Signal compensation method and apparatus, and system

Abstract

A signal compensation method and apparatus, and a system, belonging to the technical field of communications. In the method, after a sending node sends a first test signal of a first polarization state to a first receiving node on a first baseband frequency, on the basis of a sending parameter corresponding to the first polarization state sent by the first receiving node, the sending node compensates a service signal of the first polarization state to be sent. The first baseband frequency is a frequency preset in a subcarrier corresponding to the first receiving node, the first baseband frequency is different from a center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries a real signal and an imaginary signal of the first test signal at different moments; the sending parameter corresponding to the first polarization state sent by the first receiving node represents: an imbalance in the sending node between the real signal and the imaginary signal of the first test signal sent by the sending node. The present application can improve a signal transmission effect, and can be used for signal compensation.

Description

Signal compensation method, device and system

[0001] This application claims priority to Chinese patent application number 202311871960.0, filed on December 29, 2023, entitled “Signal Compensation Method, Device and System,” the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] In the field of communication technology, a sending node can send signals and a receiving node can receive signals. When the sending node and the receiving node are in communication connection, the sending node can transmit signals to the receiving node.

[0004] Typically, a transmitting node can transmit signals of any polarization state, and the real and imaginary parts of the signal of each polarization state are transmitted to the receiving node from different transmission link segments within the transmitting node.

[0005] However, differences between different transmission link segments result in different variations in the signal transmitted on these segments. Because the real and imaginary parts of a signal with any polarization state are transmitted on different transmission link segments, the real and imaginary parts of the signal are transmitted differently on these transmission link segments, affecting the effective transmission of the signal with that polarization state.

[0006] Summary of the Invention

[0007] The present application provides a signal compensation method, device and system, which can solve the problem of ineffective signal transmission. The technical solution provided by the present application is as follows.

[0008] In a first aspect, the present application provides a signal compensation method, in which, after a sending node sends a first test signal of a first polarization state to a first receiving node at a first baseband frequency, the sending node compensates for the service signal of the first polarization state to be sent according to the sending parameters corresponding to the first polarization state sent by the first receiving node. The first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node. The first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times; the sending parameters corresponding to the first polarization state sent by the first receiving node represent: the imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0009] Since in the method provided in the embodiment of the present application, the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times, the signal carried by the first baseband frequency at any time will not be affected by IQ imbalance. Moreover, based on the real signal carried by the first baseband frequency and the imaginary signal carried by the first baseband frequency, the imbalance between the real signal and the imaginary signal of the same polarization state in the sending node can be determined. In this way, the sending node can compensate for the service signal to be sent based on the sending parameters corresponding to the first polarization state that characterizes the imbalance, thereby improving the transmission effect of the service signal.

[0010] In addition, the first receiving node can determine the transmission parameters corresponding to the first polarization state based only on the test signal carried on the corresponding subcarrier. Therefore, the first receiving node does not need to rely on the signal carried on the symmetric subcarrier of the corresponding subcarrier.

[0011] In the above content, an example is taken in which a sending node sends a test signal to a receiving node at a baseband frequency. For example, the sending node sends a first test signal to a first receiving node at a first baseband frequency. It is understandable that the sending node may also send test signals to a receiving node at multiple baseband frequencies. For example, the method further includes: the sending node sends the first test signal to the first receiving node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0012] In this case, the first receiving node can determine two preliminary transmission power parameters based on the signals carried on the two baseband frequencies, and then send the average of the two preliminary transmission powers as the transmission power parameter to the sending node, so that the accuracy of the transmission power parameter sent by the first receiving node to the sending node can be improved.

[0013] Furthermore, the transmitting node transmits a first test signal in a first polarization state to the first receiving node at a first baseband frequency, and the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times. Optionally, the transmitting node may implement the following method to implement the first baseband frequency carrying the real signal and the imaginary signal of the first test signal at different times.

[0014] For example, a sending node may send a second test signal of the first polarization state to a second receiving node on a third baseband frequency, and receive a sending parameter corresponding to the first polarization state sent by the second receiving node, wherein the sending parameter corresponding to the first polarization state sent by the second receiving node represents: an imbalance between the real signal and the imaginary signal of the second test signal in the sending node; wherein the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the sending node; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal respectively at different moments; and at different moments, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate, respectively.

[0015] As another example, the sending node may further send a second test signal in the first polarization state to a second receiving node at a third baseband frequency and a fourth baseband frequency, respectively. Thereafter, the sending node receives a sending parameter corresponding to the first polarization state sent by the second receiving node, where the sending parameter corresponding to the first polarization state sent by the second receiving node represents an imbalance between a real signal and an imaginary signal of the second test signal in the sending node.

[0016] Among them, the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the sending node; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal at different moments respectively; at different moments, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-combined, respectively yoke; the fourth baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the fourth baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the fourth baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugate; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is conjugate.

[0017] Since the conjugate of a real number is equal to the real number, when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the signal carried by the first baseband frequency and the signal carried by the third baseband frequency are both real signals. At this time, the first baseband frequency carries the real signal of the first test signal, and the third baseband frequency carries the real signal of the second test signal; since the anti-conjugate of an imaginary number is equal to the imaginary number, when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the signal carried by the first baseband frequency and the signal carried by the third baseband frequency are both imaginary signals. At this time, the first baseband frequency carries the imaginary signal of the first test signal, and the third baseband frequency carries the imaginary signal of the second test signal.

[0018] Similar to the first receiving node, after receiving the second test signal, the second receiving node can also perform reception compensation on the received second test signal, and then send the transmission parameters corresponding to the first polarization state to the sending node based on the second test signal received by the second receiving node after reception compensation. The transmission parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal sent by the sending node in the sending node. It can be seen that the sending node will receive the transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node respectively, so the sending node will compensate for the service signal of the first polarization state to be sent based on the transmission parameters corresponding to the first polarization state sent by the first receiving node and the transmission parameters corresponding to the first polarization state sent by the second receiving node. For example, the sending node can compensate for the service signal of the first polarization state to be sent based on the average value of the transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node.

[0019] Optionally, the transmission parameters corresponding to the first polarization state include: a transmission power parameter, and the transmission power parameter sent by the first receiving node represents: an imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0020] Optionally, the transmission parameters corresponding to the first polarization state include: at least one of a transmission power parameter and a transmission delay parameter; the transmission power parameter sent by the first receiving node represents: the power imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the transmission delay parameter sent by the first receiving node represents: the delay imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0021] The above description uses the example of a receiving node sending transmission parameters corresponding to the first polarization state to a sending node based on a received test signal in the first polarization state, and the sending node then compensating for the service signal in the first polarization state based on the transmission parameters. Optionally, the sending node may also send a test signal in a second polarization state to the receiving node. The receiving node may also send transmission parameters corresponding to the second polarization state to the sending node based on the received test signal in the second polarization state, and the sending node then compensates for the service signal in the second polarization state based on the transmission parameters.

[0022] For example, the sending node can also send a third test signal of the second polarization state to the first receiving node at the fifth baseband frequency. The first receiving node can perform reception compensation on the received third test signal, and send the transmission parameters corresponding to the second polarization state to the sending node based on the third test signal after reception compensation. The sending node can also compensate for the service signal of the second polarization state to be sent based on the transmission parameters corresponding to the second polarization state. The fifth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node. The fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times; the transmission parameters corresponding to the second polarization state sent by the first receiving node represent: the imbalance of the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node.

[0023] The third test signal is the same as or different from the aforementioned first test signal. In addition, in order to distinguish the first polarization state from the second polarization state, the test signal of the first polarization state and the test signal of the second polarization state need to meet the following conditions: the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node. In other words, the first polarization state and the second polarization state can be distinguished from the sending time and / or the frequency carried by the test signal.

[0024] In second aspect, the present application provides a signal compensation method, which includes: after a first receiving node receives a first test signal of a first polarization state sent by a sending node at a first baseband frequency, the first receiving node performs reception compensation on the received first test signal; thereafter, the first receiving node sends the transmission parameters corresponding to the first polarization state to the sending node based on the first test signal after the reception compensation.

[0025] The first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node. The first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times respectively; the receiving compensation is used to compensate for the imbalance of the real signal and the imaginary signal of any polarization state in the receiving node; the sending parameter corresponding to the first polarization state represents: the imbalance of the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0026] Optionally, before performing reception compensation for the first test signal, the first receiving node may also receive the first test signal sent by the sending node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0027] Optionally, the transmission parameter corresponding to the first polarization state includes: a transmission power parameter, where the transmission power parameter represents an imbalance in power between a real signal and an imaginary signal of the first test signal sent by the sending node in the sending node.

[0028] Optionally, the transmission parameters corresponding to the first polarization state include: at least one of a transmission power parameter and a transmission delay parameter; the transmission power parameter represents: the imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the transmission delay parameter represents: the imbalance in delay between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0029] Optionally, the method also includes: the first receiving node receives a third test signal of the second polarization state sent by the sending node at a fifth baseband frequency; the first receiving node can also perform the receiving compensation on the received third test signal, and send the sending parameters corresponding to the second polarization state to the sending node based on the third test signal after the receiving compensation.

[0030] The fifth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times respectively; the sending parameter corresponding to the second polarization state represents: the imbalance of the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node; wherein the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node.

[0031] In the third aspect, the present application provides a signal compensation device, which belongs to a sending node, and the signal compensation device includes: a first sending module, a first receiving module and a first compensation module. The first sending module is used to send a first test signal of a first polarization state to a first receiving node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times; the first receiving module is used to receive the sending parameters corresponding to the first polarization state sent by the first receiving node, and the sending parameters corresponding to the first polarization state sent by the first receiving node represent: the imbalance of the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the first compensation module is used to compensate for the service signal of the first polarization state to be sent according to the sending parameters corresponding to the first polarization state.

[0032] Optionally, the signal compensation device also includes: a second sending module, used to send the first test signal to the first receiving node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0033] Optionally, the signal compensation device also includes: a third sending module, used to send a second test signal of the first polarization state to a second receiving node on a third baseband frequency; a second receiving module, used to receive the sending parameters corresponding to the first polarization state sent by the second receiving node, and the sending parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal in the sending node; wherein the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the sending node; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal respectively at different times; at different times, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate, respectively.

[0034] Optionally, the signal compensation device also includes: a fourth sending module, used to send a second test signal of the first polarization state to a second receiving node at a third baseband frequency and a fourth baseband frequency, respectively; a third receiving module, used to receive sending parameters corresponding to the first polarization state sent by the second receiving node, and the sending parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal in the sending node.

[0035] Among them, the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the sending node; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal at different moments respectively; at different moments, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-combined, respectively yoke; the fourth baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the fourth baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the fourth baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugate; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is conjugate.

[0036] Optionally, the first compensation module is configured to compensate for a service signal in the first polarization state to be transmitted according to an average value of transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node.

[0037] Optionally, the transmission parameters corresponding to the first polarization state include: a transmission power parameter, and the transmission power parameter sent by the first receiving node represents: an imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0038] Optionally, the transmission parameters corresponding to the first polarization state include: at least one of a transmission power parameter and a transmission delay parameter; the transmission power parameter sent by the first receiving node represents: the power imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the transmission delay parameter sent by the first receiving node represents: the delay imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0039] Optionally, the signal compensation device further includes: a fifth sending module, a fourth receiving module and a second compensation module. A fifth sending module is used to send a third test signal of a second polarization state to the first receiving node at a fifth baseband frequency; the fifth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times; a fourth receiving module is used to receive the sending parameters corresponding to the second polarization state sent by the first receiving node, and the sending parameters corresponding to the second polarization state sent by the first receiving node represent: the imbalance between the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node; a second compensation module is used to compensate for the service signal of the second polarization state to be sent according to the sending parameters corresponding to the second polarization state; wherein the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node.

[0040] In a fourth aspect, the present application provides another signal compensation device, which belongs to the above-mentioned first receiving node, and the signal compensation device includes: a first receiving module, a first compensation module and a first sending module. The first receiving module is used to receive a first test signal of a first polarization state sent by a sending node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times; the first compensation module is used to perform reception compensation on the received first test signal; the reception compensation is used to compensate for the imbalance of the real signal and the imaginary signal of any polarization state in the receiving node; the first sending module is used to send the sending parameter corresponding to the first polarization state to the sending node according to the first test signal after the reception compensation, and the sending parameter corresponding to the first polarization state represents: the imbalance of the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0041] Optionally, the signal compensation device also includes: a second receiving module, used to receive the first test signal sent by the sending node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0042] Optionally, the transmission parameter corresponding to the first polarization state includes: a transmission power parameter, where the transmission power parameter represents an imbalance in power between a real signal and an imaginary signal of the first test signal sent by the sending node in the sending node.

[0043] Optionally, the transmission parameters corresponding to the first polarization state include: at least one of a transmission power parameter and a transmission delay parameter; the transmission power parameter represents: the imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the transmission delay parameter represents: the imbalance in delay between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0044] Optionally, the signal compensation device further includes: a third receiving module, a second compensation module and a second sending module. A third receiving module is used to receive a third test signal of a second polarization state sent by the sending node at a fifth baseband frequency; the fifth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times; a second compensation module is used to perform the reception compensation on the received third test signal; a second sending module is used to send a sending parameter corresponding to the second polarization state to the sending node according to the third test signal after the reception compensation, and the sending parameter corresponding to the second polarization state represents: the imbalance of the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node; wherein the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node.

[0045] In a fifth aspect, the present application provides a signal compensation device, comprising: a transceiver and a processor;

[0046] The transceiver is configured to perform the sending operation and the receiving operation in the signal compensation method described in any design of the first aspect; the processor is configured to perform the operations other than the sending operation and the receiving operation in the signal compensation method described in any design of the first aspect;

[0047] Alternatively, the transceiver is used to perform the sending operations and the receiving operations in the signal compensation method described in any design of the second aspect; the processor is used to perform the operations other than the sending operations and the receiving operations in the signal compensation method described in any design of the second aspect.

[0048] In the sixth aspect, the present application provides a communication system comprising: a sending node and at least one receiving node; the sending node is used to execute the signal compensation method described in any design in the first aspect, and the at least one receiving node includes a first receiving node, and the first receiving node is used to execute the signal compensation method described in any design in the second aspect.

[0049] In the seventh aspect, the present application provides a chip, which includes a programmable logic circuit and / or program instructions, and when the chip is running, it is used to implement the signal compensation method described in any design in the first aspect; or, when the chip is running, it is used to implement the signal compensation method described in any design in the second aspect.

[0050] In an eighth aspect, the present application provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium; when the instructions are executed on a computer, the computer executes the signal compensation method as described in any one of the designs in the first aspect; or, when the instructions are executed on a computer, the computer executes the signal compensation method as described in any one of the designs in the second aspect.

[0051] In a ninth aspect, the present application further provides a computer program product comprising instructions, which, when run on a computer, enables the computer to execute the signal compensation method as described in any design in the first aspect or any design in the second aspect.

[0052] The effects of the second to ninth aspects mentioned above can refer to the effects of the corresponding designs in the first aspect, and this application will not go into details here. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG1 is a schematic diagram of the structure of a communication system provided in an embodiment of the present application;

[0054] FIG2 is a schematic diagram of the structure of a sending link segment and a receiving link segment provided in an embodiment of the present application;

[0055] FIG3 is a schematic diagram of a P2MP coherent network architecture provided in an embodiment of the present application;

[0056] FIG4 is a schematic diagram of a topological structure formed by connecting a sending node and multiple receiving nodes according to an embodiment of the present application;

[0057] FIG5 is a schematic diagram of another topological structure formed by connecting a sending node and multiple receiving nodes according to an embodiment of the present application;

[0058] FIG6 is a schematic diagram of a topological structure formed by connecting a sending node and multiple receiving nodes according to another embodiment of the present application;

[0059] FIG7 is a schematic diagram of crosstalk between mirror subcarriers provided in an embodiment of the present application;

[0060] FIG8 is a flow chart of a signal compensation method provided in an embodiment of the present application;

[0061] FIG9 is a schematic diagram of a first baseband frequency provided in an embodiment of the present application;

[0062] FIG10 is a schematic diagram of a second baseband frequency provided in an embodiment of the present application;

[0063] FIG11 is a schematic diagram of a first test signal provided in an embodiment of the present application;

[0064] FIG12 is a schematic diagram of a process for obtaining a transmit power parameter corresponding to a first polarization state provided in an embodiment of the present application;

[0065] FIG13 is a schematic diagram of a process for obtaining a transmission delay parameter corresponding to a first polarization state provided in an embodiment of the present application;

[0066] FIG14 is a schematic diagram of a third baseband frequency provided in an embodiment of the present application;

[0067] FIG15 is a schematic diagram of a fourth baseband frequency provided in an embodiment of the present application;

[0068] FIG16 is a schematic diagram of a first test signal and a third test signal provided in an embodiment of the present application;

[0069] FIG17 is a schematic diagram of another first test signal and a third test signal provided in an embodiment of the present application;

[0070] FIG18 is a schematic diagram of another first test signal and a third test signal provided in an embodiment of the present application;

[0071] FIG19 is a schematic diagram of a process for obtaining a transmit power parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0072] FIG20 is a schematic diagram of a process for obtaining a transmission delay parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0073] FIG21 is a schematic diagram of another process for obtaining a transmit power parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0074] FIG22 is a schematic diagram of a process for obtaining a transmission delay parameter corresponding to another second polarization state provided in an embodiment of the present application;

[0075] FIG23 is a schematic diagram of a process for obtaining a transmit power parameter corresponding to a first polarization state and a transmit power parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0076] FIG24 is a schematic diagram of a process for obtaining a transmission delay parameter corresponding to a first polarization state and a transmission delay parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0077] FIG25 is a schematic diagram of another process for obtaining a transmit power parameter corresponding to a first polarization state and a transmit power parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0078] FIG26 is a schematic diagram of another process for obtaining a transmission delay parameter corresponding to a first polarization state and a transmission delay parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0079] FIG27 is a schematic diagram of a process for obtaining a received power parameter corresponding to a first polarization state and a received power parameter corresponding to a second polarization state provided by an embodiment of the present application;

[0080] FIG28 is a schematic diagram of a process for obtaining a reception delay parameter corresponding to a first polarization state and a reception delay parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0081] FIG29 is a schematic diagram of another process for obtaining a received power parameter corresponding to a first polarization state and a received power parameter corresponding to a second polarization state provided by an embodiment of the present application;

[0082] FIG30 is a schematic diagram of another process for obtaining a reception delay parameter corresponding to a first polarization state and a reception delay parameter corresponding to a second polarization state provided in an embodiment of the present application;

[0083] FIG31 is a schematic diagram of another first test signal and a third test signal provided in an embodiment of the present application;

[0084] FIG32 is a schematic diagram of a first data frame provided in an embodiment of the present application;

[0085] FIG33 is a schematic diagram of a second data frame and a third data frame provided in an embodiment of the present application;

[0086] FIG34 is a schematic diagram of an effect of a solution provided by an embodiment of the present application;

[0087] FIG35 is a schematic diagram of another solution effect provided by an embodiment of the present application;

[0088] FIG36 is a schematic diagram of another solution effect provided by an embodiment of the present application;

[0089] FIG37 is a schematic diagram of another solution effect provided by an embodiment of the present application;

[0090] FIG38 is a schematic structural diagram of a signal compensation device provided in an embodiment of the present application;

[0091] Figure 39 is a structural schematic diagram of another signal compensation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0092] An embodiment of the present application provides a communication system, as shown in FIG1 , which includes a transmitting node 01 and a receiving node 02. Both the transmitting node 01 and the receiving node 02 can be passive optical network (PON) equipment / optical transport network (OTN) equipment of an optical access network / metropolitan area network, an optical module, a physical layer digital signal processing (DSP) chip on the optical module, and the like.

[0093] The sending node and the receiving node are connected via an optical fiber link segment 03. The sending node 01 can send a signal to the receiving node 02 via the optical fiber link segment 03, thereby achieving communication between the sending node 01 and the receiving node 02.

[0094] Typically, the transmitting node 01 can transmit signals in any polarization state, and each polarization state signal includes a real signal and an imaginary signal. For example, assume that the transmitting node 01 can transmit a signal in an X polarization state and a signal in a Y polarization state, where the X polarization state and the Y polarization state are perpendicular to each other. The signal in the X polarization state includes a real signal in the X polarization state (also called an in-phase signal, or I signal for short) and an imaginary signal in the X polarization state (also called a quadrature signal, or Q signal for short). The signal in the Y polarization state includes a real signal in the Y polarization state and an imaginary signal in the Y polarization state.

[0095] For example, referring to Figure 2 , transmitting node 01 includes a transmitting link segment 011 for transmitting a real signal with an X polarization state, a transmitting link segment 012 for transmitting an imaginary signal with an X polarization state, a transmitting link segment 013 for transmitting a real signal with an Y polarization state, and a transmitting link segment 014 for transmitting an imaginary signal with an Y polarization state. Receiving node 02 includes a receiving link segment 021 for transmitting a real signal with an X polarization state, a receiving link segment 022 for transmitting an imaginary signal with an X polarization state, a receiving link segment 023 for transmitting a real signal with an Y polarization state, and a receiving link segment 024 for transmitting an imaginary signal with an Y polarization state. Furthermore, these four transmitting link segments and the four receiving link segments are all connected via the aforementioned optical fiber link segment 03.

[0096] The real or imaginary signal of any polarization state sent by transmitting node 01 is transmitted through the transmitting link segment used to transmit such signals to optical fiber link segment 03. The real signal of X polarization state, the imaginary signal of X polarization state, the real signal of Y polarization state, and the imaginary signal of Y polarization state sent by the transmitting node are mixed in optical fiber link segment 03 and transmitted to receiving node 02. Furthermore, when these signals are transmitted in optical fiber link segment 03, polarization rotation and phase rotation may occur, causing these signals to influence each other. This may result in the real signal of the X polarization state transmitted to receiving node 02 being different from the real signal of the X polarization state emitted by transmitting node 01, the imaginary signal of the X polarization state transmitted to receiving node 02 being different from the imaginary signal of the X polarization state emitted by transmitting node 01, the real signal of the Y polarization state transmitted to receiving node 02 being different from the real signal of the Y polarization state emitted by transmitting node 01, and the real signal of the Y polarization state transmitted to receiving node 02 being different from the real signal of the Y polarization state emitted by transmitting node 01. Any real or imaginary signal of any polarization state transmitted to receiving node 02 is correlated with at least one of the real signal of the X polarization state, the imaginary signal of the X polarization state, the real signal of the Y polarization state, and the imaginary signal of the Y polarization state emitted by the transmitting node.

[0097] The four signals transmitted to receiving node 02 (the real signal of the X polarization state, the imaginary signal of the X polarization state, the real signal of the Y polarization state, and the imaginary signal of the Y polarization state) are respectively transmitted on four receiving link segments in receiving node 02. For example, the real signal of the X polarization state transmitted to the receiving node is transmitted on receiving link segment 021, the imaginary signal of the X polarization state transmitted to the receiving node is transmitted on receiving link segment 022, the real signal of the Y polarization state transmitted to the receiving node is transmitted on receiving link segment 023, and the imaginary signal of the Y polarization state transmitted to the receiving node is transmitted on receiving link segment 024.

[0098] However, differences exist between different transmission link segments, resulting in different changes in the signals transmitted on different transmission link segments, making the signals transmitted on different transmission link segments unbalanced. Since the real and imaginary signals of a signal of any polarization state are transmitted on different transmission link segments, the transmission conditions of the real and imaginary signals on the transmission link segments are different, which affects the effective transmission of the signal of this polarization state. In addition, differences exist between different reception link segments, resulting in different changes in the signals transmitted on different reception link segments, making the signals transmitted on different reception link segments unbalanced. The real and imaginary signals of any polarization state are also transmitted on different reception link segments, so the transmission conditions of the real and imaginary signals on the reception link segments are also different, which also affects the effective reception of the signal of this polarization state. This phenomenon is called IQ damage.

[0099] For example, because the physical path lengths of the transmission link segments transmitted by the real and imaginary signals of any polarization state differ, the delays of the real and imaginary signals on the transmission link segments differ. For another example, because the gains of the real and imaginary signals of any polarization state differ on the transmission link segments transmitted, the power attenuation of the real and imaginary signals on the transmission link segments differs.

[0100] As another example, because the physical path lengths of the receiving link segments transmitted by the real and imaginary signals of any polarization state differ, the delays of the real and imaginary signals on the receiving link segments differ. As another example, the gains of the real and imaginary signals of any polarization state differ on the receiving link segments transmitted, and therefore, the power attenuation of the real and imaginary signals on the receiving link segments differs.

[0101] Furthermore, point-to-multipoint (P2MP) coherent optical networks based on digital multicarriers can simplify network architecture, reduce deployment and O&M costs, and have the potential to be applied in metropolitan area networks and access networks. In digital multicarrier P2MP coherent optical networks, the aforementioned IQ impairments can lead to image crosstalk. The following describes P2MP coherent optical networks and the image crosstalk they can cause.

[0102] As shown in Figure 3, the P2MP coherent optical network based on digital multi-carrier includes: a sending node and multiple receiving nodes, and four receiving nodes are taken as an example in Figure 3. The sending node is also called a central node, and the multiple receiving nodes are also called multiple leaf nodes. In the P2MP coherent optical network, a sending node can use coherent optical signals to transmit signals to multiple leaf nodes, and each leaf node uses coherent receiving technology to receive optical signals. It can be understood that the sending node is connected to multiple receiving nodes, and the sending node and multiple receiving nodes can be connected to form a ring topology as shown in Figure 4, a tree topology as shown in Figure 5, or a horseshoe topology as shown in Figure 6. The topology formed by the sending node and multiple receiving nodes can also be different from the structures shown in Figures 4, 5 and 6.

[0103] As shown in Figure 3, a transmitting node can transmit a multicarrier signal comprising multiple subcarriers. These multiple subcarriers correspond one-to-one with multiple receiving nodes, and each receiving node receives the signal sent by the transmitting node on the corresponding subcarrier. For example, the multiple subcarriers include four subcarriers with center frequencies f1, f2, f3, and f4, respectively. The subcarrier with center frequency f1 corresponds to receiving node 1, the subcarrier with center frequency f2 corresponds to receiving node 2, the subcarrier with center frequency f3 corresponds to receiving node 3, and the subcarrier with center frequency f4 corresponds to receiving node 4. A receiving node selectively receives specific subcarriers within the multicarrier signal by adjusting the center frequency of its local oscillator light. For example, when the center frequency of the receiving node's local oscillator light aligns with the center frequency of the subcarrier corresponding to the receiving node, the receiving node performs coherent detection. After coherent detection, the subcarrier corresponding to the receiving node is located in the baseband, while the other subcarriers are located at high frequencies and can be filtered out. In this way, the receiving node can selectively receive the corresponding subcarrier from the multicarrier signal.

[0104] In the embodiment of the present application, the subcarrier is generated in the digital domain. The subcarrier is a subcarrier generated by the sending node after digital signal processing of the data (and before analog signal processing). Therefore, the subcarrier is also called a digital subcarrier. After digital-to-analog conversion and electro-optical modulation, the digital subcarrier is transmitted to the optical fiber link segment in the form of an optical signal. Accordingly, after coherent detection of the optical signal transmitted on the optical fiber link segment, the receiving node can perform analog-to-digital conversion to obtain a digital subcarrier. The multicarrier signal sent by the sending node is transmitted to each receiving node in the form of a broadcast.

[0105] In digital subcarrier systems, IQ impairments can cause image crosstalk between subcarriers, severely degrading system performance.

[0106] As shown in Figure 7, it is assumed that the multicarrier signal includes 8 subcarriers, and the center frequencies of the 8 subcarriers are f1, f2, f3, f4, f5, f6, f7, and f8, respectively. In addition, f1 and f8 are symmetrical about the center frequency of the transmitting node (also known as the zero frequency of the transmitting node), f2 and f7 are symmetrical about the center frequency of the transmitting node (also known as the zero frequency of the transmitting node), f3 and f6 are symmetrical about the center frequency of the transmitting node (also known as the zero frequency of the transmitting node), and f4 and f5 are symmetrical about the center frequency of the transmitting node (also known as the zero frequency of the transmitting node). If the center frequencies of two subcarriers are symmetrical about the center frequency of the transmitting node, then the two subcarriers are symmetrical subcarriers.

[0107] When IQ impairments are present, each subcarrier generates an image on its symmetrical subcarrier, causing image crosstalk. For example, when IQ impairments are present, the subcarrier with center frequency f1 and the subcarrier with center frequency f8 will crosstalk with each other, and the subcarrier with center frequency f2 and the subcarrier with center frequency f7 will crosstalk with each other. The same is true for other subcarriers.

[0108] In addition, image crosstalk increases as the offset value of the subcarrier's center frequency relative to the center frequency of the transmitting node increases. Therefore, subcarriers with a larger center frequency offset relative to the center frequency of the transmitting node have higher image crosstalk, causing these subcarriers to deteriorate more severely or even become completely undemodulated.

[0109] Therefore, how to estimate and compensate for IQ impairments in P2MP coherent optical networks becomes particularly important.

[0110] Based on this, an embodiment of the present application provides a signal compensation method that can estimate and compensate for IQ impairments, thereby reducing the impact of IQ impairments on signals and improving signal transmission performance. Furthermore, in P2MP coherent optical networks, it can also reduce image crosstalk between symmetric subcarriers. It is understood that the signal compensation method provided in this application can also be applied in point-to-point (P2P) optical networks.

[0111] For example, FIG8 is a flow chart of a signal compensation method provided in an embodiment of the present application. As shown in FIG8 , the signal compensation method includes:

[0112] S101. The sending node sends a first test signal of a first polarization state to the first receiving node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries the real signal and imaginary signal of the first test signal at different times.

[0113] The first receiving node has a corresponding subcarrier. When receiving a signal, the first receiving node adjusts the center frequency of the first receiving node to the center frequency of the subcarrier corresponding to the first receiving node to receive the signal sent by the sending node on the subcarrier.

[0114] A transmitting node can transmit signals on multiple subcarriers, which correspond one-to-one to multiple receiving nodes. The subcarrier corresponding to the first receiving node is any subcarrier among the multiple subcarriers. Assume that the transmitting node transmits a total of 8 subcarriers, each with a symbol rate of 8 gigabits (Gbaud). Each receiving node receives only one of the 8 subcarriers, and each receiving node corresponds to a different subcarrier.

[0115] The first baseband frequency is any frequency preset in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node. In other words, the first baseband frequency is any frequency other than the center frequency in the subcarrier corresponding to the first receiving node. For example, referring to FIG9 , assuming that the center frequency of the subcarrier corresponding to the first receiving node is fc, then the first baseband frequency can be fc+f1 and / or fc-f1, where f1 is the absolute value of the difference between the first baseband frequency and fc.

[0116] The first polarization state may be any polarization state, for example, the aforementioned X polarization state or Y polarization state.

[0117] In S101, the sending node needs to send a first test signal of a first polarization state to the first receiving node at a first baseband frequency. The real signal and the imaginary signal in the first test signal are carried on the first baseband frequency at different times. Moreover, when the first baseband frequency carries the real signal of the first test signal, the first baseband frequency does not carry the imaginary signal of the first test signal. When the first baseband frequency carries the imaginary signal of the first test signal, the first baseband frequency does not carry the real signal of the first test signal. It can be seen that the real signal and the imaginary signal of the first test signal are not carried on the first baseband frequency at the same time. For example, the sending node can send the real signal of the first test signal on the first baseband frequency at a first moment and send the imaginary signal of the first test signal on the first baseband frequency at a second moment. When the sending node sends a signal on the first baseband frequency, it can send the signal by sending a sequence corresponding to the signal on the first baseband frequency.

[0118] Because the real and imaginary signals of the first test signal are not simultaneously carried on the first baseband frequency, there is no imbalance between the real and imaginary signals across different transmission link segments when the first baseband frequency carries the real signal of the first test signal. There is also no imbalance between the real and imaginary signals across different transmission link segments when the first baseband frequency carries the imaginary signal of the first test signal. Therefore, when the first baseband frequency carries the real signal of the first test signal, the transmission status of the signal carried on the first baseband frequency in the transmission link segment can reflect the transmission status of the real signal across the transmission link segment; and when the first baseband frequency carries the imaginary signal of the first test signal in the transmission link segment, the transmission status of the signal carried on the first baseband frequency can reflect the transmission status of the imaginary signal across the transmission link segment. Therefore, when the first baseband frequency carries the real signal of the first test signal and when the first baseband frequency carries the imaginary signal of the first test signal, the signal carried on the first baseband frequency can be used to estimate the imbalance between the real and imaginary signals of the first test signal across different transmission link segments.

[0119] In addition, each of the above-mentioned different moments can be a time period. The embodiments of the present application do not limit the length of the time period. In one possible implementation, the time period can be a time slot. A time slot can be an integer multiple of a symbol. For example, a time slot is several hundred times, such as 512 times, a symbol.

[0120] S102: The first receiving node performs receiving compensation on the received first test signal; the receiving compensation is used to compensate for the imbalance between the real part signal and the imaginary part signal of the signal in the receiving node.

[0121] During the transmission of the first test signal from the transmitting node to the first receiving node, it passes through the transmitting link segment, the optical fiber link segment, and the receiving link segment in sequence, and is affected by these link segments, causing the first test signal received by the first receiving node to change relative to the first test signal actually sent by the transmitting node. Furthermore, the real signal of the first polarization state in the first test signal received by the first receiving node may differ from the real signal of the first test signal sent by the transmitting node; the imaginary signal of the first polarization state in the first test signal received by the first receiving node may differ from the imaginary signal of the first test signal sent by the transmitting node; and the first test signal received by the first node may also include real and imaginary signals of the second polarization state.

[0122] After receiving the first test signal, the first receiving node performs reception compensation on the received first test signal to compensate for the imbalance in the receiving node between the real signal and the imaginary signal of each polarization state transmitted to the first receiving node. For example, reception compensation is used to compensate for the imbalance in the delay and power of the real signal and the imaginary signal of the first polarization state in the first test signal received by the first receiving node on different receiving link segments within the first receiving node. Reception compensation is also used to compensate for the imbalance in the delay and power of the real signal and the imaginary signal of the second polarization state in the first test signal received by the first receiving node on different receiving link segments within the first receiving node.

[0123] S103. The first receiving node sends a sending parameter corresponding to the first polarization state to the sending node based on the first test signal after reception compensation. The sending parameter corresponding to the first polarization state sent by the first receiving node represents: an imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0124] After receiving compensation in S102, the imbalance between the real and imaginary signals of each polarization state in the first test signal received by the first receiving node is eliminated (or alleviated) at the receiving node. However, the imbalance between the real and imaginary signals of the first test signal sent by the sending node still exists at the sending node. In this way, the first receiving node can estimate the imbalance between the real and imaginary signals in the first test signal sent by the sending node at the sending node based on the first test signal received by the first receiving node after receiving compensation in S103, and obtain a transmission parameter corresponding to the first polarization state used to characterize the imbalance.

[0125] For example, the transmission parameters corresponding to the first polarization state include a transmission power parameter, and the transmission power parameter sent by the first receiving node represents an imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0126] Assume that the first baseband frequency carries the real signal of the first test signal at the first moment and the imaginary signal of the first test signal at the second moment. Then, when the first receiving node obtains the transmission power parameter based on the first test signal after reception compensation, it can obtain the power of the signal carried by the first baseband frequency at the first moment and the power of the signal carried by the first baseband frequency at the second moment in the first test signal received by the first receiving node after reception compensation. Afterwards, the first receiving node can use the ratio of the power of the signal carried by the first baseband frequency at the first moment and the power of the signal carried by the first baseband frequency at the second moment as the transmission power parameter; or, the first receiving node can use the ratio of the power of the signal carried by the first baseband frequency at the second moment and the power of the signal carried by the first baseband frequency at the first moment as the transmission power parameter.

[0127] It is understandable that, after receiving compensation is performed on the first test signal received by the first receiving node, the power of the signal carried by the first baseband frequency at the first moment can represent the power of the real signal of the first test signal sent by the sending node. The power of the signal carried by the first baseband frequency at the second moment can represent the power of the imaginary signal of the first test signal sent by the sending node.

[0128] Therefore, after receiving compensation for the first test signal received by the first receiving node, the ratio of the power of the signal carried by the first baseband frequency in the first moment to the power of the signal carried in the second moment can be characterized by: the power ratio of the real signal to the imaginary signal of the first test signal sent by the sending node. This ratio can reflect the power imbalance of the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node. The ratio of the power of the signal carried by the first baseband frequency in the second moment to the power of the signal carried in the first moment can be characterized by: the power ratio of the imaginary signal to the real signal of the first test signal sent by the sending node. This ratio can also reflect the power imbalance of the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0129] Optionally, the first test signal received by the first receiving node after receiving compensation can also represent the imbalance between the real and imaginary signals of the first test signal sent by the sending node in the sending node. Therefore, the first receiving node can also directly send the first test signal received by the first receiving node after receiving compensation to the sending node as the transmission parameters corresponding to the first polarization state. It can be seen that the transmission parameters corresponding to the first polarization state can directly or indirectly represent the imbalance between the real and imaginary signals of the first test signal sent by the sending node in the sending node.

[0130] S104: The sending node compensates the service signal of the first polarization state to be sent according to the sending parameters corresponding to the first polarization state.

[0131] The transmission parameters corresponding to the first polarization state can directly or indirectly characterize the imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node. When the transmission parameters corresponding to the first polarization state directly characterize the imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node, the sending node can compensate for the service signal to be sent based on the transmission parameters corresponding to the first polarization state in S104 to compensate for the imbalance between the real signal and the imaginary signal of the service signal of the first polarization state sent by the sending node in the sending node.

[0132] For example, taking the transmission parameters corresponding to the first polarization state including the above-mentioned transmission power parameters as an example, when the transmitting node compensates the service signal to be transmitted according to the transmission power parameters, it can adjust the power of the real signal and the imaginary signal of the service signal to be transmitted during the digital signal processing process, so as to reduce the imbalance in the power of the real signal and the imaginary signal of the service signal to be transmitted in the transmitting node.

[0133] For example, when the transmit power parameter can represent the ratio of the power of the real signal to the imaginary signal of the first test signal sent by the transmitting node in the transmitting node, the transmitting node can adjust the power of the real signal and the imaginary signal of the service signal to be transmitted during the digital signal processing process so that the power ratio of the real signal to the imaginary signal of the service signal to be transmitted is the inverse of the transmit power parameter. In this way, the degree of imbalance in the power of the real signal and the imaginary signal of the service signal to be transmitted in the transmitting node is minimized.

[0134] When the sending parameters corresponding to the first polarization state indirectly represent the imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node, the sending node needs to first analyze the sending parameters corresponding to the first polarization state in S104, and then determine the parameters that can directly represent this imbalance (this process can refer to S103), and then compensate for the service signal of the first polarization state to be sent according to the parameters (this process can refer to S104).

[0135] In addition, after the sending node is initially started, the sending node can compensate for the service signal of the first polarization state to be sent based on the preset sending parameters corresponding to the first polarization state. After receiving the sending parameters corresponding to the first polarization state in S103, the preset sending parameters corresponding to the first polarization state can be updated, and the service signal of the first polarization state to be sent can be compensated based on the updated sending parameters corresponding to the first polarization state. The sending node and the first receiving node can also repeatedly perform S101 to S103 so that the sending node continuously receives new sending parameters corresponding to the first polarization state, continuously updates the existing sending parameters corresponding to the first polarization state, thereby improving the accuracy of the sending parameters corresponding to the first polarization state and improving the compensation effect of the service signal.

[0136] In summary, since in the method provided in the embodiment of the present application, the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times, the signal carried by the first baseband frequency at any time will not be affected by IQ imbalance. Moreover, based on the real signal carried by the first baseband frequency and the imaginary signal carried by the first baseband frequency, the imbalance between the real signal and the imaginary signal of the same polarization state in the sending node can be determined. In this way, the sending node can compensate for the service signal to be sent according to the sending parameters corresponding to the first polarization state that characterizes the imbalance, thereby improving the transmission effect of the service signal.

[0137] In addition, the first receiving node can determine the transmission parameters corresponding to the first polarization state based only on the test signal carried on the corresponding subcarrier. Therefore, the first receiving node does not need to rely on the signal carried on the symmetric subcarrier of the corresponding subcarrier.

[0138] In the above description, a transmitting node sends a test signal to a receiving node at a single baseband frequency. For example, the transmitting node sends a first test signal to a first receiving node at a first baseband frequency. It is understood that the transmitting node may also send test signals to a receiving node at multiple baseband frequencies.

[0139] For example, based on the method shown in FIG8 , the transmitting node may further transmit the first test signal to the first receiving node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; and the second baseband frequency is also different from the center frequency of the subcarrier corresponding to the first receiving node. Furthermore, the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node. For example, when the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is f1, as shown in FIG10 , the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node may be f2, and f1 is different from f2. The second baseband frequency may be fc+f2 and / or fc-f2.

[0140] For example, the first baseband frequency fx1 = fs / 4, the second baseband frequency fx2 = fs / 2, and fs is the baud rate of the signal carried on the subcarrier corresponding to the first receiving node.

[0141] The second baseband frequency also carries the real and imaginary signals of the first test signal at different moments. However, when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal. For example, as shown in FIG11 , assuming that the first baseband frequency fx1 carries the imaginary signal of the first test signal at time t1 and the real signal of the first test signal at time t2; then, the second baseband frequency fx2 carries the real signal of the first test signal at time t1 and the imaginary signal of the second test signal at time t2.

[0142] According to the description of S103 above, the first receiving node can determine the transmit power parameter in the transmit parameter corresponding to the first polarization state based on the signal carried at one baseband frequency in the first test signal after reception compensation (that is, the first test signal received by the first receiving node after reception compensation). Therefore, when the transmitting node not only transmits the first test signal to the first receiving node at the first baseband frequency but also transmits the first test signal to the first receiving node at the second baseband frequency, the first receiving node can determine the preliminary transmit power parameter based on the signals carried at the first baseband frequency and the second baseband frequency in the first test signal after reception compensation, and then send the average value (or weighted average value) of the two preliminary transmit power parameters as the final transmit power parameter to the transmitting node.

[0143] For example, assume that the first baseband frequency fx1 carries the real signal of the first test signal at the first moment t1, and carries the imaginary signal of the first test signal at the second moment t2; the second baseband frequency fx2 carries the imaginary signal of the first test signal at the first moment t1, and carries the real signal of the second test signal at the second moment t2.

[0144] Then, when obtaining the transmission power parameter, the first receiving node can use the ratio of the power of the signal carried by the first baseband frequency fx1 at the first moment t1 and the power of the signal carried by the first baseband frequency fx1 at the second moment t2 in the first test signal after reception compensation as the first ratio; the first receiving node can also use the ratio of the power of the signal carried by the second baseband frequency fx2 at the second moment t2 and the power of the signal carried by the second baseband frequency fx2 at the first moment t1 in the first test signal after reception compensation as the second ratio; thereafter, the first receiving node sends the average of the first ratio and the second ratio as the transmission power parameter to the sending node.

[0145] For example, as shown in FIG12 , the first receiving node may cache the first test signal that has undergone reception compensation, and extract the signals transmitted at the first time t1 and the second time t2 from the cached signal. Subsequently, the first receiving node may perform a fast Fourier transform (FFT) on the signal transmitted at the first time t1 to obtain the signal carried by the first baseband frequency fx1 at the first time t1, and the signal carried by the second baseband frequency fx2 at the first time t1. The first receiving node may also perform an FFT on the signal transmitted at the second time t2 to obtain the signal carried by the first baseband frequency fx1 at the second time t2, and the signal carried by the second baseband frequency fx2 at the second time t2. The first receiving node may then calculate the power of the signal carried by the first baseband frequency fx1 at the first time t1, the power of the signal carried by the first baseband frequency fx1 at the second time t2, the power of the signal carried by the second baseband frequency fx2 at the first time t1, and the power of the signal carried by the second baseband frequency fx2 at the second time t2. The first receiving node may use the ratio of the power of the signal carried by the first baseband frequency fx1 at the first time t1 to the power of the signal carried by the first baseband frequency fx1 at the second time t2 as a first ratio. The first receiving node may also use the ratio of the power of the signal carried by the second baseband frequency fx2 at the second time t2 to the power of the signal carried by the second baseband frequency fx2 at the first time t1 as a second ratio. Thereafter, the first receiving node uses the average of the first ratio and the second ratio as the transmit power parameter.

[0146] Optionally, when obtaining the transmission power parameter, the first receiving node may also use the ratio of the power of the signal carried by the first baseband frequency in the second moment and the power of the signal carried by the first baseband frequency in the first test signal after reception compensation as the first ratio; the first receiving node may also use the ratio of the power of the signal carried by the second baseband frequency in the first moment and the power of the signal carried by the second baseband frequency in the second moment in the first test signal after reception compensation as the second ratio; thereafter, the first receiving node sends the average of the first ratio and the second ratio as the transmission power parameter to the sending node.

[0147] The first receiving node can improve the accuracy of the transmission power parameter sent by the first receiving node to the sending node by sending the average of two preliminary transmission power parameters (such as the first ratio and the second ratio mentioned above) as the final transmission power parameter to the sending node.

[0148] Furthermore, in the case where a sending node sends a test signal to a receiving node at multiple baseband frequencies, the sending parameters corresponding to the first polarization state may include: at least one parameter of a sending power parameter and a sending delay parameter. In the embodiment of the present application, the sending parameters corresponding to the first polarization state include a sending power parameter and a sending delay parameter as an example. The sending delay parameter sent by the first receiving node represents: the imbalance of the delay between the real signal and the imaginary signal of the first test signal in the sending node. When the sending node compensates for the service signal according to the sending delay parameter, if the real signal leads the imaginary signal, then a delay (linear phase in the frequency domain) is digitally added to the real signal to align the real signal with the imaginary signal; if the imaginary signal leads the real signal, then a delay (linear phase in the frequency domain) is digitally added to the imaginary signal to align the real signal with the imaginary signal.

[0149] In addition, when the transmission parameters corresponding to the first polarization state include the transmission delay parameter, the baseband frequency in the embodiment of the present application includes two sub-frequencies, and the absolute values ​​of the differences between the two sub-frequencies and the center frequency of the subcarrier where the baseband frequency is located are the same, but the two sub-frequencies are different from each other. For example, the first baseband frequency includes fc+f2 and fc-f2, and the second baseband frequency includes fc+f2 and fc-f2.

[0150] For example, assume that the first baseband frequency fx1 carries the real part signal of the first test signal at the first moment t1, and carries the imaginary part signal of the first test signal at the second moment t2; the second baseband frequency fx2 carries the imaginary part signal of the first test signal at the first moment t1, and carries the real part signal of the first test signal at the second moment t2.

[0151] Then, when the first receiving node obtains the transmission delay parameter after receiving compensation for the received first test signal, it can use the difference between the delay of the signal carried by the first baseband frequency fx1 at the first time t1 and the delay of the signal carried by the second baseband frequency fx2 at the first time t1 in the first test signal after receiving compensation as the first difference; the first receiving node can also use the difference between the delay of the signal carried by the second baseband frequency fx2 at the second time t2 and the delay of the signal carried by the first baseband frequency fx1 at the second time t2 as the second difference; thereafter, the first receiving node sends the average of the first difference and the second difference (that is, half of the sum of the first difference and the second difference) as the transmission delay parameter to the sending node.

[0152] For example, as shown in Figure 13, the first receiving node can cache the first test signal that has been received and processed, and extract the signals transmitted at the first time t1 and the second time t2 from the cached signal. Afterwards, the first receiving node can perform FFT on the signal transmitted at the first time t1 to obtain the signal carried by the first baseband frequency fx1 at the first time t1, and the signal carried by the second baseband frequency fx2 at the first time t1. The first receiving node can also perform FFT on the signal transmitted at the second time t2 to obtain the signal carried by the first baseband frequency fx1 at the second time t2, and the signal carried by the second baseband frequency fx2 at the second time t2. Then, the first receiving node can respectively calculate the delay of the signal carried by the first baseband frequency fx1 at the first time t1, the delay of the signal carried by the first baseband frequency fx1 at the second time t2, the delay of the signal carried by the second baseband frequency fx2 at the first time t1, and the delay of the signal carried by the second baseband frequency fx2 at the second time t2. The first receiving node may use the difference between the time delay of the signal carried by the first baseband frequency fx1 at the first time t1 and the time delay of the signal carried by the first baseband frequency fx2 at the first time t1 as the first difference. The first receiving node may also use the difference between the time delay of the signal carried by the second baseband frequency fx2 at the second time t2 and the time delay of the signal carried by the first baseband frequency fx1 at the second time t2 as the second difference. Thereafter, the first receiving node uses the average of the first difference and the second difference as the transmit power parameter.

[0153] After receiving and compensating the first test signal, the time delay of the signal carried by any baseband frequency at any moment can be determined by a timing error detector (TED, also known as a phase detector). The first receiving node can input the signal carried by any baseband frequency at any moment into the TED, and the result output by the TED is related to the time delay of the signal carried by any baseband frequency at any moment. It can be understood that the result output by the TED is not actually the time delay of the signal carried by any baseband frequency at any moment, and the result output by the TED is also affected by the sampling deviation and channel response. The sampling deviation is related to the moment when the signal processed by the TED is carried. The sampling deviation of the signal carried at the same moment is the same, and the sampling deviation of the signal carried at different moments is different. The channel response is related to the frequency carried by the signal processed by the TED. The channel response of the signal carried at the same frequency is the same, and the channel response of the signal carried at different frequencies is different.

[0154] Therefore, the result obtained by inputting the signal carried by the first baseband frequency at the first moment into the TED is affected by: the time delay of the signal carried by the first baseband frequency at the first moment in the transmitting node, the sampling deviation of the signal carried at the first moment, and the channel response of the signal carried by the first baseband frequency. The result obtained by inputting the signal carried by the first baseband frequency at the first moment into the TED = the time delay S11 of the signal carried by the first baseband frequency at the transmitting node at the first moment + the sampling deviation C1 of the signal carried at the first moment + the channel response D1 of the signal carried by the first baseband frequency.

[0155] The result obtained by inputting the signal carried by the second baseband frequency at the first moment into the TED is affected by: the time delay of the signal carried by the second baseband frequency at the first moment in the transmitting node, the sampling deviation of the signal carried at the first moment, and the channel response of the signal carried by the second baseband frequency. The result obtained by inputting the signal carried by the second baseband frequency at the first moment into the TED = the time delay S21 of the signal carried by the second baseband frequency at the transmitting node at the first moment + the sampling deviation C1 carried at the first moment + the channel response D2 of the signal carried by the second baseband frequency.

[0156] The result obtained by inputting the signal carried by the first baseband frequency at the second moment into the TED is affected by: the time delay of the signal carried by the first baseband frequency at the second moment in the transmitting node, the sampling deviation of the signal carried at the second moment, and the channel response of the signal carried by the first baseband frequency. The result obtained by inputting the signal carried by the first baseband frequency at the second moment into the TED = the time delay S12 of the signal carried by the first baseband frequency at the transmitting node at the second moment + the sampling deviation C2 of the signal carried at the second moment + the channel response D1 of the signal carried by the first baseband frequency.

[0157] The result obtained by inputting the signal carried by the second baseband frequency at the second moment into the TED is affected by: the time delay of the signal carried by the second baseband frequency at the second moment in the transmitting node, the sampling deviation of the signal carried at the second moment, and the channel response of the signal carried by the second baseband frequency. The result obtained by inputting the signal carried by the second baseband frequency at the second moment into the TED = the time delay S22 of the signal carried by the second baseband frequency at the transmitting node at the second moment + the sampling deviation C2 of the signal carried at the second moment + the channel response D2 of the signal carried by the second baseband frequency.

[0158] Then, the above-mentioned first difference = the result obtained by inputting the signal carried by the first baseband frequency into TED at the first moment - the result obtained by inputting the signal carried by the second baseband frequency into TED at the first moment = S11+C1+D1-S21-C1-D2.

[0159] The second difference = the result obtained by inputting the signal carried by the second baseband frequency at the second moment into the TED - the result obtained by inputting the signal carried by the first baseband frequency at the second moment into the TED = S22+C2+D2-S12-C2-D1.

[0160] Transmission delay parameter = (first difference + second difference) / 2 = (S11+C1+D1-S21-C1-D2+S22+C2+D2-S12-C2-D1) / 2 = (S11-S21+S22-S12) / 2.

[0161] It can be understood that S11 represents the delay of the signal carried by the first baseband frequency in the sending node at the first moment, that is, the delay of the real signal of the first test signal in the sending node; S21 represents the delay of the signal carried by the second baseband frequency in the sending node at the first moment, that is, the delay of the imaginary signal of the first test signal in the sending node; therefore, S11-S21 is the delay difference between the real signal and the imaginary signal of the first test signal in the sending node.

[0162] S22 represents the delay of the signal carried by the second baseband frequency in the sending node at the second moment, that is, the delay of the real signal of the first test signal in the sending node; S12 represents the delay of the signal carried by the first baseband frequency in the sending node at the second moment, that is, the delay of the imaginary signal of the first test signal in the sending node; therefore, S22-S12 is the delay difference between the real signal and the imaginary signal of the first test signal in the sending node.

[0163] (S11-S21+S22-S12) is twice the time delay difference between the real and imaginary signals of the first test signal in the sending node, and (S11-S21+S22-S12) / 2 is the time delay difference between the real and imaginary signals of the first test signal in the sending node.

[0164] It can be seen that using the average of the first difference and the second difference as the transmission delay parameter can offset the influence of sampling deviation and channel response, thereby obtaining the accurate delay difference between the real signal and the imaginary signal of the first test signal in the transmitting node.

[0165] Furthermore, in S101 above, the transmitting node transmits a first test signal of a first polarization state to the first receiving node at a first baseband frequency, and the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times. Optionally, the transmitting node may implement the following method to implement the first baseband frequency carrying the real signal and the imaginary signal of the first test signal at different times.

[0166] For example, based on the method shown in FIG. 8 , the transmitting node may further transmit a second test signal in the first polarization state to the second receiving node at a third baseband frequency, and receive a transmission parameter corresponding to the first polarization state sent by the second receiving node. For example, when executing S101, the transmitting node may transmit the second test signal in the first polarization state to the second receiving node at the third baseband frequency.

[0167] The second receiving node is different from the first receiving node, and the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the transmitting node. For example, when the center frequency of the subcarrier corresponding to the first receiving node is f1 in Figure 7, the center frequency of the subcarrier corresponding to the second receiving node can be f8 in Figure 7. Therefore, the subcarrier corresponding to the first receiving node and the subcarrier corresponding to the second receiving node are symmetrical subcarriers.

[0168] The third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node.

[0169] For example, assuming that the first baseband frequency is fc+f1 and / or fc-f1 as shown in FIG9 , and the center frequency of the subcarrier corresponding to the second receiving node is fd in FIG14 , then the third baseband frequency may be fd+f1 and / or fd-f1 in FIG14 . It can be seen that the absolute value of the difference between the third baseband frequency and the center frequency fd of the subcarrier corresponding to the second receiving node is f1, and the absolute value of the difference between the first baseband frequency and the center frequency fc of the subcarrier corresponding to the first receiving node is also f1.

[0170] When the first baseband frequency is fc+f1, the third baseband frequency can be fd-f1; when the first baseband frequency is fc-f1, the third baseband frequency can be fd+f1; when the first baseband frequencies are fc+f1 and fc-f1, the third baseband frequencies can be fd-f1 and fd+f1. This shows that not only are fc and fd symmetrical about the zero frequency of the transmitting node, but the first and third baseband frequencies are also symmetrical about the zero frequency of the transmitting node.

[0171] Similar to how the first baseband frequency carries the real and imaginary signals of the first test signal at different times, the third baseband frequency also carries the real and imaginary signals of the second test signal at different times. Furthermore, at different times, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate, respectively. Since the conjugate of a real number is equal to the real number, when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, both the signal carried by the first baseband frequency and the signal carried by the third baseband frequency are real signals. In this case, the first baseband frequency carries the real signal of the first test signal, and the third baseband frequency carries the real signal of the second test signal. Since the anti-conjugate of an imaginary number is equal to the imaginary number, when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, both the signal carried by the first baseband frequency and the signal carried by the third baseband frequency are imaginary signals. In this case, the first baseband frequency carries the imaginary signal of the first test signal, and the third baseband frequency carries the imaginary signal of the second test signal.

[0172] For example, assuming that at a first moment, the first baseband frequency carries the real signal of the first test signal, and the first baseband frequency does not carry the imaginary signal of the first test signal, and the third baseband frequency carries the real signal of the second test signal, and the third baseband frequency does not carry the imaginary signal of the second test signal; at a second moment, the first baseband frequency carries the imaginary signal of the first test signal, and the first baseband frequency does not carry the real signal of the first test signal, and the third baseband frequency carries the imaginary signal of the second test signal, and the third baseband frequency does not carry the real signal of the second test signal. Then, at the first moment, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate to each other; at the second moment, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate to each other.

[0173] Similar to the first receiving node, after receiving the second test signal, the second receiving node can also perform reception compensation on the received second test signal, and then send the transmission parameters corresponding to the first polarization state to the sending node based on the second test signal received by the second receiving node after reception compensation. The transmission parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal sent by the sending node in the sending node. It can be seen that the sending node will receive the transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node respectively. Therefore, in the above S104, the sending node will compensate for the service signal of the first polarization state to be sent based on the transmission parameters corresponding to the first polarization state sent by the first receiving node and the transmission parameters corresponding to the first polarization state sent by the second receiving node. For example, the sending node can compensate for the service signal of the first polarization state to be sent based on the average value of the transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node.

[0174] In addition, when a sending node sends a test signal to a receiving node at multiple baseband frequencies, the sending node can send a first test signal of a first polarization state to the first receiving node at a first baseband frequency and a second baseband frequency, and the sending node can also send a second test signal of a first polarization state to the second receiving node at a third baseband frequency and a fourth baseband frequency, respectively. In this case, the second receiving node can perform reception compensation on the second test signals received at the third baseband frequency and the fourth baseband frequency, respectively, and then send transmission parameters corresponding to the first polarization state to the sending node based on the signal carried at the third baseband frequency in the second test signal received after reception compensation and the signal carried at the fourth baseband frequency in the second test signal received after reception compensation. The transmission parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal sent by the sending node in the sending node.

[0175] Similar to the third baseband frequency, the fourth baseband frequency is also an arbitrary frequency preset in the subcarrier corresponding to the second receiving node, and the fourth baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the fourth baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node.

[0176] For example, assuming that the second baseband frequency is fc+f2 and / or fc-f2 as shown in Figure 10, and the center frequency of the subcarrier corresponding to the second receiving node is fd in Figure 15, then the fourth baseband frequency can be fd+f2 and / or fd-f2 in Figure 15. It can be seen that the absolute value of the difference between the fourth baseband frequency and the center frequency fd of the subcarrier corresponding to the second receiving node is f2, and the absolute value of the difference between the second baseband frequency and the center frequency fc of the subcarrier corresponding to the first receiving node is also f1.

[0177] When the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugate; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is conjugate.

[0178] For example, when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugated, the sending node can carry the repeated sequence [1+1j, -1-1j] on the first baseband frequency and the repeated sequence [1-1j, -1+1j] on the third baseband frequency, and the sequence [1+1j, -1-1j] is conjugated to the sequence [1-1j, -1+1j]; when the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugated, the sending node can carry the repeated sequence [1+1j, 1+1j, -1-1j, -1-1j] on the second baseband frequency and the repeated sequence [-1+1j, -1+1j, 1-1j, 1-1j] on the fourth baseband frequency, and the sequence [1+1j, 1+1j, -1-1j, -1-1j] is anti-conjugated to the sequence [-1+1j, -1+1j, 1-1j, 1-1j].

[0179] Optionally, the sending node may also adopt the following method to implement the first baseband frequency carrying the real signal and the imaginary signal of the first test signal at different times.

[0180] For example, the first baseband frequency includes a first sub-frequency fc+f1 and a second sub-frequency fc-f1. Then, in the first test signal, at different moments, the relationship between the signal carried by the first sub-frequency and the signal carried by the second sub-frequency is conjugate and anti-conjugate, respectively. Since the conjugate of a real number is equal to the real number, when the relationship between the signal carried by the first sub-frequency and the signal carried by the second sub-frequency is conjugate, the signal carried by the first sub-frequency and the signal carried by the second sub-frequency are both real signals. At this time, the first sub-frequency carries the real signal of the first test signal, the second sub-band frequency carries the real signal of the first test signal, and the first baseband frequency carries the real signal of the first test signal; since the anti-conjugate of an imaginary number is equal to the imaginary number, when the relationship between the signal carried by the first sub-frequency and the signal carried by the second sub-frequency is anti-conjugate, the signal carried by the first sub-frequency and the signal carried by the second sub-frequency are both imaginary signals. At this time, the first sub-frequency carries the imaginary signal of the first test signal, the second sub-frequency carries the imaginary signal of the first test signal, and the first baseband frequency carries the imaginary signal of the first test signal.

[0181] This solution is applicable to P2MP coherent optical networks or P2P optical networks.

[0182] The above description uses the example of a receiving node sending transmission parameters corresponding to the first polarization state to a sending node based on a received test signal in the first polarization state, and the sending node then compensating for the service signal in the first polarization state based on the transmission parameters. Optionally, the sending node may also send a test signal in a second polarization state to the receiving node. The receiving node may also send transmission parameters corresponding to the second polarization state to the sending node based on the received test signal in the second polarization state, and the sending node then compensates for the service signal in the second polarization state based on the transmission parameters.

[0183] For example, based on the method shown in Figure 8, the sending node may also send a third test signal of the second polarization state to the first receiving node on the fifth baseband frequency. The first receiving node may perform reception compensation on the received third test signal, and send the transmission parameters corresponding to the second polarization state to the sending node based on the third test signal after reception compensation (the third test signal received by the first receiving node after reception compensation). The sending node may also compensate for the service signal of the second polarization state to be sent based on the transmission parameters corresponding to the second polarization state. The fifth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node. The fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times; the transmission parameters corresponding to the second polarization state sent by the first receiving node represent: the imbalance of the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node.

[0184] The sending node sends the third test signal of the second polarization state to the first receiving node at the fifth baseband frequency, which can be referred to as the aforementioned S101; the first receiving node performs reception compensation for the received third test signal, which can be referred to as the aforementioned S102; the first receiving node sends the sending parameters corresponding to the second polarization state to the sending node based on the third test signal after reception compensation, which can be referred to as the aforementioned S103; the sending node compensates the service signal of the second polarization state to be sent based on the transmission parameters corresponding to the second polarization state, which can be referred to as the aforementioned S104.

[0185] The third test signal is the same as or different from the aforementioned first test signal. In addition, in order to distinguish the first polarization state from the second polarization state, the test signal of the first polarization state and the test signal of the second polarization state need to meet the following conditions: the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node. In other words, the first polarization state and the second polarization state can be distinguished from the sending time and / or the frequency carried by the test signal.

[0186] For example, it is assumed that the first baseband frequency carries the real signal of the first test signal at a first time instant, and carries the imaginary signal of the first test signal at a second time instant.

[0187] Then, the fifth baseband frequency may be the same as the first baseband frequency, and the fifth baseband frequency carries the real part signal of the third test signal at the third time, and carries the imaginary part signal of the third test signal at the fourth time. The first time, the second time, the third time, and the fourth time may be four time periods arranged sequentially, and the four time periods are different from each other.

[0188] Alternatively, the fifth baseband frequency is different from the first baseband frequency, and the fifth baseband frequency carries the real signal of the third test signal at the first moment and carries the imaginary signal of the third test signal at the second moment.

[0189] Alternatively, the fifth baseband frequency is different from the first baseband frequency, and the fifth baseband frequency carries the real part of the third test signal at a third moment and carries the imaginary part of the third test signal at a fourth moment. The first moment, the second moment, the third moment, and the fourth moment may be four moments arranged sequentially, and the four moments are different from each other.

[0190] Furthermore, similar to the first polarization state, the transmitting node may also transmit a third test signal to a receiving node at multiple baseband frequencies.

[0191] For example, based on the above method, the sending node may also send the above-mentioned third test signal to the first receiving node at the sixth baseband frequency. The sixth baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the sixth baseband frequency is also different from the center frequency of the subcarrier corresponding to the first receiving node. Moreover, the absolute value of the difference between the sixth baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the fifth baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node. The sixth baseband frequency also carries the real signal and the imaginary signal of the third test signal at different times, but when the fifth baseband frequency carries the real signal of the third test signal, the sixth baseband frequency carries the imaginary signal of the third test signal; when the fifth baseband frequency carries the imaginary signal of the third test signal, the sixth baseband frequency carries the real signal of the third test signal.

[0192] In order to distinguish the first polarization state from the second polarization state, the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between the sixth baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node.

[0193] For example, assume that the first baseband frequency fx1 carries the imaginary signal of the first test signal at a first time t1 and the real signal of the first test signal at a second time t2. The second baseband frequency fx2 carries the real signal of the first test signal at the first time t1 and the imaginary signal of the first test signal at a second time t2.

[0194] Then, as shown in Figure 16, the fifth baseband frequency can be the same as the first baseband frequency fx1, and the sixth baseband frequency can be the same as the second baseband frequency fx2; and the fifth baseband frequency carries the imaginary part signal of the third test signal at the third time t3 and the real part signal of the third test signal at the fourth time t4; the sixth baseband frequency carries the real part signal of the third test signal at the third time t3 and the imaginary part signal of the third test signal at the fourth time t4. The first time t1, the second time t2, the third time t3, and the fourth time t4 can be four times arranged in sequence, and these four times are different from each other.

[0195] Alternatively, as shown in Figure 17, the fifth baseband frequency is fx3 which is different from the first baseband frequency fx1, and the sixth baseband frequency is fx4 which is different from the second baseband frequency fx2; and the fifth baseband frequency fx3 carries the imaginary signal of the third test signal at the first moment t1, and carries the real signal of the third test signal at the second moment t2; the sixth baseband frequency fx4 carries the real signal of the third test signal at the first moment t1, and carries the imaginary signal of the third test signal at the second moment t2.

[0196] Alternatively, as shown in Figure 18, the fifth baseband frequency is fx3, which is different from the first baseband frequency fx1, and the sixth baseband frequency is fx4, which is different from the second baseband frequency fx2. Furthermore, the fifth baseband frequency fx3 carries the imaginary part of the third test signal at the third time t3 and the real part of the third test signal at the fourth time t4. The sixth baseband frequency fx4 carries the real part of the third test signal at the third time t3 and the imaginary part of the third test signal at the fourth time t4. The first time, the second time, the third time, and the fourth time can be four times arranged in sequence, and these four times are different from each other.

[0197] Furthermore, when the signal in the second polarization state is transmitted in the manner shown in Figure 16, the process of the first receiving node obtaining the transmission power parameters corresponding to the second polarization state based on the third test signal after receiving compensation can be referred to Figure 19. Figure 19 has the following changes compared to Figure 12 (the process of the first receiving node obtaining the transmission power parameters corresponding to the first polarization state based on the first test signal after receiving compensation): the first test signal is changed to the third test signal, the first polarization state is changed to the second polarization state, the first moment t1 is changed to the third moment t3, the second moment t2 is changed to the fourth moment t4, the first ratio is changed to the third ratio, and the second ratio is changed to the fourth ratio. The process of the first receiving node obtaining the transmission delay parameters corresponding to the second polarization state based on the third test signal after receiving compensation can be referred to Figure 20. Figure 20 undergoes the following changes compared to Figure 13 (the process of the first receiving node obtaining the transmission delay parameters corresponding to the first polarization state based on the first test signal after receiving compensation): the first test signal is changed to the third test signal, the first polarization state is changed to the second polarization state, the first moment t1 is changed to the third moment t3, the second moment t2 is changed to the fourth moment t4, the first difference is changed to the third difference, and the second difference is changed to the fourth difference.

[0198] Furthermore, when the signal in the second polarization state is transmitted using the manner shown in FIG17 , the process by which the first receiving node obtains the transmit power parameter corresponding to the second polarization state based on the third test signal after receiving compensation can be referred to in FIG21 . FIG21 undergoes the following changes compared to FIG12 (the process by which the first receiving node obtains the transmit power parameter corresponding to the first polarization state based on the first test signal after receiving compensation): the first test signal is changed to the third test signal, the first polarization state is changed to the second polarization state, the first ratio is changed to the fifth ratio, and the second ratio is changed to the sixth ratio. The process by which the first receiving node obtains the transmit delay parameter corresponding to the second polarization state based on the third test signal after receiving compensation can be referred to in FIG22 . FIG22 undergoes the following changes compared to FIG13 (the process by which the first receiving node obtains the transmit delay parameter corresponding to the first polarization state based on the first test signal after receiving compensation): the first test signal is changed to the third test signal, the first polarization state is changed to the second polarization state, the first difference is changed to the fifth difference, and the second difference is changed to the sixth difference.

[0199] Additionally, similar to the first polarization state, based on the aforementioned method, the transmitting node may further transmit a fourth test signal in the second polarization state to the second receiving node at the seventh baseband frequency, and receive a transmission parameter corresponding to the second polarization state sent by the second receiving node. For example, the transmitting node may transmit a fourth test signal in the seventh baseband frequency to the second receiving node while transmitting the third test signal in the fifth baseband frequency to the first receiving node.

[0200] The seventh baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the seventh baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the seventh baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the fifth baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node. Similar to how the fifth baseband frequency carries the real signal and the imaginary signal of the third test signal at different times, the seventh baseband frequency also carries the real signal and the imaginary signal of the fourth test signal at different times. Moreover, at different times, the relationship between the signal carried by the fifth baseband frequency and the signal carried by the seventh baseband frequency is conjugate and anti-conjugate, respectively.

[0201] Similar to the first receiving node, after receiving the fourth test signal, the second receiving node can also perform reception compensation on the fourth test signal, and then send the transmission parameters corresponding to the second polarization state to the sending node based on the fourth test signal after reception compensation (the fourth test signal received by the second receiving node after reception compensation). The transmission parameters corresponding to the second polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the fourth test signal sent by the sending node in the sending node. It can be seen that the sending node will receive the transmission parameters corresponding to the second polarization state sent by the first receiving node and the second receiving node respectively, so the sending node will compensate for the service signal of the second polarization state to be sent based on the transmission parameters corresponding to the second polarization state sent by the first receiving node and the transmission parameters corresponding to the second polarization state sent by the second receiving node. For example, the sending node can compensate for the service signal of the second polarization state to be sent based on the average value of the transmission parameters corresponding to the second polarization state sent by the first receiving node and the second receiving node.

[0202] In addition, when a transmitting node sends test signals to a receiving node at multiple baseband frequencies, the transmitting node may send a third test signal to the first receiving node at the fifth baseband frequency and the sixth baseband frequency, and the transmitting node may also send a fourth test signal to the second receiving node at the seventh baseband frequency and the eighth baseband frequency, respectively. In this case, the second receiving node may perform reception compensation on the fourth test signal received at the seventh baseband frequency and the eighth baseband frequency, respectively, and then send transmission parameters corresponding to the second polarization state to the transmitting node based on the fourth test signal received at the seventh baseband frequency after reception compensation and the fourth test signal received at the eighth baseband frequency after reception compensation. The transmission parameters corresponding to the second polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the fourth test signal sent by the transmitting node in the transmitting node.

[0203] Similar to the seventh baseband frequency, the eighth baseband frequency is also an arbitrary frequency preset in the subcarrier corresponding to the second receiving node, and the eighth baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the eighth baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the sixth baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the relationship between the signal carried by the fifth baseband frequency and the signal carried by the sixth baseband frequency is conjugate, the relationship between the signal carried by the seventh baseband frequency and the signal carried by the eighth baseband frequency is anti-conjugate; when the relationship between the signal carried by the fifth baseband frequency and the signal carried by the sixth baseband frequency is anti-conjugate, the relationship between the signal carried by the seventh baseband frequency and the signal carried by the eighth baseband frequency is conjugate.

[0204] According to the above content, the signal received by the receiving node will undergo phase rotation and polarization rotation compared to the signal sent by the sending node. Therefore, the real signal (or imaginary signal) of any polarization state received by the receiving node is not actually the real signal (or imaginary signal) of the polarization state sent by the sending node.

[0205] For example, based on the aforementioned embodiment, the symbol rate of the subcarrier is 8 gigabits baud (Gbaud), the residual frequency deviation is 100 megahertz (MHz), and the signal undergoes phase rotation under the action of the residual frequency deviation and phase noise. The signal also undergoes polarization rotation in the optical fiber link segment. As a result, the test signal received by each receiving node (such as the first receiving node and the second receiving node) on each receiving link segment at each moment includes the real signal and imaginary signal of the test signal of the first polarization state carried on multiple baseband frequencies, as well as the real signal and imaginary signal of the test signal of the second polarization state. In the embodiment of the present application, the residual frequency deviation can be set to be larger, for example, the residual frequency deviation is 1 / 10 of the baud rate.

[0206] When determining the transmission parameters according to the received compensated test signal, the receiving node may first perform a first filtering on the received compensated test signal to distinguish the test signal in the first polarization state from the test signal in the second polarization state.

[0207] For example, assuming that the transmit power parameter corresponding to the first polarization state is determined using the method shown in FIG12, and the transmit power parameter corresponding to the second polarization state is determined using the method shown in FIG19. Then, referring to FIG23, before determining the transmit power parameter corresponding to the first polarization state and the transmit power parameter corresponding to the second polarization state based on the first test signal and the third test signal after reception compensation, the receiving node may first perform a first filtering on the first test signal and the third test signal after reception compensation, so as to obtain signals of the first polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the first time t1 and the second time t2, and signals of the second polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the third time t3 and the fourth time t4.

[0208] For another example, assuming that the transmission delay parameter corresponding to the first polarization state is determined using the method shown in FIG13, and the transmission delay parameter corresponding to the second polarization state is determined using the method shown in FIG20. Then, referring to FIG24, before determining the transmission delay parameter corresponding to the first polarization state and the transmission delay parameter corresponding to the second polarization state based on the first test signal and the third test signal after reception compensation, the first test signal and the third test signal after reception compensation can be first filtered to obtain signals of the first polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the first time t1 and the second time t2, and signals of the second polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the third time t3 and the fourth time t4.

[0209] For another example, assuming that the transmit power parameters corresponding to the first polarization state are determined using the method shown in FIG12, and the transmit power parameters corresponding to the second polarization state are determined using the method shown in FIG21, then, referring to FIG25, before determining the transmit power parameters corresponding to the first polarization state and the transmit power parameters corresponding to the second polarization state based on the first test signal and the third test signal after reception compensation, the first test signal and the third test signal after reception compensation can be first filtered to obtain signals of the first polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the first time t1 and the second time t2, and signals of the second polarization state carried on the fifth baseband frequency fx3 and the sixth baseband frequency fx4 at the third time t1 and the fourth time t2.

[0210] For another example, assuming that the transmission delay parameters corresponding to the first polarization state are determined using the method shown in FIG13, and the transmission delay parameters corresponding to the second polarization state are determined using the method shown in FIG22, then, referring to FIG26, before determining the transmission delay parameters corresponding to the first polarization state and the transmission delay parameters corresponding to the second polarization state based on the first test signal and the third test signal after reception compensation, the first test signal and the third test signal after reception compensation can be first filtered to obtain signals of the first polarization state carried on the first baseband frequency fx1 and the second baseband frequency fx2 at the first time t1 and the second time t2, and signals of the second polarization state carried on the fifth baseband frequency fx3 and the sixth baseband frequency fx4 at the third time t1 and the fourth time t2.

[0211] When the first test signal and the 3rd test signal after receiving compensation are carried out the first filtering, the first filter adopted can be 1 tap polarization rotation filter (one-tap state of polarization filter, 1-tap SOP filter), or multi-tap SOP filter.Referring to Figure 23 to Figure 26, the first filter has hxx, hxy, hyx, hyy four tap coefficients.Hxx, hxy, hyx, hyy four tap coefficients can be gradually converged using the 1-tap SOP feedback loop in classical clock recovery algorithm, or can be calculated in one step.

[0212] Furthermore, there are multiple ways for the receiving node to perform reception compensation on the test signal. The following description will be made by taking the example of the first receiving node performing reception compensation on the received first test signal and the third test signal.

[0213] Taking the first test signal and the third test signal shown in Figure 16 as an example, according to the above content, it can be seen that the signal will undergo polarization rotation and phase rotation during transmission. Then, as shown in Figure 27, before the first receiving node performs reception compensation on the received first test signal and the third test signal, the first receiving node may also perform a second filtering on the received first test signal and the third test signal, so that at each moment, the first baseband frequency simultaneously carries the signal of the first polarization state and the signal of the second polarization state, and the second baseband frequency simultaneously carries the signal of the first polarization state and the signal of the second polarization state. Among them, the power of the signal of the first polarization state carried on the first baseband frequency, the signal of the second polarization state carried on the first baseband frequency, the signal of the first polarization state carried on the second baseband frequency, and the signal of the second polarization state carried on the second baseband frequency are equally or approximately equally divided. Optionally, the second filtering may not be performed.

[0214] After the second filtering, a signal of the first polarization state and a signal of the second polarization state can be obtained respectively. Both the signal of the first polarization state and the signal of the second polarization state are carried at the first baseband frequency and the second baseband frequency.

[0215] At the first receiving node, for the signal of the first polarization state, the first receiving node can extract the real signal (I) and the imaginary signal (Q) in the signal of the first polarization state, and perform FFT on the real signal and the imaginary signal in the signal of the first polarization state respectively, to obtain the signal carried on the first baseband frequency fx1 in the real signal of the first polarization state, the signal carried on the second baseband frequency fx2 in the real signal of the first polarization state, the signal carried on the first baseband frequency fx1 in the real signal of the first polarization state, and the signal carried on the second baseband frequency fx2 in the imaginary signal of the first polarization state. Afterwards, the first receiving node can perform power calculation on the four obtained signals respectively to obtain the power of each of the four signals. Finally, the first receiving node can use the ratio of the power of the signal carried on the first baseband frequency fx1 in the real signal of the first polarization state to the power of the signal carried on the first baseband frequency fx1 in the imaginary signal of the first polarization state as the seventh ratio. The first receiving node further uses the ratio of the power of the signal carried at the second baseband frequency fx2 in the real signal of the first polarization state to the power of the signal carried at the second baseband frequency fx2 in the imaginary signal of the first polarization state as an eighth ratio. The first receiving node then uses the average of the seventh ratio and the eighth ratio as the received power parameter corresponding to the first polarization state, and compensates the received power of the received signal of the first polarization state based on the received power parameter to compensate for the power imbalance between the real and imaginary signals of the first polarization state received by the first receiving node on different receiving link segments within the first receiving node.

[0216] The processing of the signal of the second polarization state can refer to the processing of the signal of the first polarization state by the first receiving node, except that the above-mentioned seventh ratio is replaced by the ninth ratio, and the above-mentioned eighth ratio is replaced by the tenth ratio. The embodiments of the present application are not described in detail here. The receiving node can use the average value of the ninth ratio and the tenth ratio as the receiving power parameter corresponding to the second polarization state, and compensate the received signal of the second polarization state according to the receiving power parameter to compensate for the power imbalance of the real signal and the imaginary signal of the first polarization state received by the first receiving node on different receiving link segments within the first receiving node.

[0217] The second filter used in the second filtering can be a 1-tap SOP filter, or a multi-tap SOP filter. The second filter also has four groups of tap coefficients: hxx, hxy, hyx, and hyy. The four groups of tap coefficients: hxx, hxy, hyx, and hyy can be gradually converged using the 1-tap SOP feedback loop in the classical clock recovery algorithm, or can be calculated in one step. The hxx, hxy, hyx, and hyy of the second filter are different from the hxx, hxy, hyx, and hyy of the first filter. Therefore, the hxx, hxy, hyx, and hyy of the first filter can be referred to as hxx1, hxy1, hyx1, and hyy1, and the hxx, hxy, hyx, and hyy of the second filter can be referred to as hxx2, hxy2, hyx2, and hyy2.

[0218] Continuing with the example of the first and third test signals shown in FIG16, as shown in FIG28, the first receiving node can replace the power calculation in FIG27 with TED, thereby replacing the seventh ratio obtained in FIG27 with the seventh difference in FIG28, replacing the eighth ratio in FIG27 with the eighth difference in FIG28, replacing the ninth ratio obtained in FIG27 with the ninth difference in FIG28, and replacing the tenth ratio in FIG27 with the tenth difference in FIG28. Ultimately, the receiving node can use the average of the seventh and eighth differences as the receive delay parameter corresponding to the first polarization state, and compensate for the receive delay of the received signal of the first polarization state based on the receive delay parameter, thereby compensating for the delay imbalance between the real and imaginary signals of the first polarization state received by the first receiving node on different receive link segments within the first receiving node. The receiving node can use the average of the ninth difference and the tenth difference as the receiving delay parameter corresponding to the second polarization state, and compensate for the receiving delay of the received signal of the second polarization state based on the receiving delay parameter to compensate for the delay imbalance of the real signal and the imaginary signal of the first polarization state received by the first receiving node on different receiving link segments within the first receiving node.

[0219] When the first test signal and the third test signal shown in Figure 16 are replaced by the first test signal and the third test signal shown in Figure 17, the process of the first receiving node determining the receiving power parameter can be replaced by Figure 29 from Figure 27, and the process of the first receiving node determining the receiving delay parameter can be replaced by Figure 30 from Figure 28. Compared with Figure 27 in Figure 29, and compared with Figure 28 in Figure 30, the change is that the signal of the first polarization state and the signal of the second polarization state obtained by the second filtering are both carried on the first baseband frequency fx1, the second baseband frequency fx2, the fifth baseband frequency fx3, and the sixth baseband frequency fx4.

[0220] It can be understood that in Figures 27 and 28, it is also possible that only at the first moment t1 and the second moment t2, the first baseband frequency and the second baseband frequency simultaneously carry signals of the first polarization state; and only at the third moment t3 and the fourth moment t4, the first baseband frequency and the second baseband frequency simultaneously carry signals of the second polarization state.

[0221] In Figures 29 and 30 , it is also possible that at both time t1 and time t2, the first baseband frequency and the second baseband frequency carry signals of the first polarization state simultaneously, and that at both time t1 and time t2, the third baseband frequency and the fourth baseband frequency carry signals of the second polarization state simultaneously. In this case, when processing signals of the first polarization state, the FFT result only includes signals of the first baseband frequency and the second baseband frequency; and when processing signals of the second polarization state, the FFT result only includes signals of the third baseband frequency and the fourth baseband frequency.

[0222] Of course, the first receiving node may also determine the aforementioned received power parameter and receive delay parameter based solely on the real and imaginary signals carried at a single baseband frequency in the signal of the first polarization state. Furthermore, the sampling bias and channel response are identical for the real and imaginary signals of the test signal carried at any baseband frequency received by the first receiving node. Therefore, the effects of the sampling bias and channel response on the delay can be offset by taking a difference in the TED output results.

[0223] The process of receiving compensation performed by other receiving nodes can refer to the process of receiving compensation performed by the first receiving node, and the embodiments of the present application will not be described in detail here.

[0224] Optionally, the relative delay deviation and relative power deviation between the signal of the first polarization state and the signal of the second polarization state can also be estimated in a similar manner, and the first receiving node can compensate for the relative delay deviation and relative power deviation between the signal of the first polarization state and the signal of the second polarization state or not.

[0225] The manner in which the first receiving node performs reception compensation for the received first test signal and the third test signal may also differ from the above manner. For example, the first receiving node may determine the above reception power parameter and reception delay parameter based on the service signal sent by the transmitting node, and then perform the above reception compensation based on the above reception power parameter and reception delay parameter.

[0226] In addition, the above embodiment takes the transmission of the test signal of each polarization state at two moments as an example. Optionally, the test signal of each polarization state can also be transmitted at multiple groups of moments, each group of moments includes two moments, and the transmission conditions of the test signal of each polarization state within these two moments are the same as the transmission conditions in the above embodiment.

[0227] For example, as shown in FIG31 , the first test signal shown in FIG16 can also be transmitted at the fifth time t5 and the sixth time t6, and the transmission condition of the first test signal at the fifth time t5 is the same as the transmission condition of the first test signal at the first time t1, and the transmission condition of the first test signal at the sixth time t6 is the same as the transmission condition of the first test signal at the second time t2. The third test signal shown in FIG16 can also be transmitted at the seventh time t7 and the eighth time t8, and the transmission condition of the third test signal at the seventh time t7 is the same as the transmission condition of the third test signal at the third time t3, and the transmission condition of the third test signal at the eighth time t8 is the same as the transmission condition of the third test signal at the fourth time t4. FIG31 takes the transmission of the test signal of each polarization state at two groups of time as an example, but the test signal of each polarization state can also be transmitted at more than two groups of time.

[0228] When the test signal of each polarization state is transmitted in at least two groups of time instants, the first receiving node can determine the transmission parameters and receiving parameters corresponding to each polarization state (such as the above-mentioned receiving power parameters and receiving delay parameters) based on the test signals received in each group of time instants, and then send the average value of all the transmission parameters corresponding to each polarization state as the transmission parameter corresponding to this polarization state to the transmitting node, and perform reception compensation on the received signal of this polarization state based on the average value of all the receiving parameters corresponding to each polarization state. This can improve the accuracy of the determined transmission parameters and receiving parameters.

[0229] Optionally, considering that a frequency offset may occur during signal transmission, the receiving node may adopt the following approach to address the problem of reduced accuracy of transmission parameters and / or reception parameters caused by the frequency offset.

[0230] For example, when the receiving node determines the transmission parameters and / or reception parameters based on the signal carried on an arbitrary baseband frequency, it can also offset the arbitrary baseband frequency, for example, offset the arbitrary baseband frequency by 3-5 frequency points. The receiving node can also determine the transmission parameters and / or reception parameters based on the signal carried on the frequency obtained by offsetting the arbitrary baseband frequency. Finally, the receiving node can send the transmission parameters determined based on the signal carried on the arbitrary baseband frequency and the average value of the transmission parameters determined based on the signal carried on the frequency obtained by offsetting the arbitrary baseband frequency as the final transmission parameters to the sending node. The receiving node can perform the above-mentioned reception compensation based on the reception parameters determined based on the signal carried on the arbitrary baseband frequency and the average value of the reception parameters determined based on the signal carried on the frequency obtained by offsetting the arbitrary baseband frequency.

[0231] When sending a test signal (such as the first test signal, the second test signal, the third test signal, and the fourth test signal), the sending node may stop sending a service signal. Alternatively, the sending node may send a service signal while sending a test signal. In this case, the transmission of the test signal does not affect the transmission of the service signal.

[0232] The following will take the first test signal as an example to illustrate the transmission relationship between the test signal and the service signal. The transmission relationship between other test signals and service signals can refer to the transmission relationship between the first test signal and the service signal.

[0233] For example, assuming that the service signal compensated according to the sending parameters in the aforementioned embodiment is called a first service signal, then the signal compensation method provided in the embodiment of the present application also includes: the sending node sends a second service signal in a first polarization state to the receiving node on the subcarrier corresponding to the receiving node.

[0234] The first test signal is encapsulated in the header of the first data frame and transmitted, while the second service signal is encapsulated in the payload of the first data frame and transmitted. As can be seen, the first test signal is not encapsulated in the payload of the first data frame, and therefore, the transmission of the first test signal does not affect the transmission of the second service signal encapsulated in the payload of the first data frame. As shown in Figure 32, the first data frame may include: a header and a payload, with the first test signal encapsulated in the header and the second service signal encapsulated in the payload. Optionally, the header includes other overhead portions and a test signal portion, and the first test signal may be encapsulated in the test signal portion.

[0235] Alternatively, the test signal of the first polarization state is encapsulated in the payload of the second data frame and transmitted, and the second service signal is encapsulated in the payload of the third data frame and transmitted. The second data frame and the third data frame are different data frames, and since the payloads of the second data frame and the third data frame are used to encapsulate different signals, the second data frame and the third data frame are two different types of data frames. Optionally, as shown in FIG33 , the frame header of the second data frame and the frame header of the third data frame both include a flag portion, and the information encapsulated in the flag portion in each data frame is used to indicate the type of the data frame. For example, the information encapsulated in the flag portion in the frame header of the second data frame is used to indicate that the second data frame is a data frame whose payload is encapsulated with the first test signal, and the information encapsulated in the flag portion in the frame header of the third data frame is used to indicate that the third data frame is a data frame whose payload is encapsulated with the second service signal. The frame headers of the second data frame and the third data frame may also include other overhead portions.

[0236] It is understandable that the method provided in the embodiment of the present application can be executed periodically (such as a period of one day or several days), or executed based on certain instructions, or executed based on the judgment results of certain conditions. In the case where it is not necessary to execute the method provided in the embodiment of the present application, a service signal can be transmitted between the sending node and the receiving node, and the service signal can be encapsulated in the first data frame shown in Figure 32 (the test signal part in the first data frame is empty), or the service signal can be encapsulated in the third data frame shown in Figure 33.

[0237] It can be understood that the function of each receiving node in the embodiment of the present application can refer to the function of the first receiving node mentioned above, and the embodiment of the present application will not be repeated here.

[0238] The effects of the solution provided in this application are explained below with reference to Figures 34 to 37 .

[0239] Figure 34 is a schematic diagram showing the error in the transmit delay parameter calculated by the method provided in an embodiment of the present application. Figure 35 is a schematic diagram showing the error in the transmit power parameter calculated by the method provided in an embodiment of the present application. Figure 36 is a schematic diagram showing the error in the receive delay parameter calculated by the method provided in an embodiment of the present application. Figure 37 is a schematic diagram showing the error in the receive power parameter calculated by the method provided in an embodiment of the present application.

[0240] In Figures 34 to 37, the horizontal axis represents the parameter that should be calculated in theory, the vertical axis on the right represents the parameter calculated by the method provided in the embodiment of the present application, and the vertical axis on the left represents the error of the parameter calculated by the method provided in the embodiment of the present application compared to the parameter that should be calculated in theory. The units of the horizontal and vertical axes in Figures 34 and 36 are both picoseconds (ps), and the units of the horizontal and vertical axes in Figures 35 and 37 are both decibels (dB). In Figures 34 to 37, the points of the triangle correspond to the horizontal axis and the vertical axis on the right, and the points of the circle correspond to the horizontal axis and the vertical axis on the left.

[0241] As shown in Figures 34 to 37, the errors in the transmit delay parameters, transmit power parameters, receive delay parameters, and receive power parameters calculated by the method provided in this application are all small. The errors in the transmit delay parameters and receive delay parameters calculated by the method provided in this application are all within ±0.5 ps, and the errors in the transmit power parameters and receive power parameters calculated by the method provided in this application are all within ±0.25 decibels (dB).

[0242] Based on the signal compensation method provided in the embodiment of the present application, the embodiment of the present application also provides the following signal compensation device.

[0243] For example, FIG38 is a schematic structural diagram of a signal compensation device provided in an embodiment of the present application. The signal compensation device belongs to a sending node. As shown in FIG38 , the signal compensation device includes:

[0244] The first sending module 3801 is used to send a first test signal of a first polarization state to a first receiving node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries the real signal and imaginary signal of the first test signal at different times; the operations performed by the first sending module 3801 can refer to S101 in the aforementioned embodiment.

[0245] The first receiving module 3802 is used to receive the sending parameters corresponding to the first polarization state sent by the first receiving node, and the sending parameters corresponding to the first polarization state sent by the first receiving node represent: the imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the operations performed by the first receiving module 3802 can refer to the operations performed by the sending node in the aforementioned S103.

[0246] The first compensation module 3803 is configured to compensate the service signal of the first polarization state to be transmitted according to the transmission parameters corresponding to the first polarization state. The operations performed by the first compensation module 3803 may refer to S104 in the above embodiment.

[0247] Since in the present application, the first baseband frequency carries the real signal and the imaginary signal of the first test signal at different times, the signal carried by the first baseband frequency at any time will not be affected by IQ imbalance. Moreover, based on the real signal carried by the first baseband frequency and the imaginary signal carried by the first baseband frequency, the imbalance between the real signal and the imaginary signal of the same polarization state in the sending node can be determined. In this way, the sending node can compensate for the service signal to be sent according to the sending parameters corresponding to the first polarization state that characterizes the imbalance, thereby improving the transmission effect of the service signal.

[0248] In addition, the first receiving node can determine the transmission parameters corresponding to the first polarization state based only on the test signal carried on the corresponding subcarrier. Therefore, the first receiving node does not need to rely on the signal carried on the symmetric subcarrier of the corresponding subcarrier.

[0249] Optionally, the signal compensation device also includes: a second sending module (not shown in Figure 38), used to send the first test signal to the first receiving node at a second baseband frequency; wherein the second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0250] Optionally, the signal compensation device also includes: a third sending module (not shown in Figure 38), used to send a second test signal of the first polarization state to a second receiving node at a third baseband frequency; a second receiving module (not shown in Figure 38), used to receive the sending parameters corresponding to the first polarization state sent by the second receiving node, and the sending parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal in the sending node; wherein the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are relative to the zero frequency of the sending node. Symmetric; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal at the different moments; at the different moments, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate, respectively.

[0251] Optionally, the signal compensation device also includes: a fourth sending module (not shown in Figure 38), used to send the second test signal of the first polarization state to the second receiving node at a third baseband frequency and a fourth baseband frequency, respectively; a third receiving module (not shown in Figure 38), used to receive the sending parameters corresponding to the first polarization state sent by the second receiving node, and the sending parameters corresponding to the first polarization state sent by the second receiving node represent: the imbalance between the real signal and the imaginary signal of the second test signal in the sending node.

[0252] Among them, the center frequency of the subcarrier corresponding to the first receiving node and the center frequency of the subcarrier corresponding to the second receiving node are symmetrical about the zero frequency of the sending node; the third baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; the third baseband frequency carries the real signal and the imaginary signal of the second test signal at different moments respectively; at different moments, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-combined, respectively yoke; the fourth baseband frequency is a preset frequency in the subcarrier corresponding to the second receiving node, and the fourth baseband frequency is different from the center frequency of the subcarrier corresponding to the second receiving node; the absolute value of the difference between the fourth baseband frequency and the center frequency of the subcarrier corresponding to the second receiving node is the same as the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugate; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is conjugate.

[0253] Optionally, the first compensation module 3803 is configured to compensate for a service signal in the first polarization state to be transmitted according to an average value of transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node.

[0254] Optionally, the transmission parameters corresponding to the first polarization state include: a transmission power parameter, and the transmission power parameter sent by the first receiving node represents: an imbalance in power between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0255] Optionally, the transmission parameters corresponding to the first polarization state include: at least one of a transmission power parameter and a transmission delay parameter; the transmission power parameter sent by the first receiving node represents: the power imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the transmission delay parameter sent by the first receiving node represents: the delay imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0256] Optionally, the signal compensation device further includes:

[0257] a fifth sending module (not shown in FIG38 ), configured to send a third test signal of a second polarization state to the first receiving node at a fifth baseband frequency; the fifth baseband frequency being a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency being different from the center frequency of the subcarrier corresponding to the first receiving node, and the fifth baseband frequency carrying the real part signal and the imaginary part signal of the third test signal at different times;

[0258] a fourth receiving module (not shown in FIG38 ), configured to receive a transmission parameter corresponding to the second polarization state sent by the first receiving node, where the transmission parameter corresponding to the second polarization state sent by the first receiving node represents an imbalance between the real signal and the imaginary signal of the third test signal sent by the sending node in the sending node;

[0259] A second compensation module (not shown in FIG38 ), configured to compensate for the service signal of the second polarization state to be transmitted according to the transmission parameters corresponding to the second polarization state;

[0260] In which, the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node.

[0261] FIG39 is a schematic diagram of the structure of another signal compensation device provided in an embodiment of the present application. The signal compensation device belongs to the first receiving node mentioned above. As shown in FIG39 , the signal compensation device includes:

[0262] The first receiving module 3901 is used to receive a first test signal of a first polarization state sent by a sending node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarrier corresponding to the first receiving node, and the first baseband frequency carries the real signal and imaginary signal of the first test signal at different times; the operations performed by the first receiving module 3901 can refer to the operations performed by the first receiving node in S101 in the aforementioned embodiment.

[0263] The first compensation module 3902 is used to perform receiving compensation on the received first test signal; the receiving compensation is used to compensate for the imbalance between the real signal and the imaginary signal of any polarization state in the receiving node; the operation performed by the first compensation module 3902 can refer to S102 in the aforementioned embodiment.

[0264] A first sending module 3903 is configured to send, to the sending node, a sending parameter corresponding to the first polarization state based on the first test signal after the reception compensation. The sending parameter corresponding to the first polarization state represents an imbalance between the real and imaginary parts of the first test signal sent by the sending node. The operations performed by the first sending module 3903 may refer to S103 in the aforementioned embodiment.

[0265] Optionally, the signal compensation device further includes:

[0266] a second receiving module (not shown in FIG39 ), configured to receive the first test signal sent by the sending node at a second baseband frequency;

[0267] The second baseband frequency is a preset frequency in the subcarrier corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarrier corresponding to the first receiving node;

[0268] When the first baseband frequency carries the real signal of the first test signal, the second baseband frequency carries the imaginary signal of the first test signal; when the first baseband frequency carries the imaginary signal of the first test signal, the second baseband frequency carries the real signal of the first test signal.

[0269] Optionally, the transmission parameter corresponding to the first polarization state includes: a transmission power parameter, where the transmission power parameter represents an imbalance in power between a real signal and an imaginary signal of the first test signal sent by the sending node in the sending node.

[0270] Optionally, the transmission parameter corresponding to the first polarization state includes: at least one of a transmission power parameter and a transmission delay parameter;

[0271] The sending power parameter characterizes: the power imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node; the sending delay parameter characterizes: the delay imbalance between the real signal and the imaginary signal of the first test signal sent by the sending node in the sending node.

[0272] Optionally, the signal compensation device further includes:

[0273] a third receiving module (not shown in FIG39 ), configured to receive, at a fifth baseband frequency, a third test signal of a second polarization state sent by the sending node; the fifth baseband frequency being a preset frequency in the subcarrier corresponding to the first receiving node, and the fifth baseband frequency being different from the center frequency of the subcarrier corresponding to the first receiving node, and the fifth baseband frequency carrying the real part signal and the imaginary part signal of the third test signal at different times;

[0274] a second compensation module (not shown in FIG39 ), configured to perform reception compensation on the received third test signal;

[0275] a second sending module (not shown in FIG39 ), configured to send, to the sending node, a sending parameter corresponding to the second polarization state based on the third test signal after the reception compensation, where the sending parameter corresponding to the second polarization state represents an imbalance between a real signal and an imaginary signal of the third test signal sent by the sending node in the sending node;

[0276] In which, the sending time of the first test signal is different from the sending time of the third test signal; and / or the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarrier corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarrier corresponding to the first receiving node.

[0277] The present application also provides a communication system including a transmitting node and at least one receiving node. The at least one receiving node may include the first receiving node described above, and the at least one receiving node may also include the second receiving node described above. The functions of the transmitting node, the first receiving node, and the second receiving node may be described in the aforementioned method embodiment, and are not further described in detail in the present application.

[0278] An embodiment of the present application also provides a chip, which includes a programmable logic circuit and / or program instructions, and when the chip is running, is used to implement the operations performed by a sending node or any receiving node in any signal compensation method provided in the embodiment of the present application.

[0279] The embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions;

[0280] When the instructions are executed on a computer, the computer is caused to execute the operations performed by the sending node or any receiving node in any signal compensation method provided in the embodiments of the present application.

[0281] The present application provides a computer program product comprising instructions. When the computer program product is run on a computer, the computer is enabled to perform the operations performed by a transmitting node or any receiving node in any signal compensation method provided in the present application.

[0282] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product, which includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium, or a semiconductor medium (e.g., a solid-state hard disk).

[0283] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. The term "at least one" refers to one or more, and "plurality" refers to two or more, unless otherwise expressly limited. The term "and / or" simply describes an association relationship between associated objects, indicating that three possible relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0284] The different types of embodiments, such as the method embodiments and device embodiments provided in the embodiments of this application, can refer to each other, and the embodiments of this application are not limited thereto. The order of the operations of the method embodiments provided in the embodiments of this application can be appropriately adjusted, and the operations can be increased or decreased accordingly according to the circumstances. Any person skilled in the art who can easily think of a method of variation within the technical scope disclosed in this application should be included in the scope of protection of this application, and therefore will not be described in detail.

[0285] In the corresponding embodiments provided in this application, it should be understood that the disclosed systems and devices can be implemented through other structural methods. For example, the device embodiments described above are merely illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods, such as multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or module, which can be electrical or other forms.

[0286] Units described as separate components may or may not be physically separate, and components described as units may or may not be physical units, and may be located in one place or distributed across multiple devices. Some or all of these units may be selected to achieve the purpose of this embodiment based on actual needs.

[0287] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A signal compensation method, characterized in that, The method is executed by a sending node, and the method includes: Sending a first test signal in a first polarization state to a first receiving node at a first baseband frequency; the first baseband frequency is a preset frequency among the subcarriers corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the first baseband frequency carries the real part signal and the imaginary part signal of the first test signal at different times respectively; Receiving the transmission parameters corresponding to the first polarization state sent by the first receiving node, and the transmission parameters corresponding to the first polarization state sent by the first receiving node characterize: the imbalance between the real part signal and the imaginary part signal of the first test signal sent by the sending node in the sending node; Compensating the service signal in the first polarization state to be sent according to the transmission parameters corresponding to the first polarization state.

2. The method according to claim 1, wherein The method further includes: Sending the first test signal to the first receiving node at a second baseband frequency; wherein, the second baseband frequency is a preset frequency among the subcarriers corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node; when the first baseband frequency carries the real part signal of the first test signal, the second baseband frequency carries the imaginary part signal of the first test signal; when the first baseband frequency carries the imaginary part signal of the first test signal, the second baseband frequency carries the real part signal of the first test signal.

3. The method according to claim 1, wherein The method further includes: Sending a second test signal in the first polarization state to a second receiving node at a third baseband frequency; Receiving the transmission parameters corresponding to the first polarization state sent by the second receiving node, and the transmission parameters corresponding to the first polarization state sent by the second receiving node characterize: the imbalance between the real part signal and the imaginary part signal of the second test signal in the sending node; wherein, the center frequency of the subcarriers corresponding to the first receiving node is symmetric about the zero frequency of the sending node with the center frequency of the subcarriers corresponding to the second receiving node; the third baseband frequency is a preset frequency among the subcarriers corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarriers corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarriers corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node; the third baseband frequency carries the real part signal and the imaginary part signal of the second test signal at different times respectively; at different times, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate respectively.

4. The method according to claim 2, wherein The method further includes: Sending the second test signal in the first polarization state to the second receiving node at the third baseband frequency and the fourth baseband frequency respectively; Receiving the transmission parameters corresponding to the first polarization state sent by the second receiving node, where the transmission parameters corresponding to the first polarization state sent by the second receiving node characterize the imbalance between the real part signal and the imaginary part signal of the second test signal in the transmitting node; Wherein, the center frequency of the subcarrier corresponding to the first receiving node is symmetric about the zero frequency of the transmitting node with the center frequency of the subcarrier corresponding to the second receiving node; The third baseband frequency is a preset frequency in the subcarriers corresponding to the second receiving node, and the third baseband frequency is different from the center frequency of the subcarriers corresponding to the second receiving node; the absolute value of the difference between the third baseband frequency and the center frequency of the subcarriers corresponding to the second receiving node is the same as the absolute value of the difference between the first baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node; The third baseband frequency carries the real part signal and the imaginary part signal of the second test signal at different times respectively; at different times, the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate and anti-conjugate respectively; The fourth baseband frequency is a preset frequency in the subcarriers corresponding to the second receiving node, and the fourth baseband frequency is different from the center frequency of the subcarriers corresponding to the second receiving node; the absolute value of the difference between the fourth baseband frequency and the center frequency of the subcarriers corresponding to the second receiving node is the same as the absolute value of the difference between the second baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node; When the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is anti-conjugate; when the relationship between the signal carried by the first baseband frequency and the signal carried by the third baseband frequency is anti-conjugate, the relationship between the signal carried by the second baseband frequency and the signal carried by the fourth baseband frequency is conjugate.

5. The method according to claim 3 or 4, characterized in that, Compensating the service signal of the first polarization state to be transmitted according to the transmission parameters corresponding to the first polarization state, including: Compensating the service signal of the first polarization state to be transmitted according to the average value of the transmission parameters corresponding to the first polarization state sent by the first receiving node and the second receiving node.

6. The method according to any one of claims 1 to 5, characterized in that, The transmission parameters corresponding to the first polarization state include: a transmission power parameter, where the transmission power parameter sent by the first receiving node characterizes the power imbalance between the real part signal and the imaginary part signal of the first test signal sent by the transmitting node in the transmitting node.

7. The method according to claim 2 or 4, characterized in that, The transmission parameters corresponding to the first polarization state include at least one of a transmission power parameter and a transmission delay parameter; The transmission power parameter sent by the first receiving node characterizes the power imbalance between the real part signal and the imaginary part signal of the first test signal sent by the transmitting node in the transmitting node; The transmission delay parameter sent by the first receiving node characterizes the imbalance in the time delays of the real part signal and the imaginary part signal of the first test signal sent by the sending node in the sending node.

8. The method according to any one of claims 1 to 7, characterized in that The method further includes: Sending a third test signal of a second polarization state to the first receiving node at a fifth baseband frequency; the fifth baseband frequency is a preset frequency among the subcarriers corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the fifth baseband frequency carries the real part signal and the imaginary part signal of the third test signal at different times respectively; Receiving the transmission parameter corresponding to the second polarization state sent by the first receiving node, where the transmission parameter corresponding to the second polarization state sent by the first receiving node characterizes the imbalance in the real part signal and the imaginary part signal of the third test signal sent by the sending node in the sending node; Compensating the service signal of the second polarization state to be sent according to the transmission parameter corresponding to the second polarization state; Wherein, the sending time of the first test signal is different from the sending time of the third test signal; and / or, the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarriers corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarriers corresponding to the first receiving node.

9. A signal compensation method, characterized in that, The method is executed by a first receiving node, and the method includes: Receiving a first test signal of a first polarization state sent by a sending node at a first baseband frequency; the first baseband frequency is a preset frequency among the subcarriers corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the first baseband frequency carries the real part signal and the imaginary part signal of the first test signal at different times respectively; Performing reception compensation on the received first test signal; the reception compensation is used to compensate for the imbalance in the real part signal and the imaginary part signal of any polarization state in the receiving node; Sending the transmission parameter corresponding to the first polarization state to the sending node according to the first test signal after the reception compensation, where the transmission parameter corresponding to the first polarization state characterizes the imbalance in the real part signal and the imaginary part signal of the first test signal sent by the sending node in the sending node.

10. The method according to claim 9, characterized in that, Before performing reception compensation on the first test signal, the method further includes: Receiving the first test signal sent by the sending node at a second baseband frequency; Wherein, the second baseband frequency is a preset frequency among the subcarriers corresponding to the first receiving node; the absolute value of the difference between the second baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node is different from the absolute value of the difference between the first baseband frequency and the center frequency of the subcarriers corresponding to the first receiving node is different. When the real part signal of the first test signal is carried at the first baseband frequency, the imaginary part signal of the first test signal is carried at the second baseband frequency; when the imaginary part signal of the first test signal is carried at the first baseband frequency, the real part signal of the first test signal is carried at the second baseband frequency.

11. The method according to claim 9, characterized in that, The transmission parameters corresponding to the first polarization state include: a transmission power parameter, and the transmission power parameter characterizes the power imbalance between the real part signal and the imaginary part signal of the first test signal transmitted by the transmitting node in the transmitting node.

12. The method according to claim 10, wherein The transmission parameters corresponding to the first polarization state include at least one of a transmission power parameter and a transmission delay parameter; The transmission power parameter characterizes: the power imbalance between the real part signal and the imaginary part signal of the first test signal transmitted by the transmitting node in the transmitting node; the transmission delay parameter characterizes: the delay imbalance between the real part signal and the imaginary part signal of the first test signal transmitted by the transmitting node in the transmitting node.

13. The method according to any one of claims 9 to 12, characterized in that The method further includes: Receiving a third test signal of a second polarization state transmitted by the transmitting node at a fifth baseband frequency; the fifth baseband frequency is a preset frequency in the subcarriers corresponding to the first receiving node, and the fifth baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the fifth baseband frequency carries the real part signal and the imaginary part signal of the third test signal at different times respectively; Performing the reception compensation on the received third test signal; According to the third test signal after the reception compensation, sending the transmission parameters corresponding to the second polarization state to the transmitting node, and the transmission parameters corresponding to the second polarization state characterize: the imbalance between the real part signal and the imaginary part signal of the third test signal transmitted by the transmitting node in the transmitting node; Wherein, the transmission time of the first test signal is different from the transmission time of the third test signal; and / or, the absolute value of the difference between any frequency carried by the first test signal and the center frequency of the subcarriers corresponding to the first receiving node is different from the absolute value of the difference between any frequency carried by the third test signal and the center frequency of the subcarriers corresponding to the first receiving node.

14. A signal compensation device, characterized in that, The signal compensation device belongs to the transmitting node, and the signal compensation device includes: A first transmitting module, configured to transmit a first test signal of a first polarization state to a first receiving node at a first baseband frequency; the first baseband frequency is a preset frequency in the subcarriers corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the first baseband frequency carries the real part signal and the imaginary part signal of the first test signal at different times respectively; A first receiving module, configured to receive the transmission parameters corresponding to the first polarization state sent by the first receiving node, and the transmission parameters corresponding to the first polarization state sent by the first receiving node characterize: the imbalance between the real part signal and the imaginary part signal of the first test signal transmitted by the transmitting node in the transmitting node; A first compensation module, configured to compensate the service signal of the first polarization state to be transmitted according to the transmission parameters corresponding to the first polarization state.

15. A signal compensation device, characterized in that, The signal compensation device belongs to a first receiving node, and the signal compensation device includes: A first receiving module, configured to receive a first test signal of a first polarization state sent by a sending node at a first baseband frequency; the first baseband frequency is a preset frequency among subcarriers corresponding to the first receiving node, and the first baseband frequency is different from the center frequency of the subcarriers corresponding to the first receiving node, and the first baseband frequency respectively carries the real part signal and the imaginary part signal of the first test signal at different times; A first compensation module, configured to perform reception compensation on the received first test signal; the reception compensation is used to compensate for the imbalance of the real part signal and the imaginary part signal of any polarization state in the receiving node; A first sending module, configured to send the transmission parameters corresponding to the first polarization state to the sending node according to the first test signal after the reception compensation, where the transmission parameters corresponding to the first polarization state characterize the imbalance of the real part signal and the imaginary part signal of the first test signal sent by the sending node in the sending node.

16. A signal compensation device, characterized in that, including: a transceiver and a processor; The transceiver is configured to perform the sending operation and the receiving operation in the signal compensation method according to any one of claims 1 to 8; The processor is configured to perform the operations in the signal compensation method according to any one of claims 1 to 8 other than the sending operation and the receiving operation; Alternatively, the transceiver is configured to perform the sending operation and the receiving operation in the signal compensation method according to any one of claims 9 to 13; the processor is configured to perform the operations in the signal compensation method according to any one of claims 9 to 13 other than the sending operation and the receiving operation.

17. A communication system, characterized in that, including: a sending node and at least one receiving node; The sending node is configured to perform the signal compensation method according to any one of claims 1 to 8, and the at least one receiving node includes a first receiving node, and the first receiving node is configured to perform the signal compensation method according to any one of claims 9 to 13.

18. A chip, characterized in that, The chip includes a programmable logic circuit and / or program instructions, and when the chip runs, it is configured to implement the signal compensation method according to any one of claims 1 to 8; or, when the chip runs, it is configured to implement the signal compensation method according to any one of claims 9 to 13.

19. A computer-readable storage medium, characterized in that, Instructions are stored in the computer-readable storage medium; When the instructions run on a computer, the computer is caused to execute the signal compensation method according to any one of claims 1 to 8; or, when the instructions run on a computer, the computer is caused to execute the signal compensation method according to any one of claims 9 to 13.

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