​​of all symbols in the second modulated signal is equal to 0.

19. The transmitting end device according to claim 18, characterized in that: The processing unit is specifically used for: Obtain the sum of the values ​​of all symbols in the i-th first symbol set, where 0≤i≤M-1; If the sum of the values ​​of all symbols in the i-th first symbol set is equal to 0, the polarities of all symbols in the i-th first symbol set remain unchanged; If the sum of the values ​​of all symbols in the i-th first symbol set is not equal to 0, the polarity of at least one symbol in the i-th first symbol set is flipped to obtain the i-th second symbol set, and the sum of the values ​​of all symbols in the i-th second symbol set is equal to 0.

20. The transmitting end device according to claim 19, characterized in that: The processing unit is specifically used for: The polarities of all symbols after the jth symbol in the i-th first symbol set are reversed to obtain the i-th second symbol set, 0≤j≤N-2.

21. The transmitting end device according to claim 20, characterized in that: The processing unit is also used for: Generate identification information, where the identification information is used to indicate a position of the jth symbol in the i-th second symbol set.

22. The transmitting end device according to any one of claims 15 to 21, characterized in that: Before sending the second modulated signal, the processing unit is further used for: The symbols in the second modulated signal are interleaved.

23. The transmitting end device according to claim 22, characterized in that: The second modulation signal includes N shape symbol groups, each of which includes K symbols, M×N=N shape × K, N shape is an integer greater than 1, K is an integer greater than 1, and the second modulated signal after the interleaving is expressed as: {the 0th symbol in the 0th symbol group, the 0th symbol in the 1st symbol group, ..., the Nth shape The 0th symbol in the -1st symbol group, the 1st symbol in the 0th symbol group, the 1st symbol in the 1st symbol group, ..., the Nth symbol shape -1 symbol in the 1st symbol group, ..., the K-1th symbol in the 0th symbol group, the K-1th symbol in the 1st symbol group, ..., the Nth shape -1 symbol group}.

24. The transmitting end device according to any one of claims 15 to 21, characterized in that: After acquiring the first modulated signal, before flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, the processing unit is further used to: interleaving each symbol of the first symbol set in the first modulated signal; After flipping the polarity of at least one symbol in at least one of the first symbol sets of the first modulated signal to obtain a second modulated signal including M×N symbols, and before sending the second modulated signal, the processing unit is further used to: The symbols in the second modulated signal are deinterleaved according to the interleaving method.

25. The transmitting end device according to claim 24, characterized in that: Each first symbol set in the first modulated signal includes R consecutive symbol subsets, each of the symbol subsets includes L symbols, N=R×L, R is an integer greater than 1, and L is an integer greater than 1. The first symbol set in the first modulated signal after the interleaving is expressed as: {the 0th symbol in the 0th symbol subset, the 0th symbol in the 1st symbol subset,…, the 0th symbol in the R-1th symbol subset, the 1st symbol in the 0th symbol subset, the 1st symbol in the 1st symbol subset,…, the 1st symbol in the R-1th symbol subset,…, the L-1th symbol in the 0th symbol subset, the L-1th symbol in the 1st symbol subset,…, the L-1th symbol in the R-1th symbol subset}.

26. A receiving device, characterized in that: include: a receiving unit and a processing unit; The receiving unit is used to: receive a first signal and identification information sent by a transmitting end and transmitted through a channel; The processing unit is used to: perform DC removal processing on the first signal to obtain a second signal, the second signal includes M symbol sets, each of the symbol sets includes N symbols, M is an integer greater than 1, N is an integer greater than 1, and the identification information is used to indicate the polarity reversal of the symbols in each of the symbol sets; The polarity of at least one symbol in at least one of the symbol sets is flipped according to the identification information to obtain a third signal including M×N symbols.

27. The receiving end device according to claim 26, characterized in that: The processing unit is specifically used for: Determine the jth symbol in the i-th second symbol set according to the identification information, where 0≤i≤M-1, 0≤j≤N-2; The polarities of all symbols after the jth symbol in the i-th second symbol set are reversed.

28. A communication system, characterized in that: include: A sending end device as described in any one of claims 15 to 25 and a receiving end device as described in any one of claims 26 to 27.

Images