CN115913837A

CN115913837A - Communication method, device and system

Info

Publication number: CN115913837A
Application number: CN202110891555.XA
Authority: CN
Inventors: 王晖; 黄林; 罗龙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2023-04-04

Abstract

A communication method, a device and a system belong to the technical field of communication. The method comprises the following steps: and the receiving end receives a first subcarrier carrying a target sequence and a second subcarrier carrying a zero sequence which are sent by the sending end. The power spectrum of the target sequence comprises at least one first frequency at which the signal power is greater than the noise power; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the second sub-carrier comprises at least one second frequency and the at least one first frequency comprises the at least one second frequency. Then, the receiving end can determine the target deviation of the interval of the center frequencies of the two subcarriers relative to the signal baud rate of the transmitting end according to the target signal. The target signal is a signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of a second frequency. The method and the device solve the problem that the target deviation cannot be determined, and are used for determining the target deviation.

Description

Communication method, device and system

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method, apparatus, and system.

Background

With the development of communication technology, signals can be transmitted between communication apparatuses through a plurality of subcarriers, wherein a communication apparatus that transmits a subcarrier is referred to as a transmitting end, and a communication apparatus that receives a subcarrier is referred to as a receiving end.

Generally, there is an overlap in the frequency bands of the above-mentioned multiple kinds of subcarriers. In this case, the deviation of the center frequency interval of adjacent subcarriers (subcarriers adjacent to each other in frequency band) from the signal baud rate of the transmitting end can represent the Interference between the adjacent subcarriers, and if the deviation can be obtained, the Inter-Channel Interference (ICI) between the adjacent subcarriers can be compensated according to the deviation.

However, the frequency of the laser emitted by the laser in the transmitting end is easy to shift, so that the actual deviation between the center frequency interval of the adjacent subcarriers and the signal baud rate of the transmitting end cannot be determined.

Disclosure of Invention

The application provides a communication method, a device and a system, which can solve the problem that the actual deviation between the center frequency interval of adjacent subcarriers and the signal baud rate of a sending end cannot be determined, and the technical scheme is as follows:

in a first aspect, a communication method is provided, and the method includes: and the receiving end receives a first subcarrier carrying a target sequence and a second subcarrier carrying a zero sequence, which are sent by the sending end. Wherein the power spectrum of the target sequence comprises at least one first frequency at which the signal power is greater than the noise power; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency. And then, the receiving end determines a target deviation according to a target signal, wherein the target deviation is the deviation of a frequency interval relative to the signal baud rate of the transmitting end, and the frequency interval is the interval between the central frequency of the first subcarrier and the central frequency of the second subcarrier. The target signal is a signal obtained by the receiving end receiving the second subcarrier, and the target signal includes the signal of the at least one second frequency.

The target signal is a signal obtained by the receiving end receiving the second subcarrier. The frequency band of the second subcarrier includes at least one second frequency, and therefore, the target signal obtained by the receiving end receiving the second subcarrier includes a signal of the at least one second frequency. In this application, the transmitting end transmits the second subcarrier to the receiving end and also transmits the first subcarrier to the receiving end, the frequency band of the first subcarrier and the frequency band of the second subcarrier both include the at least one second frequency, and the signal power of the second frequency in the first subcarrier is greater than the noise power. Therefore, the signal of the second frequency in the first subcarrier can be leaked to the second subcarrier, so that the signal of the second frequency in the target signal received by the receiving end from the second subcarrier is affected by the first subcarrier, and the signal of the second frequency in the target signal is related to both the first subcarrier and the second subcarrier, so that the target signal can reflect the relationship between the two subcarriers. Thus, the receiving end can determine the target deviation of the interval of the center frequencies of the two subcarriers actually relative to the signal baud rate of the transmitting end according to the target signal.

The target sequence may include one or more first frequencies in the power spectrum, and the first frequencies may be separated from the center frequency of the first subcarrier by any interval, which is not limited in this application. Illustratively, the absolute value of the difference between any of said first frequencies and the center frequency of said first subcarrier is equal to one-half of said signal baud rate. Further illustratively, the power spectrum of the target sequence includes two first frequencies, and the absolute value of the difference between the two first frequencies and the center frequency of the first subcarrier is the same.

The target sequence can be realized in various ways, and the application does not limit the implementation way of the target sequence. Taking an alternative implementation of the target sequence as an example, the value of the nth element in the target sequence is equal to the power of e (1 j × pi (n-1)), e represents a natural constant, j is an imaginary unit, and n ≧ 1. The target sequence may include a plurality of bits in succession, each bit in the target sequence being an element in the target sequence.

The first sub-carrier has various modes of carrying the target sequence, and the second sub-carrier has various modes of carrying the zero sequence, which is not limited in the embodiment of the present application. For example, the first subcarrier carries a first multiframe (multiframe is also called optical interface frame), where the first multiframe includes the target sequence; the second sub-carrier carries a second multiframe, and the second multiframe comprises the zero sequence. The position of the target sequence in the overhead of the first multiframe is the same as the position of the zero sequence in the overhead of the second multiframe.

Illustratively, a reserved field in the overhead of the first multiframe includes the target sequence; a reserved field in the overhead of the second multiframe includes the sequence of zeros. Of course, the target sequence may not be included in the first multiframe, or other fields except the reserved field in the overhead of the first multiframe may include the target sequence, or the target sequence may be included in the overhead of the first multiframe (for example, included in the payload of the first multiframe), which is not limited in this application.

Further, in order to protect the target sequence and the zero sequence and prevent the target sequence and the zero sequence from being affected by other signals, the reserved field in the overhead of the first multiframe may further include a first protection sequence and a second protection sequence, and the reserved field in the overhead of the second multiframe may further include a third protection sequence and a fourth protection sequence. The target sequence may be located between the first guard sequence and the second guard sequence, and the zero sequence is located between the third guard sequence and the fourth guard sequence. The lengths of the first protection sequence, the second protection sequence, the third protection sequence and the fourth protection sequence can be any lengths, and the value of each element in the protection sequences can be zero.

Alternatively, the third protection sequence may be identical to the first protection sequence and the fourth protection sequence may be identical to the second protection sequence. Of course, the third protection sequence may be different from the first protection sequence (for example, the third protection sequence has a different length from the first protection sequence), and the fourth protection sequence may be different from the second protection sequence (for example, the fourth protection sequence has a different length from the second protection sequence).

Optionally, when determining the target deviation according to the target signal, the receiving end may first determine a conjugate signal according to the target signal and the target sequence, then determine a slope of the conjugate signal, and finally determine the target deviation according to the slope of the conjugate signal. Wherein the target deviation F = a B/2/pi, a representing the slope and B representing the signal baud rate; the target signal includes m first sub-signals, the m first sub-signals correspond to m elements in the zero sequence one by one, and the xth first sub-signal is a signal obtained by the receiving end receiving a part of the second sub-carrier carrying the corresponding elements; the conjugate signal comprises m second sub-signals, m is more than or equal to 1, and m is less than or equal to the length of the zero sequence; the x-th second sub-signal S2= (conj (S1)) × a,1 ≦ x ≦ m, conj (S1) represents the conjugate of S1, S1 represents the x-th first sub-signal, and a represents the x-th element in the target sequence.

Optionally, after determining a target offset according to the target signal, the receiving end may further compensate for inter-channel interference ICI of the first subcarrier and the second subcarrier according to a first offset, where a sign of the first offset is the same as a sign of the target offset, and an absolute value of the first offset is smaller than or equal to an absolute value of the target offset. The first deviation may be the same as or different from the target deviation. After the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation, the mutual influence between the first sub-carrier and the second sub-carrier can be reduced, and the communication effect between the transmitting end and the receiving end is improved.

In the above description, the receiving end compensates the ICI between the first subcarrier and the second subcarrier according to the first deviation after determining the first deviation. Optionally, the receiving end may further compare an absolute value of the target offset with an absolute value threshold before compensating for ICI between the first subcarrier and the second subcarrier according to the first offset. And when the absolute value of the target deviation is larger than the absolute value threshold, the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation. When the absolute value of the target offset is smaller than or equal to the absolute value threshold, the receiving end may not compensate for the ICI between the first subcarrier and the second subcarrier according to the first offset.

Optionally, after determining the target deviation according to the target signal, the receiving end may further send a second deviation or the target signal to the transmitting end, where a sign of the second deviation is the same as a sign of the target deviation, and an absolute value of the second deviation is smaller than or equal to an absolute value of the target deviation. The second deviation may be the same as or different from the target deviation. For example, the sum of the first deviation and the second deviation is equal to the target deviation.

In the above description, the receiving end sends the second deviation to the transmitting end after determining the second deviation. Optionally, before the receiving end sends the second deviation to the sending end, the receiving end may further compare an absolute value of the target deviation with an absolute value threshold. And when the absolute value of the target deviation is larger than the absolute value threshold, the receiving end sends the second deviation to the sending end. When the absolute value of the target offset is less than or equal to the absolute value threshold, the receiving end may not send the second offset to the sending end.

In a second aspect, a communication method is provided, the method comprising: the sending end sends a first subcarrier carrying a target sequence and a second subcarrier carrying a zero sequence to the receiving end. Wherein the power spectrum of the target sequence comprises at least one first frequency at which the signal power is greater than the noise power; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency. Then, the sending end may obtain a second deviation, where a sign of the second deviation is the same as a sign of a target deviation, and an absolute value of the second deviation is smaller than or equal to an absolute value of the target deviation; the target deviation is a deviation of a frequency interval from a signal baud rate of the transmitting end, the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier, the target deviation is determined according to the target sequence and a target signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of the second frequency.

The target signal is a signal obtained by the receiving end receiving the second subcarrier. The frequency band of the second subcarrier includes at least one second frequency, and therefore, the target signal obtained by the receiving end receiving the second subcarrier includes the signal of the at least one second frequency. In the application, the sending end sends the second subcarrier to the receiving end, and simultaneously sends the first subcarrier to the receiving end, the frequency band of the first subcarrier and the frequency band of the second subcarrier both include the at least one second frequency, and the signal power of the second frequency in the first subcarrier is greater than the noise power. Therefore, the signal of the second frequency in the first subcarrier can be leaked to the second subcarrier, so that the signal of the second frequency in the target signal received by the receiving end from the second subcarrier is affected by the first subcarrier, and the signal of the second frequency in the target signal is related to both the first subcarrier and the second subcarrier, so that the target signal can reflect the relationship between the two subcarriers. Thus, the target deviation of the interval of the center frequencies of the two subcarriers from the baud rate of the signal at the transmitting end can be determined according to the target signal.

The manner of acquiring the second deviation by the transmitting end is various. In an implementation manner, the sending end may obtain the second deviation by receiving the second deviation sent by the receiving end. In another implementation manner, the second deviation is equal to the target deviation, and at this time, when the sending end obtains the second deviation, the sending end may first receive the target signal sent by the receiving end, and then determine the second deviation according to the target signal and the target sequence. The process of determining the second deviation according to the target signal and the target sequence by the transmitting end may refer to the process of determining the second deviation according to the target signal and the target sequence by the receiving end, which is not described herein again.

Optionally, after obtaining the second deviation, the sending end may pre-compensate inter-channel interference ICI of the first subcarrier and the second subcarrier according to the second deviation. The sending end has various modes for pre-compensating the ICI between the first subcarrier and the second subcarrier. For example, when the transmitting end performs pre-compensation on the ICI between the first subcarrier and the second subcarrier, the transmitting end may perform pre-processing on the ICI of the signal to be transmitted to the receiving end according to the second deviation to reduce the ICI between the first subcarrier and the second subcarrier, and/or adjust the frequency interval to make the second deviation approach zero.

Alternatively, if the transmitting end can obtain the target deviation, the transmitting end may determine the absolute value of the target deviation and the absolute value threshold before pre-compensating for the ICI between the first subcarrier and the second subcarrier. And when the absolute value of the target deviation is larger than the absolute value threshold, the sending end pre-compensates the ICI between the first sub-carrier and the second sub-carrier. When the absolute value of the target deviation is smaller than or equal to the absolute value threshold, the transmitting end may not pre-compensate for the ICI between the first subcarrier and the second subcarrier.

In a third aspect, a communication apparatus is provided, where the communication apparatus is used for a receiving end, and the receiving end is in communication connection with a sending end, and the communication apparatus includes: the device comprises a receiving module and a determining module. The receiving module is configured to receive a first subcarrier carrying a target sequence sent by the sending end, where a power spectrum of the target sequence includes at least one first frequency at which a signal power is greater than a noise power; the receiving module is further configured to receive a second subcarrier carrying a zero sequence sent by the sending end to obtain a target signal; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency; the target signal comprises a signal of the at least one second frequency; and the determining module is used for determining a target deviation according to the target signal, wherein the target deviation is the deviation of a frequency interval relative to the baud rate of the signal of the transmitting end, and the frequency interval is the interval between the central frequency of the first subcarrier and the central frequency of the second subcarrier.

The target sequence can be realized in various ways, and the application does not limit the implementation way of the target sequence. Taking an alternative implementation of the target sequence as an example, the value of the nth element in the target sequence is equal to the power of e (1 j × pi × n-1)), e represents a natural constant, j is an imaginary unit, and n ≧ 1. The target sequence may include a plurality of bits in succession, each bit in the target sequence being an element in the target sequence.

Illustratively, a reserved field in the overhead of the first multiframe includes the target sequence; a reserved field in the overhead of the second multiframe includes the zero sequence. Of course, the target sequence may not be included in the first multiframe, or other fields except for the reserved field in the overhead of the first multiframe may include the target sequence, or the target sequence may be included in the overhead of the first multiframe (for example, included in the payload of the first multiframe), which is not limited in this application.

Alternatively, the third protection sequence may be identical to the first protection sequence and the fourth protection sequence may be identical to the second protection sequence. Of course, the third protection sequence may be different from the first protection sequence (e.g., the third protection sequence has a different length from the first protection sequence), and the fourth protection sequence may be different from the second protection sequence (e.g., the fourth protection sequence has a different length from the second protection sequence).

Optionally, the determining module is configured to: determining a conjugate signal according to the target signal and the target sequence, determining the slope of the conjugate signal, and determining the target deviation according to the slope of the conjugate signal. Wherein the target deviation F = a B/2/pi, a representing the slope and B representing the signal baud rate; the target signal includes m first sub-signals, the m first sub-signals correspond to m elements in the zero sequence one by one, and the xth first sub-signal is a signal obtained by the receiving end receiving a part of the second sub-carrier that carries the corresponding elements; the conjugate signal comprises m second sub-signals, m is more than or equal to 1, and m is less than or equal to the length of the zero sequence; the x-th second sub-signal S2= (conj (S1)) × a,1 ≦ x ≦ m, conj (S1) represents the conjugate of S1, S1 represents the x-th first sub-signal, and a represents the x-th element in the target sequence.

Optionally, the communication device further comprises: and a compensation module, configured to compensate for inter-channel interference ICI of the first subcarrier and the second subcarrier according to a first deviation, where a sign of the first deviation is the same as a sign of the target deviation, and an absolute value of the first deviation is smaller than or equal to an absolute value of the target deviation. The first deviation may be the same as or different from the target deviation. After the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation, the mutual influence between the first sub-carrier and the second sub-carrier can be reduced, and the communication effect between the transmitting end and the receiving end is improved.

In the above description, for example, after the determining module determines the first deviation, the compensating module compensates the ICI between the first subcarrier and the second subcarrier according to the first deviation. Optionally, the compensation module may further compare an absolute value of the target offset with an absolute value threshold before compensating for ICI between the first subcarrier and the second subcarrier according to the first offset. And when the absolute value of the target deviation is greater than the absolute value threshold, the compensation module compensates the ICI between the first subcarrier and the second subcarrier according to the first deviation. When the absolute value of the target offset is smaller than or equal to the absolute value threshold, the compensation module may not compensate for the ICI between the first subcarrier and the second subcarrier according to the first offset.

Optionally, the communication device further comprises: and the sending module is used for sending a second deviation or the target signal to the sending end, wherein the sign of the second deviation is the same as that of the target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation. The second deviation may be the same as or different from the target deviation. For example, the sum of the first deviation and the second deviation is equal to the target deviation.

In the above description, the sending module sends the second deviation to the sending end after the receiving end determines the second deviation. Optionally, before sending the second deviation to the sending end, the sending module may further compare an absolute value of the target deviation with an absolute value threshold. And when the absolute value of the target deviation is greater than the absolute value threshold, the sending module sends the second deviation to the sending end. When the absolute value of the target deviation is less than or equal to the absolute value threshold, the sending module may not send the second deviation to the sending end.

In a fourth aspect, a communication apparatus is provided, where the communication apparatus is used at a sending end, and the sending end is communicatively connected to a receiving end, and the communication apparatus includes: the device comprises a sending module and an obtaining module. The receiving end is configured to receive a first subcarrier carrying a target sequence, where a power spectrum of the target sequence includes at least one first frequency whose signal power is greater than a noise power; the sending module is further configured to send a second subcarrier carrying a zero sequence to the receiving end; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency; the acquisition module is used for acquiring a second deviation, wherein the sign of the second deviation is the same as that of a target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation; the target deviation is a deviation of a frequency interval from a signal baud rate of the transmitting end, the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier, the target deviation is determined according to the target sequence and a target signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of the second frequency.

The obtaining module obtains the second deviation in various ways. In an implementation manner, the obtaining module may obtain the second deviation by receiving the second deviation sent by the receiving end. In another implementation manner, the second deviation is equal to the target deviation, and at this time, when acquiring the second deviation, the acquiring module may first receive the target signal sent by the receiving end, and then determine the second deviation according to the target signal and the target sequence. The obtaining module determines a second deviation process according to the target signal and the target sequence, and may refer to a process in which the receiving end determines the second deviation according to the target signal and the target sequence, which is not described herein again.

Optionally, the communication device further comprises: and a pre-compensation module, configured to pre-compensate inter-channel interference ICI of the first subcarrier and the second subcarrier according to the second deviation. The pre-compensation module pre-compensates ICI between the first sub-carrier and the second sub-carrier in various ways. For example, when the pre-compensation module pre-compensates the ICI between the first sub-carrier and the second sub-carrier, the pre-compensation module may pre-process the ICI of the signal to be transmitted to the receiving end according to the second deviation to reduce the ICI between the first sub-carrier and the second sub-carrier, and/or adjust the frequency interval to make the second deviation approach zero.

Optionally, if the transmitting end can obtain the target deviation, the pre-compensation module may determine the absolute value of the target deviation and the absolute value threshold before pre-compensating for the ICI between the first subcarrier and the second subcarrier. And when the absolute value of the target deviation is greater than the absolute value threshold, the pre-compensation module pre-compensates the ICI between the first sub-carrier and the second sub-carrier. When the absolute value of the target deviation is smaller than or equal to the absolute value threshold, the pre-compensation module may not pre-compensate the ICI between the first subcarrier and the second subcarrier.

In a fifth aspect, a communication system is provided, which includes: a sending terminal and a receiving terminal; the receiving end comprises the communication device designed according to any one of the third aspect; the transmitting end comprises the communication device as set forth in any of the fourth aspects.

The technical effects brought by any one of the design manners in the second aspect to the fifth aspect can be referred to the technical effects brought by the corresponding design manner in the first aspect, and are not described herein again.

Drawings

Fig. 1 is a schematic structural diagram of a communication system according to an embodiment of the present application;

fig. 2 is a spectrum distribution diagram according to an embodiment of the present application;

fig. 3 is another spectrum distribution diagram provided in the embodiment of the present application;

fig. 4 is a flowchart of a communication method according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a power spectrum of a target sequence provided by an embodiment of the present application;

fig. 6 is a schematic structural diagram of a first multiframe provided by an embodiment of the present application;

fig. 7 is a schematic structural diagram of a second multiframe provided by an embodiment of the present application;

fig. 8 is a signal constellation diagram of a target signal according to an embodiment of the present disclosure;

fig. 9 is a schematic phase diagram of each second sub-signal in a conjugate signal according to an embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a target deviation calculated 30 times according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

To make the principles and technical solutions of the present application clearer, the following detailed description of embodiments of the present application will be made with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a communication system according to an embodiment of the present application, and as shown in fig. 1, the communication system includes a transmitting end and a receiving end, and the transmitting end and the receiving end are connected by an optical fiber.

In a communication system, signals can be transmitted between a transmitting end and a receiving end through a plurality of subcarriers (also referred to as a plurality of channels). The transmitting end comprises a plurality of transmitters which are in one-to-one correspondence with a plurality of subcarriers, and the receiving end comprises a plurality of receivers which are in one-to-one correspondence with the plurality of subcarriers. Each transmitter is configured to transmit a corresponding subcarrier to a receiving end, and each receiver is configured to receive the corresponding subcarrier from the transmitting end.

Illustratively, as shown in fig. 1, the transmitting end includes a first transmitter and a second transmitter, and the receiving end includes a first receiver and a second receiver. The first transmitter is used for transmitting a first subcarrier to the receiving end, and the first receiver is used for receiving the first subcarrier transmitted by the transmitting end. The second transmitter is configured to send the second subcarrier to the receiving end, and the second receiver is configured to receive the second subcarrier sent by the sending end. It should be noted that, in the embodiment of the present application, the plurality of subcarriers include a first subcarrier and a second subcarrier (two channels) as an example. Alternatively, the number of subcarriers in the plurality of subcarriers may be other values, such as 3, 4, 5, 6, or 7.

With continued reference to fig. 1, the transmitter includes: digital Signal Processing (DSP) chips, digital to analog converters (DACs), drivers, modulators, and lasers. The digital signal processing device comprises a DSP chip, a DAC and a digital-to-analog converter, wherein the DSP chip is used for generating a digital signal, and the DAC is used for converting the digital signal into an analog signal; the driver is used for amplifying the analog signal output by the DAC; the laser is used for emitting laser; the modulator is used for modulating the laser emitted by the laser into the subcarrier corresponding to the transmitter according to the analog signal. The receiver includes: coherent Receiver (ICR), analog to digital converter (ADC), and DSP chips. Wherein, the ICR is used for converting the received subcarrier into an analog signal; the ADC is used for converting the analog signal into a digital signal; the DSP chip is used for processing the digital signal.

Further, the transmitting end may further include a combiner, and the receiving end may further include a splitter. The wave combiner is used for combining multiple subcarriers sent by multiple transmitters to obtain combined wave signals and transmitting the combined wave signals to the optical fibers. The wave separator is used for separating the wave-combined signal from the optical fiber to obtain the plurality of subcarriers, and sending the plurality of subcarriers to a plurality of receivers in a one-to-one correspondence manner.

At present, the frequency bands of multiple subcarriers for transmitting signals between a transmitting end and a receiving end may be spaced from each other, or may overlap.

Fig. 2 is a diagram illustrating a spectrum distribution of a Dense Wavelength Division Multiplexing (DWDM) system according to an embodiment of the present application, where a horizontal axis in fig. 2 represents a frequency of a signal and a vertical axis represents a power of the signal. As shown in fig. 2, the various subcarriers for transmitting signals between the transmitting end and the receiving end may include: subcarriers 1, 2,. And q, with q > 2 in fig. 2 as an example. The frequency bands of the q sub-carriers are not overlapped, and a guard interval exists between adjacent frequency bands, so that the sub-carriers of different frequency bands are prevented from being influenced mutually. However, due to the existence of the guard interval, the utilization rate of the spectrum resource is low.

Further exemplarily, fig. 3 is a spectrum distribution diagram of a Super Channel (SC) system according to an embodiment of the present application, where a horizontal axis in fig. 3 represents a frequency of a signal and a vertical axis represents a power of the signal. As shown in fig. 3, the various subcarriers for transmitting signals between the transmitting end and the receiving end may include: subcarriers 1, 2,. And q, with q > 2 being an example in fig. 3. The frequency bands of adjacent subcarriers in the q subcarriers are overlapped, and no guard interval exists, so that the problem of low utilization rate of frequency spectrum resources caused by the guard interval is solved.

However, since there is no guard interval between adjacent frequency bands in the SC system, adjacent subcarriers (subcarriers adjacent to frequency bands) may affect each other, ICI between adjacent subcarriers is high, and thus communication effect between the transmitting end and the receiving end is poor.

Illustratively, for adjacent subcarrier 1 and subcarrier 2 in the SC system, the baseband signal corresponding to subcarrier 1 is assumed to be s ₁ (t), t represents time, and the baseband signal corresponding to subcarrier 2 is s ₂ And (t), each subcarrier is obtained by modulating the sending end according to the baseband signal corresponding to the subcarrier. Then, the signal received by the receiving end for subcarrier 1 can be represented as y ₁ ＝s ₁ (t)+s ₂ (t) exp (j 2 pi (B + F) t), where exp (j 2 pi (B + F) t) denotes the power of j2 pi (B + F) t of e, e denotes a natural constant, j is an imaginary unit, pi is a circumferential rate, B denotes a signal baud rate of a transmitting end, and F denotes a deviation of an interval of center frequencies of the subcarrier 1 and the subcarrier 2 from the signal baud rate B.

According to y ₁ ＝s ₁ (t)+s ₂ (t) exp (j 2 π (B + F) t) indicates that y ₁ ICI due to subcarrier 2 may be represented by s ₂ (t) exp (j 2 pi (B + F) t) indicates that the receiving end can compensate for ICI in order to cancel the ICI. If the interval between the center frequencies of the sub-carrier 1 and the sub-carrier 2 is equal to the signal baud rate B, the deviation F is zero, and at this time, the receiving end can directly compensate the ICI according to the signal baud rate B. If the interval between the center frequencies of the sub-carrier 1 and the sub-carrier 2 is not equal to the signal baud rate B, the receiving end needs to obtain not only the signal baud rate B but also the aforementioned deviation F, and compensate the ICI according to the signal baud rate B and the aforementioned deviation F. As can be seen, if the deviation F can be obtained, the receiving end may compensate for the ICI between the sub-carrier 1 and the sub-carrier 2 according to the deviation F. In addition, the transmitting end may also pre-compensate the ICI between the sub-carrier 1 and the sub-carrier 2 according to the offset F. For example, the sending end may utilize the DSP chip to perform preprocessing on the signals that need to be respectively carried by the first subcarrier and the second subcarrier according to the deviation F, so as to reduce ICI between the subcarrier 1 and the subcarrier 2. For another example, the transmitting end may adjust the frequency interval according to the deviation F, so that the deviation F approaches to zero, and the receiving end may compensate the ICI only according to the signal baud rate B, thereby implementing pre-compensation of the ICI.

However, in the SC system, due to the influence of factors such as drive current variation, temperature fluctuation, and cavity aging, the frequency of the laser emitted by the laser at the transmitting end is easily shifted, so that the actual deviation between the center frequency interval of adjacent subcarriers and the baud rate of the signal at the transmitting end cannot be determined. Therefore, both the receiving end and the transmitting end cannot acquire the actual deviation F, both the receiving end and the transmitting end cannot compensate the ICI between adjacent sub-carriers according to the signal baud rate B and the actual deviation F, and the communication effect between the transmitting end and the receiving end is poor.

The embodiment of the application provides a communication method, which can determine the actual deviation of the central frequency interval of adjacent subcarriers relative to the signal baud rate of a sending end. Therefore, the receiving end and/or the transmitting end can compensate the ICI between the adjacent sub-carriers according to the actual deviation so as to improve the communication effect between the transmitting end and the receiving end.

Fig. 4 is a flowchart of a communication method provided in an embodiment of the present application, and the method may be used in the communication system shown in fig. 1. As shown in fig. 4, the method includes:

s101, a sending end sends a first subcarrier carrying a target sequence to a receiving end.

The transmitting end may transmit a first subcarrier carrying a target sequence to the receiving end using a first transmitter.

The first subcarrier carries a target sequence, and a power spectrum of the target sequence includes at least one first frequency at which signal power is greater than noise power, where the noise power is power of noise in a channel between a transmitting end and a receiving end. Since the signal power of the first frequency is greater than the noise power, the signal of the first frequency in the first subcarrier can be effectively received by the receiving end.

The target sequence may include one or more first frequencies in the power spectrum, and the interval between the first frequency and the center frequency of the first subcarrier may be any interval, which is not limited in this embodiment of the present application. For example, the power spectrum of the target sequence may be as shown in fig. 5, and the power spectrum includes two first frequencies f1 and f2, and the absolute values of the differences between the two first frequencies and the center frequency f0 of the first subcarrier are the same, | f1-f0| = | f2-f0|. Optionally, an absolute value of a difference between each first frequency and the center frequency of the first subcarrier is equal to one-half of the baud rate of the signal, that is, | f1-f0| = | f2-f0| = B/2, B represents the baud rate of the signal.

The target sequence can be realized in various ways, and the embodiment of the application does not limit the implementation way of the target sequence. Taking an alternative implementation of the target sequence as an example, the target sequence may include a plurality of consecutive symbols, and each symbol in the target sequence is an element in the target sequence. The value of the nth element in the target sequence is equal to the power of e (1 j × pi (n-1)), wherein e represents a natural constant, j is an imaginary unit, pi represents a circumferential ratio, and n is larger than or equal to 1. In this case, the target sequence may be [1, -1,.., 1, -1].

It should be noted that, in the embodiment of the present application, signal powers of other frequencies than the at least one first frequency in the power spectrum of the target sequence are not limited, for example, the signal powers of the other frequencies may all be zero.

Optionally, the manner of carrying the target sequence by the first subcarrier is various, and this is not limited in this embodiment of the present application. For example, the first sub-carrier carries a first multiframe (multiframe is also called optical interface frame), and the overhead of the first multiframe includes the target sequence. Illustratively, the reserved field in the overhead of the first multiframe includes the target sequence. Of course, the target sequence may not be included in the first multiframe, or other fields except for the reserved field in the overhead of the first multiframe may include the target sequence, or the target sequence may be included in the overhead of the first multiframe (for example, included in the payload of the first multiframe), which is not limited in this embodiment of the application.

Further, in order to protect the target sequence and prevent the target sequence from being affected by other signals, the reserved field in the overhead of the first multiframe may further include a first protection sequence and a second protection sequence. As shown in fig. 6, the target sequence may be located between the first protection sequence and the second protection sequence. For example, the lengths of the first protection sequence and the second protection sequence may be any lengths, and the value of each element in the protection sequence may be zero.

And S102, the transmitting end transmits the second subcarrier carrying the zero sequence to the receiving end.

The transmitting end may transmit a second subcarrier carrying the zero sequence to the receiving end using a second transmitter.

The second subcarrier carries a zero sequence, the lengths of the zero sequence and a target sequence carried by the first subcarrier are equal, and the time domain positions of the target sequence and the zero sequence are the same. Therefore, the transmission time of the target sequence is the same as that of the zero sequence, and the time for the transmitting end to transmit the part carrying the target sequence in the first subcarrier is the same as that of the part carrying the zero sequence in the second subcarrier.

The frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier. For example, the first subcarrier and the second subcarrier may be any two adjacent subcarriers in the SC system.

The frequency band of the second sub-carriers comprises at least one second frequency and at least one first frequency in the frequency band of the first sub-carriers comprises the at least one second frequency. It can be seen that at least a part of the first frequency (i.e. the at least one second frequency) in the power spectrum of the target sequence falls within the frequency band of the second subcarrier. The frequency band of the first subcarrier and the frequency band of the second subcarrier both include the at least one second frequency. For example, referring to fig. 5, the power spectrum of the target sequence includes two first frequencies f1 and f2, the first frequency f2 falls into the frequency band of the second subcarrier, and the first frequency f2 is the second frequency.

The time domain positions of the target sequence and the zero sequence are the same, so the way of the second subcarrier carrying the zero sequence can refer to the way of the first subcarrier carrying the target sequence.

Illustratively, when the first sub-carrier carries a first multiframe and the overhead of the first multiframe includes a target sequence, the second sub-carrier carries a second multiframe and the overhead of the second multiframe includes a zero sequence. And, the position of the target sequence in the overhead of the first multiframe is the same as the position of the zero sequence in the overhead of the second multiframe.

Further illustratively, when the reserved field in the overhead of the first multiframe includes the target sequence, the reserved field in the overhead of the second multiframe includes a sequence of zeros. The position of the target sequence in the reserved field of the first multiframe is the same as the position of the zero sequence in the reserved field of the second multiframe.

Further, when the reserved field in the overhead of the first multiframe further includes the first protection sequence and the second protection sequence, as shown in fig. 7, the reserved field in the overhead of the second multiframe may also further include a third protection sequence and a fourth protection sequence, and the zero sequence carried by the second subcarrier is located between the third protection sequence and the fourth protection sequence.

It should be noted that the transmitting end transmits the first subcarrier and the second subcarrier to the receiving end in S101 and S102, and the receiving end needs to receive the two subcarriers. Illustratively, the receiving end may receive the first subcarrier with a first receiver and the second subcarrier with a second receiver.

Optionally, when the target sequence and the zero sequence are carried in a multiframe, the receiving end needs to perform frame search on the multiframe before receiving the multiframe, where frame search refers to determining transmission resources of the multiframe. After the multi-frame searching is successful, the receiving end can receive the multi-frame on the transmission resource obtained by searching the frame. For example, the receiving end needs to search for a first multiframe before receiving a first subcarrier, and needs to search for a second multiframe before receiving a second subcarrier. After the first multiframe searching is successful, the receiving end can receive the first multiframe; after the second multiframe search succeeds, the receiving end can receive the second multiframe.

S103, the receiving end determines a target deviation according to the target signal; the target signal is a signal obtained by receiving the second subcarrier by the receiving end; the target deviation is the deviation of the frequency interval relative to the signal baud rate of the sending end; the frequency spacing is the spacing of the center frequency of the first subcarrier from the center frequency of the second subcarrier.

The target signal is a signal obtained by the receiving end receiving the second subcarrier, for example, the target signal is a signal obtained by the receiving end receiving the second subcarrier with the second receiver in fig. 1. The frequency band of the second subcarrier includes at least one second frequency, and therefore, the target signal obtained by the receiving end receiving the second subcarrier includes the signal of the at least one second frequency.

In this embodiment of the present application, while sending the second subcarrier to the receiving end, the sending end also sends the first subcarrier to the receiving end, where both the frequency band of the first subcarrier and the frequency band of the second subcarrier include the at least one second frequency, and the signal power of the second frequency in the first subcarrier is greater than the noise power. Therefore, the signal of the second frequency in the first subcarrier can be leaked to the second subcarrier, so that the signal of the second frequency in the target signal received by the receiving end from the second subcarrier is affected by the first subcarrier, and the signal of the second frequency in the target signal is related to both the first subcarrier and the second subcarrier, so that the target signal can reflect the relationship between the two subcarriers. Thus, the receiving end can determine the target deviation of the interval of the center frequencies of the two subcarriers actually relative to the signal baud rate of the transmitting end according to the target signal.

In addition, in the embodiment of the present application, the target sequence may be designed, so that the signal of the second frequency in the first subcarrier can be maximally leaked into the second subcarrier, and thus the signal of the second frequency in the target signal is greatly influenced by the first subcarrier, and the target signal can more accurately reflect the relationship between the two subcarriers.

Optionally, assuming that a signal obtained by receiving a portion carrying an nth element in the second subcarrier by the receiving end is Sn, sn = N × exp (1j × 2 × pi × F/(B × N)), where N denotes the nth element in the target sequence, exp (1j 2 × pi × F/B × N) denotes the power of e to 1j × 2 pi × F/(B × N), e denotes a natural constant, j is an imaginary unit, pi is a circumferential rate, F denotes a target deviation of a frequency interval from a signal baud rate of the transmitting end, B denotes a signal baud rate of the transmitting end, and N ≧ 1.

Alternatively, when determining the target deviation, the receiving end may first determine a conjugate signal according to the target signal and the target sequence. It should be noted that, it is assumed that the target signal includes m first sub-signals, m ≧ 1, and m is less than or equal to the length of the above-mentioned zero sequence (i.e., the length of the target sequence). The m first sub-signals correspond to m elements in the zero sequence one by one, and the xth first sub-signal is a signal obtained by receiving the part of the second sub-carrier carrying the corresponding elements by the receiving end. Then, the conjugate signal includes m second sub-signals, the x-th second sub-signal S2= (conj (S1)) × a,1 ≦ x ≦ m, conj (S1) represents the conjugate of S1, S1 represents the x-th first sub-signal, and a represents the x-th element in the target sequence. The receiving end may obtain m second sub-signals according to the formula S2= (conj (S1)) × a, thereby obtaining the above conjugate signal.

After the receiving end determines the conjugate signal, the target offset may be determined according to a slope of the conjugate signal, and different slopes correspond to different target offsets. Wherein, the target deviation of the frequency interval relative to the signal baud rate of the transmitting end is F = a B/2/pi, a represents the slope, and B represents the signal baud rate. Before determining the target deviation according to the slope of the conjugate signal, the receiving end needs to determine the slope of the conjugate signal, and then determines the target deviation according to the slope. For example, when determining the slope, the receiving end may first determine the phase of the conjugate signal, and then determine the frequency according to the phase.

S104, the receiving end compensates ICI between the first sub-carrier and the second sub-carrier according to the first deviation, the sign of the first deviation is the same as that of the target deviation, and the absolute value of the first deviation is smaller than that of the target deviation.

After the receiving end obtains the target deviation, a first deviation and a second deviation can be determined according to the target deviation, the sign of the first deviation and the sign of the second deviation are both the same as the sign of the target deviation, and the absolute value of the first deviation and the absolute value of the second deviation are both smaller than the absolute value of the target deviation. Optionally, a sum of the first deviation and the second deviation is equal to the target deviation. For example, the target deviation is 5, the first deviation is 3, and the second deviation is 2. The sum of the first deviation and the second deviation may also be smaller than the target deviation, which is not limited in the embodiment of the present application.

After determining the first deviation, the receiving end may use the first deviation as the deviation F according to y ₁ ＝s ₁ (t)+s ₂ (t) exp (j 2 pi (B + F) t), which compensates for the ICI between the first subcarrier and the second subcarrier (e.g., compensates for the ICI of a signal obtained by subsequently receiving the first subcarrier and the second subcarrier), so as to reduce the mutual influence between the first subcarrier and the second subcarrier and improve the communication effect between the transmitting end and the receiving end.

And S105, the receiving end sends the second deviation to the sending end.

After determining the second deviation, the receiving end may further feed back the second deviation to the transmitting end, so that the transmitting end performs S106 pre-compensation for the ICI between the first subcarrier and the second subcarrier according to the second deviation.

And S106, the transmitting end pre-compensates the ICI between the first sub-carrier and the second sub-carrier according to the second deviation.

The sending end has various modes for pre-compensating the ICI between the first subcarrier and the second subcarrier. For example, when the transmitting end performs pre-compensation on the ICI between the first subcarrier and the second subcarrier, the transmitting end may perform pre-processing on the ICI of the signal to be transmitted to the receiving end according to the second deviation to reduce the ICI between the first subcarrier and the second subcarrier, and/or adjust the frequency interval to make the second deviation approach zero. It should be noted that, when the second deviation approaches zero, the target deviation approaches the first deviation, and the receiving end uses the first deviation as the deviation F according to y ₁ ＝s ₁ (t)+s ₂ The (t) exp (j 2 pi (B + F) t) has a good effect of compensating for ICI between the first subcarrier and the second subcarrier.

On one hand, when the transmitting end performs ICI pre-compensation on the signal to be transmitted to the receiving end according to the second deviation, the DSP chip therein may be used to perform the pre-compensation.

On the other hand, when adjusting the frequency interval according to the second deviation, the transmitting end may adjust the center frequency of the first subcarrier and the center frequency of the second subcarrier according to the second deviation so as to reduce the second deviation.

For example, when the second deviation is a positive number, the transmitting end may decrease the frequency interval. The sending end may adjust the center frequency of the first subcarrier to a direction close to the center frequency of the second subcarrier, and/or adjust the center frequency of the second subcarrier to a direction close to the center frequency of the first subcarrier, so as to reduce the frequency interval and reduce the second deviation.

For another example, when the second deviation is negative, the transmitting end may increase the frequency interval. The sending end may adjust the center frequency of the first subcarrier in a direction away from the center frequency of the second subcarrier, and/or adjust the center frequency of the second subcarrier in a direction away from the center frequency of the first subcarrier, so as to increase the frequency interval and reduce the second deviation.

The embodiment shown in fig. 4 exemplifies that the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation (as in S104), and the transmitting end pre-compensates the ICI between the first sub-carrier and the second sub-carrier according to the second deviation (as in S106).

Alternatively, only the receiving end performs ICI compensation on the effect between the first sub-carrier and the second sub-carrier according to the first deviation (as in S104), and in this case, the receiving end does not need to perform S105, and the transmitting end does not need to perform S106. In this case, the first deviation may be equal to the target deviation.

Alternatively, only the transmitting end may pre-compensate ICI for the effect between the first sub-carrier and the second sub-carrier according to the second deviation (as in S106 described above), and in this case, the receiving end does not need to perform S104. In this case, the second deviation may be equal to the target deviation.

The embodiment shown in fig. 4 takes an example that the receiving end sends the second offset to the transmitting end, so that the transmitting end acquires the second offset. Optionally, the sending end may also obtain the second deviation in other manners. For example, when the second deviation is the target deviation, the receiving end may transmit a target signal to the transmitting end in S105, and the transmitting end may determine the target deviation according to the target signal before S106. The process of determining the second deviation according to the target signal by the sending end may refer to the process of determining the target deviation according to the target signal by the receiving end, which is not described herein in detail in this embodiment of the application.

In the above, the receiving end compensates ICI between the first sub-carrier and the second sub-carrier according to the first deviation after determining the first deviation, and the receiving end transmits the second deviation (or the target signal) to the transmitting end after determining the second deviation (or the target signal). Optionally, before compensating for the ICI between the first subcarrier and the second subcarrier according to the first deviation, the receiving end further determines to compare an absolute value of the target deviation with an absolute value threshold. And when the absolute value of the target deviation is greater than the absolute value threshold, the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation. When the absolute value of the target offset is smaller than or equal to the absolute value threshold, the receiving end may not compensate for the ICI between the first subcarrier and the second subcarrier according to the first offset. Alternatively, the receiving end may compare the absolute value of the target offset with an absolute value threshold before transmitting the second offset (or the target signal) to the transmitting end. When the absolute value of the target deviation is greater than the absolute value threshold, the receiving end transmits the second deviation (or the target signal) to the transmitting end. When the absolute value of the target offset is less than or equal to the absolute value threshold, the receiving end may not transmit the second offset (or the target signal) to the transmitting end.

When the absolute value of the target deviation is greater than or equal to the absolute value threshold, it indicates that the absolute value of the target deviation is large, and at this time, the influence between the first subcarrier and the second subcarrier is large, and the communication effect between the transmitting end and the receiving end is poor. Therefore, the receiving end needs to compensate the ICI between the first sub-carrier and the second sub-carrier according to the first deviation, and/or send the second deviation (or the target signal) to the transmitting end, so that the transmitting end pre-compensates the ICI between the first sub-carrier and the second sub-carrier according to the second deviation (or the target signal), and the communication effect between the transmitting end and the receiving end is ensured. And when the absolute value of the target deviation is greater than or equal to the absolute value threshold, if the receiving end also compensates the ICI, the ICI can be effectively compensated through the dual compensation of the transmitting end and the receiving end.

When the absolute value of the target deviation is smaller than the absolute value threshold, it indicates that the absolute value of the target deviation is smaller, and at this time, the influence between the first subcarrier and the second subcarrier is smaller, and the communication effect between the transmitting end and the receiving end is not worse, so that the receiving end may not compensate the ICI between the first subcarrier and the second subcarrier according to the first deviation, and/or may not transmit the second deviation (or the target signal) to the transmitting end, thereby reducing the load of the receiving end and/or the transmitting end.

Further, if the second deviation sent by the receiving end is the target deviation, or the sending end can determine the target deviation according to the target signal, the sending end may determine the absolute value of the target deviation and the absolute value threshold before pre-compensating for the ICI between the first subcarrier and the second subcarrier regardless of whether the receiving end determines the absolute value of the target deviation and the absolute value threshold. And when the absolute value of the target deviation is larger than the absolute value threshold, the sending end pre-compensates the ICI between the first sub-carrier and the second sub-carrier. When the absolute value of the target deviation is smaller than or equal to the absolute value threshold, the transmitting end may not pre-compensate for the ICI between the first subcarrier and the second subcarrier.

Moreover, when both the sending end and the receiving end judge the absolute value of the target deviation and the absolute value threshold, the accuracy of the judgment result can be improved through double judgment of the sending end and the receiving end.

In this embodiment of the application, a sending end can send a first subcarrier and a second subcarrier to a receiving end, where the first subcarrier carries a target sequence and the second subcarrier carries a zero sequence. The target signal obtained by the receiving end receiving the second subcarrier comprises a signal with the second frequency, and the signal with the second frequency is influenced by the first subcarrier, so that a subsequent receiving end or a subsequent transmitting end can determine the target deviation of the interval transmitting end of the central frequencies of the two subcarriers relative to the baud rate of the signal according to the target signal comprising the signal with the second frequency. Then, based on the target deviation, the transmitting end may compensate the ICI between the first sub-carrier and the second sub-carrier, and/or the receiving end may pre-compensate the ICI between the first sub-carrier and the second sub-carrier, so as to ensure effective communication between the transmitting end and the receiving end. In addition, the communication method provided by the embodiment of the application is simple, and cannot bring large power consumption to a communication system. In addition, the communication method provided by the embodiment of the application can determine the target deviation quickly at any time, so that the method can be applied to a communication system with quick change (also called a quick change system).

The following will describe the effects of the communication method provided by the embodiments of the present application, taking an example as an example.

For example, it is assumed that the Modulation format of the sub-carriers is a 16 Quadrature Amplitude Modulation (QAM) format, the baud rate of the signal at the transmitting end is gigahertz (GHz), and the actual deviation of the frequency interval of the center frequencies of the first sub-carrier and the second sub-carrier from the baud rate of the signal is 200 megahertz (MHz).

Fig. 8 shows a signal constellation diagram of a target signal obtained by receiving the second subcarrier at the receiving end, where the horizontal axis of fig. 8 represents an in-phase component of the target signal and the vertical axis represents a quadrature component of the target signal. It should be noted that, when the signal constellation diagram of a certain signal is in a central symmetry state, it indicates that the signal contains frequency information, and the signal power of the signal at some frequencies is greater than zero. As can be seen from fig. 8, the signal constellation of the target signal is in a central symmetry state, and therefore, the signal power of the target signal at some frequencies (such as the second frequency mentioned above) is greater than zero, and it can be seen that the target signal is affected by the signal at the second frequency in the first subcarrier.

The phase of each second sub-signal in the conjugate signal determined by the receiving end (or the transmitting end) according to the target signal may be as shown in fig. 9, where the horizontal axis of fig. 9 represents the index of the second sub-signal in the conjugate signal, and the vertical axis represents the phase of the second sub-signal. The slope of the phase of the conjugate signal shown in fig. 9 corresponds to the target deviation, and the receiving end (or the transmitting end) can determine the target deviation according to the slope.

The target deviations calculated by the method provided by the embodiment of the application for 30 times continuously are respectively shown in fig. 10, wherein the horizontal axis of fig. 10 represents the number of times of calculating the target deviations, and the vertical axis represents the target deviations calculated at the number of times. It can be seen from fig. 10 that the errors of the above target deviation and the actual deviation (200 MHz) obtained by the 30 calculations are within 20MHz, and the errors are small. Based on the target deviation, the sending end pre-compensates the ICI between the first sub-carrier and the second sub-carrier, and/or the receiving end pre-compensates the ICI between the first sub-carrier and the second sub-carrier, so that the ICI between the first sub-carrier and the second sub-carrier can be effectively reduced, and the effective communication between the sending end and the receiving end is ensured.

While the communication method provided in the present application is described in detail in conjunction with fig. 1 to 10, it is understood that the communication device includes hardware and/or software modules for performing the functions of the methods. The implementation of the methods described in connection with the embodiments disclosed herein can be realized in hardware or a combination of hardware and computer software. Whether a function is performed in hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, with the embodiment described in connection with the particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In this embodiment, the functional modules of the corresponding communication device may be divided according to the method embodiments, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware.

When the functional block division is adopted, the communication apparatus provided by the present application will be described below with reference to fig. 11 and 12.

Fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application, where the communication device may be a receiving end in the foregoing embodiments, for example. The receiving end is connected to the transmitting end in a communication manner, as shown in fig. 11, the communication apparatus includes: a receiving module 1101 and a determining module 1102.

A receiving module 1101 is configured to receive a first subcarrier carrying a target sequence sent by the sending end, where a power spectrum of the target sequence includes at least one first frequency that a signal power is greater than a noise power; the receiving module 1101 is configured to perform the above-mentioned operations related to the receiving end in S101.

The receiving module 1101 is further configured to receive a second subcarrier carrying a zero sequence sent by the sending end, so as to obtain a target signal; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency; the target signal comprises a signal of the at least one second frequency; the receiving module 1101 is configured to perform the part of the operations related to the receiving end in S102.

A determining module 1102, configured to determine a target deviation according to the target signal, where the target deviation is a deviation of a frequency interval from a baud rate of a signal at the sending end, and the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier. The operation performed by the determining module 1102 may refer to the content related to the receiving end in S103.

The target signal is a signal obtained by the receiving end receiving the second subcarrier. The frequency band of the second subcarrier includes at least one second frequency, and therefore, the target signal obtained by the receiving end receiving the second subcarrier includes the signal of the at least one second frequency. In this application, the transmitting end transmits the second subcarrier to the receiving end and also transmits the first subcarrier to the receiving end, the frequency band of the first subcarrier and the frequency band of the second subcarrier both include the at least one second frequency, and the signal power of the second frequency in the first subcarrier is greater than the noise power. Therefore, the signal of the second frequency in the first subcarrier can be leaked to the second subcarrier, so that the signal of the second frequency in the target signal received by the receiving end from the second subcarrier is affected by the first subcarrier, and the signal of the second frequency in the target signal is related to both the first subcarrier and the second subcarrier, so that the target signal can reflect the relationship between the two subcarriers. Thus, the receiving end can determine the target deviation of the interval of the center frequencies of the two subcarriers actually relative to the signal baud rate of the transmitting end according to the target signal.

The target sequence may include one or more first frequencies in the power spectrum, and the interval between the first frequency and the center frequency of the first subcarrier may be any interval, which is not limited in this application. Illustratively, the absolute value of the difference between any of said first frequencies and the center frequency of said first subcarrier is equal to one-half of said signal baud rate. Further illustratively, the power spectrum of the target sequence includes two first frequencies, and the absolute value of the difference between the two first frequencies and the center frequency of the first subcarrier is the same.

The first sub-carrier has various modes of carrying the target sequence, and the second sub-carrier has various modes of carrying the zero sequence, which is not limited in the embodiment of the present application. For example, the first sub-carrier carries a first multiframe (multiframe is also called an optical interface frame), where the first multiframe includes the target sequence; the second sub-carrier carries a second multiframe, and the second multiframe comprises the zero sequence. The position of the target sequence in the overhead of the first multiframe is the same as the position of the zero sequence in the overhead of the second multiframe.

Illustratively, a reserved field in the overhead of the first multiframe includes the target sequence; a reserved field in the overhead of the second multiframe includes the zero sequence. Of course, the target sequence may not be included in the first multiframe, or other fields except the reserved field in the overhead of the first multiframe may include the target sequence, or the target sequence may be included in the overhead of the first multiframe (for example, included in the payload of the first multiframe), which is not limited in this application.

Optionally, the determining module 1102 is configured to: determining a conjugate signal according to the target signal and the target sequence, determining the slope of the conjugate signal, and determining the target deviation according to the slope of the conjugate signal. Wherein the target deviation F = a B/2/pi, a representing the slope and B representing the signal baud rate; the target signal includes m first sub-signals, the m first sub-signals correspond to m elements in the zero sequence one by one, and the xth first sub-signal is a signal obtained by the receiving end receiving a part of the second sub-carrier carrying the corresponding elements; the conjugate signal comprises m second sub-signals, m is more than or equal to 1, and m is less than or equal to the length of the zero sequence; the x-th second sub-signal S2= (conj (S1)) × a,1 ≦ x ≦ m, conj (S1) represents the conjugate of S1, S1 represents the x-th first sub-signal, and a represents the x-th element in the target sequence.

Optionally, the communication device further comprises: a compensation module (not shown in fig. 11) configured to compensate for inter-channel interference ICI of the first subcarrier and the second subcarrier according to a first offset, where a sign of the first offset is the same as a sign of the target offset, and an absolute value of the first offset is smaller than or equal to an absolute value of the target offset. The first deviation may be the same as or different from the target deviation. After the receiving end compensates the ICI between the first sub-carrier and the second sub-carrier according to the first deviation, the mutual influence between the first sub-carrier and the second sub-carrier can be reduced, and the communication effect between the transmitting end and the receiving end is improved. The operation performed by the compensation module may refer to the content related to the receiving end in S104.

In the above description, for example, after the determining module determines the first deviation, the compensating module compensates the ICI between the first subcarrier and the second subcarrier according to the first deviation. Optionally, the compensation module may further compare an absolute value of the target offset with an absolute value threshold before compensating for ICI between the first subcarrier and the second subcarrier according to the first offset. And when the absolute value of the target deviation is greater than the absolute value threshold, the compensation module compensates the ICI between the first subcarrier and the second subcarrier according to the first deviation. When the absolute value of the target deviation is less than or equal to the absolute value threshold, the compensation module may not compensate for the ICI between the first subcarrier and the second subcarrier according to the first deviation.

Optionally, the communication device further comprises: a sending module (not shown in fig. 11) configured to send, to the sending end, a second offset or the target signal, where a sign of the second offset is the same as a sign of the target offset, and an absolute value of the second offset is smaller than or equal to an absolute value of the target offset. The second deviation may be the same as or different from the target deviation. For example, the sum of the first deviation and the second deviation is equal to the target deviation. The operation performed by the sending module may refer to the content related to the receiving end in S105.

The respective modules in the communication apparatus may be implemented by software and/or hardware, for example, the receiving module 1101 may be implemented in the first receiver and the second receiver in the receiving end shown in fig. 1. The first receiver is configured to receive the first subcarrier, and the second receiver is configured to receive the second subcarrier.

Fig. 12 is a schematic structural diagram of another communication apparatus provided in this embodiment of the present application, where the communication apparatus may be, for example, a transmitting end in each of the foregoing embodiments. As shown in fig. 12, the communication apparatus includes: a sending module 1201 and an obtaining module 1202.

A sending module 1201, configured to send a first subcarrier carrying a target sequence to the receiving end, where a power spectrum of the target sequence includes at least one first frequency whose signal power is greater than a noise power; the part of the operations performed by the sending module 1201 may refer to the content related to the sending end in S101 described above.

A sending module 1201, configured to send a second subcarrier carrying a zero sequence to the receiving end; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the first subcarrier overlaps with the frequency band of the second subcarrier, and the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency; the part of the operations performed by the sending module 1201 may refer to the content related to the sending end in S102.

An obtaining module 1202, configured to obtain a second deviation, where a sign of the second deviation is the same as a sign of a target deviation, and an absolute value of the second deviation is smaller than or equal to an absolute value of the target deviation; the target deviation is a deviation of a frequency interval from a signal baud rate of the transmitting end, the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier, the target deviation is determined according to the target sequence and a target signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of the second frequency. The operation performed by the obtaining module 1202 may refer to the content related to the sending end in S105.

The respective modules in the communication apparatus may be implemented by software and/or hardware, for example, the transmitting module 1201 may be implemented in the first transmitter and the second transmitter in the transmitting end as shown in fig. 1. The first transmitter is configured to send the first subcarrier to a receiving end, and the second transmitter is configured to send the second subcarrier to the receiving end.

The target signal is a signal obtained by receiving the second subcarrier at the receiving end. The frequency band of the second subcarrier includes at least one second frequency, and therefore, the target signal obtained by the receiving end receiving the second subcarrier includes a signal of the at least one second frequency. In the application, the sending end sends the second subcarrier to the receiving end, and simultaneously sends the first subcarrier to the receiving end, the frequency band of the first subcarrier and the frequency band of the second subcarrier both include the at least one second frequency, and the signal power of the second frequency in the first subcarrier is greater than the noise power. Therefore, the signal of the second frequency in the first subcarrier can be leaked to the second subcarrier, so that the signal of the second frequency in the target signal received by the receiving end from the second subcarrier is affected by the first subcarrier, and the signal of the second frequency in the target signal is related to both the first subcarrier and the second subcarrier, so that the target signal can reflect the relationship between the two subcarriers. Thus, the target deviation of the interval of the center frequencies of the two subcarriers from the baud rate of the signal at the transmitting end can be determined according to the target signal.

The manner in which the obtaining module 1202 obtains the second deviation is various. In an implementation manner, the obtaining module 1202 may obtain the second deviation by receiving the second deviation sent by the receiving end. In another implementation manner, the second deviation is equal to the target deviation, and in this case, when obtaining the second deviation, the obtaining module 1202 may first receive the target signal sent by the receiving end, and then determine the second deviation according to the target signal and the target sequence. The obtaining module 1202 determines the second deviation according to the target signal and the target sequence, and may refer to the process in which the receiving end determines the second deviation according to the target signal and the target sequence, which is not described herein again.

Optionally, the communication device further comprises: a pre-compensation module (not shown in fig. 12) configured to pre-compensate for inter-channel interference ICI of the first sub-carrier and the second sub-carrier according to the second offset. The pre-compensation module has various ways of pre-compensating for the ICI between the first sub-carrier and the second sub-carrier. For example, when the pre-compensation module pre-compensates the ICI between the first sub-carrier and the second sub-carrier, the pre-compensation module may pre-process the ICI of the signal to be transmitted to the receiving end according to the second deviation to reduce the ICI between the first sub-carrier and the second sub-carrier, and/or adjust the frequency interval to make the second deviation approach zero. The operations performed by the pre-compensation module may refer to the contents related to the transmitting end in S106.

An embodiment of the present application further provides a communication system, including: a transmitting end and a receiving end. The sending end includes any one of the communication devices (such as the communication device shown in fig. 11) for the receiving end provided in the embodiment of the present application; the receiving end includes any one of the communication apparatuses (such as the communication apparatus shown in fig. 12) for the transmitting end provided in the embodiments of the present application.

In this application, the terms "first" and "second," etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "at least one" means one or more, and "a plurality" means two or more, unless expressly defined otherwise. The term "and/or" is merely an associative relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

Different types of embodiments such as the method embodiment and the apparatus embodiment provided by the embodiment of the present application can be mutually referred to, and the embodiment of the present application does not limit this. The sequence of operations in the method embodiments provided in the present application can be appropriately adjusted, and the operations can be increased or decreased according to the circumstances, and any method that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application shall be covered by the protection scope of the present application, and therefore, the details are not repeated.

In the corresponding embodiments provided in the present application, it should be understood that the disclosed system and apparatus, etc. may be implemented by other configurations. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of modules is merely a division of logical functions, and an actual implementation may have another division, for example, a plurality of modules may be combined or may be integrated into another system, or some features may be omitted, or not executed. Units described as separate parts may or may not be physically separate, and parts described as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of devices. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above description is only an alternative embodiment of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present application, and these modifications or substitutions should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A communication method, for a receiving end, wherein the receiving end is in communication connection with a transmitting end, the method comprising:

receiving a first subcarrier carrying a target sequence sent by the sending end, wherein a power spectrum of the target sequence comprises at least one first frequency with signal power larger than noise power;

receiving a second subcarrier carrying a zero sequence sent by the sending end to obtain a target signal; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency; the target signal comprises a signal of the at least one second frequency;

and determining a target deviation according to the target signal, wherein the target deviation is the deviation of a frequency interval relative to the baud rate of the signal of the transmitting end, and the frequency interval is the interval between the central frequency of the first subcarrier and the central frequency of the second subcarrier.

2. The method of claim 1 wherein the absolute value of the difference between any of said first frequencies and the center frequency of said first subcarrier is equal to one-half of the baud rate of said signal.

3. The method according to claim 1 or 2, wherein the power spectrum of the target sequence comprises two first frequencies, and the absolute value of the difference between the two first frequencies and the center frequency of the first subcarrier is the same.

4. The method according to any one of claims 1 to 3, wherein the value of the nth element in the target sequence is equal to the power of e to (1 j x pi x (n-1)), e representing a natural constant, j being an imaginary unit, n ≧ 1.

5. The method according to any of claims 1 to 4, wherein the first sub-carrier carries a first multiframe, and wherein the overhead of the first multiframe comprises the target sequence; the second sub-carrier carries a second multiframe, and the overhead of the second multiframe comprises the zero sequence.

6. The method of claim 5, wherein a reserved field in the overhead of the first multiframe comprises the target sequence; a reserved field in the overhead of the second multiframe includes the zero sequence.

7. The method of claim 6, wherein the reserved field in the overhead of the first multiframe further comprises a first protection sequence and a second protection sequence, and wherein the target sequence is located between the first protection sequence and the second protection sequence;

the reserved field in the overhead of the second multiframe further comprises a third protection sequence and a fourth protection sequence, and the zero sequence is located between the third protection sequence and the fourth protection sequence.

8. The method of any of claims 1 to 7, wherein determining a target deviation from the target signal comprises:

determining a conjugate signal from the target signal and the target sequence;

determining a slope of the conjugate signal;

determining the target deviation from the slope of the conjugate signal;

wherein the target deviation F = a B/2/pi, a representing the slope and B representing the signal baud rate;

the target signal includes m first sub-signals, the m first sub-signals correspond to m elements in the zero sequence one by one, and the xth first sub-signal is a signal obtained by the receiving end receiving a part of the second sub-carrier that carries the corresponding elements; the conjugate signal comprises m second sub-signals, m is more than or equal to 1, and m is less than or equal to the length of the zero sequence; the x-th second sub-signal S2= (conj (S1)) × a,1 ≦ x ≦ m, conj (S1) represents the conjugate of S1, S1 represents the x-th first sub-signal, and a represents the x-th element in the target sequence.

9. The method of any of claims 1 to 8, wherein after determining a target deviation from the target signal, the method further comprises:

and compensating the inter-channel interference ICI of the first subcarrier and the second subcarrier according to a first deviation, wherein the sign of the first deviation is the same as that of the target deviation, and the absolute value of the first deviation is smaller than or equal to that of the target deviation.

10. The method of claim 9, wherein compensating for inter-channel interference ICI for the first sub-carrier and the second sub-carrier according to a first bias comprises:

and when the absolute value of the target deviation is larger than an absolute value threshold, compensating the inter-channel interference ICI of the first subcarrier and the second subcarrier according to the first deviation.

11. The method of any one of claims 1 to 10, wherein after determining a target deviation from the target signal, the method further comprises:

and sending a second deviation or the target signal to the sending end, wherein the sign of the second deviation is the same as that of the target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation.

12. The method of claim 11, wherein sending the second offset or the target signal to the sending end comprises:

and when the absolute value of the target deviation is greater than an absolute value threshold, sending the second deviation or the target signal to the sending end.

13. A communication method, used in a sending end, where the sending end is communicatively connected to a receiving end, the method comprising:

sending a first subcarrier carrying a target sequence to the receiving end, wherein the power spectrum of the target sequence comprises at least one first frequency with the signal power being greater than the noise power;

sending a second subcarrier carrying a zero sequence to the receiving end; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the second sub-carrier comprises at least one second frequency, the at least one first frequency comprises the at least one second frequency;

acquiring a second deviation, wherein the sign of the second deviation is the same as that of a target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation; the target deviation is a deviation of a frequency interval from a signal baud rate of the transmitting end, the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier, the target deviation is determined according to the target sequence and a target signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of the second frequency.

14. The method of claim 13, wherein obtaining the second deviation comprises:

and receiving the second deviation sent by the receiving end.

15. The method of claim 13, wherein the second deviation is equal to the target deviation, and wherein the obtaining the second deviation comprises:

receiving the target signal sent by the receiving end;

determining the second deviation based on the target signal and the target sequence.

16. The method of any of claims 13 to 15, wherein after said obtaining a second deviation, the method further comprises:

and pre-compensating the inter-channel interference ICI of the first subcarrier and the second subcarrier according to the second deviation.

17. A communication apparatus, configured for a receiving end, the receiving end being in communication connection with a transmitting end, the communication apparatus comprising:

a receiving module, configured to receive a first subcarrier carrying a target sequence sent by the sending end, where a power spectrum of the target sequence includes at least one first frequency with a signal power greater than a noise power;

the receiving module is further configured to receive a second subcarrier carrying a zero sequence and sent by the sending end, so as to obtain a target signal; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the second sub-carrier comprises at least one second frequency, the at least one first frequency comprises the at least one second frequency; the target signal comprises a signal of the at least one second frequency;

and the determining module is used for determining a target deviation according to the target signal, wherein the target deviation is the deviation of a frequency interval relative to the baud rate of the signal of the transmitting end, and the frequency interval is the interval between the central frequency of the first subcarrier and the central frequency of the second subcarrier.

18. The communications apparatus as claimed in claim 17, wherein an absolute value of a difference between any of the first frequencies and a center frequency of the first subcarrier is equal to one-half of the baud rate of the signal.

19. The communication apparatus according to claim 17 or 18, wherein the power spectrum of the target sequence includes two first frequencies, and the absolute value of the difference between the two first frequencies and the center frequency of the first subcarrier is the same.

20. A communications device according to any one of claims 17 to 19 wherein the value of the nth element in the target sequence is equal to the power of e to (1 j x pi x (n-1)), e representing a natural constant, j being an imaginary unit and n ≧ 1.

21. A communications device according to any one of claims 17 to 20, wherein the first sub-carrier carries a first multiframe, the overhead of the first multiframe comprising the target sequence; the second sub-carrier carries a second multiframe, and the overhead of the second multiframe comprises the zero sequence.

22. The communications apparatus of claim 21, wherein a reserved field in the overhead of the first multiframe comprises the target sequence; a reserved field in the overhead of the second multiframe includes the sequence of zeros.

23. The communications apparatus of claim 22, wherein a reserved field in the overhead of the first multiframe further comprises a first protection sequence and a second protection sequence, the target sequence being located between the first protection sequence and the second protection sequence;

24. The communications apparatus according to any of claims 17 to 23, wherein the determining module is configured to:

determining a conjugate signal from the target signal and the target sequence;

determining a slope of the conjugate signal;

determining the target deviation from the slope of the conjugate signal;

25. The communication device according to any of claims 17 to 24, further comprising:

a compensation module, configured to compensate inter-channel interference ICI of the first subcarrier and the second subcarrier according to a first offset, where a sign of the first offset is the same as a sign of the target offset, and an absolute value of the first offset is smaller than or equal to an absolute value of the target offset.

26. The communications apparatus of claim 25, wherein the compensation module is configured to:

27. The communication device according to any of claims 17 to 26, wherein the communication device further comprises:

and the sending module is used for sending a second deviation or the target signal to the sending end, wherein the sign of the second deviation is the same as that of the target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation.

28. The communications apparatus of claim 27, wherein the means for transmitting is configured to:

and when the absolute value of the target deviation is larger than an absolute value threshold, sending the second deviation or the target signal to the sending end.

29. A communication apparatus, configured to be used at a transmitting end, the transmitting end being communicatively coupled to a receiving end, the communication apparatus comprising:

a sending module, configured to send a first subcarrier carrying a target sequence to the receiving end, where a power spectrum of the target sequence includes at least one first frequency at which a signal power is greater than a noise power;

the sending module is further configured to send a second subcarrier carrying a zero sequence to the receiving end; the lengths of the target sequence and the zero sequence are equal, and the time domain positions of the target sequence and the zero sequence are the same; the frequency band of the second subcarrier comprises at least one second frequency, and the at least one first frequency comprises the at least one second frequency;

the acquisition module is used for acquiring a second deviation, wherein the sign of the second deviation is the same as that of a target deviation, and the absolute value of the second deviation is smaller than or equal to that of the target deviation; the target deviation is a deviation of a frequency interval from a signal baud rate of the transmitting end, the frequency interval is an interval between a center frequency of the first subcarrier and a center frequency of the second subcarrier, the target deviation is determined according to the target sequence and a target signal obtained by the receiving end receiving the second subcarrier, and the target signal includes at least one signal of the second frequency.

30. The communications apparatus of claim 29, wherein the means for obtaining is configured to:

and receiving the second deviation sent by the receiving end.

31. The communications apparatus of claim 29, wherein the second bias is equal to the target bias, and wherein the means for obtaining is configured to:

receiving the target signal sent by the receiving end;

32. The communication device according to any of claims 29 to 31, wherein the communication device further comprises:

and a pre-compensation module, configured to pre-compensate inter-channel interference ICI of the first subcarrier and the second subcarrier according to the second deviation.

33. A communication system, comprising: a sending terminal and a receiving terminal;

the receiving end comprising the communication device of any of claims 17 to 28;

the transmitting end comprising the communication device of any one of claims 29 or 32.