Communication method, apparatus and system

Abstract

The application discloses a communication method, device and system, and belongs to the technical field of communication. The method comprises the following steps: a target third node receives a first electromagnetic wave signal sent by a first adjacent node, carries out target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal, and sends the second electromagnetic wave signal to a second adjacent node. The first node, at least one third node and the second node are sequentially arranged on a cable, the target third node is adjacent to the first adjacent node and the second adjacent node among the nodes, and the target processing comprises processing for carrying out conjugate inversion on the spectrum of the electromagnetic wave signal. The application can solve the problem that nodes cannot effectively communicate, and is used for processing electromagnetic wave signals transmitted on the cable.

Description

[0001] This application claims priority to Chinese Patent Application No. 202111223482.3, filed on October 20, 2021, entitled "Communication Method, Device and System", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method, device and system. BACKGROUND

[0003] In a communication system, nodes can be connected by a cable, and the nodes can communicate by transmitting electromagnetic wave signals on the cable.

[0004] Taking a first node and a second node in a communication system as an example. The first node can load data to be sent to the second node on an electromagnetic wave signal, and send the electromagnetic wave signal to the second node through the cable. The second node can recover the data carried by the electromagnetic wave signal after receiving the electromagnetic wave signal. In this way, the communication between the first node and the second node is realized.

[0005] However, the electromagnetic wave signal transmitted on the cable will be affected by the cable, resulting in distortion of the electromagnetic wave signal received by the second node, and the accuracy of the data recovered by the second node from the electromagnetic wave signal is low, affecting the effective communication between the nodes. SUMMARY

[0006] The present application provides a communication method, device and system, which can solve the problem of ineffective communication between nodes. The technical solution is as follows:

[0007] In a first aspect, a communication method is provided, which is performed by a target third node between a first node and a second node; the first node and the second node are connected by a cable, at least one third node is arranged on the cable, and the target third node is one of the at least one third node; among the first node, the second node and the at least one third node, the target third node is adjacent to a first adjacent node and a second adjacent node;

[0008] The method comprises: after receiving a first electromagnetic wave signal sent by the first adjacent node, the target third node performs target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal, and sends the second electromagnetic wave signal to the second adjacent node; wherein the target processing includes processing for conjugate inversion of the frequency spectrum of the electromagnetic wave signal.

[0009] Optionally, the amplitude-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion is symmetric about a target straight line axis; the phase-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion is symmetric about a target point center; wherein the target straight line is perpendicular to the horizontal coordinate axis of the coordinate system in which the amplitude-frequency curve is located, and the frequency corresponding to the intersection point of the target straight line and the horizontal coordinate axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal coordinate axis of the coordinate system in which the phase-frequency curve is located corresponding to the center frequency.

[0010] Optionally, when the target third node processes the first electromagnetic wave signal to make the spectrum of the electromagnetic wave signal undergo conjugate inversion, on the one hand, for the amplitude-frequency curve in the spectrum of the first electromagnetic wave signal, the target third node exchanges the amplitudes corresponding to the frequencies on the left and right sides of the target straight line symmetrically with the target straight line as the axis of symmetry, so that the amplitude-frequency curve of the first electromagnetic wave signal before and after the spectrum undergoes conjugate inversion is symmetric about the target straight line axis. On the other hand, for the phase-frequency curve in the spectrum of the first electromagnetic wave signal, the target third node multiplies the phase corresponding to each frequency in the phase-frequency curve by -1, and at the same time, exchanges the phases corresponding to the frequencies on the left and right sides of the target straight line symmetrically with the target straight line as the axis of symmetry, so that the phase-frequency curve of the first electromagnetic wave signal before and after the spectrum undergoes conjugate inversion is symmetric about the target point center. Of course, the target third node can also realize the processing of the first electromagnetic wave signal to make the spectrum of the electromagnetic wave signal undergo conjugate inversion in other ways, such as filtering the first electromagnetic wave signal, which is not limited in the present application.

[0011] According to the above, the electromagnetic wave signal will undergo the first distortion in the process of being transmitted from the first adjacent node to the target third node, and the electromagnetic wave signal will undergo the third distortion similar to the first distortion in the process of being transmitted from the target third node to the second adjacent node. The target processing of the first electromagnetic wave signal received by the target second node includes the processing for making the spectrum of the electromagnetic wave signal undergo conjugate inversion, so that the second electromagnetic wave signal obtained by the target third node processing the first electromagnetic wave will undergo the second distortion opposite to the first distortion of the signal emitted by the first adjacent node. In the process of transmitting the electromagnetic wave signal from the target third node to the second adjacent node, the electromagnetic wave signal undergoes the third distortion. Under the action of the second distortion and the third distortion, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can be reduced, the communication quality between the first adjacent node and the second adjacent node is guaranteed, and the communication quality between the first node and the second node is further guaranteed.

[0012] In addition, the target third node does not need to restore the original electromagnetic wave signal sent by the first node when performing the processing on the first electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal, so the complexity of the target third node is lower.

[0013] Further, it is assumed that the amplitude-frequency curve of the conjugate inversion signal is axisymmetric about the target straight line with respect to the amplitude-frequency curve of the first electromagnetic wave signal, and the phase-frequency curve of the conjugate inversion signal is center-symmetric about the target point with respect to the phase-frequency curve of the first electromagnetic wave signal, wherein the target straight line is perpendicular to the horizontal coordinate axis of the coordinate system in which the amplitude-frequency curve is located, and the frequency corresponding to the intersection point of the target straight line and the horizontal coordinate axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal coordinate axis of the coordinate system in which the phase-frequency curve is located corresponding to the center frequency.

[0014] The second electromagnetic wave signal obtained by the target third node finally can be the same as the conjugate inversion signal, or can be different, which is not limited in the present application. When the second electromagnetic wave signal obtained by the target third node finally is different from the conjugate inversion signal, at least one information of the center frequency, the amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal and the conjugate inversion signal can be different.

[0015] When the second electromagnetic wave signal obtained by the target third node finally can be different from the conjugate inversion signal, the second electromagnetic wave signal and the conjugate inversion signal can satisfy at least one of the following conditions.

[0016] Condition 1.1: In the amplitude-frequency curve of the conjugate inversion signal, the first amplitude sum and the second amplitude sum have a target size relationship; in the amplitude-frequency curve of the second electromagnetic wave signal, the third amplitude sum and the fourth amplitude sum also have the target size relationship.

[0017] The first amplitude is the amplitude corresponding to the first frequency, and the second amplitude is the amplitude corresponding to the second frequency; the first frequency is less than the center frequency of the conjugate inversion signal, and the second frequency is greater than the center frequency of the conjugate inversion signal; the third amplitude is the amplitude corresponding to the third frequency, and the fourth amplitude is the amplitude corresponding to the fourth frequency; the third frequency is less than the center frequency of the second electromagnetic wave signal, and the fourth frequency is greater than the center frequency of the second electromagnetic wave signal.

[0018] Condition 1.2: The fluctuation rate of the phase corresponding to any frequency in the additional phase-frequency curve is less than 40% (or 20%, 30%, etc.). Wherein, the fluctuation rate is the ratio of the fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is the phase corresponding to the any frequency in the normalized additional phase-frequency curve.

[0019] The additional phase-frequency curve is a curve obtained by subtracting the reference phase-frequency curve from the phase-frequency curve of the second electromagnetic wave signal; the center frequency of the reference phase-frequency curve is the same as the center frequency of the second electromagnetic wave signal; when the center frequency of the conjugate inversion signal is the same as the center frequency of the second electromagnetic wave signal, the reference phase-frequency curve is the phase-frequency curve of the conjugate inversion signal; when the center frequency of the conjugate inversion signal is different from the center frequency of the second electromagnetic wave signal, the reference phase-frequency curve is a phase-frequency curve obtained by moving the phase-frequency curve of the conjugate inversion signal along the abscissa axis of the phase-frequency curve.

[0020] The fluctuation rate is a ratio of the fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is a phase corresponding to any frequency in the normalized additional phase-frequency curve; it should be noted that the above normalization is used to rotate and move the additional phase-frequency curve, so that both end points and the target intersection point of the additional phase-frequency curve are moved to the abscissa axis of the additional phase-frequency curve, and the target intersection point corresponds to the center frequency of the first electromagnetic wave signal; the target intersection point is an intersection point of a line connecting the two end points and a reference straight line, the reference straight line is perpendicular to the abscissa axis, and the frequency corresponding to the intersection point of the abscissa axis is the center frequency of the first electromagnetic wave signal.

[0021] When the second electromagnetic wave signal and the conjugate inversion signal satisfy condition 1.1, the difference between the amplitude-frequency curve of the second electromagnetic wave signal and the amplitude-frequency curve of the conjugate inversion signal is small; when the second electromagnetic wave signal and the conjugate inversion signal satisfy condition 1.2, the difference between the phase-frequency curve of the second electromagnetic wave signal and the phase-frequency curve of the conjugate inversion signal is small. At this time, the difference between the second electromagnetic wave signal and the conjugate inversion signal is small, so that the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can also be reduced.

[0022] According to the above content, the second electromagnetic wave signal and the conjugate inversion signal can be the same or different. When the second electromagnetic wave signal and the conjugate inversion signal are different, it can be caused by the factors of the device itself in the target third node; or when the second electromagnetic wave signal and the conjugate inversion signal are different, it can also be caused by other processing (such as auxiliary processing) different from the above processing for making the spectrum of the electromagnetic wave signal undergo conjugate inversion; or when the second electromagnetic wave signal and the conjugate inversion signal are different, it can be caused by the factors of the device itself in the target third node and the above other processing.

[0023] When the second electromagnetic wave signal and the conjugate inversion signal are the same, it is equivalent to that the spectrum of the first electromagnetic wave signal undergoes conjugate inversion in an ideal case, and the second electromagnetic wave signal can be obtained. When the second electromagnetic wave signal and the conjugate inversion signal are different, it is equivalent to that the spectrum of the first electromagnetic wave signal undergoes conjugate inversion in a non-ideal case, and the second electromagnetic wave signal can be obtained.

[0024] Further, the target third node has various ways to target process the first electromagnetic wave signal, and the following will take several ways as examples for explanation. In the following several ways, the conjugate inversion of the spectrum of the first electromagnetic wave signal can be the conjugate inversion in the ideal case, or the conjugate inversion in the non-ideal case, and when the conjugate inversion is the conjugate inversion in the non-ideal case, the second electromagnetic wave signal is different from the conjugate inversion signal due to the factors of the devices in the target third node.

[0025] Way 1: When the target third node targets processes the first electromagnetic wave signal, it can first down-convert the first electromagnetic wave signal to obtain a first baseband signal; then, obtain a second baseband signal from the first baseband signal, the second baseband signal being conjugate to the first baseband signal; finally, up-convert the second baseband signal to obtain a second electromagnetic wave signal.

[0026] When the target third node adopts way 1 to target process the first electromagnetic wave signal, the target third node can include a signal source unit, a first phase shift unit, a second phase shift unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, an inversion unit, and a combining unit; the signal source unit is configured to provide a local oscillation electromagnetic wave signal, the center frequency of the local oscillation electromagnetic wave signal being the same as the center frequency of the first electromagnetic wave signal; the first phase shift unit, the second phase shift unit, the first mixing unit, and the third mixing unit are connected with the signal source unit, the first phase shift unit is further connected with the second mixing unit, the second phase shift unit is further connected with the fourth mixing unit, the first mixing unit is connected with the third mixing unit, the second mixing unit and the fourth mixing unit are connected through the inversion unit, and the third mixing unit and the fourth mixing unit are connected with the combining unit;

[0027] When the target third node down-converts the first electromagnetic wave signal to obtain a first baseband signal, the first mixing unit mixes the first electromagnetic wave signal and the local oscillation electromagnetic wave signal to obtain a real part signal of the first baseband signal; the first phase shift unit moves the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain a first phase shift signal, where π represents the circular constant; and the second mixing unit mixes the first electromagnetic wave signal and the first phase shift signal obtained by the first phase shift unit to obtain an imaginary part signal of the first baseband signal;

[0028] When the target third node obtains a second baseband signal from the first baseband signal, the inversion unit inverts the imaginary part signal to obtain an inverted signal of the imaginary part signal, and the second baseband signal includes the real part signal and the inverted signal;

[0029] The target third node, when up-converting the second baseband signal to obtain the second electromagnetic wave signal, mixes the real part signal and the local oscillation electromagnetic wave signal by the third mixing unit to obtain a first mixed signal; the second phase shifting unit shifts the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain the first phase shifted signal; the fourth mixing unit mixes the reverse signal and the first phase shifted signal obtained by the second phase shifting unit to obtain a second mixed signal; and the combining unit combines the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

[0030] Option 2: When the target third node performs target processing on the first electromagnetic wave signal, the target third node can first down-convert the first electromagnetic wave signal to obtain a first baseband signal; and then, the target third node performs conjugate up-conversion on the first baseband signal to obtain a second electromagnetic wave signal.

[0031] It should be noted that when the target third node performs target processing on the first electromagnetic wave signal by using option 2, the processing mode of the target third node is various.

[0032] In the first optional processing mode of option 2, the target third node comprises a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit and a combining unit; the signal source unit is configured to provide a local oscillation electromagnetic wave signal, the center frequency of the local oscillation electromagnetic wave signal being the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit and the third mixing unit are connected with the signal source unit; the first phase shifting unit is further connected with the second mixing unit; the second phase shifting unit is further connected with the fourth mixing unit; the first mixing unit is connected with the third mixing unit; the second mixing unit and the fourth mixing unit are connected; and the third mixing unit and the fourth mixing unit are connected with the combining unit.

[0033] The target third node, when down-converting the first electromagnetic wave signal to obtain a first baseband signal, mixes the first electromagnetic wave signal and the local oscillation electromagnetic wave signal by the first mixing unit to obtain a real part signal of the first baseband signal; the first phase shifting unit shifts the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain a first phase shifted signal, where π represents a circular constant; and the second mixing unit mixes the first electromagnetic wave signal and the first phase shifted signal to obtain an imaginary part signal of the first baseband signal.

[0034] The third mixing unit mixes the real part signal and the local oscillation electromagnetic wave signal to obtain a first mixed signal; the second phase shifting unit shifts the phase of the local oscillation electromagnetic wave signal by -π / 2 to obtain a second phase shifted signal; the fourth mixing unit mixes the imaginary part signal and the second phase shifted signal to obtain a second mixed signal; and the combining unit combines the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

[0035] In the first alternative processing mode of mode 2, since the second phase shifting unit shifts the phase of the local oscillation electromagnetic wave signal by -π / 2 to obtain a second phase shifted signal, the fourth mixing unit mixes the imaginary part signal and the second phase shifted signal, which is equivalent to mixing the inverse signal of the imaginary part signal and the second phase shifted signal in mode 1. Therefore, the second mixed signal obtained by the fourth mixing unit in the first alternative processing mode of mode 2 is equivalent to the second mixed signal in mode 1, and further, the second electromagnetic wave signal obtained by the combining unit in the first alternative processing mode of mode 2 is equivalent to the second electromagnetic wave signal in mode 1.

[0036] In the second alternative processing mode of mode 2, the target third node comprises a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit and a combining unit; the signal source unit is configured to provide a local oscillation electromagnetic wave signal, the center frequency of the local oscillation electromagnetic wave signal being the same as that of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit and the third mixing unit are connected with the signal source unit; the first phase shifting unit is further connected with the second mixing unit; the second phase shifting unit is further connected with the fourth mixing unit; the first mixing unit is connected with the fourth mixing unit; the second mixing unit and the third mixing unit are connected; and the third mixing unit and the fourth mixing unit are connected with the combining unit.

[0037] The first mixing unit mixes the first electromagnetic wave signal and the local oscillation electromagnetic wave signal to obtain the real part signal; the first phase shifting unit shifts the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain a first phase shifted signal, where π represents a circular constant; and the second mixing unit mixes the first electromagnetic wave signal and the first phase shifted signal obtained by the first phase shifting unit to obtain the imaginary part signal.

[0038] The third mixing unit mixes the imaginary part signal and the local oscillation electromagnetic wave signal to obtain a first mixed signal; the second phase-shifting unit shifts the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal; the fourth mixing unit mixes the real part signal and the first phase-shifted signal obtained by the second phase-shifting unit to obtain a second mixed signal; and the combining unit combines the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

[0039] It can be seen that, in the second alternative processing manner of manner 2, the conjugate of the first baseband signal is realized by crossing the real part signal and the imaginary part signal in the input signal of the up-mixing unit. At this time, the up-mixing unit is equivalent to additionally adding a phase rotation of 90° after the conjugate of the first baseband signal is performed. The phase rotation of 90° does not affect the effect of the target processing.

[0040] Manner 3: When the target third node performs target processing on the first electromagnetic wave signal, the target third node can perform spectrum shifting on the first electromagnetic wave signal to obtain a third electromagnetic wave signal; and then, filter the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0041] It should be noted that the first electromagnetic wave signal is a bandpass real signal, and the spectrum of the first electromagnetic wave signal has conjugate symmetry, that is, the spectrum of the first electromagnetic wave signal is conjugate symmetric about the longitudinal coordinate axis (the point passing through the 0 frequency) of the coordinate system in which the spectrum is located. At this time, the spectrum of the baseband signal of the first electromagnetic wave signal is on the positive half axis of the coordinate system, and the center frequency of the first electromagnetic wave signal is the center frequency. According to the conjugate symmetry of the spectrum of the first electromagnetic wave signal, there is a spectrum conjugate symmetric with the baseband signal spectrum of the first electromagnetic wave signal on the interval on the negative half axis of the spectrum of the first electromagnetic wave signal. Therefore, only the spectrum on the interval on the negative half axis of the spectrum of the first electromagnetic wave signal needs to be shifted to the positive half axis, and the conjugate symmetry of the original positive half axis signal spectrum can be equivalently realized.

[0042] When the target third node performs target processing on the first electromagnetic wave signal by manner 3, the target third node comprises a signal source unit, a frequency multiplication unit, a mixing unit and a filtering unit; the signal source unit, the frequency multiplication unit, the mixing unit and the filtering unit are connected in sequence; the signal source unit is configured to provide a local oscillation electromagnetic wave signal, the center frequency of the local oscillation electromagnetic wave signal being the same as the center frequency of the first electromagnetic wave signal;

[0043] The target third node obtains a frequency-doubled signal of the local oscillation electromagnetic wave signal when performing frequency spectrum shifting on the first electromagnetic wave signal to obtain a third electromagnetic wave signal, a center frequency of the frequency-doubled signal being twice a center frequency of the first electromagnetic wave signal; the mixing unit mixes the first electromagnetic wave signal with the frequency-doubled signal to obtain the third electromagnetic wave signal.

[0044] The target third node filters the third electromagnetic wave signal to obtain the second electromagnetic wave signal when performing filtering on the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0045] Mode 4: When the target third node performs target processing on the first electromagnetic wave signal, the target third node can sequentially perform frequency conversion, frequency spectrum shifting, filtering, and frequency conversion on the first electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0046] When the target third node performs target processing on the first electromagnetic wave signal in Mode 4, the target third node comprises a first signal source unit, a second signal source unit, a frequency-doubled unit, a first mixing unit, a second mixing unit, a third mixing unit, a first filtering unit, and a second filtering unit; the first mixing unit, the first filtering unit, the second mixing unit, the second filtering unit, and the third mixing unit are sequentially connected; the first signal source unit is connected with the first mixing unit, and the second signal source unit is connected with the second mixing unit through the frequency-doubled unit; the first signal source unit is configured to generate a first local oscillation electromagnetic wave signal, and the second signal source unit is configured to generate a second local oscillation electromagnetic wave signal; a center frequency of the first local oscillation electromagnetic wave signal is f1, a center frequency of the second local oscillation electromagnetic wave signal is f2, and a center frequency of the first electromagnetic wave signal is f0, f1+f2=f0, and f1<f0-F / 2, F representing a bandwidth of the first electromagnetic wave signal.

[0047] The first mixing unit mixes the first electromagnetic wave signal with the first local oscillation electromagnetic wave signal to obtain a first mixed signal when the target third node targets the first electromagnetic wave signal to obtain a second electromagnetic wave signal; the first filtering unit filters the first mixed signal to obtain a first sub-signal in the first mixed signal, and the first sub-signal has a center frequency f2; the frequency multiplication unit obtains a frequency multiplication signal of the second local oscillation electromagnetic wave signal, and the frequency multiplication signal has a center frequency twice of f2; the second mixing unit mixes the first sub-signal with the frequency multiplication signal to obtain a second mixed signal; the second filtering unit filters the second mixed signal to obtain a second sub-signal in the second mixed signal, and the second sub-signal has the center frequency f2; and the third mixing unit mixes the second sub-signal with the first local oscillation electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0048] Optionally, the target third node targets the first electromagnetic wave signal to obtain a second electromagnetic wave signal in the following manner 5: the target third node can perform parametric amplification on the first electromagnetic wave signal to obtain the second electromagnetic wave signal. It should be noted that the target third node has various processing manners when the target third node targets the first electromagnetic wave signal in the manner 5.

[0049] In the first processing manner of the manner 5, the target third node comprises a signal source unit, a first filtering unit, a second filtering unit, a third filtering unit and a nonlinear unit; the signal source unit is configured to provide a local oscillation electromagnetic wave signal; the signal source unit is connected with the second filtering unit, and the first filtering unit, the second filtering unit and the third filtering unit are all connected with the nonlinear unit.

[0050] The first filtering unit filters the first electromagnetic wave signal to obtain a first filtered signal when the target third node performs parametric amplification on the first electromagnetic wave signal to obtain the second electromagnetic wave signal, and the first filtered signal has a center frequency of the first electromagnetic wave signal; the second filtering unit filters the local oscillation electromagnetic wave signal to obtain a second filtered signal; the nonlinear unit performs parametric amplification on the first filtered signal according to the second filtered signal to obtain a parametric amplification signal; and the third filtering unit filters the parametric amplification signal to obtain the second electromagnetic wave signal; wherein the second electromagnetic wave signal has a center frequency of Mf p +Nf0, M and N are both non-zero integers, N is less than zero, f0 represents the center frequency of the first electromagnetic wave signal, and f p represents the center frequency of the second filtered signal.

[0051] It should be noted that the second filtered signal obtained by filtering the local electromagnetic wave signal generated by the signal source unit through the second filter unit is used as a pump signal, and the first filtered signal obtained by filtering the first electromagnetic wave signal input into the target third node through the first filter unit is used together on the nonlinear unit. The nonlinear unit has nonlinear effects under the action of the pump signal, and the nonlinear unit will transfer the energy in the pump signal to the output parametric amplification signal to realize parametric amplification. The nonlinear unit can generate a parametric amplification signal at any Af p +Bf0(A and B are both non-zero integers) frequency point, at this time, the third filter unit can filter the parametric amplification signal output by the nonlinear unit to obtain a second electromagnetic wave signal with a center frequency of Mf p +Nf0. And in order to realize the spectrum of the second electromagnetic wave signal relative to the spectrum of the first electromagnetic wave signal, N needs to be selected as a negative integer. For example, M=2, N=-1, at this time, the center frequency of the second electromagnetic wave signal is 2f p -f0, f p may be a frequency close to f0; when f p is a frequency similar to 2f0, M=1 and N=-1 can also be selected, at this time, the center frequency of the second electromagnetic wave signal is f p -f0=f0.

[0052] And since the target third node performs parametric amplification on the first electromagnetic wave signal in the process of target processing on the first electromagnetic wave signal, the power of the second electromagnetic wave signal can also be improved, thereby reducing the transmission loss of the electromagnetic wave signal on the cable.

[0053] In the second optional processing mode of mode 5, the target third node includes a signal source unit, a connection unit, a first filter unit, a second filter unit, and a nonlinear unit; the connection unit has a first end, a second end, and a third end, the first end is connected to the first adjacent node, the second end is connected to the second adjacent node, and the third end is connected to one end of the first filter unit; the connection unit is used to transmit the signal input from the first end to the third end, and transmit the signal input from the third end to the second end; the other end of the first filter unit and the second filter unit are connected with the nonlinear unit; the signal source unit is connected with the second filter unit, and the signal source unit is used to provide a local electromagnetic wave signal;

[0054] The first filter unit filters the first electromagnetic wave signal input from one end of the first filter unit to obtain a first filtered signal, and outputs the first filtered signal from the other end of the first filter unit, the center frequency of the first filtered signal being the center frequency of the first electromagnetic wave signal; the second filter unit filters the local oscillation electromagnetic wave signal to obtain a second filtered signal; the nonlinear unit parametrically amplifies the first filtered signal according to the second filtered signal to obtain a parametric amplification signal; and the first filter unit filters the parametric amplification signal from the nonlinear unit to obtain the second electromagnetic wave signal and outputs the second electromagnetic wave signal from one end of the first filter unit; wherein the center frequency of the second electromagnetic wave signal is Mf p +Nf0, Mf p +Nf0=f0, M and N are both non-zero integers, and N is less than zero, f0 represents the center frequency of the first electromagnetic wave signal, and f p represents the center frequency of the second filtered signal.

[0055] In the second optional processing mode, filtering the parametric amplification signal to obtain the second electromagnetic wave signal and filtering the first electromagnetic wave signal to obtain the first filtered signal are both implemented on the first filter unit, and the second electromagnetic wave signal and the first filtered signal are separated by a connection unit (such as a circulator or the like) through different signal paths.

[0056] Optionally, before the target third node performs the target processing on the first electromagnetic wave signal, the target third node can also perform low-noise amplification on the first electromagnetic wave signal to improve the quality of the first electromagnetic wave signal.

[0057] Optionally, after the target third node performs the target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal, and before the target third node transmits the second electromagnetic wave signal to the second adjacent node, the target third node can also perform power amplification on the second electromagnetic wave signal to improve the power of the second electromagnetic wave signal, thereby reducing the transmission loss of the electromagnetic wave signal on the cable.

[0058] Optionally, the first electromagnetic wave signal is a terahertz signal or an optical signal, etc.

[0059] In a second aspect, a communication device is provided, the communication device being a target third node between a first node and a second node; the first node and the second node being connected by a cable, at least one third node being disposed on the cable, the target third node being one of the at least one third node, the target third node being adjacent to a first neighbor node and a second neighbor node among the first node, the second node and the at least one third node; the communication device comprising: a receiving module, a target processing module and a sending module. The receiving module is configured to receive a first electromagnetic wave signal sent by the first neighbor node; the target processing module is configured to perform target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal, the target processing comprising processing for causing a conjugate inversion of a spectrum of the electromagnetic wave signal; and the sending module is configured to send the second electromagnetic wave signal to the second neighbor node.

[0060] Optionally, an amplitude-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is axisymmetric about a target straight line, and a phase-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is center-symmetric about a target point, wherein the target straight line is perpendicular to an abscissa axis of a coordinate system in which the amplitude-frequency curve is located, and a frequency corresponding to an intersection point of the target straight line and the abscissa axis is a center frequency of the first electromagnetic wave signal; and the target point is a point on an abscissa axis of a coordinate system in which the phase-frequency curve is located, corresponding to the center frequency.

[0061] Optionally, when the target processing module performs the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal on the first electromagnetic wave signal, on one hand, for the amplitude-frequency curve in the spectrum of the first electromagnetic wave signal, the target processing module exchanges the amplitudes corresponding to the frequencies on the left and right sides of the target straight line symmetrically with the target straight line as the axis of symmetry, so that the amplitude-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is axisymmetric about the target straight line. On the other hand, for the phase-frequency curve in the spectrum of the first electromagnetic wave signal, the target processing module multiplies each frequency corresponding phase in the phase-frequency curve by -1, and also exchanges the phases corresponding to the frequencies on the left and right sides of the target straight line symmetrically with the target straight line as the axis of symmetry, so that the phase-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is center-symmetric about the target point. Of course, the target processing module can also perform the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal on the first electromagnetic wave signal in other ways, such as a filtering way.

[0062] According to the above, the electromagnetic wave signal will be distorted in the first distortion when transmitted from the first adjacent node to the target third node, and the electromagnetic wave signal will be distorted in the third distortion when transmitted from the target third node to the second adjacent node, and the third distortion is similar to the first distortion. The target processing of the target second node on the received first electromagnetic wave signal includes processing for conjugate inversion of the spectrum of the electromagnetic wave signal, so that the second electromagnetic wave signal obtained by the target third node performing target processing on the first electromagnetic wave will be distorted in the second distortion opposite to the first distortion of the signal emitted by the first adjacent node. In the process of transmitting the electromagnetic wave signal from the target third node to the second adjacent node, the electromagnetic wave signal is distorted in the third distortion. Under the action of the second distortion and the third distortion, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can be reduced, the communication quality between the first adjacent node and the second adjacent node is ensured, and the communication quality between the first node and the second node is ensured.

[0063] In addition, when the target processing module performs processing on the first electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal, it is not necessary to restore the original electromagnetic wave signal emitted by the first node, so the complexity of the target processing module is low.

[0064] Further, it is assumed that the amplitude-frequency curve of the conjugate inversion signal is axisymmetric about the target straight line with respect to the amplitude-frequency curve of the first electromagnetic wave signal; the phase-frequency curve of the conjugate inversion signal is center-symmetric about the target point with respect to the phase-frequency curve of the first electromagnetic wave signal; wherein the target straight line is perpendicular to the horizontal coordinate axis of the coordinate system in which the amplitude-frequency curve is located, and the frequency corresponding to the intersection point of the horizontal coordinate axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal coordinate axis of the coordinate system in which the phase-frequency curve is located corresponding to the center frequency.

[0065] The second electromagnetic wave signal finally obtained by the target third node can be the same as the conjugate inversion signal, or can be different, which is not limited in the present application. When the second electromagnetic wave signal finally obtained by the target third node is different from the conjugate inversion signal, at least one of the center frequency, the amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal and the conjugate inversion signal can be different.

[0066] When the second electromagnetic wave signal finally obtained by the target third node can be different from the conjugate inversion signal, the second electromagnetic wave signal and the conjugate inversion signal can satisfy at least one of the following conditions.

[0067] Condition 1.1: In the amplitude-frequency curve of the conjugate inversion signal, the first amplitude sum and the second amplitude sum have a target size relationship; in the amplitude-frequency curve of the second electromagnetic wave signal, the third amplitude sum and the fourth amplitude sum also have the target size relationship.

[0068] The first amplitude is an amplitude corresponding to a first frequency, and the second amplitude is an amplitude corresponding to a second frequency; the first frequency is less than a center frequency of the conjugate inverted signal, and the second frequency is greater than the center frequency of the conjugate inverted signal; the third amplitude is an amplitude corresponding to a third frequency, and the fourth amplitude is an amplitude corresponding to a fourth frequency; the third frequency is less than a center frequency of the second electromagnetic wave signal, and the fourth frequency is greater than the center frequency of the second electromagnetic wave signal.

[0069] Condition 1.2: a fluctuation rate of a phase corresponding to any frequency in the additional phase-frequency curve is less than 40% (or 20%, 30%, etc.). The fluctuation rate is a ratio of a fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is the phase corresponding to the any frequency in the normalized additional phase-frequency curve.

[0070] The additional phase-frequency curve is a curve obtained by subtracting a reference phase-frequency curve from a phase-frequency curve of the second electromagnetic wave signal; the center frequency of the reference phase-frequency curve is the same as the center frequency of the second electromagnetic wave signal; when the center frequency of the conjugate inverted signal is the same as the center frequency of the second electromagnetic wave signal, the reference phase-frequency curve is a phase-frequency curve of the conjugate inverted signal; when the center frequency of the conjugate inverted signal is different from the center frequency of the second electromagnetic wave signal, the reference phase-frequency curve is a phase-frequency curve obtained by moving the phase-frequency curve of the conjugate inverted signal along the horizontal coordinate axis.

[0071] The fluctuation rate is a ratio of a fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is the phase corresponding to the any frequency in the normalized additional phase-frequency curve; it should be noted that the normalization is used to rotate and move the additional phase-frequency curve, so that both end points and a target intersection point of the additional phase-frequency curve are moved to the horizontal coordinate axis of the additional phase-frequency curve, and the target intersection point corresponds to the center frequency of the first electromagnetic wave signal; the target intersection point is an intersection point of a line connecting the two end points and a reference straight line, the reference straight line is perpendicular to the horizontal coordinate axis, and a frequency corresponding to an intersection point of the reference straight line and the horizontal coordinate axis is the center frequency of the first electromagnetic wave signal.

[0072] When the second electromagnetic wave signal and the conjugate inverted signal satisfy the condition 1.1, the amplitude-frequency curve of the second electromagnetic wave signal and the amplitude-frequency curve of the conjugate inverted signal have a small difference; when the second electromagnetic wave signal and the conjugate inverted signal satisfy the condition 1.2, the phase-frequency curve of the second electromagnetic wave signal and the phase-frequency curve of the conjugate inverted signal have a small difference. At this time, the second electromagnetic wave signal and the conjugate inverted signal have a small difference, so that the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can also be reduced.

[0073] According to the above, the second electromagnetic wave signal and the conjugate inverted signal can be the same or different. When the second electromagnetic wave signal and the conjugate inverted signal are different, it can be caused by the device itself in the target third node; or, when the second electromagnetic wave signal and the conjugate inverted signal are different, it can also be caused by other processing (such as auxiliary processing) in the target processing in addition to the processing for making the spectrum of the electromagnetic wave signal undergo conjugate inversion; or, when the second electromagnetic wave signal and the conjugate inverted signal are different, it can be caused by the device itself in the target third node and the other processing in the target processing.

[0074] When the second electromagnetic wave signal and the conjugate inverted signal are the same, it is equivalent to that the spectrum of the first electromagnetic wave signal undergoes conjugate inversion in an ideal case, and the second electromagnetic wave signal can be obtained. When the second electromagnetic wave signal and the conjugate inverted signal are different, it is equivalent to that the spectrum of the first electromagnetic wave signal undergoes conjugate inversion in a non-ideal case, and the second electromagnetic wave signal can be obtained.

[0075] Further, the target processing module can perform target processing on the first electromagnetic wave signal in various ways, and the following will be explained by taking several ways as examples. In the following several ways, the conjugate inversion of the spectrum of the first electromagnetic wave signal can be conjugate inversion in an ideal case or conjugate inversion in a non-ideal case, and when the conjugate inversion is conjugate inversion in a non-ideal case, the second electromagnetic wave signal and the conjugate inverted signal are different caused by the device itself in the target third node.

[0076] Way 1: The target processing module is configured to: down-convert the first electromagnetic wave signal to obtain a first baseband signal; obtain a second baseband signal according to the first baseband signal, the second baseband signal being conjugate to the first baseband signal; and up-convert the second baseband signal to obtain the second electromagnetic wave signal.

[0077] Optionally, when the target processing module adopts the mode 1 to perform target processing on the first electromagnetic wave signal, the target processing module comprises: a signal source unit, a first phase shift unit, a second phase shift unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, an inversion unit and a combining unit; the signal source unit is configured to provide a local oscillation electromagnetic wave signal, the local oscillation electromagnetic wave signal has the same center frequency as the first electromagnetic wave signal; the first phase shift unit, the second phase shift unit, the first mixing unit and the third mixing unit are connected with the signal source unit; the first phase shift unit is further connected with the second mixing unit; the second phase shift unit is further connected with the fourth mixing unit; the first mixing unit is connected with the third mixing unit; the second mixing unit and the fourth mixing unit are connected through the inversion unit; the third mixing unit and the fourth mixing unit are connected with the combining unit.

[0078] The first mixing unit is configured to mix the first electromagnetic wave signal and the local oscillation electromagnetic wave signal to obtain a real part signal of the first baseband signal; the first phase shift unit is configured to shift the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain a first phase shift signal, where π represents a circular constant; the second mixing unit is configured to mix the first electromagnetic wave signal and the first phase shift signal obtained by the first phase shift unit to obtain an imaginary part signal of the first baseband signal; the inversion unit is configured to invert the imaginary part signal to obtain an inverted signal of the imaginary part signal; the second baseband signal comprises the real part signal and the inverted signal; the third mixing unit is configured to mix the real part signal and the local oscillation electromagnetic wave signal to obtain a first mixing signal; the second phase shift unit is configured to shift the phase of the local oscillation electromagnetic wave signal by π / 2 to obtain the first phase shift signal; the fourth mixing unit is configured to mix the inverted signal and the first phase shift signal obtained by the second phase shift unit to obtain a second mixing signal; and the combining unit is configured to combine the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

[0079] Mode 2: the target processing module is configured to: first, perform frequency down conversion on the first electromagnetic wave signal to obtain a first baseband signal; and then, a target third node performs conjugate frequency up conversion on the first baseband signal to obtain the second electromagnetic wave signal.

[0080] It should be noted that when the target processing module adopts the mode 2 to perform target processing on the first electromagnetic wave signal, the target processing module has various processing modes.

[0081] (2.1) In the first optional processing manner, the target processing module comprises: a signal source unit, a first phase shift unit, a second phase shift unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit and a combining unit; the signal source unit is configured to provide a local electromagnetic wave signal, a center frequency of the local electromagnetic wave signal being the same as a center frequency of the first electromagnetic wave signal; the first phase shift unit, the second phase shift unit, the first mixing unit and the third mixing unit are connected with the signal source unit; the first phase shift unit is further connected with the second mixing unit; the second phase shift unit is further connected with the fourth mixing unit; the first mixing unit is connected with the third mixing unit; the second mixing unit and the fourth mixing unit are connected; and the third mixing unit and the fourth mixing unit are connected with the combining unit;

[0082] The first mixing unit is configured to mix the first electromagnetic wave signal and the local electromagnetic wave signal to obtain a real part signal of the first baseband signal; the first phase shift unit is configured to shift a phase of the local electromagnetic wave signal by π / 2 to obtain a first phase shift signal, where π represents a circular constant; the second mixing unit is configured to mix the first electromagnetic wave signal and the first phase shift signal to obtain an imaginary part signal of the first baseband signal; the third mixing unit is configured to mix the real part signal and the local electromagnetic wave signal to obtain a first mixing signal; the second phase shift unit is configured to shift the phase of the local electromagnetic wave signal by -π / 2 to obtain a second phase shift signal; the fourth mixing unit is configured to mix the imaginary part signal and the second phase shift signal to obtain a second mixing signal; and the combining unit is configured to combine the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

[0083] In the second optional processing manner of the manner 2, the target processing module comprises: a signal source unit, a first phase shift unit, a second phase shift unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit and a combining unit; the signal source unit is configured to provide a local electromagnetic wave signal, a center frequency of the local electromagnetic wave signal being the same as a center frequency of the first electromagnetic wave signal; the first phase shift unit, the second phase shift unit, the first mixing unit and the third mixing unit are connected with the signal source unit; the first phase shift unit is further connected with the second mixing unit; the second phase shift unit is further connected with the fourth mixing unit; the first mixing unit is connected with the fourth mixing unit; the second mixing unit and the third mixing unit are connected; and the third mixing unit and the fourth mixing unit are connected with the combining unit;

[0084] The first mixing unit is configured to mix the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part signal; the first phase shift unit is configured to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain a first phase shift signal, where π represents a circular constant; the second mixing unit is configured to mix the first electromagnetic wave signal and the first phase shift signal obtained by the first phase shift unit to obtain the imaginary part signal; the third mixing unit is configured to mix the imaginary part signal and the local oscillator electromagnetic wave signal to obtain a first mixed signal; the second phase shift unit is configured to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase shift signal; the fourth mixing unit is configured to mix the real part signal and the first phase shift signal obtained by the second phase shift unit to obtain a second mixed signal; and the combining unit is configured to combine the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

[0085] In mode 3, the target processing module is configured to: perform frequency spectrum shifting on the first electromagnetic wave signal to obtain a third electromagnetic wave signal; and perform filtering on the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0086] When the target third node performs target processing on the first electromagnetic wave signal in mode 3, the target processing module includes: a signal source unit, a frequency multiplication unit, a mixing unit, and a filtering unit; the signal source unit, the frequency multiplication unit, the mixing unit, and the filtering unit are connected in sequence; the signal source unit is configured to provide a local oscillator electromagnetic wave signal, the center frequency of the local oscillator electromagnetic wave signal being the same as that of the first electromagnetic wave signal;

[0087] the frequency multiplication unit is configured to obtain a frequency multiplication signal of the local oscillator electromagnetic wave signal, the center frequency of the frequency multiplication signal being twice that of the first electromagnetic wave signal; the mixing unit is configured to mix the first electromagnetic wave signal and the frequency multiplication signal to obtain the third electromagnetic wave signal; and the filtering unit is configured to filter the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0088] In mode 4, the target processing module performs target processing on the first electromagnetic wave signal by sequentially performing frequency conversion, frequency spectrum shifting, filtering, and frequency conversion on the first electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0089] When the target third node adopts mode 4 to perform target processing on the first electromagnetic wave signal, the target processing module comprises: a first signal source unit, a second signal source unit, a frequency multiplication unit, a first mixing unit, a second mixing unit, a third mixing unit, a first filtering unit and a second filtering unit; the first mixing unit, the first filtering unit, the second mixing unit, the second filtering unit and the third mixing unit are connected in sequence; the first signal source unit is connected with the first mixing unit, and the second signal source unit is connected with the second mixing unit through the frequency multiplication unit; the first signal source unit is used for generating a first local oscillation electromagnetic wave signal, and the second signal source unit is used for generating a second local oscillation electromagnetic wave signal; the center frequency of the first local oscillation electromagnetic wave signal is f1, the center frequency of the second local oscillation electromagnetic wave signal is f2, and the center frequency of the first electromagnetic wave signal is f0, f1+f2=f0, f1<f0-F / 2, F representing the bandwidth of the first electromagnetic wave signal;

[0090] The first mixing unit is used for mixing the first electromagnetic wave signal with the first local oscillation electromagnetic wave signal to obtain a first mixed signal; the first filtering unit is used for filtering the first mixed signal to obtain a first sub-signal in the first mixed signal, and the center frequency of the first sub-signal is f2; the frequency multiplication unit is used for obtaining a frequency multiplication signal of the second local oscillation electromagnetic wave signal, and the center frequency of the frequency multiplication signal is twice f2; the second mixing unit is used for mixing the first sub-signal with the frequency multiplication signal to obtain a second mixed signal; the second filtering unit is used for filtering the second mixed signal to obtain a second sub-signal in the second mixed signal, and the center frequency of the second sub-signal is f2; and the third mixing unit is used for mixing the second sub-signal with the first local oscillation electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0091] Mode 5: When the target processing module performs target processing on the first electromagnetic wave signal, the target processing module can perform parametric amplification on the first electromagnetic wave signal to obtain the second electromagnetic wave signal. It should be noted that when the target processing module adopts mode 5 to perform target processing on the first electromagnetic wave signal, the processing mode of the target third node is various.

[0092] In the first optional processing mode of mode 5, the target processing module comprises: a signal source unit, a first filtering unit, a second filtering unit, a third filtering unit and a nonlinear unit; the signal source unit is used for providing a local oscillation electromagnetic wave signal; the signal source unit is connected with the second filtering unit, and the first filtering unit, the second filtering unit and the third filtering unit are all connected with the nonlinear unit;

[0093] The first filter unit is configured to filter the first electromagnetic wave signal to obtain a first filtered signal, and a center frequency of the first filtered signal is a center frequency of the first electromagnetic wave signal; the second filter unit is configured to filter the local electromagnetic wave signal to obtain a second filtered signal; the nonlinear unit is configured to parametrically amplify the first filtered signal according to the second filtered signal to obtain a parametrically amplified signal; and the third filter unit is configured to filter the parametrically amplified signal to obtain the second electromagnetic wave signal; wherein a center frequency of the second electromagnetic wave signal is Mf p +Nf0, M and N are both non-zero integers, and N is less than zero, f0 represents the center frequency of the first electromagnetic wave signal, and f p represents the center frequency of the second filtered signal.

[0094] In a second alternative processing mode of the mode 5, the target processing module comprises a signal source unit, a connection unit, a first filter unit, a second filter unit and a nonlinear unit; the connection unit has a first end, a second end and a third end, the first end is connected to the first adjacent node, the second end is connected to the second adjacent node, and the third end is connected to one end of the first filter unit; the connection unit is configured to transmit a signal input from the first end to the third end, and transmit a signal input from the third end to the second end; the other end of the first filter unit and the second filter unit are both connected to the nonlinear unit; the signal source unit is connected to the second filter unit, and the signal source unit is configured to provide a local electromagnetic wave signal;

[0095] The first filter unit is configured to filter the first electromagnetic wave signal input from one end of the first filter unit to obtain a first filtered signal, and output the first filtered signal from the other end of the first filter unit, and a center frequency of the first filtered signal is a center frequency of the first electromagnetic wave signal; the second filter unit is configured to filter the local electromagnetic wave signal to obtain a second filtered signal; the nonlinear unit is configured to parametrically amplify the first filtered signal according to the second filtered signal to obtain a parametrically amplified signal; and the first filter unit is configured to filter the parametrically amplified signal from the nonlinear unit to obtain the second electromagnetic wave signal, and output the second electromagnetic wave signal from one end of the first filter unit; wherein a center frequency of the second electromagnetic wave signal is Mf p +Nf0, Mf p +Nf0=f0, M and N are both non-zero integers, and N is less than zero, f0 represents the center frequency of the first electromagnetic wave signal, and f p represents the center frequency of the second filtered signal.

[0096] Optionally, the target processing module is further configured to perform low noise amplification on the first electromagnetic wave signal to improve the quality of the first electromagnetic wave signal before performing target processing on the first electromagnetic wave signal.

[0097] Optionally, the target processing module is further configured to perform power amplification on the second electromagnetic wave signal to improve the power of the second electromagnetic wave signal after performing target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal, and before transmitting the second electromagnetic wave signal to the second adjacent node, thereby reducing the transmission loss of the electromagnetic wave signal on the cable.

[0098] Optionally, the first electromagnetic wave signal is a terahertz signal or an optical signal.

[0099] In a third aspect, a chip is provided, which includes programmable logic circuitry and / or program instructions; and when the chip is running, is configured to implement the communication method according to any one of the first aspect.

[0100] In a fourth aspect, a communication method is provided, which is performed by a second node, the second node and a first node are connected through a cable, and at least one third node is arranged on the cable; the method includes: after receiving an electromagnetic wave signal transmitted by an adjacent third node, the second node can determine data carried by an electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0101] Further, in the present application, each third node can be a target third node, and each third node performs processing on the first electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal in the process of performing target processing on the received first electromagnetic wave signal. Therefore, when an even number of third nodes are arranged on the cable, the even number of third nodes can be divided into multiple groups of third nodes arranged in sequence in the direction from the first node to the second node, and each group of third nodes includes two third nodes. After the electromagnetic wave signal passes through the target processing of the two third nodes, the spectrum of the electromagnetic wave signal will not be conjugate inverted, and therefore, the electromagnetic wave signal received by the second node will not be conjugate inverted relative to the spectrum of the electromagnetic wave signal emitted by the first node.

[0102] However, when the cable is provided with an odd number of third nodes, the odd number of third nodes can be divided into a plurality of groups of third nodes arranged in sequence in the direction from the first node to the second node, and one third node, each group of third nodes including two third nodes. After the electromagnetic wave signal passes through the target processing of the two third nodes, the spectrum of the electromagnetic wave signal will not appear conjugate inversion. However, after the electromagnetic wave signal passes through the processing of the last one third node, the spectrum of the electromagnetic wave signal will appear conjugate inversion, so that the electromagnetic wave signal received by the second node will be conjugate inversion relative to the spectrum of the electromagnetic wave signal emitted by the first node. Therefore, when the cable is provided with an odd number of third nodes, the second node needs to perform processing on the received electromagnetic wave signal for making the spectrum of the electromagnetic wave signal conjugate inversion.

[0103] For example, when the cable is provided with an odd number of third nodes, in determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal, the second node can first perform processing on the received electromagnetic wave signal to obtain the electromagnetic wave signal emitted by the first node, then obtain the baseband signal of the electromagnetic wave signal, and perform constellation mapping according to the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node. The process of the second node performing processing on the received electromagnetic wave signal to obtain the electromagnetic wave signal emitted by the first node is the same as the process of the target third node performing target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal, which will not be repeated here.

[0104] For another example, when the cable is provided with an odd number of third nodes, in determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal, the second node can first obtain the second baseband signal of the received electromagnetic wave signal, the second baseband signal including a real part signal and an imaginary part signal; then, the second node can obtain the first baseband signal according to the second baseband signal, the first baseband signal being conjugate to the second baseband signal; finally, the second node can perform constellation mapping according to the first baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

[0105] When the cable is provided with an even number of third nodes, the second node can directly obtain the baseband signal of the received electromagnetic wave signal, and perform constellation mapping according to the real part signal and the imaginary part signal in the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

[0106] In addition, if the second electromagnetic wave signal is different from the conjugate inversion signal, the second node can compensate for the difference before determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0107] In a fifth aspect, a communication apparatus is provided, the communication apparatus is a second node, the second node and a first node are connected through a cable, and at least one third node is arranged on the cable; the communication apparatus comprises a receiving module and a determining module. The receiving module is configured to receive an electromagnetic wave signal transmitted by a neighboring third node; and the determining module is configured to determine data carried by an electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0108] Further, in the present application, each third node can be a target third node, and each third node performs processing on a first electromagnetic wave signal for conjugate inversion of a spectrum of the electromagnetic wave signal in a process of performing target processing on the received first electromagnetic wave signal. Therefore, when an even number of third nodes are arranged on the cable, the even number of third nodes can be divided into multiple groups of third nodes arranged in sequence in a direction from the first node to the second node, and each group of third nodes comprises two third nodes. After the electromagnetic wave signal is processed by the two third nodes, the spectrum of the electromagnetic wave signal will not be conjugate inverted, and therefore, the electromagnetic wave signal received by the second node will not be conjugate inverted relative to the spectrum of the electromagnetic wave signal emitted by the first node.

[0109] However, when an odd number of third nodes are arranged on the cable, the odd number of third nodes can be divided into multiple groups of third nodes arranged in sequence in a direction from the first node to the second node, and one third node, and each group of third nodes comprises two third nodes. After the electromagnetic wave signal is processed by the two third nodes, the spectrum of the electromagnetic wave signal will not be conjugate inverted. However, after the electromagnetic wave signal is processed by the last third node, the spectrum of the electromagnetic wave signal will be conjugate inverted, and therefore, the electromagnetic wave signal received by the second node will be conjugate inverted relative to the spectrum of the electromagnetic wave signal emitted by the first node. Therefore, when an odd number of third nodes are arranged on the cable, the determining module in the second node needs to perform processing on the received electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal.

[0110] For example, when an odd number of third nodes are arranged on the cable, the determining module can first process the electromagnetic wave signal received by the second node to obtain the electromagnetic wave signal emitted by the first node, then obtain a baseband signal of the electromagnetic wave signal, and perform constellation mapping according to the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node when determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal. The process of processing the received electromagnetic wave signal by the second node to obtain the electromagnetic wave signal emitted by the first node is the same as the process of performing target processing on the first electromagnetic wave signal by the target third node to obtain the second electromagnetic wave signal, which will not be described herein.

[0111] For example, when the cable is provided with an odd number of third nodes, the determining module can first obtain a second baseband signal of the received electromagnetic wave signal, the second baseband signal including a real part signal and an imaginary part signal, when determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0112] When the cable is provided with an even number of third nodes, the determining module can directly obtain a baseband signal of the received electromagnetic wave signal, and perform constellation mapping according to the real part signal and the imaginary part signal in the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

[0113] In addition, if the second electromagnetic wave signal is different from the conjugate inverted signal, the second node can compensate for the difference before determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0114] In a sixth aspect, a chip is provided, the chip including programmable logic circuitry and / or program instructions; when the chip is running, the chip is used to implement the communication method according to any one of the fourth aspect.

[0115] In a seventh aspect, a communication system is provided, the communication system including a first node, a second node, and at least one third node, the first node and the second node being connected by a cable, the at least one third node being provided on the cable; a target third node being one of the at least one third node, the target third node being the communication device according to any one of the second aspect, or the target third node including the chip according to the third aspect; the second node being the communication device according to any one of the fifth aspect, or the second node including the chip according to the sixth aspect.

[0116] Further, the cable is divided into a plurality of cable segments by the first node, the at least one third node, and the second node. A cable segment between the 2n+1th node and the 2n+2th node among the first node, the at least one third node, and the second node is referred to as a first cable segment, n≥0; a cable segment between the 2n+2th node and the 2n+3th node among the first node, the at least one third node, and the second node is referred to as a second cable segment.

[0117] The lengths of the cable segments in the cable satisfy certain constraint conditions.

[0118] For example, the lengths of the cable segments in the cable satisfy a first constraint condition: the absolute value of the difference between the sum of the lengths of the first cable segments and the sum of the lengths of the second cable segments in the cable is less than a first length.

[0119] The first length is the minimum of a frequency-selective fading transmission length and a dispersion transmission length. After the frequency-selective fading transmission length is transmitted in the cable, the maximum fading amplitude of the fading amplitudes of the frequencies in the electromagnetic wave signal emitted by the first node is a maximum fading amplitude that can be processed by the second node. The frequency-selective fading transmission length can be the quotient of the maximum fading amplitude and a unit fading amplitude in the cable, the unit fading amplitude being the maximum fading amplitude of the fading amplitudes of the frequencies in the electromagnetic wave signal emitted by the first node when a unit length of the cable segment in the cable is transmitted. After the dispersion transmission length is transmitted in the cable, the dispersion of the electromagnetic wave signal emitted by the first node is a maximum dispersion that can be processed by the second node. The dispersion transmission length can be the quotient of the maximum dispersion and the dispersion amount of a unit length of the cable segment in the cable.

[0120] When the first length is the minimum of the frequency-selective fading transmission length and the dispersion transmission length, the absolute value of the difference between the sum of the lengths of the first cable segments and the sum of the lengths of the second cable segments in the cable is less than the minimum, which can ensure that the frequency-selective fading and the group delay dispersion of the electromagnetic wave signal received by the second node are both small.

[0121] For another example, the lengths of the cable segments in the cable satisfy a second constraint condition: the length of the cable segment between any two adjacent nodes in the cable is less than or equal to a second length, the second length being a maximum length that can be transmitted by the electromagnetic wave signal emitted by the first node.

[0122] The maximum length that can be transmitted by the electromagnetic wave signal emitted by the first node is also the maximum length that can be transmitted by the electromagnetic wave signal under the condition that the electromagnetic wave signal emitted by the first node can be effectively received by the second node when there is no any node between the first node and the second node. The maximum length is determined by device parameters such as the transmission loss of the electromagnetic wave signal in the cable, the power of the electromagnetic wave signal emitted by the first node, and the sensitivity of the second node for receiving the electromagnetic wave signal. When the length of the cable segment between the above-mentioned any two adjacent nodes is less than or equal to the maximum length that can be transmitted by the electromagnetic wave signal emitted by the first node, it can be ensured that the electromagnetic wave signal can be effectively transmitted between the cable segments.

[0123] Further, at least one fourth node can be arranged on the cable; the fourth node is configured to amplify power of the electromagnetic wave signal transmitted on the cable. When the transmission length between the first node and the second node is long and the number of the third nodes is large, the fourth node can be arranged on one or more cable segments to amplify power of the electromagnetic wave signal transmitted on the cable, so as to ensure that the power of the electromagnetic wave signal received by the second node is high and the transmission loss of the electromagnetic wave signal is reduced.

[0124] The technical effects brought by the corresponding design manners in any two of the above first aspect to seventh aspect can be mutually referred, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0125] Figure 1 A structural schematic diagram of a communication system provided by an embodiment of the present application is provided.

[0126] Figure 2 A structural schematic diagram of another communication system provided by an embodiment of the present application is provided.

[0127] Figure 3 A structural schematic diagram of another communication system provided by an embodiment of the present application is provided.

[0128] Figure 4 A structural schematic diagram of another communication system provided by an embodiment of the present application is provided.

[0129] Figure 5 A structural schematic diagram of another communication system provided by an embodiment of the present application is provided.

[0130] Figure 6 A schematic diagram of group delay dispersion provided by an embodiment of the present application is provided.

[0131] Figure 7 A schematic diagram of frequency selective fading provided by an embodiment of the present application is provided.

[0132] Figure 8 A structural schematic diagram of a fourth node provided by an embodiment of the present application is provided.

[0133] Figure 9 A structural schematic diagram of another fourth node provided by an embodiment of the present application is provided.

[0134] Figure 10 A structural schematic diagram of another communication system provided by an embodiment of the present application is provided.

[0135] Figure 11 A variation schematic diagram of an amplitude-frequency curve provided by an embodiment of the present application is provided.

[0136] Figure 12 A variation schematic diagram of a phase-frequency curve provided by an embodiment of the present application is provided.

[0137] Figure 13 Another amplitude-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0138] Figure 14 Another phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0139] Figure 15 An amplitude-frequency curve and phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0140] Figure 16 Another amplitude-frequency curve and phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0141] Figure 17 Another amplitude-frequency curve and phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0142] Figure 18 A normalized schematic diagram of an additional phase-frequency curve provided for an embodiment of the present application;

[0143] Figure 19 Another amplitude-frequency curve and phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0144] Figure 20 Another amplitude-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0145] Figure 21 Another phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0146] Figure 22 Another amplitude-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0147] Figure 23 Another phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0148] Figure 24 Another amplitude-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0149] Figure 25 Another amplitude-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0150] Figure 26 Another phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0151] Figure 27 Another phase-frequency curve variation schematic diagram provided for an embodiment of the present application;

[0152] Figure 28A folding schematic diagram of a phase-frequency curve provided for an embodiment of the present application;

[0153] Figure 29 A structural schematic diagram of a target third node provided for an embodiment of the present application;

[0154] Figure 30 Another variation schematic diagram of an amplitude-frequency curve and a phase-frequency curve provided for an embodiment of the present application;

[0155] Figure 31 Another variation schematic diagram of an amplitude-frequency curve and a phase-frequency curve provided for an embodiment of the present application;

[0156] Figure 32 Another variation schematic diagram of an amplitude-frequency curve and a phase-frequency curve provided for an embodiment of the present application;

[0157] Figure 33 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0158] Figure 34 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0159] Figure 35 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0160] Figure 36 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0161] Figure 37 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0162] Figure 38 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0163] Figure 39 Another structural schematic diagram of a target third node provided for an embodiment of the present application;

[0164] Figure 40 A schematic diagram of a cable segment provided for an embodiment of the present application;

[0165] Figure 41 A length schematic diagram of a cable segment provided for an embodiment of the present application;

[0166] Figure 42 Another length schematic diagram of a cable segment provided for an embodiment of the present application;

[0167] Figure 43 Another length schematic diagram of a cable segment provided for an embodiment of the present application;

[0168] Figure 44 Another structural schematic diagram of a communication system provided by an embodiment of the present application is provided.

[0169] Figure 45 A flowchart of a communication method provided by an embodiment of the present application is provided. DETAILED DESCRIPTION

[0170] To make the principles and technical solutions of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0171] An embodiment of the present application provides a communication system, as shown in the figure, the communication system comprises a first node and a second node, the number of the first node and the second node in the communication system is not limited. The first node and the second node are connected through a cable. The cable can be a polymer cable, and the cable can transmit electromagnetic wave signals, such as terahertz signals (electromagnetic wave signals with terahertz frequency), optical signals, etc. Figure 1 For example, as shown in the figure, the communication system provided by an embodiment of the present application can be a data center, the first node in the communication system can be a switch or a server in a cabinet, and the second node can be a convergence switch. The communication interface in the first node and the second node can be a quad small form-factor pluggable (QSFP) interface, a small form-factor pluggable (SFP) interface, a CXP interface (an interface with a transmission rate of 12*10 gigabits per second), a CX4 interface (an interface with a transmission rate of 10 gigabits per second), etc.

[0172] Figure 2 For example, as shown in the figure, the communication system provided by an embodiment of the present application can be a data center, the first node in the communication system can be a switch or a server in a cabinet, and the second node can be a convergence switch. The communication interface in the first node and the second node can be a quad small form-factor pluggable (QSFP) interface, a small form-factor pluggable (SFP) interface, a CXP interface (an interface with a transmission rate of 12*10 gigabits per second), a CX4 interface (an interface with a transmission rate of 10 gigabits per second), etc. Figure 2 As shown in the figure, the communication system comprises two first nodes and two second nodes, and each first node is connected with each second node through a cable.

[0173] For example, as shown in the figure, the communication system provided by an embodiment of the present application can be an audio and video data transmission system, the first node in the communication system can be an audio and video data source device in a multimedia center, and the second node can be a display or a projector in a conference room (or an entertainment place). The communication interface in the first node and the second node can be a high definition multimedia interface (HDMI), a display interface (DP), etc. Figure 3 Figure 3 As shown in the figure, the communication system comprises one first node and two second nodes, and the first node is connected with each second node through a cable. As shown in the figure, the communication system comprises one first node and two second nodes, and the first node is connected with each second node through a cable.​

[0174] For example, as shown in Figure 4 , the communication system provided by the embodiments of the present application can be a vehicle-mounted wired network system, which includes a vehicle body, at least one distributed gateway node (GW) (for example, two GWs), Figure 4 a centralized vehicle control center, and at least one sensor (for example, one sensor). Figure 4 The centralized vehicle control center includes at least one electronic control unit (ECU) (for example, two ECUs). Figure 4 Figure 4 In the system shown, in each two parts connected by a cable, one part is a first node, and the other part is a second node, and the two parts communicate through the cable. For example, ECU1 can be the first node, and the sensor can be the second node; or, in the two GWs, one GW is the first node, and the other GW is the second node.

[0175] In the communication system provided by the embodiments of the present application, the first node and the second node can transmit electromagnetic wave signals through the cable to communicate. For example, the first node can modulate an electromagnetic wave signal according to the data to be transmitted to the second node, and send the electromagnetic wave signal into the cable. After being transmitted through the cable, the electromagnetic wave signal is received and demodulated by the second node to recover the data to be transmitted by the first node.

[0176] For example, as shown in Figure 5 , the first node can include a transmitter. The transmitter includes a modulator configured to modulate an electromagnetic wave signal according to data to be transmitted to the second node. Optionally, the transmitter can further include a power amplifier (PA) and a coupler. The PA is connected to the modulator and configured to perform power amplification on the electromagnetic wave signal modulated by the modulator. One end of the coupler is connected to the PA, and the other end is connected to the cable, so as to transmit the electromagnetic wave signal power amplified by the PA to the cable.

[0177] For example, as shown in Figure 5 , the second node includes a receiver. The receiver includes a demodulator configured to demodulate the electromagnetic wave signal into data. Optionally, the receiver can further include a low noise amplifier (LNA) and a coupler. One end of the coupler is connected to the cable, and the other end is connected to the LNA. The coupler is configured to receive the electromagnetic wave signal transmitted by the cable. The LNA is configured to perform low noise amplification on the electromagnetic wave signal from the coupler. The demodulator is configured to demodulate the electromagnetic wave signal after low noise amplification.

[0178] ​Optionally, the second node can further include other devices, such as the second node further includes a clock restorer and an equalizer (not shown in FIG. 7). The clock restorer is configured to extract a clock signal from the baseband signal (the baseband signal obtained by demodulating the electromagnetic wave signal by the demodulator), and the equalizer is configured to equalize the baseband signal according to the clock signal to obtain data carried by the baseband signal. Figure 5

[0179] It should be noted that, in the embodiments of the present application, the first node transmits the electromagnetic wave signal to the second node as an example. Alternatively, the second node can also transmit the electromagnetic wave signal to the first node, in which case the first node includes a receiver in the first node, and the second node includes a transmitter in the second node. Figure 5 Figure 5

[0180] According to the above, the first node and the second node can communicate by transmitting the electromagnetic wave signal through the cable. However, due to the material properties and structural properties of the cable itself, the transmission of the electromagnetic wave signal in the cable will be greatly affected. The following will explain three aspects of the influence.

[0181] Firstly, the transmission of the electromagnetic wave signal in the cable will have transmission loss, which causes the energy loss of the electromagnetic wave signal. Moreover, the longer the transmission length of the electromagnetic wave signal in the cable, the greater the energy loss of the electromagnetic wave signal. When the energy of the electromagnetic wave signal received by the second node is lower than the sensitivity of the second node, the second node will not be able to demodulate and restore the data that the first node needs to send. Wherein, the signal energy received by the second node is lower than the sensitivity of the second node, which means that the transmission loss of the electromagnetic wave signal received by the second node is greater than the maximum transmission loss of the electromagnetic wave signal that the second node can demodulate and restore.

[0182] Secondly, the transmission of the electromagnetic wave signal in the cable will have group delay dispersion. The group delay dispersion refers to the different propagation speeds of different frequencies of signals in the electromagnetic wave signal when transmitted in the cable. When the electromagnetic wave signal is a terahertz signal, due to the large bandwidth of the terahertz signal, the frequency difference of the signals within the band is large, so the group delay dispersion will cause serious waveform distortion of the terahertz signal. Moreover, the longer the transmission length of the electromagnetic wave signal in the cable, the more serious the group delay dispersion, and the greater the waveform distortion of the electromagnetic wave signal. For example, as shown in FIG. 8, if the channel transmission function of the cable is H(f), f represents the frequency of the electromagnetic wave signal, then the image of the group delay dispersion of the electromagnetic wave signal (represented as the image of ang{H(f)} changing with frequency) will have the change characteristics of a quadratic curve; and the more serious the group delay dispersion, the greater the curvature of the quadratic curve. ang{H(f)} represents the phase of H(f). Figure 6

[0183] ​​​​In a third aspect, the electromagnetic wave signal suffers from frequency selective fading when transmitted in the cable. Frequency selective fading refers to the fact that different frequencies of the electromagnetic wave signal suffer from different fading (energy loss). Moreover, when the electromagnetic wave signal is a terahertz signal, typically the high frequency signals suffer from more fading than the low frequency signals, and this uneven fading of the signal spectrum also causes distortion of the signal waveform. Moreover, the longer the electromagnetic wave signal is transmitted in the cable, the more severe the frequency selective fading, the greater the difference in fading between the high and low frequency signals of the electromagnetic wave signal, and thus the greater the unevenness in the band of the electromagnetic wave signal, and the more severe the distortion of the electromagnetic wave signal. For example, as shown in Figure 7 if the channel transfer function of the cable is H(f), f representing the frequency of the electromagnetic wave signal, then the graph of the frequency selective fading of the electromagnetic wave signal (represented as the graph of │H(f)│ varying with frequency) tilts towards high frequencies, and the more severe the magnitude of the frequency selective fading, the greater the degree of tilting of the frequency selective fading curve. │H(f)│ represents the absolute value of H(f).

[0184] It can be seen that the cable has a large impact on the transmission of the electromagnetic wave signal, resulting in distortion of the electromagnetic wave signal received by the second node, and affecting the effective communication between the first node and the second node.

[0185] In the related art, in order to reduce the impact of the electromagnetic wave signal when transmitted in the cable, a fourth node can be provided on the cable between the first node and the second node.

[0186] For example, as shown in Figure 8 the fourth node is configured to boost the power of the electromagnetic wave signal transmitted in the cable. The fourth node includes two couplers and a PA connected in series between the two couplers. The couplers are connected to the cable, and the PA is configured to amplify the power of the passing electromagnetic wave signal. However, as shown in Figure 8 the fourth node cannot avoid the impact of the electromagnetic wave signal on group delay dispersion and frequency selective fading.

[0187] For another example, as shown in Figure 9As shown, the fourth node comprises: two couplers, and an LNA, a demodulator, an equalizer, a modulator and a PA connected in sequence between the two couplers, and a clock restorer connected with the demodulator and the equalizer. The couplers are connected with the cable, the LNA is configured to perform low noise amplification on the electromagnetic wave signal from one coupler; the demodulator is configured to demodulate the electromagnetic wave signal to obtain a baseband signal carrying data; the clock restorer is configured to extract a clock signal from the baseband signal; the equalizer is configured to equalize the baseband signal according to the clock signal to obtain the data carried by the baseband signal; the modulator is configured to modulate the electromagnetic wave signal according to the data; and the PA is configured to perform power amplification on the electromagnetic wave signal modulated by the modulator, and transmit the power amplified electromagnetic wave signal to the cable through the other coupler.

[0188] As can be seen, Figure 9 The fourth node shown is configured to demodulate and restore the received electromagnetic wave signal to obtain the data carried by the electromagnetic wave signal, and then modulate the data to obtain a new electromagnetic wave signal, so as to compensate for the influence of the electromagnetic wave signal transmitted on the cable between the first node and the fourth node. However, the fourth node shown has a complex processing process for the electromagnetic wave signal, which affects the transmission efficiency of the electromagnetic wave signal, and also cannot compensate for the influence of the electromagnetic wave signal transmitted between the fourth node and the second node. Figure 9

[0189] In order to reduce the influence of the electromagnetic wave signal transmitted in the cable, the embodiments of the present application provide a communication system, as shown in Figure 10 As shown in Figure 1 Based on the communication system shown, at least one third node can be arranged on the cable between the first node and the second node. The number of third nodes can be one or more, Figure 10 The third node can be a gateway, a router or the like.

[0190] The target third node is one of the at least one third node, and among the first node, the second node and the at least one third node, the target third node is adjacent to the first adjacent node and the second adjacent node. The first adjacent node can be the first node or another third node between the first node and the target third node, and the second adjacent node can be the second node or another third node between the target third node and the second node.

[0191] The target third node is configured to, after receiving the first electromagnetic wave signal sent by the first adjacent node, perform target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal, and send the second electromagnetic wave signal to the second adjacent node. The target processing includes processing for conjugate inversion of the spectrum of the electromagnetic wave signal.

[0192] ​Optionally, the amplitude-frequency curve of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum is symmetrical about the target straight line; the phase-frequency curve of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum is symmetrical about the center of the target point; wherein, the target straight line is perpendicular to the horizontal axis of the coordinate system where the amplitude-frequency curve is located, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal axis of the coordinate system where the phase-frequency curve is located that corresponds to the center frequency.

[0193] For example, the amplitude-frequency curves of the first electromagnetic wave signal and the second electromagnetic wave signal are as follows: Figure 11 As shown, the phase frequency curves of the first electromagnetic wave signal and the second electromagnetic wave signal can be represented as follows: Figure 12 As shown.

[0194] For example, the amplitude-frequency curves of the first electromagnetic wave signal and the second electromagnetic wave signal are as follows: Figure 13 As shown, the phase frequency curves of the first electromagnetic wave signal and the second electromagnetic wave signal can be represented as follows: Figure 14 As shown. Figure 13 and Figure 14 In this paper, the first electromagnetic wave signal is taken as a two-tone signal, and the first electromagnetic wave signal includes signal A and signal B.

[0195] Optionally, when the target third node processes the first electromagnetic wave signal to cause a conjugate reversal in the electromagnetic wave signal's spectrum, on the one hand, for the amplitude-frequency curve in the spectrum, the target third node will symmetrically exchange the amplitudes corresponding to the frequencies on both sides of the target straight line, using the aforementioned target straight line as the axis of symmetry, so that the amplitude-frequency curve of the electromagnetic wave signal before and after the spectrum conjugate reversal is symmetrical about the target straight line axis. On the other hand, for the phase-frequency curve in the spectrum, the target third node will multiply the phase corresponding to each frequency in the phase-frequency curve by -1, for example, changing the phase from 10° (degrees) to -10°. At the same time, it will also symmetrically exchange the phases corresponding to the frequencies on both sides of the target straight line, using the aforementioned target straight line as the axis of symmetry, so that the phase-frequency curve of the electromagnetic wave signal before and after the spectrum conjugate reversal is symmetrical about the target point center.

[0196] Of course, the target third node can also perform other processing on the first electromagnetic wave signal to cause the spectrum of the electromagnetic wave signal to be reversed, such as filtering the first electromagnetic wave signal. This application embodiment does not limit this.

[0197] The following analysis will examine the effects of the aforementioned processing method that causes the electromagnetic wave signal spectrum to undergo conjugate inversion:

[0198] by Figure 10As shown in the scenario, after the first electromagnetic wave signal is transmitted through the first cable segment, the first electromagnetic wave signal is affected by group delay dispersion and frequency selective fading, and the first distortion occurs, such as Figure 15 As shown, the part of the high frequency band in the amplitude-frequency curve of the first electromagnetic wave signal received by the target third node is concave, and the phase-frequency curve of the first electromagnetic wave signal is curved upwards.

[0199] After receiving the first electromagnetic wave signal, the target third node can perform target processing on the first electromagnetic wave signal. For example, when the target third node performs target processing on the first electromagnetic wave signal, the target third node can perform processing on the first electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal to obtain a second electromagnetic wave signal. The amplitude-frequency curve of the second electromagnetic wave signal is symmetric about the target straight line axis with the amplitude-frequency curve of the first electromagnetic wave signal, and the phase-frequency curve of the second electromagnetic wave signal is symmetric about the target point center with the phase-frequency curve of the first electromagnetic wave signal. The amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal are shown in Figure 16 As shown in Figure 16 It can be seen that the part of the high frequency band in the amplitude-frequency curve of the first electromagnetic wave signal is concave, and the part of the low frequency band in the amplitude-frequency curve of the second electromagnetic wave signal is concave, and the frequency bands of the two concave parts are different; the phase-frequency curve of the first electromagnetic wave signal is curved upwards, and the phase-frequency curve of the second electromagnetic wave signal is curved downwards, and the bending directions of the two phase-frequency curves are opposite. By comparing the first electromagnetic wave signal sent by the first adjacent node, the first electromagnetic wave signal received by the target third node, and the second electromagnetic wave signal obtained by the target node, it can be seen that the first distortion exists between the first electromagnetic wave signal received by the target third node and the first electromagnetic wave signal sent by the first adjacent node, the second distortion exists between the second electromagnetic wave signal and the first electromagnetic wave signal sent by the first adjacent node, and the first distortion and the second distortion are opposite.

[0200] After obtaining the second electromagnetic wave signal, the target third node can send the second electromagnetic wave signal to the second adjacent node through the second cable segment, as shown in Figure 17 The second electromagnetic wave signal is affected by frequency selective fading and group delay dispersion during transmission through the second cable segment, and the third distortion (similar to the first distortion) occurs, causing the amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal received by the second adjacent node to change. The amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal received by the second adjacent node are shown in Figure 17 As shown, the part of the high frequency band in the amplitude-frequency curve of the second electromagnetic wave signal is concave, and the phase-frequency curve of the first electromagnetic wave signal is curved upwards.

[0201] According to Figure 15 to Figure 17As shown in the process, after the electromagnetic wave signal is transmitted through the first cable segment or the second cable segment, the electromagnetic wave signal is distorted (e.g., the first distortion or the third distortion described above), at which time, the high-frequency part of the amplitude-frequency curve of the electromagnetic wave signal is concave, and the phase-frequency curve of the electromagnetic wave signal is curved upward. However, since the target third node performs the target processing on the first electromagnetic wave signal (including processing for performing conjugate inversion on the spectrum of the electromagnetic wave signal), the target processing causes the low-frequency part of the amplitude-frequency curve of the electromagnetic wave signal to be concave, and the phase-frequency curve of the electromagnetic wave signal to be curved downward, so that the second electromagnetic wave signal is subjected to the second distortion opposite to the first distortion relative to the first electromagnetic wave signal emitted by the first adjacent node. In this way, after the second electromagnetic wave signal is transmitted through the second cable, although the second electromagnetic wave signal is subjected to the third distortion due to the influence of the second cable, under the effects of the second distortion and the third distortion, the distortion of the second electromagnetic wave signal received by the second adjacent node relative to the first electromagnetic wave signal emitted by the first adjacent node is reduced.

[0202] In summary, in the communication system provided by the embodiments of the present application, the electromagnetic wave signal is subjected to the first distortion in the process of being transmitted from the first adjacent node to the target third node, and is subjected to the third distortion in the process of being transmitted from the target third node to the second adjacent node, and the third distortion is similar to the first distortion. The target processing performed by the target second node on the received first electromagnetic wave signal includes processing for performing conjugate inversion on the spectrum of the electromagnetic wave signal, so that the second electromagnetic wave signal obtained by the target third node performing the target processing on the first electromagnetic wave signal is subjected to the second distortion opposite to the first distortion relative to the signal emitted by the first adjacent node. In the process of transmitting the electromagnetic wave signal from the target third node to the second adjacent node, the electromagnetic wave signal is subjected to the third distortion. Under the effects of the second distortion and the third distortion, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node is reduced, the communication quality between the first adjacent node and the second adjacent node is ensured, and the communication quality between the first node and the second node is further ensured.

[0203] In addition, when the target third node performs the processing for performing conjugate inversion on the spectrum of the electromagnetic wave signal on the first electromagnetic wave signal, the target third node does not need to restore the original electromagnetic wave signal emitted by the first node, so that the complexity of the target third node is low.

[0204] The effect of the target processing will be further analyzed by using formulas below.

[0205] Suppose that the channel transfer function of a cable is H(f) = exp{k(f-f0)+c}·exp{i*(β(f-f0) 2+ αf), where exp{k(f-f0)+c} represents the k(f-f0)+c power of e, e represents a natural constant, k represents a slope of a frequency-selective fading image of the cable segment at a center frequency f0 of the electromagnetic wave signal transmitted on the cable segment (related to frequency-selective fading), f represents any frequency in a frequency band of the electromagnetic wave signal, and c is an average transmission loss coefficient of the cable segment at the frequency f0 (related to transmission loss); exp{i*(β(f-f0) 2 + αf) represents the i*(β(f-f0) 2 + αf) power of e, i is an imaginary unit, β represents a group delay dispersion coefficient of the cable segment within a bandwidth of the electromagnetic wave signal (related to group delay dispersion); and α is a constant coefficient corresponding to a transmission delay of the cable segment, which does not affect energy loss and waveform distortion of the electromagnetic wave signal.

[0206] If the channel parameters of the first cable segment are k1, c1, β1, and α1, the signal transfer function of the first cable segment is represented as H1(f).

[0207] H1(f) = exp{k1(f-f0)+c1}·exp{i*(β1(f-f0) 2 + α1f)}.

[0208] After the first electromagnetic wave signal is transmitted through the first cable segment, the frequency spectrum S(f) of the first electromagnetic wave signal becomes S1(f).

[0209] S1(f) = S(f)H1(f) = S(f)exp{k1(f-f0)+c1}·exp{i*(β1(f-f0) 2 + α1f)}.

[0210] The target third node performs target processing on the received first electromagnetic wave signal, and the frequency spectrum of the obtained second electromagnetic wave signal can be represented as S2(f). S2(f) = S * (-f)exp{k1(-f+f0)+c1}·exp{i*(-β1(f-f0) 2 + α1f)}.

[0211] S * (-f) represents a conjugate symmetry of S(f);

[0212] exp{k1(-f+f0)+c1} represents the k1(-f+f0)+c1 power of e;

[0213] exp{i*(-β1(f-f0) 2 + α1f) represents the i*(-β1(f-f0) 2 + α1f) power of e.

[0214] After obtaining the second electromagnetic wave signal, the target third node can send the second electromagnetic wave signal to the second adjacent node through the second cable segment. During the transmission of the second electromagnetic wave signal through the second cable segment, the second electromagnetic wave signal is affected by frequency selective fading and group delay dispersion, resulting in changes in the amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal received by the second adjacent node.

[0215] Supposing that the channel parameters of the second cable segment are k2, c2, β2, and α2, the signal transfer function of the second cable segment is represented as H2(f). H2(f) = exp{k2(f-f0)+c2}·exp{i*(β2(f-f0)+α2f)}. 2

[0216] The frequency spectrum S3(f) of the second electromagnetic wave signal received by the second adjacent node is S3(f) = S2(f)H2(f) = S * (-f)exp{(k2-k1)(f-f0)+c1+c2}·exp{i*((β2-β1)(f-f0) 2 +(α2+α1)f)}.

[0217] exp{(k2-k1)(f-f0)+c1+c2} represents e raised to the power of (k2-k1)(f-f0)+c1+c2.

[0218] exp{i*((β2-β1)(f-f0) 2 +(α2+α1)f)} represents e raised to the power of i*((β2-β1)(f-f0) 2 +(α2+α1)f).

[0219] If the lengths of the first cable segment and the second cable segment are similar, the channel parameters (k1, c1, β1, α1) of the first cable segment are approximately the same as the channel parameters (k2, c2, β2, α2) of the second cable segment.

[0220] At this time, for S3(f) = S * (-f)exp{(k2-k1)(f-f o )+c1+c2}·exp{i*((β2-β1)(f-f o ) 2 +(α2+α1)f)}, (k2-k1)(f-f o ) approaches zero, (β2-β1)(f-f o ) 2 also approaches zero.

[0221] S3(f) ≈ S * ​(-f)exp{c1+c2}·exp{i*((a2+a1)f)}.

[0222] It can be seen that S3(f) is irrelevant to k and β, k is related to frequency selective fading, and β is related to group delay dispersion. Therefore, S3(f) has a low correlation with frequency selective fading and group delay dispersion, and the distortion of the electromagnetic wave signal caused by frequency selective fading and group delay dispersion in S3(f) is greatly reduced.

[0223] Further, it is assumed that the amplitude-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is axisymmetric about a target straight line, and the phase-frequency curve of the first electromagnetic wave signal before and after the conjugate inversion of the spectrum is center-symmetric about a target point. Moreover, the first electromagnetic wave signal after the conjugate inversion of the spectrum is referred to as a conjugate inversion signal. According to the above content, it can be known that the amplitude-frequency curve of the conjugate inversion signal is axisymmetric about a target straight line with the amplitude-frequency curve of the first electromagnetic wave signal, and the phase-frequency curve of the conjugate inversion signal is center-symmetric about a target point with the phase-frequency curve of the first electromagnetic wave signal, wherein the target straight line is perpendicular to the horizontal coordinate axis of the coordinate system in which the amplitude-frequency curve is located, and the frequency corresponding to the intersection of the target straight line and the horizontal coordinate axis is the center frequency of the first electromagnetic wave signal; the target point is the point corresponding to the center frequency on the horizontal coordinate axis of the coordinate system in which the phase-frequency curve is located.

[0224] The second electromagnetic wave signal obtained by the target third node finally can be the same as the conjugate inversion signal, or can be different, which is not limited in the embodiments of the present application. When the second electromagnetic wave signal obtained by the target third node finally is different from the conjugate inversion signal, at least one information of the center frequency, the amplitude-frequency curve and the phase-frequency curve of the second electromagnetic wave signal and the conjugate inversion signal can be different.

[0225] When the second electromagnetic wave signal obtained by the target third node finally can be different from the conjugate inversion signal, the second electromagnetic wave signal and the conjugate inversion signal can satisfy at least one of the following conditions.

[0226] Condition 1.1: In the amplitude-frequency curve of the conjugate inversion signal, the first amplitude sum and the second amplitude sum have a target size relationship; in the amplitude-frequency curve of the second electromagnetic wave signal, the third amplitude sum and the fourth amplitude sum also have the target size relationship.

[0227] The first amplitude is the amplitude corresponding to the first frequency, and the second amplitude is the amplitude corresponding to the second frequency; the first frequency is less than the center frequency of the conjugate inversion signal, and the second frequency is greater than the center frequency of the conjugate inversion signal; the third amplitude is the amplitude corresponding to the third frequency, and the fourth amplitude is the amplitude corresponding to the fourth frequency; the third frequency is less than the center frequency of the second electromagnetic wave signal, and the fourth frequency is greater than the center frequency of the second electromagnetic wave signal.

[0228] Condition 1.2: the fluctuation rate of the phase corresponding to any frequency in the additional phase-frequency curve is less than 40% (or 20%, 30%, etc.). Wherein, the fluctuation rate is the ratio of the fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is the phase corresponding to any frequency in the normalized additional phase-frequency curve.

[0229] The additional phase-frequency curve is a curve obtained by subtracting the reference phase-frequency curve from the phase-frequency curve of the second electromagnetic wave signal; the center frequency of the reference phase-frequency curve is the same as that of the second electromagnetic wave signal; when the center frequency of the conjugate inverted signal is the same as that of the second electromagnetic wave signal, the reference phase-frequency curve is the phase-frequency curve of the conjugate inverted signal; when the center frequency of the conjugate inverted signal is different from that of the second electromagnetic wave signal, the reference phase-frequency curve is the phase-frequency curve of the conjugate inverted signal after moving along the horizontal coordinate axis of the phase-frequency curve.

[0230] The fluctuation rate is the ratio of the fluctuation phase to the phase corresponding to any frequency, and the fluctuation phase is the phase corresponding to any frequency in the normalized additional phase-frequency curve; it should be noted that please refer to Figure 18 The above normalization is used to rotate and move the additional phase-frequency curve, so that both ends and the target intersection point of the additional phase-frequency curve are moved to the horizontal coordinate axis of the additional phase-frequency curve, and the target intersection point corresponds to the center frequency of the first electromagnetic wave signal; the target intersection point is the intersection point of the line connecting the two ends and the reference straight line (not marked in Figure 18 ). The reference straight line is perpendicular to the horizontal coordinate axis, and the intersection point of the reference straight line and the horizontal coordinate axis corresponds to the center frequency of the first electromagnetic wave signal.

[0231] When the second electromagnetic wave signal and the conjugate inverted signal satisfy condition 1.1, the amplitude-frequency curve of the second electromagnetic wave signal and the amplitude-frequency curve of the conjugate inverted signal have small differences; when the second electromagnetic wave signal and the conjugate inverted signal satisfy condition 1.2, the phase-frequency curve of the second electromagnetic wave signal and the phase-frequency curve of the conjugate inverted signal have small differences. At this time, the second electromagnetic wave signal and the conjugate inverted signal have small differences, so as to also reduce the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node.

[0232] According to the above, the second electromagnetic wave signal and the conjugate inverted signal can be the same or different. When the second electromagnetic wave signal and the conjugate inverted signal are different, it can be caused by factors of the device itself in the target third node; or, when the second electromagnetic wave signal and the conjugate inverted signal are different, it can be caused by other processing (e.g., auxiliary processing) in addition to the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal; or, when the second electromagnetic wave signal and the conjugate inverted signal are different, it can be caused by factors of the device itself in the target third node and the other processing. The auxiliary processing is different from the above.

[0233] For example, the factors of the device itself in the target third node can be: frequency instability of the local oscillator circuit, limited bandwidth of the device, limited in-band flatness, nonlinear group delay, etc. Under the influence of the factors of the device itself in the target third node, the target third node performs the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal on the first electromagnetic wave signal, but the obtained electromagnetic wave signal is difficult to be completely the same as the conjugate inverted signal. The spectrum of the signal obtained by the conjugate inversion will usually additionally have at least one of the following changes 1 to 3.

[0234] Change 1: Since the device in the target third node for performing the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal usually has objective uncontrollable frequency jitter, the center frequency of the first electromagnetic wave signal after the conjugate inversion of the spectrum can be different from the center frequency of the first electromagnetic wave signal. For example, as shown in Figure 19 , the center frequency of the first electromagnetic wave signal after the conjugate inversion of the spectrum is fd, which is not equal to the center frequency fc of the first electromagnetic wave signal.

[0235] Change 2: Since the amplitude-frequency response of the device in the target third node for performing the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal will change the amplitude-frequency curve of the signal, the amplitude-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum can be different from the amplitude-frequency curve of the conjugate inverted signal.

[0236] For example, as shown in Figure 20 , the amplitude-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum will further superimpose the amplitude-frequency response curve of the device in the target third node for performing the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal on the mirror-symmetry curve of the input first electromagnetic wave signal (the amplitude-frequency curve of the conjugate inverted signal).

[0237] For another example, if the amplitude-frequency curve of the first electromagnetic wave signal is as shown in Figure 13At this time, the amplitude of signal A and the amplitude of signal B in the amplitude-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum are changed. For example, the amplitude of signal A in the amplitude-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is different from the amplitude of signal A in the second electromagnetic wave signal. Figure 13 The amplitude of signal B in the amplitude-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is different from the amplitude of signal B in the second electromagnetic wave signal. Figure 13

[0238] Change 3: Since the phase-frequency response of the device in the target third node changes the phase-frequency curve of the signal, the phase-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum can be different from the phase-frequency curve of the conjugate inversion signal. The phase-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is additionally superimposed with the phase-frequency response of the device in the target third node for performing the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal.

[0239] For example, as shown in Figure 21 , the phase-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is further superimposed with the phase-frequency response curve of the device in the target third node for performing the processing for causing the conjugate inversion of the spectrum of the electromagnetic wave signal on the center-symmetrical curve of the phase-frequency curve of the input first electromagnetic wave signal (the phase-frequency curve of the conjugate inversion signal).

[0240] For example, as shown in Figure 14 , the phase of signal A in the phase-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is not zero, and the phase of signal B in the phase-frequency curve of the first electromagnetic wave signal after the conjugate inversion of the spectrum is not zero.

[0241] Further, when the second electromagnetic wave signal is the same as the conjugate inversion signal, it is equivalent to that the spectrum of the first electromagnetic wave signal has undergone the conjugate inversion in an ideal case, and the second electromagnetic wave signal can be obtained. When the second electromagnetic wave signal is different from the conjugate inversion signal, it is equivalent to that the spectrum of the first electromagnetic wave signal has undergone the conjugate inversion in a non-ideal case, and the second electromagnetic wave signal can be obtained.

[0242] On the basis of the conjugate inversion in the ideal case described above, the conjugate inversion in the non-ideal case can satisfy at least one of the following conditions 2.1 to 2.4.

[0243] Condition 2.1: The amplitude-frequency curve of the electromagnetic wave signal before and after the conjugate inversion in the non-ideal case is not symmetrical about the target straight line axis, but is approximately symmetrical about the target straight line. ​

[0244] Condition 2.2: The phase-frequency curve of the electromagnetic wave signal before and after the conjugate inversion under the non-ideal condition is not symmetric about the center of the target point, but is approximately symmetric about the center of the target point.

[0245] Condition 2.3: The intersection point of the target straight line and the horizontal coordinate axis corresponds to a frequency deviating from the center frequency of the electromagnetic wave signal.

[0246] Condition 2.4: The target point is not the point on the horizontal coordinate axis of the coordinate system of the phase-frequency curve corresponding to the center frequency of the electromagnetic wave signal, but is the point on the horizontal coordinate axis of the coordinate system of the phase-frequency curve corresponding to the frequency deviating from the center frequency.

[0247] For example, when the conjugate inversion under the non-ideal condition satisfies the above conditions 2.1 to 2.4, the amplitude-frequency curve of the electromagnetic wave signal before and after the conjugate inversion under the non-ideal condition is approximately symmetric about the target straight line, and the phase-frequency curve of the electromagnetic wave signal before and after the conjugate inversion under the non-ideal condition is approximately symmetric about the center of the target point. The target straight line is perpendicular to the horizontal coordinate axis of the coordinate system of the amplitude-frequency curve, and the intersection point of the target straight line and the horizontal coordinate axis corresponds to a frequency deviating from the center frequency of the electromagnetic wave signal; the target point is the point on the horizontal coordinate axis of the coordinate system of the phase-frequency curve corresponding to the frequency deviating from the center frequency.

[0248] For example, assuming that after the conjugate inversion under the ideal condition on the first electromagnetic wave signal, the amplitude-frequency curve of the obtained second electromagnetic wave signal can be as shown in Figure 22 , and the phase-frequency curve of the second electromagnetic wave signal can be as shown in Figure 23 . After the conjugate inversion under the non-ideal condition on the first electromagnetic wave signal, the amplitude-frequency curve of the obtained second electromagnetic wave signal can be as shown in Figure 24 or Figure 25 , and the phase-frequency curve of the second electromagnetic wave signal can be as shown in Figure 26 or Figure 27 . Wherein, Figure 24 satisfies the above condition 2.1, Figure 25 satisfies the above condition 2.3, Figure 26 satisfies the above condition 2.2, Figure 27 satisfies the above condition 2.4.

[0249] Further, the conjugate inversion under the non-ideal condition and the conjugate inversion under the ideal condition have a certain relationship, which will be described below.

[0250] For example, for the same electromagnetic wave signal, assuming that the frequency spectrum of the electromagnetic wave signal is conjugate inverted in an ideal case, the amplitude-frequency curve of the electromagnetic wave signal is referred to as a first amplitude-frequency curve, and the phase-frequency curve of the electromagnetic wave signal is referred to as a first phase-frequency curve. After the frequency spectrum of the electromagnetic wave signal is conjugate inverted in a non-ideal case, the electromagnetic wave signal corresponds to a second amplitude-frequency curve and a second phase-frequency curve.

[0251] It should be noted that, assuming that the amplitude-frequency curve of the electromagnetic wave signal is a target amplitude-frequency curve and the phase-frequency curve of the electromagnetic wave signal is a target phase-frequency curve after the frequency spectrum of the electromagnetic wave signal is conjugate inverted in a non-ideal case. If the center frequency of the electromagnetic wave signal does not change after the frequency spectrum is conjugate inverted in a non-ideal case, then the second amplitude-frequency curve is the target amplitude-frequency curve, and the second phase-frequency curve is the target phase-frequency curve. If the center frequency of the electromagnetic wave signal changes after the frequency spectrum is conjugate inverted in a non-ideal case, then the second amplitude-frequency curve is a curve obtained by moving the target amplitude-frequency curve along the horizontal coordinate axis on which the target amplitude-frequency curve is located, and the second phase-frequency curve is a curve obtained by moving the target phase-frequency curve along the horizontal coordinate axis on which the target phase-frequency curve is located. Moreover, the center frequency of the second amplitude-frequency curve and the center frequency of the second phase-frequency curve are the same, and these center frequencies are the center frequency of the electromagnetic wave signal before the frequency spectrum is conjugate inverted in a non-ideal case.

[0252] Assuming that the first amplitude-frequency curve is represented as y = f1(x) and the second amplitude-frequency curve is represented as y = f2(x), where x represents a frequency and y represents an amplitude. Then, the first amplitude-frequency curve and the second amplitude-frequency curve satisfy formula (1): ∑ x |f 2n (x)-f1(x)| 2 <∑ x |f1(x)| 2 , the value range of x is within the bandwidth range of the electromagnetic wave signal. Wherein, y=f 2n (x) represents a normalized second amplitude-frequency curve obtained by normalizing the energy of the second amplitude-frequency curve to the energy of the first amplitude-frequency curve.

[0253] The conjugate inversion in a non-ideal case is related to the conjugate inversion in an ideal case and non-ideal factors. In formula (1), ∑ x |f 2n (x)-f1(x)| 2 represents the influence value of the non-ideal factor on the amplitude of the second amplitude-frequency curve, and ∑ x |f1(x)| 2 represents the influence value of the conjugate inversion in an ideal case on the amplitude of the second amplitude-frequency curve. Since ∑ x |f 2n (x)-f1(x)| 2<∑ x |f1(x)| 2 Therefore, the influence value of the non-ideal factor on the amplitude of the second amplitude-frequency curve will not exceed the influence value of the conjugate inversion in the ideal case on the amplitude of the second amplitude-frequency curve, and the conjugate inversion in the non-ideal case can also have the effect of the conjugate inversion in the ideal case. Thus, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can also be reduced.

[0254] Suppose that the first phase-frequency curve is represented as y=f3(x) and the second phase-frequency curve is represented as y=f4(x), where x represents frequency and y represents phase. Then, the first phase-frequency curve and the second phase-frequency curve satisfy formula (2): ∑ x |f dn (x)|<∑ x |f3(x)|. Wherein, y=f dn (x) represents the normalized error curve, and the error curve is y=f d (x)=f4(x)-f3(x), x U and x D represent the frequencies corresponding to the two end points of the error curve, and the phases corresponding to the two end points in the normalized error curve are both 0.

[0255] The conjugate inversion in the non-ideal case is related to both the conjugate inversion in the ideal case and the non-ideal factor. In formula (2), ∑ x |f dn (x)| represents the influence value of the non-ideal factor on the phase of the second phase-frequency curve, and ∑ x |f3(x)| represents the influence value of the conjugate inversion in the ideal case on the phase of the second phase-frequency curve. Since ∑ x |f dn (x)|<∑ x |f3(x)|, therefore, the influence value of the non-ideal factor on the phase of the second phase-frequency curve will not exceed the influence value of the conjugate inversion in the ideal case on the phase of the second phase-frequency curve, and the conjugate inversion in the non-ideal case can also have the effect of the conjugate inversion in the ideal case. Thus, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node can also be reduced.

[0256] It should be noted that the phase-frequency curve of the electromagnetic wave signal (such as the first electromagnetic wave signal, the second electromagnetic wave signal, etc.) can be the same as or different from the phase-frequency curve of the electromagnetic wave signal collected by the device (such as an oscilloscope).

[0257] For example, since electromagnetic wave signals are complex signals, and the phase of a complex signal can be any one of β + 2*N*π (β represents the phase of the complex signal between -π and π, π represents pi, and N is an integer), when measuring the phase frequency curve of an electromagnetic wave signal using equipment, the phase value in the phase frequency curve is often restricted to the interval [-π, π]. In this case, the phase frequency curve of the electromagnetic wave signal differs from the phase frequency curve acquired by the equipment.

[0258] For example, suppose the phase frequency curves of the first electromagnetic wave signal and the second electromagnetic wave signal are as follows: Figure 23 As shown, the phase frequency curves of the first and second electromagnetic wave signals acquired by the device will become... Figure 28 As shown in the curves, these phase frequency curves are wrapped within the phase interval of [-π, π]. If we take the phase value corresponding to the center frequency of the phase frequency curve of the electromagnetic wave signal acquired by the oscilloscope as a reference point and unwrap the phase frequency curve, we can obtain the following... Figure 23 The phase frequency curve of the electromagnetic wave signal is shown.

[0259] It should be noted that at least one third node can be provided on the cable between the first node and the second node. When multiple third nodes are provided on the cable, each third node can be a target third node, which will not be elaborated here in the embodiments of this application.

[0260] Furthermore, in the embodiments of this application, the target third node performs target processing on the first electromagnetic wave signal in various ways. Several of these methods will be explained below as examples. It should be noted that in the following methods, the conjugate inversion of the first electromagnetic wave signal can be either ideal or non-ideal. Moreover, when the conjugate inversion is non-ideal, it is due to factors inherent in the device itself within the target third node that the second electromagnetic wave signal differs from the conjugate inversion signal.

[0261] (1) Method 1: When the target third node performs target processing on the first electromagnetic wave signal, it can first down-convert the first electromagnetic wave signal to obtain the first baseband signal; then, it can obtain the second baseband signal based on the first baseband signal, and the second baseband signal is conjugate with the first baseband signal; finally, it can up-convert the second baseband signal to obtain the second electromagnetic wave signal.

[0262] It should be noted that the first electromagnetic wave signal is assumed to be s. i (t), where t represents time. If the center frequency of the first electromagnetic wave signal is f0, then the spectrum of the first electromagnetic wave signal is represented as B. i (f-f0), B i(f) a baseband signal (first baseband signal) b i (t) whose spectrum is centered at 0 frequency.

[0263] The second electromagnetic wave signal is denoted as s o (t). Since the spectrum of the first electromagnetic wave signal is conjugate symmetric to the spectrum of the second electromagnetic wave signal, the spectrum of the second electromagnetic wave signal is B i *(-f-f0), where * denotes taking the conjugate of a complex value. The baseband signal (second baseband signal) of the second electromagnetic wave signal is denoted as b o (t). The spectrum of the second baseband signal is denoted as B o (f). When the spectrum of the first electromagnetic wave signal is conjugate symmetric to the spectrum of the second electromagnetic wave signal, the spectrum of the baseband signal of the first electromagnetic wave signal is also conjugate symmetric to the spectrum of the baseband signal of the second electromagnetic wave signal, and thus the baseband signal b o (t) of the second electromagnetic wave signal has a spectrum B o (f) = B i *(-f).

[0264] From the Fourier transform property of a time-domain signal, when b o (t) = b i *(t), B o (f) = B i *(-f), and the spectrum of the second electromagnetic wave signal is B i *(-f-f0). Since the baseband signal is a time-domain signal, the target third node can conjugate the baseband signal b o (t) of the first electromagnetic wave signal (first baseband signal) to obtain the baseband signal b i *(t) of the second electromagnetic wave signal, and then up-convert the baseband signal of the second electromagnetic wave signal to obtain the second electromagnetic wave signal s o (t). The spectrum B i *(-f-f0) of the second electromagnetic wave signal is conjugate symmetric to the spectrum B i (f-f0) of the first electromagnetic wave signal.

[0265] When the target third node performs target processing on the first electromagnetic wave signal in Mode 1, as Figure 29As shown, the target third node can include: a signal source unit 01, a first phase shift unit 02, a second phase shift unit 03, a first mixing unit 04, a second mixing unit 05, a third mixing unit 06, a fourth mixing unit 07, a reverse unit 08, and a combining unit 09. Among them, the signal source unit 01 is used to provide a local electromagnetic wave signal, and the center frequency of the local electromagnetic wave signal is the same as that of the first electromagnetic wave signal; the first phase shift unit 02, the second phase shift unit 02, the first mixing unit 04, and the third mixing unit 06 are all connected with the signal source unit 01, the first phase shift unit 02 is also connected with the second mixing unit 05, the second phase shift unit 03 is also connected with the fourth mixing unit 07, the first mixing unit 04 is connected with the third mixing unit 06, the second mixing unit 05 and the fourth mixing unit 07 are connected through the reverse unit 08, and the third mixing unit 06 and the fourth mixing unit 07 are both connected with the combining unit 09. The first mixing unit 04, the second mixing unit 05, and the first phase shift unit 02 can constitute a down-conversion module, and the third mixing unit 06, the fourth mixing unit 07, the second phase shift unit 03, and the combining unit 09 constitute an up-conversion module.

[0266] It should be noted that for the units in each of the embodiments provided in the present application (such as the signal source unit 01, the first phase shift unit 02, the second phase shift unit 03, the first mixing unit 04, the second mixing unit 05, the third mixing unit 06, the fourth mixing unit 07, the reverse unit 08, and the combining unit 09), the unit can be an independent device, or multiple units can be integrated together, and each unit is a logical unit thereof, and the present application does not limit this.

[0267] When the target third node down-converts the first electromagnetic wave signal, the first mixing unit 04 mixes the first electromagnetic wave signal and the local electromagnetic wave signal provided by the signal source unit 01 to obtain a real part signal I of the first baseband signal; the first phase shift unit 02 moves the phase of the local electromagnetic wave signal provided by the signal source unit 01 by π / 2 to obtain a first phase shift signal, the first phase shift signal is orthogonal to the local electromagnetic wave signal, and π represents the circular constant; the second mixing unit 05 mixes the first electromagnetic wave signal and the first phase shift signal obtained by the first phase shift unit 02 to obtain an imaginary part signal Q of the first baseband signal. In this way, the first baseband signal including the real part signal I and the imaginary part signal Q is obtained. The first baseband signal b i (t) = I + Q.

[0268] Taking the amplitude-frequency curve of the first electromagnetic wave signal as shown in Figure 22 and the phase-frequency curve of the first electromagnetic wave signal as shown in Figure 23 for example. After the first electromagnetic wave signal is down-converted, the signal spectrum (including amplitude-frequency components and phase-frequency components) of the first electromagnetic wave signal is moved from the original center frequency fc to 0 frequency as a whole, as shown in Figure 30As shown, the center frequencies of the amplitude-frequency curve and phase-frequency curve of the first electromagnetic wave signal (first baseband signal) after down-conversion both changed from fc to 0.

[0269] When the target third node obtains the second baseband signal based on the first baseband signal, the inverting unit 08 inverts the imaginary part signal Q obtained by the second mixing unit 05 to obtain the inverted signal -Q of the imaginary part signal Q. At this time, the second baseband signal includes: the real part signal I of the first baseband signal, and the inverted signal -Q of the imaginary part signal of the first baseband signal. The second baseband signal b o (t)=IQ=(I+Q)*=b i *(t). With Figure 30 Taking the amplitude-frequency and phase-frequency curves of the first baseband signal as an example, after passing through the inversion unit, the spectrum of the first baseband signal undergoes conjugate inversion, resulting in the spectrum of the second baseband signal as shown below. Figure 31 As shown.

[0270] When the target third node upconverts the second baseband signal, the third mixing unit 07 mixes the real part signal I obtained by the first mixing unit 04 with the local oscillator electromagnetic wave signal provided by the signal source unit 01 to obtain the first mixed signal; the second phase shifting unit 03 shifts the phase of the local oscillator electromagnetic wave signal provided by the signal source unit 01 by π / 2 to obtain the first phase shifted signal; the fourth mixing unit 07 mixes the inverted signal -Q obtained by the above-mentioned inverting unit 08 with the first phase shifted signal obtained by the second phase shifting unit 03 to obtain the second mixed signal; finally, the combining unit 09 combines the first mixed signal obtained by the third mixing unit 07 and the second mixed signal obtained by the fourth mixing unit 08 to obtain the second electromagnetic wave signal.

[0271] by Figure 31 Taking the amplitude-frequency curve and phase-frequency curve of the second baseband signal as an example, after up-conversion, the signal spectrum (including amplitude-frequency and phase-frequency components) of the second baseband signal is shifted from the original center frequency 0 to the fc frequency, as shown. Figure 32 As shown, the center frequencies of the amplitude-frequency curve and phase-frequency curve of the second baseband signal (second electromagnetic wave signal) after up-conversion both changed from 0 to fc.

[0272] It should be noted that, Figure 30 , Figure 31 and Figure 32 Taking the ideal conjugate reversal of the first electromagnetic wave signal as an example, it can be understood that in mode 1, due to factors of the device itself in the target third node, the first electromagnetic wave signal may also undergo a non-ideal conjugate reversal. This application embodiment does not limit this.

[0273] (2) Method 2: When the target third node performs target processing on the first electromagnetic wave signal, it can first down-convert the first electromagnetic wave signal to obtain the first baseband signal; then, the target third node performs conjugate up-conversion on the first baseband signal to obtain the second electromagnetic wave signal.

[0274] It should be noted that when the target third node uses method 2 to process the first electromagnetic wave signal, the processing methods of the target third node are diverse.

[0275] (2.1) In the first optional processing method, such as Figure 33 As shown, the target third node may include: a signal source unit 11, a first phase shifting unit 12, a second phase shifting unit 13, a first mixing unit 14, a second mixing unit 15, a third mixing unit 16, a fourth mixing unit 17, and a combining unit 18; the signal source unit 11 is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit 12, the second phase shifting unit 13, the first mixing unit 14, and the third mixing unit 16 are all connected to the signal source unit 11, the first phase shifting unit 12 is also connected to the second mixing unit 15, the second phase shifting unit 13 is also connected to the fourth mixing unit 17, the first mixing unit 14 is connected to the third mixing unit 16, the second mixing unit 15 is connected to the fourth mixing unit 17, and the third mixing unit 16 and the fourth mixing unit 17 are both connected to the combining unit 18. The first mixing unit 14, the second mixing unit 15 and the first phase shifting unit 12 can form a downconverter module, and the third mixing unit 16, the fourth mixing unit 17, the second phase shifting unit 13 and the combining unit 18 can form a conjugate upconverter module.

[0276] When the target third node down-converts the first electromagnetic wave signal, the first mixing unit 14 mixes the first electromagnetic wave signal and the local oscillator electromagnetic wave signal provided by the signal source unit 11 to obtain the real part signal I of the first baseband signal; the first phase shifting unit 12 shifts the phase of the local oscillator electromagnetic wave signal provided by the signal source unit 11 by π / 2 to obtain the first phase-shifted signal, where π represents pi; the second mixing unit 15 mixes the first electromagnetic wave signal and the first phase-shifted signal to obtain the imaginary part signal Q of the first baseband signal. Thus, a first baseband signal including the real part signal I and the imaginary part signal Q is obtained. The first baseband signal b i (t) = I + Q.

[0277] The third mixing unit 16 mixes the real part signal I obtained by the first mixing unit 14 with the local electromagnetic wave signal provided by the signal source unit 11 to obtain a first mixing signal when the target third node performs the conjugate up-conversion on the first baseband signal. The second phase shifting unit 13 shifts the phase of the local electromagnetic wave signal provided by the signal source unit 11 by -π / 2 to obtain a second phase shifting signal. The fourth mixing unit 17 mixes the imaginary part signal Q obtained by the second mixing unit 15 with the second phase shifting signal obtained by the second phase shifting unit 13 to obtain a second mixing signal. Finally, the combining unit 18 combines the first mixing signal obtained by the third mixing unit 16 and the second mixing signal obtained by the fourth mixing unit 17 to obtain a second electromagnetic wave signal.

[0278] In the first alternative processing mode of the mode 2, since the second phase shifting unit 13 shifts the phase of the local electromagnetic wave signal by -π / 2 to obtain a second phase shifting signal, the fourth mixing unit 17 mixes the imaginary part signal with the second phase shifting signal, which is equivalent to mixing the inverse signal of the imaginary part signal with the second phase shifting signal in the mode 1. Therefore, the second mixing signal obtained by the fourth mixing unit 17 in the first alternative processing mode of the mode 2 is equivalent to the second mixing signal in the mode 1, and further, the second electromagnetic wave signal obtained by the combining unit in the first alternative processing mode of the mode 2 is equivalent to the second electromagnetic wave signal in the mode 1.

[0279] (2.2) In the second alternative processing mode of the mode 2, as shown in Figure 34 the target third node comprises a signal source unit 21, a first phase shifting unit 22, a second phase shifting unit 23, a first mixing unit 24, a second mixing unit 25, a third mixing unit 26, a fourth mixing unit 27 and a combining unit 28. The signal source unit 21 is configured to provide a local electromagnetic wave signal, and the center frequency of the local electromagnetic wave signal is the same as that of the first electromagnetic wave signal. The first phase shifting unit 22, the second phase shifting unit 23, the first mixing unit 24 and the third mixing unit 26 are connected with the signal source unit 21. The first phase shifting unit 22 is further connected with the second mixing unit 25. The second phase shifting unit 23 is further connected with the fourth mixing unit 27. The first mixing unit 24 is connected with the fourth mixing unit 27. The second mixing unit 25 is connected with the third mixing unit 26. The third mixing unit 26 and the fourth mixing unit 27 are connected with the combining unit 28. The first mixing unit 24, the second mixing unit 25 and the first phase shifting unit 22 can constitute a down-conversion module. The third mixing unit 26, the fourth mixing unit 27, the second phase shifting unit 23 and the combining unit 28 constitute a conjugate up-conversion module.

[0280] The target third node, when down-converting the first electromagnetic wave signal, mixes the first electromagnetic wave signal and the local oscillator electromagnetic wave signal provided by the signal source unit 21 by the first mixing unit 24 to obtain a real part signal I of the first baseband signal; the first phase-shifting unit 22 shifts the phase of the local oscillator electromagnetic wave signal provided by the signal source unit 21 by π / 2 to obtain a first phase-shifted signal; the second mixing unit 25 mixes the first electromagnetic wave signal and the first phase-shifted signal to obtain an imaginary part signal Q of the first baseband signal. In this way, the first baseband signal including the real part signal I and the imaginary part signal Q is obtained. i (t) = I + Q.

[0281] The target third node, when up-converting the first baseband signal, mixes the imaginary part signal Q and the local oscillator electromagnetic wave signal provided by the signal source unit 21 by the third mixing unit 26 to obtain a first mixed signal; the second phase-shifting unit 23 shifts the phase of the local oscillator electromagnetic wave signal provided by the signal source unit 21 by π / 2 to obtain a first phase-shifted signal; the fourth mixing unit 27 mixes the real part signal I and the first phase-shifted signal obtained by the second phase-shifting unit 23 to obtain a second mixed signal; the combining unit 28 combines the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

[0282] It can be seen that, in the second alternative processing manner of the manner 2, the conjugation of the first baseband signal is realized by crossing the real part signal and the imaginary part signal in the input signal of the up-mixing unit. At this time, the up-mixing unit is equivalent to additionally adding a phase rotation of 90° after the conjugation of the first baseband signal. The phase rotation of 90° does not affect the effect of the target processing.

[0283] (3) Manner 3: The target third node, when performing the target processing on the first electromagnetic wave signal, can perform spectrum shifting on the first electromagnetic wave signal to obtain a third electromagnetic wave signal; and then, performs filtering on the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

[0284] It should be noted that the first electromagnetic wave signal S i (t) is a bandpass real signal, and the spectrum of the first electromagnetic wave signal has conjugate symmetry, that is, the spectrum S i (f) of the first electromagnetic wave signal is conjugate symmetric about the longitudinal coordinate axis (the point passing through the 0 frequency) of the coordinate system in which the spectrum is located, that is, S i (f) = S i (-f). At this time, the spectrum B i (t) of the baseband signal b i (t) of the first electromagnetic wave signal is located on the positive half axis of S i (f), and the center frequency of which is the center frequency f0 of the first electromagnetic wave signal, that is, B i (f) = Si (f+f0), -F / 2<f<F / 2, where F is the bandwidth of the first electromagnetic wave signal.

[0285] According to S i (f) conjugate symmetry, in S i (f) The interval on one side of the negative half-axis Above, there exists a [something] with B. i (f) Conjugate symmetric spectrum, i.e.,

[0286] Therefore, simply put S i (f) Spectrum at the negative half-axis -f0 By shifting the signal to f0 on the positive half-axis, the conjugate symmetry of the original positive half-axis signal spectrum can be achieved.

[0287] When the target third node processes the first electromagnetic wave signal using method 3, such as Figure 35 As shown, the target third node may include: a signal source unit 31, a frequency multiplier unit 32, a frequency mixer unit 33, and a filter unit 34; the signal source unit 31, the frequency multiplier unit 32, the frequency mixer unit 33, and the filter unit 34 are connected in sequence; the signal source unit 31 is used to provide a local oscillator electromagnetic wave signal, and the center frequency of the local oscillator electromagnetic wave signal is the same as the center frequency of the first electromagnetic wave signal. The filter unit 34 may be a band-pass filter (BPF).

[0288] When the target third node performs spectrum shifting on the first electromagnetic wave signal, the frequency multiplier unit 32 acquires the frequency multiplier signal of the local oscillator electromagnetic wave signal generated by the signal source unit 31.

[0289] The center frequency 2f0 of the frequency-doubled signal is twice the center frequency f0 of the first electromagnetic wave signal; then, the mixing unit 33 mixes the first electromagnetic wave signal with the frequency-doubled signal to obtain the third electromagnetic wave signal.

[0290] The spectrum of the third electromagnetic wave signal includes: the spectrum near 2f0+f0=3f0, the spectrum near f0-2f0=-f0, the spectrum near -f0+2f0=f0, and the spectrum near -f0-2f0=-3f0.

[0291] At this point, the spectrum of the first electromagnetic wave signal that was near -f0 is shifted to the vicinity of f0 and -3f0, and the original spectrum near f0 is shifted to the vicinity of -f0 and 3f0.

[0292] When the target third node filters the third electromagnetic wave signal, the filtering unit 34 filters the third electromagnetic wave signal to obtain a second electromagnetic wave signal. The center frequency of the filtering unit 34 is f0. Therefore, after the filtering unit 34 filters the third electromagnetic wave signal, the spectra near 3f0 and -3f0 in the spectrum of the third electromagnetic wave signal are filtered out, and the spectrum of the obtained second electromagnetic wave signal includes the spectra near f0 and -f0. Moreover, the spectrum near f0 in the spectrum of the second electromagnetic wave signal is conjugate symmetric with the spectrum near f0 in the spectrum of the first electromagnetic wave signal.

[0293] (4) Method 4: When the target third node performs target processing on the first electromagnetic wave signal, it can sequentially perform frequency conversion, spectrum shifting, filtering, and frequency conversion on the first electromagnetic wave signal to obtain a second electromagnetic wave signal.

[0294] When the target third node uses Method 4 to perform target processing on the first electromagnetic wave signal, as Figure 36 shown, the target third node may include: a first signal source unit 41, a second signal source unit 42, a frequency doubling unit 43, a first mixing unit 44, a second mixing unit 45, a third mixing unit 46, a first filtering unit 47, and a second filtering unit 48; the first mixing unit 44, the first filtering unit 47, the second mixing unit 45, the second filtering unit 48, and the third mixing unit 46 are connected in sequence; the first signal source unit 41 is connected to the first mixing unit 44, and the second signal source unit 42 is connected to the second mixing unit 45 through the frequency doubling unit 43; the first signal source unit 41 is used to generate a first local oscillation electromagnetic wave signal, and the second signal source unit 42 is used to generate a second local oscillation electromagnetic wave signal; the center frequency of the first local oscillation electromagnetic wave signal is f1, the center frequency of the second local oscillation electromagnetic wave signal is f2, the center frequency of the first electromagnetic wave signal is f0, f1 + f2 = f0, and f1 < f0 - F / 2, where F represents the bandwidth of the first electromagnetic wave signal. Both the first filtering unit 47 and the second filtering unit 48 can be low-pass filter units (low-pass filter, LPF).

[0295] The target third node performs target processing on the first electromagnetic wave signal. The first mixing unit 44 mixes the first electromagnetic wave signal with the first local oscillation electromagnetic wave signal to obtain a first mixed signal. After mixing by the first mixing unit 44, the spectrum near f0 in the spectrum of the first electromagnetic wave signal is moved to near f0-f1=f2 and near f0+f1, and the spectrum near-f0 is moved to near-f0-f1 and near-f0+f1=-f2. Then, the first filtering unit 47 filters the first mixed signal to obtain a first sub-signal in the first mixed signal, and the center frequency of the first sub-signal is f2. After filtering by the first filtering unit 47, the spectrum near f0+f1 and near-f0-f1 in the first mixed signal is filtered out. At this time, the spectrum obtained by filtering includes the spectrum near f2 and the spectrum near-f2, and the spectrum near f2 is consistent with the spectrum near f2 in the spectrum of the first electromagnetic wave signal, and no conjugate symmetry occurs. Optionally, in order to avoid the spectrum near f2 and the spectrum near-f2 in the spectrum of the first sub-signal aliasing, f1f0-F / 2, that is, f2F / 2.

[0296] The target third node performs target processing on the first electromagnetic wave signal. The frequency multiplication unit 43 can obtain a frequency multiplication signal of the second local oscillation electromagnetic wave signal, and the center frequency of the frequency multiplication signal is twice the center frequency f2 (that is, 2f2). Then, the second mixing unit 45 mixes the first sub-signal obtained by the first filtering unit 47 with the frequency multiplication signal to obtain a second mixed signal. The spectrum of the second mixed signal includes the spectrum near 2f2+f2=3f2, the spectrum near f2-2f2=-f2, the spectrum near-f2+2f2=f2, and the spectrum near-f2-2f2=-3f2. At this time, the part of the negative half-axis in the spectrum of the first sub-signal is moved from near-f2 to near f2 on the positive half-axis and near-3f2 on the negative half-axis, and the part of the positive half-axis in the spectrum of the first sub-signal is moved from near the center frequency f2 to near 3f2 and near-f2 on the negative half-axis. Then, the second filtering unit 48 filters the second mixed signal to filter out the spectrum near 3f2 and -3f2 in the second mixed signal to obtain a second sub-signal in the second mixed signal, and the spectrum of the second sub-signal includes the spectrum near f2 and the spectrum near-f2. Finally, the third mixing unit 48 mixes the second sub-signal with the first local oscillation electromagnetic wave signal to obtain a second electromagnetic wave signal.

[0297] (5) Mode 5: When the target third node performs target processing on the first electromagnetic wave signal, the target third node can perform parametric amplification on the first electromagnetic wave signal to obtain a second electromagnetic wave signal. It should be noted that when the target third node performs target processing on the first electromagnetic wave signal in mode 5, the processing mode of the target third node is various.

[0298] (5.1) In the first optional processing mode, as shown in FIG. 5, the target third node can include a signal source unit 51, a first filter unit 52, a second filter unit 53, a third filter unit 54, and a nonlinear unit 55; the signal source unit 51 is configured to provide a local electromagnetic wave signal; the signal source unit 51 is connected with the second filter unit 53, and the first filter unit 52, the second filter unit 53, and the third filter unit 54 are all connected with the nonlinear unit 55. The nonlinear unit 55 can be a varactor diode or a Josephson junction. Figure 37

[0299] When the target third node performs parametric amplification on the first electromagnetic wave signal, the first filter unit 52 filters the first electromagnetic wave signal to obtain a first filtered signal, and the center frequency of the first filtered signal is the center frequency f0 of the first electromagnetic wave signal; at the same time, the second filter unit 53 filters the local electromagnetic wave signal to obtain a second filtered signal, and the center frequency of the second filtered signal is f p ; then, the nonlinear unit 55 can perform parametric amplification on the first filtered signal according to the second filtered signal to obtain a parametric amplification signal. The third filter unit 54 can filter the parametric amplification signal to obtain a second electromagnetic wave signal; wherein the center frequency of the second electromagnetic wave signal is Mf p +Nf0, M and N are both non-zero integers, and N is less than zero, Mf p +Nf0 = f0.

[0300] It should be noted that the second filtered signal obtained by filtering the local electromagnetic wave signal generated by the signal source unit 51 through the second filter unit 53 serves as a pump signal, and together with the first filtered signal obtained by filtering the first electromagnetic wave signal (with a center frequency of f0) input into the target third node through the first filter unit 52, acts on the nonlinear unit 55. The nonlinear unit 55 has a nonlinear effect under the action of the pump signal, and the nonlinear unit 55 will transfer the energy in the pump signal to the output parametric amplification signal to achieve parametric amplification. The nonlinear unit 55 can generate a parametric amplification signal at any frequency point of Af p +Bf0 (A and B are both non-zero integers), at this time, the third filter unit 54 can filter the parametric amplification signal output by the nonlinear unit 55 to obtain a second electromagnetic wave signal with a center frequency of Mf p +Nf0. In order to realize the frequency spectrum of the second electromagnetic wave signal being conjugate symmetric to the frequency spectrum of the first electromagnetic wave signal, N needs to be selected as a negative integer. For example, M = 2, N = -1, at this time, the center frequency of the second electromagnetic wave signal is 2f p -f0, and f p may be a frequency close to f0; when f p ​When the frequency is similar to 2f0, M = 1 and N = -1 can also be chosen. In this case, the center frequency of the second electromagnetic wave signal is f. p -f0=f0.

[0301] Furthermore, since the target third node parametrically amplifies the first electromagnetic wave signal during target processing, the power of the second electromagnetic wave signal can also be increased, thereby reducing the transmission loss of the electromagnetic wave signal on the cable.

[0302] (5.2) In the second alternative processing method, such as Figure 38 As shown, the target third node includes: a signal source unit 61, a connection unit 62, a first filter unit 63, a second filter unit 64, and a nonlinear unit 65; the connection unit 62 has a first end 621, a second end 622, and a third end 623, the first end 621 is connected to a first neighboring node, the second end 622 is connected to a second neighboring node, and the third end 623 is connected to one end of the first filter unit 63; the connection unit 62 is used to transmit the signal input from the first end 621 to the third end 623, and to transmit the signal input from the third end 623 to the second end 622; the other end of the first filter unit 63 and the second filter unit 64 are both connected to the nonlinear unit 65; the signal source unit 61 is connected to the second filter unit 64, and the signal source unit 61 is used to provide a local oscillator electromagnetic wave signal;

[0303] When the target third node parametrically amplifies the first electromagnetic wave signal, the first electromagnetic wave signal from the first neighboring node is input to the first terminal 621 of the connection unit 62. The connection unit 62 then transmits the first electromagnetic wave signal to the third terminal 623, which in turn inputs to one end of the first filtering unit 63. The first filtering unit 63 filters the first electromagnetic wave signal input from one end to obtain a first filtered signal, and outputs the first filtered signal from the other end of the first filtering unit 63. The center frequency of the first filtered signal is the center frequency f0 of the first electromagnetic wave signal. Simultaneously, the second filtering unit 64 filters the local oscillator electromagnetic wave signal to obtain a second filtered signal. The center frequency of the second filtered signal is f0. p Subsequently, the nonlinear unit 65 parametrically amplifies the first filtered signal according to the second filtered signal to obtain a parametric amplified signal. This parametric amplified signal is then sent to the other end of the first filtering unit 63, which filters it to obtain a second electromagnetic wave signal and outputs it from one end of the first filtering unit 63. The second electromagnetic wave signal output from one end of the first filtering unit 63 is then input to the third end 623 of the connecting unit 62 and transmitted by the connecting unit 62 to the second end 622, and then to the second neighboring node. The center frequency of the second electromagnetic wave signal is Mf. p +Nf0,Mfp +Nf0=f0, M and N are both non-zero integers, and N is less than zero.

[0304] In the second optional processing manner, filtering the parametric amplification signal to obtain the second electromagnetic wave signal, and filtering the first electromagnetic wave signal to obtain the first filtered signal are both implemented on the first filtering unit, and the second electromagnetic wave signal and the first filtered signal are separated by the connection unit (such as a circulator or the like) through different signal paths.

[0305] Optionally, in the embodiment of the present application, the target third node can further amplify the first electromagnetic wave signal with low noise before performing the target processing on the first electromagnetic wave signal, so as to improve the quality of the first electromagnetic wave signal. For example, referring to any one of the drawings in Figure 29 , Figure 33 to Figure 36 , the target third node can further include a low noise amplifier (LNA) for amplifying the first electromagnetic wave signal with low noise. For example, in Figure 29 , the LNA is connected with the first mixing unit 04 and the second mixing unit 05 in the frequency down-conversion module, and the LNA inputs the first electromagnetic wave signal amplified with low noise into the frequency down-conversion module after amplifying the first electromagnetic wave signal with low noise, so as to facilitate the frequency down-conversion module to perform frequency down-conversion on the first electromagnetic wave signal amplified with low noise.

[0306] Optionally, in the embodiment of the present application, the target third node can further amplify the second electromagnetic wave signal with power after performing the target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal, and before sending the second electromagnetic wave signal to the second adjacent node, so as to improve the power of the second electromagnetic wave signal, thereby reducing the transmission loss of the electromagnetic wave signal on the cable. For example, referring to any one of the drawings in Figure 29 , Figure 33 to Figure 36 , the target third node can further include a power amplifier (PA) for amplifying the second electromagnetic wave signal with power.

[0307] In addition, the part of the target third node for performing the above target processing can be a spectrum processing unit. When the target third node includes the PA and the LNA, as shown in Figure 39 , the LNA, the spectrum processing unit and the PA can be connected in sequence.

[0308] According to the function of the target third node provided in the embodiment of the present application, the target third node does not need to perform the target processing on the first electromagnetic wave signal as Figure 9The complex signal processing performed by the fourth node is shown, and therefore, the power consumption, delay and implementation complexity of the target third node are low, which is suitable for large-scale deployment in the case of high-speed communication between the first node and the second node, and can greatly expand the transmission length of the first node and the second node in the communication system.

[0309] The module for performing the above target processing in the target third node can be referred to as a target processing module, and at this time, each unit for implementing the target processing in the above mode 1 to mode 5 belongs to the target processing module. The target third node can also include other modules, such as a receiving module for receiving the first electromagnetic wave signal sent by the first neighbor node, and a sending module for sending the second electromagnetic wave signal to the second neighbor node, which will not be described here.

[0310] Further, in the communication system provided by the embodiment of the present application, at least one third node (one third node or multiple third nodes) can be arranged on the cable between the first node and the second node, and each third node can have the function of the above target third node. The cable is divided into multiple cable segments by the first node, the at least one third node and the second node. The cable segment between the 2n+1th node and the 2n+2th node among the first node, the at least one third node and the second node is referred to as a first cable segment, and n≥0; the cable segment between the 2n+2th node and the 2n+3th node among the first node, the at least one third node and the second node is referred to as a second cable segment. For example, as shown in the figure, assuming that three third nodes are arranged on the cable, the cable segment between the first node and the first third node is the first cable segment, the cable segment between the first third node and the second third node is the second cable segment, the cable segment between the second third node and the third third node is the first cable segment, and the cable segment between the third third node and the fourth third node is the second cable segment. Figure 40

[0311] The lengths of the cable segments in the cable satisfy certain constraint conditions.

[0312] For example, the lengths of the cable segments in the cable satisfy a first constraint condition: the absolute value of the difference between the sum of the lengths of the first cable segments and the sum of the lengths of the second cable segments in the cable is less than a first length.

[0313] ​The first length is the minimum of a frequency-selective fading transmission length and a dispersion transmission length. The maximum fading amplitude in the fading amplitudes of the respective frequencies in the electromagnetic wave signal emitted by the first node after the frequency-selective fading transmission length is transmitted in the cable is a maximum fading amplitude that can be processed by the second node. The frequency-selective fading transmission length can be a quotient of the maximum fading amplitude and a unit fading amplitude in the cable, where the unit fading amplitude is a maximum fading amplitude in the fading amplitudes of the respective frequencies in the electromagnetic wave signal emitted by the first node when transmitted in a unit length of the cable segment in the cable. The dispersion of the electromagnetic wave signal emitted by the first node after the dispersion transmission length is transmitted in the cable is a maximum dispersion that can be processed by the second node. The dispersion transmission length can be a quotient of the maximum dispersion and a dispersion amount of a unit length of the cable segment in the cable.

[0314] When the first length is the minimum of the frequency-selective fading transmission length and the dispersion transmission length, the absolute value of the difference between the sum of the lengths of the first cable segments and the sum of the lengths of the second cable segments in the cable is less than the minimum, which can ensure that the frequency-selective fading and the group delay dispersion of the electromagnetic wave signal received by the second node are both small.

[0315] For another example, the lengths of the respective cable segments in the cable satisfy a second constraint condition: the length of the cable segment between any two adjacent nodes in the cable is less than or equal to a second length, which is a maximum length that the electromagnetic wave signal emitted by the first node can be transmitted.

[0316] The maximum length that the electromagnetic wave signal emitted by the first node can be transmitted is a maximum length that the electromagnetic wave signal emitted by the first node can be effectively received by the second node when there is no any node between the first node and the second node. The maximum length is determined by the transmission loss of the electromagnetic wave signal transmitted in the cable, the power of the electromagnetic wave signal emitted by the first node, and the sensitivity of the second node to receive the electromagnetic wave signal, and the like. When the length of the cable segment between the any two adjacent nodes is less than or equal to the maximum length that the electromagnetic wave signal emitted by the first node can be transmitted, it can be ensured that the electromagnetic wave signal can be effectively transmitted between the cable segments.

[0317] For example, as Figure 41As shown, assume the transmission length (i.e., cable length) between the first and second nodes is 30 meters (m), and the second length is 8 meters. The second node uses a self-mixing demodulation architecture, with a frequency-selective fading transmission length of 3 meters, a dispersion transmission length of 2 meters, and a first length of 2 meters. Therefore, the total cable length is 30 meters, with the first cable segment being 8 meters long and the second cable segment being 6 meters long. Both the lengths of the first and second cable segments are less than or equal to the second length of 8 meters. Furthermore, the absolute value (2 meters) of the difference between the sum of the lengths of the first cable segments (16 meters) and the sum of the lengths of the second cable segments (14 meters) is less than or equal to the first length (2 meters). Therefore, both the first and second constraints are satisfied.

[0318] Furthermore, based on the first and second constraints mentioned above, the number of third nodes on the cable should be minimized. However, when the transmission length between the first and second nodes is a certain length, a simple arrangement of third nodes (such as distributing the cable segments as evenly as possible) may result in a large absolute value of the difference between the sum of the lengths of the first and second cable segments, causing the first constraint to be unsatisfactory. In this case, adding third nodes can satisfy the first constraint.

[0319] For example, such as Figure 42 As shown, assume the transmission length between the first and second nodes is 23m, and the second length is 8m. The second node uses a self-mixing demodulation architecture with a frequency-selective fading transmission length of 3m, a dispersion transmission length of 2m, and a first length of 2m. Therefore, the total cable length is 23m. If the length of the first cable segment is 8m and the length of the second cable segment is 7m, then both the lengths of the first and second cable segments are less than or equal to the second length of 8m, satisfying the second constraint. However, the absolute value of the difference between the sum of the lengths of the first cable segments (15m) and the sum of the lengths of the second cable segments (8m) (7m) does not meet the requirement of being less than or equal to the first length (2m), thus the first constraint is not satisfied. Furthermore, since the length of each cable segment is close to the second length of 8m, it is difficult to make large-scale adjustments to the position of the third node.

[0320] At this point, a third node can be added to the cable, and then the length of the cable segment can be distributed as evenly as possible. Figure 43As shown, the total length of the cable is 23m. The length of the first cable segment in the cable is 6m, the length of one second cable segment is 7m, and the length of another second cable segment is 5m. At this time, the length of the first cable segment and the length of the second cable segment are both less than or equal to the second length 8m. And the absolute value of the difference between the sum of the lengths of the first cable segment (12m) and the sum of the lengths of the second cable segment (11m) (1m) is less than or equal to the first length (2m). It can be seen that both the first constraint condition and the second constraint condition are satisfied.

[0321] Further, at least one fourth node can also be arranged on the cable; the fourth node is used for power amplification of the electromagnetic wave signal transmitted on the cable. When the transmission length between the first node and the second node is relatively long and the number of third nodes is relatively large, the fourth node can also be arranged on one or more cable segments in the embodiment of the application, so that the fourth node performs power amplification on the electromagnetic wave signal transmitted on the cable, ensures that the power of the electromagnetic wave signal received by the second node is relatively high, and reduces the transmission loss of the electromagnetic wave signal.

[0322] For example, as shown in Figure 44 , it is assumed that the transmission length between the first node and the second node is 36m, and the second length is 8m. The second node adopts a coherent demodulation architecture, the frequency selective fading transmission length is 5m, the chromatic dispersion transmission length is 4m, and the first length is 4m. Therefore, the total length of the cable is 36m. Two third nodes are arranged on the cable, the cable segment between the first node and the first third node is the first first cable segment, the cable segment between the second third node and the second node is the second first cable segment, and the cable segment between the two third nodes is the second cable segment. A fourth node can be arranged on the first first cable segment, and a fourth node can be arranged on the second cable segment. The first cable segment includes a third cable segment and a fourth cable segment, and the second cable segment includes a fifth cable segment and a sixth cable segment.

[0323] The length of the first first cable segment is 16m, the length of the second first cable segment is 4m, and the length of the second cable segment is 16m. At this time, the absolute value of the difference between the sum of the lengths of the first cable segment (20m) and the sum of the lengths of the second cable segment (16m) (4m) is less than or equal to the first length (4m), satisfying the first constraint condition. And the length of each cable segment in the cable is less than or equal to the second length (8m), satisfying the second constraint condition.

[0324] The fourth node has the function of the fourth node shown in Figure 8 as an example. Alternatively, the fourth node can also have the function of the fourth node shown in Figure 9 ; or, part of the fourth nodes have the function of the fourth node shown in Figure 8 , and the other part of the fourth nodes have the function of the fourth node shown in Figure 9The fourth node shown has no limitation in the embodiments of the present application.

[0325] The embodiments of the present application also provide a second node, which can be a second node in the communication system. The second node is configured to receive an electromagnetic wave signal transmitted by a third node, and determine data carried by the electromagnetic wave signal transmitted by the first node according to the electromagnetic wave signal. The electromagnetic wave signal received by the second node can be a second electromagnetic wave signal obtained by target processing of the third node.

[0326] Further, in the embodiments of the present application, the target third node performs processing on the received first electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal in the process of target processing. Therefore, when there are an even number of third nodes on the cable, and each third node has the function of the target third node, the even number of third nodes can be divided into groups of third nodes arranged in sequence in the direction from the first node to the second node, and each group of third nodes includes two third nodes. After the target processing of the two third nodes, the spectrum of the electromagnetic wave signal will not be conjugate inverted, and thus the electromagnetic wave signal received by the second node will not be conjugate inverted relative to the spectrum of the electromagnetic wave signal transmitted by the first node.

[0327] However, when there are an odd number of third nodes on the cable, and each third node has the function of the target third node, the odd number of third nodes can be divided into groups of third nodes arranged in sequence in the direction from the first node to the second node, and one third node, and each group of third nodes includes two third nodes. After the target processing of the two third nodes, the spectrum of the electromagnetic wave signal will not be conjugate inverted. However, after the processing of the last third node, the spectrum of the electromagnetic wave signal will be conjugate inverted, and thus the electromagnetic wave signal received by the second node will be conjugate inverted relative to the spectrum of the electromagnetic wave signal transmitted by the first node. Therefore, when there are an odd number of third nodes on the cable, the second node needs to perform processing on the received electromagnetic wave signal for conjugate inversion of the spectrum of the electromagnetic wave signal.

[0328] For example, when an odd number of third nodes are provided on the cable, the second node can first process the received electromagnetic wave signal to obtain the electromagnetic wave signal emitted by the first node, then obtain the baseband signal of the electromagnetic wave signal emitted by the first node, and perform constellation mapping according to the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node when determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal. The process of processing the received electromagnetic wave signal by the second node to obtain the electromagnetic wave signal emitted by the first node is the same as the process of processing the first electromagnetic wave signal by the target third node to obtain the second electromagnetic wave signal, and the embodiments of the present application will not be repeated here.

[0329] For example, when an odd number of third nodes are provided on the cable, the second node can first obtain the second baseband signal of the received electromagnetic wave signal, the second baseband signal including a real part signal and an imaginary part signal; then, the second node can obtain the first baseband signal according to the second baseband signal, the first baseband signal being conjugate to the second baseband signal; finally, the second node can perform constellation mapping according to the first baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node when determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0330] When an even number of third nodes are provided on the cable, the second node can directly obtain the baseband signal of the received electromagnetic wave signal, and perform constellation mapping according to the real part signal and the imaginary part signal in the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

[0331] In addition, if the second electromagnetic wave signal is different from the conjugate inverted signal, the second node can compensate for the difference before determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal, so as to reduce the difference.

[0332] For example, if the amplitude-frequency curve of the second electromagnetic wave signal moves x units to the left along the horizontal coordinate axis of the amplitude-frequency coordinate system relative to the amplitude-frequency curve of the conjugate inverted signal, and y third nodes are provided on the cable, the compensation for the difference causes the amplitude-frequency curve of the electromagnetic wave signal received by the second node to move x*y units to the right along the horizontal coordinate axis of the amplitude-frequency coordinate system, and x and y are greater than or equal to 1.

[0333] For example, if the phase-frequency curve of the second electromagnetic wave signal moves x units to the left along the horizontal coordinate axis of the phase-frequency coordinate system relative to the phase-frequency curve of the conjugate inverted signal, and y third nodes are provided on the cable, the compensation for the difference causes the phase-frequency curve of the electromagnetic wave signal received by the second node to move x*y units to the right along the horizontal coordinate axis of the phase-frequency coordinate system.

[0334] For example, if the phase-frequency curve of the second electromagnetic wave signal moves x units upward along the longitudinal coordinate axis of the phase-frequency coordinate system relative to the phase-frequency curve of the conjugate inverted signal, and y third nodes are arranged on the cable, the different compensation causes the phase-frequency curve of the electromagnetic wave signal received by the second node to move x*y units downward along the longitudinal coordinate axis.

[0335] For example, if the left end point of the phase-frequency curve of the second electromagnetic wave signal moves x units upward along the longitudinal coordinate axis of the phase-frequency coordinate system relative to the left end point of the phase-frequency curve of the conjugate inverted signal, and the right end point of the phase-frequency curve of the second electromagnetic wave signal moves z units downward along the longitudinal coordinate axis of the phase-frequency coordinate system relative to the right end point of the phase-frequency curve of the conjugate inverted signal, and y third nodes are arranged on the cable, the different compensation causes the left end point of the phase-frequency curve of the electromagnetic wave signal received by the second node to move x*y units downward along the longitudinal coordinate axis, and the right end point to move z*y units upward along the longitudinal coordinate axis.

[0336] The module for determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal in the second node can be referred to as a determination module. The second node can further include other modules, such as a receiving module for receiving the electromagnetic wave signal sent by the adjacent third node. The second node can further include a compensation module for compensating for the above-mentioned difference.

[0337] The functions of the communication system provided by the embodiments of the present application will be further described below in combination with the communication method provided by the embodiments of the present application.

[0338] For example, Figure 45 A flowchart of a communication method provided by the embodiments of the present application is shown in FIG. 1. The method can be used in the communication system provided by the embodiments of the present application. As shown in FIG. 1, the communication method includes the following steps. Figure 45

[0339] S101, the first adjacent node sends a first electromagnetic wave signal to the target third node.

[0340] The first adjacent node can be the first node. The first node can modulate the first electromagnetic wave signal according to the data to be sent to the second node, and transmit the first electromagnetic wave signal to the cable between the first node and the second node. In this way, the target third node on the cable can receive the first electromagnetic wave signal, and the first electromagnetic wave signal carries the data to be sent by the first node to the second node.

[0341] The first adjacent node can also be another third node between the first node and the target third node. At this time, the first electromagnetic wave signal emitted by the first adjacent node can be a second electromagnetic wave signal obtained by the first adjacent node by performing target processing on the received electromagnetic wave signal. ​

[0342] S102, the target third node low-noise amplifies the first electromagnetic wave signal.

[0343] The explanation of the target third node low-noise amplifying the first electromagnetic wave signal can refer to the related explanation in the foregoing embodiments, and will not be described here in detail.

[0344] S103, the target third node performs target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal; wherein the target processing includes processing for conjugate inversion of the frequency spectrum of the electromagnetic wave signal.

[0345] The explanation of the target processing performed by the target third node on the first electromagnetic wave signal can refer to the related explanation in the foregoing embodiments, and will not be described here in detail.

[0346] S104, the target third node power amplifies the second electromagnetic wave signal.

[0347] The explanation of the target third node power amplifying the second electromagnetic wave signal can refer to the related explanation in the foregoing embodiments, and will not be described here in detail.

[0348] S105, the target third node sends the second electromagnetic wave signal to the second adjacent node.

[0349] The target third node can deliver the second electromagnetic wave signal to the cable to send the second electromagnetic wave signal to the second adjacent node.

[0350] When the second adjacent node is the second node, the second node can also determine the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal.

[0351] The process of the second node determining the data carried by the electromagnetic wave signal emitted by the first node according to the received electromagnetic wave signal can refer to the related process in the foregoing embodiments, and will not be described here in detail.

[0352] Optionally, after receiving the first electromagnetic wave signal, the target third node can also not need to low-noise amplify the first electromagnetic wave signal. Before sending the second electromagnetic wave signal, the target third node can also not need to power amplify the second electromagnetic wave signal.

[0353] Optionally, at least one fourth node can also be arranged on the cable between the first node and the second node; the fourth node is configured to power amplify the electromagnetic wave signal transmitted on the cable.

[0354] To sum up, in the communication method provided by the embodiment of the application, the electromagnetic wave signal will occur the first distortion in the process of being transmitted from the first adjacent node to the target third node, and the electromagnetic wave signal will occur the third distortion in the process of being transmitted from the target third node to the second adjacent node, and the third distortion is similar to the first distortion. The target processing performed by the target second node on the received first electromagnetic wave signal includes processing for performing conjugate inversion on the spectrum of the electromagnetic wave signal, so that the second electromagnetic wave signal obtained by the target third node performing the target processing on the first electromagnetic wave will occur the second distortion opposite to the first distortion of the signal emitted by the first adjacent node. In the process of transmitting the electromagnetic wave signal from the target third node to the second adjacent node, the electromagnetic wave signal occurs the third distortion. Under the action of the second distortion and the third distortion, the distortion of the electromagnetic wave signal received by the second adjacent node relative to the electromagnetic wave signal emitted by the first adjacent node is reduced, the communication quality between the first adjacent node and the second adjacent node is ensured, and then the communication quality between the first node and the second node is ensured.

[0355] In addition, when the target third node performs the processing for performing conjugate inversion on the spectrum of the electromagnetic wave signal on the first electromagnetic wave signal, the target third node does not need to restore the original electromagnetic wave signal emitted by the first node, so that the complexity of the target third node is low.

[0356] The sequence of the method embodiments provided by the embodiment of the application can be adjusted appropriately, and the operations can also be increased or decreased according to the situation. For example, at least one of S102 and S104 described above can not be executed. Any person skilled in the art can easily think of changes within the technical range disclosed in the application, which should be covered within the protection scope of the application, and therefore will not be described again.

[0357] In the application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. The term "at least one" means one or more, and "multiple" means two or more, unless otherwise explicitly limited.

[0358] The different types of embodiments such as the method embodiments and the device embodiments provided by the embodiment of the application can be mutually referred to, and the embodiment of the application does not limit this.

[0359] In the corresponding embodiments provided by the application, it should be understood that the disclosed system and device can be realized by other constitutions. For example, the device embodiments described above are only schematic. The parts described as separate components can or can not be physically separate. Some or all of them can be selected to achieve the purpose of the embodiment of the application according to actual needs.

[0360] The above merely provides the optional embodiments of the present application, but the protection scope of the present application is not limited thereto, and any modification or replacement within the technical range disclosed by the present application can be easily thought by those skilled in the art, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method, characterized in that, The method is executed by a target third node between a first node and a second node; the first node and the second node are connected by a cable, and at least one third node is provided on the cable, the target third node being one of the at least one third node; the method includes: Receives a first electromagnetic wave signal sent by a first neighboring node, wherein the target third node is adjacent to the first neighboring node and the second neighboring node among the first node, the second node and the at least one third node; The first electromagnetic wave signal is subjected to target processing to obtain a second electromagnetic wave signal. The target processing includes: processing to cause the spectrum of the electromagnetic wave signal to undergo conjugate inversion. The second electromagnetic wave signal is sent to the second neighboring node.

2. The method according to claim 1, characterized in that, The amplitude-frequency curves of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum are symmetrical about the target straight line axis; the phase-frequency curves of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum are symmetrical about the center of the target point. Wherein, the target straight line is perpendicular to the horizontal axis of the coordinate system where the amplitude-frequency curve is located, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal axis of the coordinate system where the phase-frequency curve is located that corresponds to the center frequency.

3. The method according to claim 1 or 2, characterized in that, The second electromagnetic wave signal is different from the conjugate inversion signal; The amplitude-frequency curve of the conjugate inverted signal is symmetrical to the amplitude-frequency curve of the first electromagnetic wave signal about the target straight line axis; The phase frequency curve of the conjugate inverted signal is symmetrical to the phase frequency curve of the first electromagnetic wave signal about the center of the target point; Wherein, the target straight line is perpendicular to the horizontal axis of the coordinate system where the amplitude-frequency curve is located, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal axis of the coordinate system where the phase-frequency curve is located that corresponds to the center frequency.

4. The method according to claim 3, characterized in that, In the amplitude-frequency curve of the conjugate inverted signal, the sum of the first amplitude and the sum of the second amplitude have a target magnitude relationship; wherein, the first amplitude is the amplitude corresponding to the first frequency, and the second amplitude is the amplitude corresponding to the second frequency; the first frequency is less than the center frequency of the conjugate inverted signal, and the second frequency is greater than the center frequency of the conjugate inverted signal; In the amplitude-frequency curve of the second electromagnetic wave signal, the sum of the third amplitude and the sum of the fourth amplitude have the target magnitude relationship; wherein, the third amplitude is the amplitude corresponding to the third frequency, and the fourth amplitude is the amplitude corresponding to the fourth frequency; the third frequency is less than the center frequency of the second electromagnetic wave signal, and the fourth frequency is greater than the center frequency of the second electromagnetic wave signal.

5. The method according to claim 3, characterized in that, The variability of the phase corresponding to any frequency in the additional phase-frequency curve is less than 40%. The additional phase frequency curve is the curve obtained by subtracting the reference phase frequency curve from the phase frequency curve of the second electromagnetic wave signal; the center frequency of the reference phase frequency curve is the same as the center frequency of the second electromagnetic wave signal; when the center frequency of the conjugate inverted signal is the same as the center frequency of the second electromagnetic wave signal, the reference phase frequency curve is the phase frequency curve of the conjugate inverted signal; when the center frequency of the conjugate inverted signal is different from the center frequency of the second electromagnetic wave signal, the reference phase frequency curve is the phase frequency curve of the conjugate inverted signal after shifting along the horizontal axis of the phase frequency curve. The volatility rate is the ratio of the volatile phase to the phase corresponding to any frequency, and the volatile phase is the phase corresponding to any frequency in the normalized additional phase frequency curve. The normalization is used to rotate and move the additional phase frequency curve so that the two endpoints and the target intersection point of the additional phase frequency curve are all moved to the horizontal axis of the additional phase frequency curve, and the target intersection point corresponds to the center frequency of the first electromagnetic wave signal; the target intersection point is the intersection of the line connecting the two endpoints and the reference line, the reference line is perpendicular to the horizontal axis, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal.

6. The method according to claim 3, characterized in that, The second electromagnetic wave signal differs from the conjugate inverted signal in at least one of the following: center frequency, amplitude frequency curve, and phase frequency curve.

7. The method according to claim 3, characterized in that, The target processing also includes auxiliary processing related to the aforementioned differences.

8. The method according to claim 1 or 2, characterized in that, The step of performing target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The first electromagnetic wave signal is down-converted to obtain the first baseband signal; A second baseband signal is obtained based on the first baseband signal, and the second baseband signal is conjugate with the first baseband signal; The second baseband signal is up-converted to obtain the second electromagnetic wave signal.

9. The method according to claim 8, characterized in that, The target third node includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, an inverting unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the third mixing unit, the second mixing unit and the fourth mixing unit are connected through the inverting unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first electromagnetic wave signal is down-converted to obtain a first baseband signal, including: The first mixing unit mixes the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit mixes the first electromagnetic wave signal and the first phase-shifted signal obtained by the first phase-shifting unit to obtain the imaginary part of the first baseband signal; The second baseband signal is obtained based on the first baseband signal, including: The inverting unit inverts the imaginary part signal to obtain the inverted signal of the imaginary part signal, and the second baseband signal includes: the real part signal and the inverted signal; Up-converting the second baseband signal to obtain the second electromagnetic wave signal includes: The third mixing unit mixes the real part signal and the local oscillator electromagnetic wave signal to obtain the first mixing signal; The second phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal; The fourth mixing unit mixes the inverted signal with the first phase-shifted signal obtained by the second phase-shifting unit to obtain a second mixed signal; The combining unit combines the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

10. The method according to claim 1 or 2, characterized in that, The step of performing target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The first electromagnetic wave signal is down-converted to obtain the first baseband signal; The first baseband signal is subjected to conjugate up-conversion to obtain the second electromagnetic wave signal.

11. The method according to claim 10, characterized in that, The target third node includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the third mixing unit, the second mixing unit is connected to the fourth mixing unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first electromagnetic wave signal is down-converted to obtain a first baseband signal, including: The first mixing unit mixes the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit mixes the first electromagnetic wave signal and the first phase-shifting signal to obtain the imaginary part of the first baseband signal; The first baseband signal is subjected to conjugate up-conversion to obtain the second electromagnetic wave signal, including: The third mixing unit mixes the real part signal and the local oscillator electromagnetic wave signal to obtain the first mixing signal; The second phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by -π / 2 to obtain the second phase-shifted signal; The fourth mixing unit mixes the imaginary part signal with the second phase-shifted signal to obtain the second mixed signal; The combining unit combines the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

12. The method according to claim 10, characterized in that, The target third node includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the fourth mixing unit, the second mixing unit is connected to the third mixing unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first electromagnetic wave signal is down-converted to obtain a first baseband signal, including: The first mixing unit mixes the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit mixes the first electromagnetic wave signal and the first phase-shifted signal obtained by the first phase-shifting unit to obtain the imaginary part of the first baseband signal; The first baseband signal is subjected to conjugate up-conversion to obtain the second electromagnetic wave signal, including: The third mixing unit mixes the imaginary part signal with the local oscillator electromagnetic wave signal to obtain the first mixing signal; The second phase-shifting unit shifts the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal; The fourth mixing unit mixes the real part signal with the first phase-shifted signal obtained by the second phase-shifting unit to obtain a second mixed signal; The combining unit combines the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

13. The method according to claim 1 or 2, characterized in that, The step of performing target processing on the first electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The first electromagnetic wave signal is subjected to spectrum shifting to obtain the third electromagnetic wave signal; The third electromagnetic wave signal is filtered to obtain the second electromagnetic wave signal.

14. The method according to claim 13, characterized in that, The target third node includes: a signal source unit, a frequency multiplier unit, a frequency mixer unit, and a filter unit; the signal source unit, the frequency multiplier unit, the frequency mixer unit, and the filter unit are connected in sequence; the signal source unit is used to provide a local oscillator electromagnetic wave signal, and the center frequency of the local oscillator electromagnetic wave signal is the same as the center frequency of the first electromagnetic wave signal; The step of spectrum shifting the first electromagnetic wave signal to obtain the third electromagnetic wave signal includes: The frequency multiplier unit acquires a frequency multiplier signal of the local oscillator electromagnetic wave signal, and the center frequency of the frequency multiplier signal is twice the center frequency of the first electromagnetic wave signal; The mixing unit mixes the first electromagnetic wave signal with the frequency - doubled signal to obtain the third electromagnetic wave signal; Filtering the third electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The filtering unit filters the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

15. The method according to claim 1 or 2, characterized in that, The target third node includes: a first signal source unit, a second signal source unit, a frequency - doubling unit, a first mixing unit, a second mixing unit, a third mixing unit, a first filtering unit, and a second filtering unit; the first mixing unit, the first filtering unit, the second mixing unit, the second filtering unit, and the third mixing unit are connected in sequence; the first signal source unit is connected to the first mixing unit, and the second signal source unit is connected to the second mixing unit through the frequency - doubling unit; the first signal source unit is used to generate a first local oscillator electromagnetic wave signal, and the second signal source unit is used to generate a second local oscillator electromagnetic wave signal; the center frequency of the first local oscillator electromagnetic wave signal is f1, the center frequency of the second local oscillator electromagnetic wave signal is f2, the center frequency of the first electromagnetic wave signal is f0, f1 + f2 = f0, and f1 < f0 - F / 2, where F represents the bandwidth of the first electromagnetic wave signal; Performing target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal includes: The first mixing unit mixes the first electromagnetic wave signal with the first local oscillator electromagnetic wave signal to obtain a first mixed signal; The first filtering unit filters the first mixed signal to obtain a first sub - signal in the first mixed signal, and the center frequency of the first sub - signal is f2; The frequency - doubling unit obtains a frequency - doubled signal of the second local oscillator electromagnetic wave signal, and the center frequency of the frequency - doubled signal is twice that of f2; The second mixing unit mixes the first sub - signal with the frequency - doubled signal to obtain a second mixed signal; The second filtering unit filters the second mixed signal to obtain a second sub - signal in the second mixed signal, and the center frequency of the second sub - signal is f2; The third mixing unit mixes the second sub - signal with the first local oscillator electromagnetic wave signal to obtain the second electromagnetic wave signal.

16. The method according to claim 1 or 2, characterized in that, Performing target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal includes: Performing parametric amplification on the first electromagnetic wave signal to obtain the second electromagnetic wave signal.

17. The method according to claim 16, characterized in that, The target third node includes: a signal source unit, a first filtering unit, a second filtering unit, a third filtering unit, and a nonlinear unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal; the signal source unit is connected to the second filtering unit, and the first filtering unit, the second filtering unit, and the third filtering unit are all connected to the nonlinear unit; Performing parametric amplification on the first electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The first filtering unit filters the first electromagnetic wave signal to obtain a first filtered signal, and the center frequency of the first filtered signal is the center frequency of the first electromagnetic wave signal; The second filtering unit filters the local oscillator electromagnetic wave signal to obtain a second filtered signal; The nonlinear unit parametrically amplifies the first filtered signal according to the second filtered signal to obtain a parametrically amplified signal; The third filtering unit filters the parametric amplified signal to obtain the second electromagnetic wave signal; wherein a center frequency of the second electromagnetic wave signal is Mf p +Nf0, M and N are both non-zero integers, and N is less than zero, f0represents a center frequency of the first electromagnetic wave signal, f p represents a center frequency of the second filtered signal.

18. The method according to claim 16, characterized in that, The target third node includes: a signal source unit, a connection unit, a first filtering unit, a second filtering unit, and a nonlinear unit; the connection unit has a first end, a second end, and a third end, the first end being connected to the first neighboring node, the second end being connected to the second neighboring node, and the third end being connected to one end of the first filtering unit; the connection unit is used to transmit a signal input from the first end to the third end, and to transmit a signal input from the third end to the second end; the other end of the first filtering unit and the second filtering unit are both connected to the nonlinear unit; the signal source unit is connected to the second filtering unit, and the signal source unit is used to provide a local oscillator electromagnetic wave signal; The step of parametrically amplifying the first electromagnetic wave signal to obtain the second electromagnetic wave signal includes: The first filtering unit filters the first electromagnetic wave signal input from one end of the first filtering unit to obtain a first filtered signal, and outputs the first filtered signal from the other end of the first filtering unit. The center frequency of the first filtered signal is the center frequency of the first electromagnetic wave signal. The second filtering unit filters the local oscillator electromagnetic wave signal to obtain a second filtered signal; The nonlinear unit parametrically amplifies the first filtered signal according to the second filtered signal to obtain a parametrically amplified signal; The first filtering unit filters the parametric amplified signal from the nonlinear unit to obtain the second electromagnetic wave signal, and outputs the second electromagnetic wave signal from one end of the first filtering unit; Wherein, the center frequency of the second electromagnetic wave signal is Mf p +Nf0,Mf p +Nf0=f0, where M and N are both non-zero integers, and N is less than zero. f0 represents the center frequency of the first electromagnetic wave signal. p This represents the center frequency of the second filtered signal.

19. A communication device, characterized in that, The communication device is a target third node between the first node and the second node; the first node and the second node are connected by a cable, and at least one third node is provided on the cable, and the target third node is one of the at least one third node; The communication device includes: A receiving module is used to receive a first electromagnetic wave signal sent by a first neighboring node, wherein, among the first node, the second node, and the at least one third node, the target third node is adjacent to the first neighboring node and the second neighboring node. The target processing module is used to perform target processing on the first electromagnetic wave signal to obtain a second electromagnetic wave signal. The target processing includes: processing to cause the spectrum of the electromagnetic wave signal to undergo conjugate inversion. The transmitting module is used to transmit the second electromagnetic wave signal to the second neighboring node.

20. The communication device according to claim 19, characterized in that, The amplitude-frequency curves of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum are symmetrical about the target straight line axis; the phase-frequency curves of the first electromagnetic wave signal before and after the conjugate reversal of the spectrum are symmetrical about the center of the target point. Wherein, the target straight line is perpendicular to the horizontal axis of the coordinate system where the amplitude-frequency curve is located, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal axis of the coordinate system where the phase-frequency curve is located that corresponds to the center frequency.

21. The communication device according to claim 19 or 20, characterized in that, The second electromagnetic wave signal is different from the conjugate inversion signal; The amplitude-frequency curve of the conjugate inverted signal is symmetrical to the amplitude-frequency curve of the first electromagnetic wave signal about the target straight line axis; The phase frequency curve of the conjugate inverted signal is symmetrical to the phase frequency curve of the first electromagnetic wave signal about the center of the target point; Wherein, the target straight line is perpendicular to the horizontal axis of the coordinate system where the amplitude-frequency curve is located, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal; the target point is the point on the horizontal axis of the coordinate system where the phase-frequency curve is located that corresponds to the center frequency.

22. The communication device according to claim 21, characterized in that, In the amplitude-frequency curve of the conjugate inverted signal, the sum of the first amplitude and the sum of the second amplitude have a target magnitude relationship; wherein, the first amplitude is the amplitude corresponding to the first frequency, and the second amplitude is the amplitude corresponding to the second frequency; the first frequency is less than the center frequency of the conjugate inverted signal, and the second frequency is greater than the center frequency of the conjugate inverted signal; In the amplitude-frequency curve of the second electromagnetic wave signal, the sum of the third amplitude and the sum of the fourth amplitude have the target magnitude relationship; wherein, the third amplitude is the amplitude corresponding to the third frequency, and the fourth amplitude is the amplitude corresponding to the fourth frequency; the third frequency is less than the center frequency of the second electromagnetic wave signal, and the fourth frequency is greater than the center frequency of the second electromagnetic wave signal.

23. The communication device according to claim 21, characterized in that, The variability of the phase corresponding to any frequency in the additional phase-frequency curve is less than 40%. The additional phase frequency curve is the curve obtained by subtracting the reference phase frequency curve from the phase frequency curve of the second electromagnetic wave signal; the center frequency of the reference phase frequency curve is the same as the center frequency of the second electromagnetic wave signal; when the center frequency of the conjugate inverted signal is the same as the center frequency of the second electromagnetic wave signal, the reference phase frequency curve is the phase frequency curve of the conjugate inverted signal; when the center frequency of the conjugate inverted signal is different from the center frequency of the second electromagnetic wave signal, the reference phase frequency curve is the phase frequency curve of the conjugate inverted signal after shifting along the horizontal axis of the phase frequency curve. The volatility rate is the ratio of the volatile phase to the phase corresponding to any frequency, and the volatile phase is the phase corresponding to any frequency in the normalized additional phase frequency curve. The normalization is used to rotate and move the additional phase frequency curve so that the two endpoints and the target intersection point of the additional phase frequency curve are all moved to the horizontal axis of the additional phase frequency curve, and the target intersection point corresponds to the center frequency of the first electromagnetic wave signal; the target intersection point is the intersection of the line connecting the two endpoints and the reference line, the reference line is perpendicular to the horizontal axis, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal.

24. The communication device according to claim 21, characterized in that, The second electromagnetic wave signal differs from the conjugate inverted signal in at least one of the following: center frequency, amplitude frequency curve, and phase frequency curve.

25. The communication device according to claim 21, characterized in that, The target processing also includes auxiliary processing related to the aforementioned differences.

26. The communication device according to claim 19 or 20, characterized in that, The target processing module is used for: The first electromagnetic wave signal is down-converted to obtain the first baseband signal; A second baseband signal is obtained based on the first baseband signal, and the second baseband signal is conjugate with the first baseband signal; The second baseband signal is up-converted to obtain the second electromagnetic wave signal.

27. The communication device according to claim 26, characterized in that, The target processing module includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, an inverting unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the third mixing unit, the second mixing unit and the fourth mixing unit are connected through the inverting unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first mixing unit is used to mix the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit is used to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit is used to mix the first electromagnetic wave signal and the first phase-shifted signal obtained by the first phase-shifting unit to obtain the imaginary part signal of the first baseband signal; The inverting unit is used to invert the imaginary part signal to obtain the inverted signal of the imaginary part signal, and the second baseband signal includes: the real part signal and the inverted signal; The third mixing unit is used to mix the real part signal and the local oscillator electromagnetic wave signal to obtain a first mixed signal; The second phase-shifting unit is used to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal; The fourth mixing unit is used to mix the inverted signal with the first phase-shifted signal obtained by the second phase-shifting unit to obtain a second mixed signal; The combining unit is used to combine the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

28. The communication device according to claim 19 or 20, characterized in that, The target processing module is used for: The first electromagnetic wave signal is down-converted to obtain the first baseband signal; The first baseband signal is subjected to conjugate up-conversion to obtain the second electromagnetic wave signal.

29. The communication device according to claim 28, characterized in that, The target processing module includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the third mixing unit, the second mixing unit is connected to the fourth mixing unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first mixing unit is used to mix the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit is used to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit is used to mix the first electromagnetic wave signal and the first phase-shifting signal to obtain the imaginary part of the first baseband signal; The third mixing unit is used to mix the real part signal and the local oscillator electromagnetic wave signal to obtain a first mixed signal; The second phase-shifting unit is used to shift the phase of the local oscillator electromagnetic wave signal by -π / 2 to obtain a second phase-shifted signal; The fourth mixing unit is used to mix the imaginary part signal with the second phase-shifted signal to obtain the second mixed signal; The combining unit is used to combine the first mixing signal and the second mixing signal to obtain the second electromagnetic wave signal.

30. The communication device according to claim 28, characterized in that, The target processing module includes: a signal source unit, a first phase shifting unit, a second phase shifting unit, a first mixing unit, a second mixing unit, a third mixing unit, a fourth mixing unit, and a combining unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal, the center frequency of which is the same as the center frequency of the first electromagnetic wave signal; the first phase shifting unit, the second phase shifting unit, the first mixing unit, and the third mixing unit are all connected to the signal source unit, the first phase shifting unit is also connected to the second mixing unit, the second phase shifting unit is also connected to the fourth mixing unit, the first mixing unit is connected to the fourth mixing unit, the second mixing unit is connected to the third mixing unit, and the third mixing unit and the fourth mixing unit are both connected to the combining unit; The first mixing unit is used to mix the first electromagnetic wave signal and the local oscillator electromagnetic wave signal to obtain the real part of the first baseband signal; The first phase-shifting unit is used to shift the phase of the local oscillator electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal, where π represents pi. The second mixing unit is used to mix the first electromagnetic wave signal and the first phase-shifted signal obtained by the first phase-shifting unit to obtain the imaginary part signal of the first baseband signal; The third mixing unit is configured to mix the imaginary part signal with the local electromagnetic wave signal to obtain a first mixed signal; The second phase shifter unit is configured to shift the phase of the local electromagnetic wave signal by π / 2 to obtain the first phase-shifted signal; The fourth mixing unit is configured to mix the real part signal and the first phase-shifted signal obtained by the second phase shifter unit to obtain a second mixed signal; The combining unit is configured to combine the first mixed signal and the second mixed signal to obtain the second electromagnetic wave signal.

31. The communication device according to claim 19 or 20, characterized in that, The target processing module is configured to: Perform spectrum shifting on the first electromagnetic wave signal to obtain a third electromagnetic wave signal; Filter the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

32. The communication device according to claim 31, characterized in that, The target processing module includes: a signal source unit, a frequency doubling unit, a mixing unit, and a filtering unit; the signal source unit, the frequency doubling unit, the mixing unit, and the filtering unit are connected in sequence; the signal source unit is configured to provide a local electromagnetic wave signal, and the center frequency of the local electromagnetic wave signal is the same as the center frequency of the first electromagnetic wave signal; The frequency doubling unit is configured to obtain a frequency-doubled signal of the local electromagnetic wave signal, and the center frequency of the frequency-doubled signal is twice the center frequency of the first electromagnetic wave signal; The mixing unit is configured to mix the first electromagnetic wave signal with the frequency-doubled signal to obtain the third electromagnetic wave signal; The filtering unit is configured to filter the third electromagnetic wave signal to obtain the second electromagnetic wave signal.

33. The communication device according to claim 19 or 20, characterized in that, The target processing module includes: a first signal source unit, a second signal source unit, a frequency doubling unit, a first mixing unit, a second mixing unit, a third mixing unit, a first filtering unit, and a second filtering unit; the first mixing unit, the first filtering unit, the second mixing unit, the second filtering unit, and the third mixing unit are connected in sequence; the first signal source unit is connected to the first mixing unit, and the second signal source unit is connected to the second mixing unit through the frequency doubling unit; the first signal source unit is configured to generate a first local electromagnetic wave signal, and the second signal source unit is configured to generate a second local electromagnetic wave signal; the center frequency of the first local electromagnetic wave signal is f1, the center frequency of the second local electromagnetic wave signal is f2, the center frequency of the first electromagnetic wave signal is f0, f1 + f2 = f0, and f1 < f0 - F / 2, where F represents the bandwidth of the first electromagnetic wave signal; The first mixing unit is configured to mix the first electromagnetic wave signal with the first local electromagnetic wave signal to obtain a first mixed signal; The first filtering unit is configured to filter the first mixed signal to obtain a first sub-signal in the first mixed signal, and the center frequency of the first sub-signal is f2; The frequency doubling unit is configured to obtain a frequency-doubled signal of the second local electromagnetic wave signal, and the center frequency of the frequency-doubled signal is twice f2; The second mixing unit is configured to mix the first sub-signal with the frequency-doubled signal to obtain a second mixed signal; The second filtering unit is used to filter the second mixing signal to obtain a second sub-signal in the second mixing signal, wherein the center frequency of the second sub-signal is f2; The third mixing unit is used to mix the second sub-signal with the first local oscillator electromagnetic wave signal to obtain the second electromagnetic wave signal.

34. The communication device according to claim 19 or 20, characterized in that, The target processing module is used for: The first electromagnetic wave signal is parametrically amplified to obtain the second electromagnetic wave signal.

35. The communication device according to claim 34, characterized in that, The target processing module includes: a signal source unit, a first filtering unit, a second filtering unit, a third filtering unit, and a nonlinear unit; the signal source unit is used to provide a local oscillator electromagnetic wave signal; the signal source unit is connected to the second filtering unit, and the first filtering unit, the second filtering unit, and the third filtering unit are all connected to the nonlinear unit; The first filtering unit is used to filter the first electromagnetic wave signal to obtain a first filtered signal, wherein the center frequency of the first filtered signal is the center frequency of the first electromagnetic wave signal. The second filtering unit is used to filter the local oscillator electromagnetic wave signal to obtain a second filtered signal; The nonlinear unit is used to parametrically amplify the first filtered signal according to the second filtered signal to obtain a parametric amplified signal; The third filtering unit is used to filter the parametric amplified signal to obtain the second electromagnetic wave signal; Wherein, the center frequency of the second electromagnetic wave signal is Mf p +Nf0, where M and N are both non-zero integers, and N is less than zero, f0 represents the center frequency of the first electromagnetic wave signal, f p This represents the center frequency of the second filtered signal.

36. The communication device according to claim 34, characterized in that, The target processing module includes: a signal source unit, a connection unit, a first filtering unit, a second filtering unit, and a nonlinear unit; the connection unit has a first end, a second end, and a third end, the first end being connected to a first neighboring node, the second end being connected to a second neighboring node, and the third end being connected to one end of the first filtering unit; the connection unit is used to transmit a signal input from the first end to the third end, and to transmit a signal input from the third end to the second end; the other end of the first filtering unit and the second filtering unit are both connected to the nonlinear unit; the signal source unit is connected to the second filtering unit, and the signal source unit is used to provide a local oscillator electromagnetic wave signal; The first filtering unit is used to filter the first electromagnetic wave signal input from one end of the first filtering unit to obtain a first filtered signal, and output the first filtered signal from the other end of the first filtering unit. The center frequency of the first filtered signal is the center frequency of the first electromagnetic wave signal. The second filtering unit is used to filter the local oscillator electromagnetic wave signal to obtain a second filtered signal; The nonlinear unit is used to parametrically amplify the first filtered signal according to the second filtered signal to obtain a parametric amplified signal; The first filtering unit is used to filter the parametric amplified signal from the nonlinear unit to obtain the second electromagnetic wave signal, and output the second electromagnetic wave signal from one end of the first filtering unit; Wherein, the center frequency of the second electromagnetic wave signal is Mf p +Nf0,Mf p +Nf0=f0, where M and N are both non-zero integers, and N is less than zero. f0 represents the center frequency of the first electromagnetic wave signal. p This represents the center frequency of the second filtered signal.

37. A chip, characterized in that, The chip includes programmable logic circuitry and / or program instructions; when the chip is running, it is used to implement the communication method as described in any one of claims 1 to 18.

38. A communication system, characterized in that, The communication system includes: a first node, a second node, and at least one third node, wherein the first node and the second node are connected by a cable, and the at least one third node is disposed on the cable; The target third node is one of the at least three nodes, and the target third node is the communication device according to any one of claims 19 to 36, or the target third node includes the chip according to claim 37; The first node is used to send electromagnetic wave signals to the adjacent third node; The second node is used to receive electromagnetic wave signals sent by the adjacent third node, and to obtain the data carried by the electromagnetic wave signals sent by the first node based on the received electromagnetic wave signals.

39. The communication system according to claim 38, characterized in that, The absolute value of the difference between the sum of the lengths of the first cable segment and the sum of the lengths of the second cable segment is less than the first length; The first cable segment is located between the (2n+1)th node and the (2n+2)th node in the first node, the at least one third node, and the second node, where n ≥ 0; The second cable segment is located between the (2n+2)th node and the (2n+3)th node among the first node, the at least one third node, and the second node; The first length is the minimum of the frequency-selective fading transmission length and the dispersion transmission length; after the frequency-selective fading transmission length is transmitted in the cable, the maximum fading amplitude among the fading amplitudes of each frequency in the electromagnetic wave signal emitted by the first node is the maximum fading amplitude that the second node can handle; after the dispersion transmission length is transmitted in the cable, the dispersion of the electromagnetic wave signal emitted by the first node is the maximum dispersion that the second node can handle.

40. The communication system according to claim 38 or 39, characterized in that, The cable is provided with an odd number of the third nodes, and the second node is used for: The received electromagnetic wave signal is processed to obtain the electromagnetic wave signal emitted by the first node; Obtain the baseband signal of the electromagnetic wave signal emitted by the first node; Constellation mapping is performed based on the baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

41. The communication system according to claim 38 or 39, characterized in that, The cable is provided with an odd number of third nodes, and the second node is used for: Acquire the second baseband signal of the received electromagnetic wave signal, the second baseband signal including a real part signal and an imaginary part signal; A first baseband signal is obtained based on the second baseband signal, and the first baseband signal is conjugate with the second baseband signal; Constellation mapping is performed based on the first baseband signal to obtain the data carried by the electromagnetic wave signal emitted by the first node.

42. The communication system according to claim 38 or 39, characterized in that, The second electromagnetic wave signal differs from the conjugate inverted signal. The amplitude-frequency curve of the conjugate inverted signal is symmetrical to the amplitude-frequency curve of the first electromagnetic wave signal about the target straight line axis. The phase-frequency curve of the conjugate inverted signal is symmetrical to the phase-frequency curve of the first electromagnetic wave signal about the center of the target point. The target straight line is perpendicular to the horizontal axis of the coordinate system containing the amplitude-frequency curve, and the frequency corresponding to the intersection point with the horizontal axis is the center frequency of the first electromagnetic wave signal. The target point is the point on the horizontal axis of the coordinate system containing the phase-frequency curve that corresponds to the center frequency. The second node is also used to compensate for the differences before obtaining the data carried by the electromagnetic wave signal emitted by the first node based on the received electromagnetic wave signal.

43. The communication system according to claim 38 or 39, characterized in that, The cable is also provided with at least one fourth node; the fourth node is used to amplify the power of the electromagnetic wave signal transmitted on the cable.

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