CN114830546B - Signal transceiving circuit and method for power line communication - Google Patents

Abstract

This application discloses a signal transceiving circuit and method for power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. The differential mode coupling circuit and the common mode coupling circuit are respectively connected to the power line. The noise The processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit. The power line includes at least one of the following: live line, neutral line and ground line, wherein the differential mode coupling circuit is used to couple and receive differential mode signals on the power line; The common mode coupling circuit is used for coupling and receiving the common mode signal on the power line; the noise processing circuit is used for processing the common mode signal and the differential mode signal to eliminate noise in the differential mode signal. By introducing a common-mode coupling circuit, the common-mode signal on the power line is obtained, and the received differential-mode signal and common-mode signal are processed by the noise processing circuit to eliminate the noise, thereby improving the performance of power line communication.

Description

Signal transceiving circuit and method for power line communication

Technical field

The present application relates to the field of communication technology, and in particular to a signal transceiving circuit and method for power line communication.

Background technique

Power line communication (PLC) technology refers to a communication method that uses power lines to transmit data and media signals.

Noise in power line communications mainly comes from electrical appliances in the power line network, and the load impedance of various electrical appliances added to the power line network changes in real time, and the noise interference also changes in real time. Electrical appliance noise in power line communications usually takes the form of various forms of pulse noise, and the pulse amplitude is large, which degrades the performance of power line communications. At present, the periodic characteristics of electrical appliance noise are usually used to communicate using the channel carrying capacity of the time period in different time periods. However, this does not improve the electrical noise. It only matches the channel carrying capacity for communication under existing noise conditions. Therefore, the performance of power line communication is poor.

Contents of the invention

Embodiments of the present application provide a signal transceiver circuit and method for power line communication. The common mode signal on the power line is obtained by introducing a common mode coupling circuit, and the received differential mode signal and common mode signal are processed by the noise processing circuit to eliminate noise. , thereby improving the performance of power line communications.

In a first aspect, embodiments of the present application provide a signal transceiver circuit for power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. The differential mode coupling circuit and the common mode coupling circuit are respectively connected to power lines, and the noise processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit. The power lines include at least one of the following: live wire, neutral wire and ground wire, wherein the differential mode coupling The circuit is used for coupling and receiving the differential mode signal on the power line; the common mode coupling circuit is used for coupling and receiving the common mode signal on the power line; the noise processing circuit is used for coupling the common mode signal and The differential mode signal is processed to eliminate noise in the differential mode signal.

In the above circuit, the common mode signal on the power line is obtained by introducing a common mode coupling circuit. Since the noise in the differential mode signal obtained through the differential mode coupling circuit is correlated with the noise in the common mode signal, the difference can be processed by the noise processing circuit. Mode signals and common-mode signals are processed to eliminate noise in the received signal, thereby improving the performance of power line communications.

In conjunction with the first aspect, in a possible implementation of the first aspect, the differential mode coupling circuit includes at least one coupling transformer and at least one transceiver circuit, and each of the at least one coupling transformers is connected to the At least two of the power lines are connected, each of the at least one coupling transformer is coupled to one of the at least one transceiver circuit, wherein each of the at least one coupling transformer, for coupling differential mode signals received from at least two of the power lines to one of the at least one transceiver circuit; each of the at least one transceiver circuit, for receiving Each coupling transformer couples to the differential mode signal of each transceiver circuit.

In conjunction with the first aspect, in a possible implementation of the first aspect, the common mode coupling circuit includes a common mode transformer and a common mode signal receiving circuit, and the common mode transformer is connected to the live wire, the neutral wire and the ground wire, The common mode transformer is coupled to the common mode signal receiving circuit, wherein the common mode transformer is used to couple common mode signals received from the live line, neutral line and ground line to the common mode signal receiving circuit. ; The common mode signal receiving circuit is used to receive the common mode signal coupled to the common mode signal receiving circuit by the common mode transformer.

With reference to the first aspect, in a possible implementation of the first aspect, the differential mode coupling circuit includes a first coupling transformer, a first transceiver circuit, a second coupling transformer and a second transceiver circuit. The first coupling circuit A transformer is connected to two lines of the power line, the first coupling transformer is coupled to the first transceiver circuit, the second coupling transformer is connected to two lines of the power line, the second coupling transformer Coupled to the second transceiver circuit, two of the power lines are two of the live wire, the neutral wire and the ground wire, and the two of the power lines connected to the first coupling transformer are connected to the Two of the power lines connected by the second coupling transformer are different, wherein the first coupling transformer is used to couple the first differential mode signal received from the two lines of the power line to the a first transceiver circuit; the first transceiver circuit is used to receive the first differential mode signal coupled from the first coupling transformer to the first transceiver circuit; the second coupling transformer is used to couple the first differential mode signal from the first transceiver circuit to the first transceiver circuit; The second differential mode signal received on two lines of the power line is coupled to the second transceiver circuit; the second transceiver circuit is used to receive the second differential mode signal coupled to the second transceiver circuit by the second coupling transformer. the second differential mode signal.

In conjunction with the first aspect, in a possible implementation of the first aspect, the differential mode coupling circuit further includes a third coupling transformer and a third transceiver circuit, and the third coupling transformer is connected to two of the power lines. line connection, the third coupling transformer is coupled to the third transceiver circuit, two of the power lines connected to the third coupling transformer are connected to two of the power lines connected to the first coupling transformer lines are different, and two of the power lines connected to the second coupling transformer are different, wherein the third coupling transformer is used to receive a third power line from the two lines of the power lines. The differential mode signal is coupled to the third transceiver circuit; the third transceiver circuit is configured to receive the third differential mode signal coupled to the third transceiver circuit by the third coupling transformer.

With reference to the first aspect, in a possible implementation of the first aspect, the differential mode coupling circuit includes a fourth coupling transformer, a fourth transceiver circuit, a fifth coupling transformer and a fifth transceiver circuit. The fourth coupling A transformer is connected to at least two of the power lines, the fourth coupling transformer is coupled to the fourth transceiver circuit, the fifth coupling transformer is connected to at least two of the power lines, and the fifth coupling transformer is coupled to at least two of the power lines. A coupling transformer is coupled to the fifth transceiver circuit, at least two of the power lines are two of the live line, the neutral line and the ground line or the live line, the neutral line and the ground line, the fourth coupling transformer and the At least one of the fifth coupling transformers is connected to the live wire, the neutral wire and the ground wire, wherein the fourth coupling transformer is used to receive a fourth difference from at least two of the power lines. The fourth differential mode signal is coupled to the fourth transceiver circuit; the fourth transceiver circuit is used to receive the fourth differential mode signal coupled to the fourth transceiver circuit by the fourth coupling transformer; the fifth coupling transformer , for coupling the fifth differential mode signal received from at least two lines in the power line to the fifth transceiver circuit; the fifth transceiver circuit, for receiving the fifth coupling transformer coupled to The fifth differential mode signal of the fifth transceiver circuit.

In conjunction with the first aspect, in a possible implementation of the first aspect, the differential mode coupling circuit further includes a sixth coupling transformer and a sixth transceiver circuit, and the sixth coupling transformer is connected to at least two of the power lines. lines are connected, and the sixth coupling transformer is coupled to the sixth transceiver circuit, wherein the sixth coupling transformer is used to receive a sixth differential mode signal from at least two lines in the power line. Coupled to the sixth transceiver circuit; the sixth transceiver circuit is configured to receive the sixth differential mode signal coupled to the sixth transceiver circuit by the sixth coupling transformer.

With reference to the first aspect, in a possible implementation of the first aspect, the noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end, and the analog front end communicates with the differential mode through the analog interface. The coupling circuit is connected to the common mode coupling circuit, and the digital front end is connected to the analog front end through the digital interface. The analog front end includes an adjustable amplifier and an analog-to-digital converter, wherein the analog interface is used for Receive the differential mode signal and the common mode signal; the adjustable amplifier is used to amplify the differential mode signal and the common mode signal received by the analog interface to obtain an amplified differential mode signal. signal and common-mode signal; the analog-to-digital converter is used to sample the amplified differential mode signal and common-mode signal to obtain a digital signal; the digital interface is used to receive the digital signal; The digital front end is used to process the digital signal received by the digital interface to eliminate noise.

In a second aspect, embodiments of the present application provide a signal transceiving method for power line communication, which is applied to a signal transceiving circuit for power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. The differential mode The coupling circuit and the common mode coupling circuit are respectively connected to power lines, the noise processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit, and the power lines include at least one of the following: live wire, neutral wire and ground. line, the method includes: the differential mode coupling circuit is coupled to receive a differential mode signal on the power line; the common mode coupling circuit is coupled to receive a common mode signal on the power line; the noise processing circuit is The differential mode signal and the differential mode signal are processed to eliminate noise in the differential mode signal.

In the above method, the common mode signal on the power line is obtained by introducing a common mode coupling circuit. Since the noise in the differential mode signal obtained through the differential mode coupling circuit is correlated with the noise in the common mode signal, the difference can be processed by the noise processing circuit. Mode signals and common-mode signals are processed to eliminate noise in the received signal, thereby improving the performance of power line communications.

In conjunction with the second aspect, in a possible implementation of the second aspect, the differential mode coupling circuit includes at least one coupling transformer and at least one transceiver circuit, and each coupling transformer in the at least one coupling transformer is connected to the At least two of the power lines are connected, each of the at least one coupling transformers is coupled to one of the at least one transceiver circuits, and the differential mode coupling circuit is coupled to receive the differential mode on the power line. The signals include: each of the at least one coupling transformers couples differential mode signals received from at least two of the power lines to one of the at least one transceiver circuits; the at least one Each transceiver circuit in one transceiver circuit receives the differential mode signal coupled to each transceiver circuit by the coupling transformer.

In conjunction with the second aspect, in a possible implementation of the second aspect, the common mode coupling circuit includes a common mode transformer and a common mode signal receiving circuit, and the common mode transformer is connected to the live wire, the neutral wire and the ground wire, The common mode transformer is coupled to the common mode signal receiving circuit, and the common mode coupling circuit is coupled to receive the common mode signal on the power line including: the common mode transformer will receive the live line, the neutral line and the ground line. The common mode signal is coupled to the common mode signal receiving circuit; the common mode signal receiving circuit receives the common mode signal coupled to the common mode signal receiving circuit by the common mode transformer.

In conjunction with the second aspect, in a possible implementation of the second aspect, the differential mode coupling circuit includes a first coupling transformer, a first transceiver circuit, a second coupling transformer and a second transceiver circuit. The first coupling circuit A transformer is connected to two lines of the power line, the first coupling transformer is coupled to the first transceiver circuit, the second coupling transformer is connected to two lines of the power line, the second coupling transformer Coupled to the second transceiver circuit, two of the power lines are two of the live wire, the neutral wire and the ground wire, and the two of the power lines connected to the first coupling transformer are connected to the The two lines of the power line connected by the second coupling transformer are different, and the differential mode coupling circuit coupling to receive the differential mode signal on the power line includes: the first coupling transformer converts the two lines of the power line from the The first differential mode signal received on the first transceiver circuit is coupled to the first transceiver circuit; the first transceiver circuit receives the first differential mode signal coupled to the first transceiver circuit by the first coupling transformer; A second coupling transformer couples a second differential mode signal received from two of the power lines to the second transceiver circuit; the second transceiver circuit receives the second differential mode signal and couples it to the third The second differential mode signal of the two transceiver circuits.

In conjunction with the second aspect, in a possible implementation of the second aspect, the differential mode coupling circuit further includes a third coupling transformer and a third transceiver circuit, and the third coupling transformer is connected to two of the power lines. line connection, the third coupling transformer is coupled to the third transceiver circuit, two of the power lines connected to the third coupling transformer are connected to two of the power lines connected to the first coupling transformer lines are different, and two of the power lines connected to the second coupling transformer are different, the differential mode coupling circuit coupling to receive the differential mode signal on the power line further includes: the third coupling transformer will receive the differential mode signal from the power line. The third differential mode signal received on two of the power lines is coupled to the third transceiver circuit; the third transceiver circuit receives the third differential mode signal coupled to the third transceiver circuit by the third coupling transformer. The third differential mode signal.

In conjunction with the second aspect, in a possible implementation of the second aspect, the differential mode coupling circuit includes a fourth coupling transformer, a fourth transceiver circuit, a fifth coupling transformer, and a fifth transceiver circuit. The fourth coupling A transformer is connected to at least two of the power lines, the fourth coupling transformer is coupled to the fourth transceiver circuit, the fifth coupling transformer is connected to at least two of the power lines, and the fifth coupling transformer is coupled to at least two of the power lines. A coupling transformer is coupled to the fifth transceiver circuit, at least two of the power lines are two of the live line, the neutral line and the ground line or the live line, the neutral line and the ground line, the fourth coupling transformer and the At least one of the fifth coupling transformers is connected to the live wire, the neutral wire and the ground wire, and the differential mode coupling circuit is coupled to receive the differential mode signal on the power line including: the fourth coupling transformer receives the differential mode signal from the power line. The fourth differential mode signal received on at least two lines in is coupled to the fourth transceiver circuit; the fourth transceiver circuit receives the fourth coupling transformer and is coupled to the fourth transceiver circuit. a differential mode signal; the fifth coupling transformer couples a fifth differential mode signal received from at least two of the power lines to the fifth transceiver circuit; the fifth transceiver circuit receives the fifth A coupling transformer couples to the fifth differential mode signal of the fifth transceiver circuit.

In conjunction with the second aspect, in a possible implementation of the second aspect, the differential mode coupling circuit further includes a sixth coupling transformer and a sixth transceiver circuit, and the sixth coupling transformer is connected to at least two of the power lines. The sixth coupling transformer is coupled to the sixth transceiver circuit, and the differential mode coupling circuit is coupled to receive the differential mode signal on the power line. The sixth coupling transformer is coupled to the power line to receive the differential mode signal from the power line. The sixth differential mode signal received on at least two lines is coupled to the sixth transceiver circuit; the sixth transceiver circuit receives the sixth differential mode signal coupled to the sixth transceiver circuit by the sixth coupling transformer. mode signal.

With reference to the second aspect, in a possible implementation of the second aspect, the noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end, and the analog front end communicates with the differential mode through the analog interface. The coupling circuit is connected to the common mode coupling circuit, the digital front end is connected to the analog front end through the digital interface, the analog front end includes an adjustable amplifier and an analog-to-digital converter, and the noise processing circuit Processing the differential mode signal and the differential mode signal to eliminate noise in the differential mode signal includes: the analog interface receives the differential mode signal and the common mode signal; the adjustable amplifier The received differential mode signal and the common mode signal are amplified to obtain amplified differential mode signals and common mode signals; the analog-to-digital converter performs amplification on the amplified differential mode signal and common mode signal. Sampling is performed to obtain a digital signal; the digital interface receives the digital signal; the digital front end processes the digital signal received by the digital interface to eliminate noise.

Description of the drawings

Figure 1a is a schematic diagram of a Delta type differential mode coupling circuit;

Figure 1b is a schematic diagram of a T-type differential mode coupling circuit;

Figure 1c is a schematic diagram of noise changes;

Figure 1d is a schematic diagram of the changes in the noise generated by Delixi spotlights during the AC cycle;

Figure 1e is a schematic diagram of receiving signals under interference from Delixi spotlights;

Figure 2a is a schematic diagram of a signal transceiver circuit for power line communication provided by an embodiment of the present application;

Figure 2b is a schematic diagram of the correlation between differential mode electrical noise and common mode electrical noise;

Figure 3 is a schematic structural diagram of the common mode transformer in Figure 2a;

Figure 4a is a schematic diagram of a power line communication system provided by an embodiment of the present application;

Figure 4b is a schematic diagram of the differential mode coupling circuit 2 and the common mode coupling circuit included in the electronic device 2 in Figure 4a;

Figure 4c is a schematic diagram of another differential mode coupling circuit 2 and a common mode coupling circuit included in the electronic device 2 in Figure 4a;

Figure 5a is a schematic diagram of another power line communication system provided by an embodiment of the present application;

Figure 5b is a schematic diagram of the differential mode coupling circuit 4 and the common mode coupling circuit included in the electronic device 4 in Figure 5a;

Figure 5c is a schematic diagram of another differential mode coupling circuit 4 and a common mode coupling circuit included in the electronic device 4 in Figure 5a;

Figure 6 is a schematic diagram of a noise processing circuit provided by an embodiment of the present application;

Figure 7 is a schematic diagram of another signal transceiver circuit for power line communication provided by an embodiment of the present application;

Figure 8 is a schematic diagram of a signal sending and receiving method for power line communication provided by an embodiment of the present application;

Figure 9 is a schematic diagram of another signal sending and receiving method for power line communication provided by an embodiment of the present application;

Figure 10 is a schematic diagram of another signal sending and receiving method for power line communication provided by an embodiment of the present application;

Figure 11 is a schematic diagram of the performance gain achieved by receiving signals through the signal transceiver circuit provided in the embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

In the following, some terms used in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

“At least one” in the embodiments of this application refers to one or more, and “multiple” refers to two or more. "And/or" describes the association of associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A, B can be singular or plural. The character "/" generally indicates that the related objects are in an "or" relationship. "At least one of the following" or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items). For example, at least one of a, b, or c can mean: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .

And, unless otherwise stated, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or priority of multiple objects. Importance. For example, the first information and the second information are only used to distinguish different information, but do not indicate the difference in content, priority, sending order or importance of the two types of information.

In order to facilitate the understanding of this application, the background technology of this application is first introduced here:

Power line communication: Power line communication (PLC) technology refers to a communication method that uses power lines to transmit data and media signals, also known as power line network. PLC technology uses existing low-frequency (50/60 Hz) power lines to send broadband data. Digital subscriber line (DSL) technology uses telephone lines for data transmission, while cable modem (CM) uses coaxial cable lines of cable TV for data transmission. Relatively speaking, power line communication technology basically does not require In addition, network lines are re-laid, and the area covered by power lines is wider than that of other carriers.

Broadband technologies for power line communications currently mainly include IEEE Homeplug AV and ITU-T G.hn. Both technologies use orthogonal frequency division multiplexing (OFDM) modulation. Among them, orthogonal frequency division multiplexing modulation This method is conducive to ensuring stable and complete data transmission in communication environments with severe electromagnetic interference.

The advantage of power line communication is that power lines have wide coverage and naturally cover residents' homes and corridors. However, the load impedance on the power line changes in real time, and the noise also changes in real time, affecting the transmission rate on the power line, and puts forward the design of the transceiver. higher requirements. Among them, the greatest impact on power line communications is the addition of various electrical loads on power lines, which introduce time-varying load impedance changes and time-varying noise changes.

Power modem: Power modem is a power line communication modem, which is a modem for broadband Internet access through power lines. Use existing power lines and socket components in the home or office to form a network to connect personal computers (PCs), broadband Internet devices (such as asymmetric digital subscriber line modems (ADSL modem)), set-top boxes , audio equipment, monitoring equipment and other intelligent electrical equipment to transmit data, voice and video. Power Modem has plug-and-play characteristics and can transmit network IP digital signals through ordinary household power lines.

Power line multiple-input multiple-output technology: Power line multiple-input multiple-output (MIMO) technology refers to the three lines of power line live (L), zero (neutral, N) and earth (protective earth, PE). Multiple-input multiple-output communication technology. In the power line MIMO technology, three lines of the power line can form two signals. When sending and receiving signals, two receivers and two transmitters (2T2R) or two receivers and three transmitters (2T3R) are generally used. Currently, Delta type coupling circuits or T-type coupling circuits are usually used to transmit and receive signals.

Refer to Figure 1a, which is a schematic diagram of a Delta type differential mode coupling circuit. As shown in Figure 1a, the Delta type differential mode coupling circuit includes three signal transceiver terminals D1, D2 and D3. D1, D2 and D3 are used to send or receive signals respectively. The Delta type differential mode coupling circuit also includes a coupling transformer C1 , C2 and C3, the coupling transformer is used to couple the differential mode signal sent by the signal transceiver end to the power line, or used to couple the differential mode signal received from the power line to the signal transceiver end. When the 2T2R signal transceiver mode is used, two of the signal transceiver terminals D1, D2, and D3 are used to send or receive signals. For example, D1 and D2 are used to send and receive signals. When D1 is used to send signals, C1 is connected to the live and neutral wires, and C1 is coupled to D1. The differential mode signal sent by D1 can be coupled to the live and neutral wires through C1, and then through The live and neutral wires send differential mode signals; when D2 is used to send signals, C2 is connected to the live and ground wires, and C2 is coupled to D2. The differential mode signal sent by D2 can be coupled to the live and ground wires through C2, and then through the live wires and the ground wire to send differential mode signals; when D1 is used to receive signals, the differential mode signals on the live and neutral wires can be coupled to D1 through C1, and then D1 receives the differential mode signals on the live and neutral wires; when D2 is used to receive signals , the differential mode signals on the live and ground lines can be coupled to D2 through C2, and then D2 receives the differential mode signals on the live and ground lines. When the 2T3R signal transceiver mode is adopted, two signal transceivers among D1, D2, and D3 are used to send signals or three signal transceivers are used to receive signals. For example, D1 and D2 are used for signal transmission, and D1, D2, and D3 are used for signal reception. When D1 is used to send signals, C1 is connected to the live wire and neutral wire, and C1 is coupled to D1. The differential mode signal sent by D1 can pass through C1 Coupled to the live and neutral wires, and then sends differential mode signals through the live and neutral wires; when using D2 to send signals, C2 is connected to the live and ground wires, and C2 is coupled to D2, and the differential mode signal sent by D2 can be coupled through C2 to the live and ground wires, and then send differential mode signals through the live and ground wires; when D1 is used to receive signals, the differential mode signals on the live and neutral wires can be coupled to D1 through C1, and then D1 receives the differential mode signals on the live and neutral wires. Differential mode signal; when D2 is used to receive signals, the differential mode signals on the live and ground lines can be coupled to D2 through C2, and then D2 receives the differential mode signals on the live and ground lines; when D3 is used to receive signals, C3 and zero The line and the ground line are connected, and C3 is coupled to D3, the differential mode signal on the neutral line and the ground line can be coupled to D3 through C3, and then D3 receives the differential mode signal on the neutral line and the ground line.

See Figure 1b, which is a schematic diagram of a T-type differential mode coupling circuit. As shown in Figure 1b, the T-type differential mode coupling circuit includes two signal transceiver terminals T1 and T2. T1 and T2 are used to send or receive signals respectively. The T-type differential mode coupling circuit also includes coupling transformers C4 and C5. The transformer is used to couple the differential mode signal sent from the signal transceiver end to the power line, or to couple the differential mode signal received from the power line to the signal transceiver end. When the 2T2R signal transmission and reception method is adopted, T1 and T2 are used for signal transmission and reception. When T1 is used to send signals, C4 is connected to the live wire and neutral wire, and C4 is coupled to T1. The differential mode signal sent by T1 can be coupled to the live wire and neutral wire through C4, and then the differential mode signal is sent through the live wire and neutral wire; when When T2 is used to send signals, C5 is connected to the live wire, neutral wire and ground wire, and C5 is coupled to T2. The differential mode signal sent by T2 can be coupled to the live wire, neutral wire and ground wire through C5, and then through the live wire, neutral wire and The ground wire sends a differential mode signal (the common mode signal of the live wire and the neutral wire, and then forms a differential mode signal with the ground wire); when T1 is used to receive the signal, the differential mode signal on the live wire and the neutral wire can be coupled to T1 through C4, and then T1 receives the differential mode signal on the live wire and neutral wire; when T2 is used to receive the signal, the differential mode signal on the live wire, neutral wire and ground wire (the common mode signal on the live wire and neutral wire, and the differential mode signal composed of the ground wire signal) can be coupled to T2 through C5, and then T2 receives the differential mode signal on the live wire, neutral wire, and ground wire. When the 2T3R signal transceiver mode is used, the T-type differential mode coupling circuit includes three signal transceiver terminals, and two of the signal transceiver terminals are used to send signals or three signal transceiver terminals are used to receive signals. When two of the signal transceivers are used to send signals, you can refer to the above-mentioned method of sending signals through T1 and T2; when using three signal transceivers to receive signals, two of the signal transceivers can receive signals by referring to the above-mentioned method of receiving signals through T1 and T2. , the other signal transceiver can receive differential mode signals on the live wire and ground wire, or receive differential mode signals on the neutral wire and ground wire.

Electrical appliance noise: Electrical appliance noise is one of the main noises in power line communications. It usually appears as various forms of pulse noise. The amplitude of some electrical appliance noise is very large, which has a great impact on the performance of power line communications. At the same time, electrical appliance noise has rich frequency characteristics, and the real-time changes in the noise of most electrical appliances in the power line system have periodic characteristics consistent with the alternating current (AC) cycle.

See Figure 1c, which is a schematic diagram of noise changes. As shown in Figure 1c, where 1c-1 is a schematic diagram of the periodic change of alternating current. 1c-2 is a schematic diagram of the channel response changing with time at different frequencies. The real-time change of the channel response has periodic characteristics consistent with the AC cycle. 1c-3 is a schematic diagram of the change of noise over time. The real-time change of noise has periodic characteristics consistent with the AC cycle.

There are various types and models of electrical appliances in actual homes and working environments, resulting in diversity of noise characteristics in power line systems. In addition, the noise characteristics generated by the same electrical appliance are not consistent within the power line cycle, and the electrical appliance noise received through different receiving channels changes differently. See Figure 1d, which is a schematic diagram of the changes in the noise generated by Delixi spotlights during the AC cycle. Among them, 1d-1, 1d-2 and 1d-3 are schematic diagrams of the changes in the AC cycle of the noise generated by the Delixi spotlights received through the three receiving channels.

The pulse amplitude of electrical noise in power line systems is usually large, resulting in degradation of the performance of power line communications. See Figure 1e, which is a schematic diagram of receiving signals under interference from Delixi spotlights. As shown in Figure 1e, the received signal collected under 40dB attenuation is greatly affected by the noise generated by the Delixi spotlight, thus affecting the demodulation performance.

The background technology of the present application is introduced as above, and the technical features of the embodiments of the present application are introduced below.

Referring to Figure 2a, Figure 2a is a schematic diagram of a signal transceiver circuit for power line communication provided by an embodiment of the present application. As shown in Figure 2a, the signal transceiver circuit includes a differential mode coupling circuit 201, a common mode coupling circuit 202 and a noise processing circuit 203. The signal transceiver circuit is applied to electronic equipment, and the electronic equipment may be a power cat, for example.

Among them, the differential mode coupling circuit 201 and the common mode coupling circuit 202 are respectively connected to the power line, the noise processing circuit 203 is connected to the differential mode coupling circuit 201 and the common mode coupling circuit 202, and the power line includes at least one of the following: live wire, neutral wire and ground wire. .

The differential mode coupling circuit 201 is used for coupling and receiving differential mode signals on the power line. Among them, the differential mode signals on the power line include differential mode signals on two lines of the power line or differential mode signals on three lines of the power line. The differential mode signals on the two lines in the power line include differential mode signals on the live and neutral lines, differential mode signals on the live and ground lines, or differential mode signals on the neutral and ground lines. The differential mode signals on the three lines of the power line include the differential mode signal composed of the common mode signal on the live and neutral wires and the ground wire, the differential mode signal composed of the common mode signal on the live and ground wires and the neutral wire, or the differential mode signal composed of the neutral wire and the ground wire. The common mode signal on the line and the differential mode signal composed of the live wire.

Optionally, the differential mode coupling circuit 201 includes at least one coupling transformer and at least one transceiver circuit, wherein each of the at least one coupling transformer is connected to at least two of the power lines, and each coupling transformer Coupled to one of the at least one transceiver circuit. Each coupling transformer is used to couple differential mode signals received from at least two of the power lines to one of the at least one transceiver circuits, and each of the at least one transceiver circuits is used to receive Each coupling transformer couples to the differential mode signal of each transceiver circuit.

The common mode coupling circuit 202 is used to couple common mode signals on the receiving power line. Among them, the common mode signals on the power line are the common mode signals on the live wire, neutral wire and ground wire.

Optionally, the common mode coupling circuit 202 includes a common mode transformer and a common mode signal receiving circuit, wherein the common mode transformer is connected to the live wire, the neutral wire and the ground wire, and the common mode transformer is coupled to the common mode signal receiving circuit. . The common mode transformer is used to couple common mode signals received from the live line, neutral line and ground line to the common mode signal receiving circuit, and the common mode signal receiving circuit is used to receive the common mode transformer coupled to the common mode signal receiving circuit. common mode signal of the circuit.

The noise processing circuit 203 is used to process common mode signals and differential mode signals to eliminate noise in the differential mode signals. Among them, in the power line communication system, signals are transmitted through the power line. Since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise. The differential mode signal on the power line can be coupled through the differential mode coupling circuit 201 ( Including differential mode electrical appliance noise), and because electrical appliance noise has strong common mode characteristics, the common mode signal (including common mode electrical appliance noise) on the power line can be obtained by introducing the common mode coupling circuit 202. The electrical appliance noise in the differential mode signal coupled through the differential mode coupling circuit 201 is correlated with the electrical appliance noise coupled through the common mode coupling circuit 202. Therefore, the common mode signal and the differential mode signal can be processed through the noise processing circuit 203. Eliminate electrical noise in differential mode signals to improve the performance of power line communications.

Among them, the correlation between differential mode electrical noise and common mode electrical noise is shown in Figure 2b. As shown in Figure 2b, 2b-1 is a schematic diagram of the time domain noise collected through the differential mode path and the common mode path. The solid line is a schematic diagram of the differential mode electrical noise received through the differential mode coupling circuit, and the dotted line is Schematic diagram of common-mode electrical noise received through a common-mode coupling circuit. 2b-2 is a schematic diagram of the correlation coefficient between differential mode electrical appliance noise and common mode electrical appliance noise. It can be seen that by performing cross-correlation calculations on differential mode electrical appliance noise and common mode electrical appliance noise, it can be seen that differential mode electrical appliance noise and common mode electrical appliance noise Electrical appliance noise has a strong correlation.

The following is a detailed introduction to the working principle of the common-mode transformer in Figure 2a. The structure of the common-mode transformer is shown in Figure 3. The common mode transformer includes a signal input port, a differential mode signal output port and a common mode signal output port. The signal input port includes port 1, port 3 and port 5, and the differential mode signal output port includes port 2, port 4 and port 6. , the common mode signal output port includes port 7 and port 8. The common mode transformer is connected to three wires of the power line. For example, the live wire is connected to port 1 and port 2, and the signal on the live wire is input to the common mode transformer through port 1 and output through port 2; the neutral wire is connected to port 3 and port 4, and the signal on the neutral line is input to the common mode transformer through port 3. , output through port 4; the ground wire is connected to port 5 and port 6. The signal on the ground wire is input to the common mode transformer through port 5 and output through port 6. Coil A, coil B, coil C and coil D are wound together on a magnetic core. When the differential mode signal flows through the common mode transformer, the common mode transformer can be equivalent to a common mode inductor. The magnetic field generated by the differential mode signal interacts with each other. Offset, the differential mode signal can pass through the differential mode signal output port with basically no attenuation; when the common mode signal flows through the common mode transformer, the magnetic fields generated by the common mode signal strengthen each other. At this time, on the one hand, for the differential mode signal output port , coil A, coil B and coil C show high impedance, and the differential mode signal output port has a strong attenuation effect on the common mode signal. On the other hand, for the common mode signal output port, coil D will induce the common mode The magnetic flux of the signal generates an induced electromotive force and passes through the common mode signal output port. Therefore, when the signal on the power line is input to the common mode transformer through port 1, port 3, and port 5, and output through port 2, port 4, and port 6, the loss of the differential mode signal is very small, while the loss of the common mode signal is very large. The signal on the power line is input to the common mode transformer through port 1, port 3 and port 5. When output through port 7 and port 8, the differential mode signal loss is very large, while the common mode signal loss is very small, so the common mode transformer can Couple and receive the common mode signals on the three lines of the power line.

Referring to Figure 4a, Figure 4a is a schematic diagram of a power line communication system provided by an embodiment of the present application. As shown in Figure 4a, based on the Delta type differential mode coupling circuit and 2T2R, a common mode coupling circuit is introduced as the third channel of reception. On the signal transmission side, the signal is transmitted through the electronic device 1 , which includes a differential mode coupling circuit 1 . Specifically, the first transceiver circuit and the second transceiver circuit of the differential mode coupling circuit 1 are used to transmit the differential mode signal, and the differential mode signal is coupled to the power line through the differential mode coupling circuit 1, thereby transmitting the differential mode signal using the live wire and the neutral wire. , and use live wires and ground wires to send differential mode signals, and then the signals sent by the electronic device 1 are transmitted through the power lines. On the signal receiving side, the signal is received through the electronic device 2, which includes a differential mode coupling circuit 2 and a common mode coupling circuit. Specifically, the signals on the three lines of the power line first pass through the common mode transformer. The common mode transformer couples the common mode signals on the live line, neutral line and ground line. The common mode signal is received through the common mode signal receiving circuit, and then the three lines of the power line The signal on the power line is then input into the differential mode coupling circuit 2, and the differential mode signal on the power line is coupled to the first transceiver circuit and the second transceiver circuit of the differential mode coupling circuit 2. The first transceiver circuit and the second transceiver circuit of the differential mode coupling circuit 2 are The circuit receives differential mode signals, thereby receiving differential mode signals on the live and neutral lines, and receiving differential mode signals on the live and ground lines.

Referring to Figure 4b, Figure 4b is a schematic diagram of the differential mode coupling circuit 2 and the common mode coupling circuit included in the electronic device 2 in Figure 4a. As shown in Figure 4b, the differential mode coupling circuit 2 includes a first coupling transformer 401, a first transceiver circuit 402, a second coupling transformer 403 and a second transceiver circuit 404. The common mode coupling circuit includes a common mode transformer 405 and a common mode signal. Receive circuit 406. Among them, the first coupling transformer 401 is connected to the live wire and the neutral wire, the first coupling transformer 401 is coupled to the first transceiver circuit 402, the input terminal TX0 of the first transceiver circuit 402 is used to send signals, and the output terminal RX0 of the first transceiver circuit 402 used to receive signals. The second coupling transformer 403 is connected to the live wire and the ground wire. The second coupling transformer 403 is coupled to the second transceiver circuit 404. The input terminal TX1 of the second transceiver circuit 404 is used to send signals, and the output terminal RX1 of the second transceiver circuit 404 is used to transmit signals. receive signal. The common mode transformer 405 is connected to the live wire, the neutral wire and the ground wire. The common mode transformer 405 is coupled to the common mode signal receiving circuit 406. The output terminal RX2 of the common mode signal receiving circuit 406 is used to receive signals.

Specifically, when receiving signals on the power line, the signals on the live line and the neutral line are input to the first coupling transformer 401, and the first coupling transformer 401 couples the first differential mode signal received from the live line and the neutral line to the first Transceiver circuit 402, and receive the first differential mode signal through the output terminal RX0 of the first transceiver circuit 402. The signals on the live wire and the ground wire are input to the second coupling transformer 403. The second coupling transformer 403 couples the second differential mode signal received from the live wire and the ground wire to the second transceiver circuit 404, and passes through the second transceiver circuit 404. The output terminal RX1 receives the second differential mode signal. The signals on the live wire, neutral wire and ground wire are respectively input to the common mode transformer 405. The common mode transformer 405 couples the common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit 406, and passes through the common mode transformer 405. The output terminal RX2 of the mode signal receiving circuit 406 receives the common mode signal.

Among them, in the differential mode coupling circuit 2 shown in Figure 4b, the first differential mode signal is received through the output terminal RX0 of the first transceiver circuit 402, and the second differential mode signal is received through the output terminal RX1 of the second transceiver circuit 404. Since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise. That is to say, both the first differential mode signal and the second differential mode signal include differential mode electrical appliance noise. At the same time, since electrical appliance noise has strong common-mode characteristics, the common-mode signal (including common-mode electrical appliance noise) on the power line can be coupled by introducing the common-mode transformer 405, which is received through the output terminal RX2 of the common-mode signal receiving circuit 406. the common mode signal. Since the electrical noise in the first differential mode signal and the second differential mode signal is correlated with the common mode electrical noise, the received three signals (the first differential mode signal, the second differential mode signal) can be processed later through the digital terminal algorithm. signals and common-mode signals) to eliminate electrical noise in differential-mode signals, thereby improving the performance of power line communications.

In one possible example, the differential mode coupling circuit 2 also includes a third coupling transformer 407 and a third transceiver circuit 408. The schematic diagram of the differential mode coupling circuit 2 and the common mode coupling circuit is shown in Figure 4c. The third coupling transformer 407 is connected to the neutral line and the ground line. The third coupling transformer 407 is coupled to the third transceiver circuit 408. The output terminal RX3 of the third transceiver circuit 408 is used to receive signals.

Specifically, the signals on the neutral line and the ground line are input to the third coupling transformer 407, and the third coupling transformer 407 couples the third differential mode signal received from the neutral line and the ground line to the third transceiver circuit 408, and The third differential mode signal is received through the output terminal RX3 of the third transceiver circuit 408 .

Among them, in the differential mode coupling circuit 2 as shown in Figure 4c, the first differential mode signal is received through the output terminal RX0 of the first transceiver circuit 402, and the second differential mode signal is received through the output terminal RX1 of the second transceiver circuit 404, The third differential mode signal is received through the output terminal RX3 of the third transceiver circuit 408. Since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise, that is to say, the first differential mode signal, the second differential mode signal Both the mode signal and the third differential mode signal include differential mode electrical noise. At the same time, since electrical appliance noise has strong common-mode characteristics, the common-mode signal (including common-mode electrical appliance noise) on the power line can be coupled by introducing the common-mode transformer 405, which is received through the output terminal RX2 of the common-mode signal receiving circuit 406. the common mode signal. Since the electrical noise in the first differential mode signal, the second differential mode signal and the third differential mode signal is correlated with the electrical noise in the common mode, the received four signals (the first differential mode signal) can subsequently be processed through the digital terminal algorithm. signal, the second differential mode signal, the third differential mode signal and the common mode signal) are processed to eliminate electrical noise in the differential mode signal, thereby improving the performance of power line communication.

Referring to Figure 5a, Figure 5a is a schematic diagram of another power line communication system provided by an embodiment of the present application. As shown in Figure 5a, based on the T-type differential mode coupling circuit and 2T2R, a common mode coupling circuit is introduced as the third channel of reception. On the signal transmission side, the signal is transmitted through the electronic device 3, which includes a differential mode coupling circuit 3. Specifically, the fourth transceiver circuit and the fifth transceiver circuit of the differential mode coupling circuit 3 are used to transmit the differential mode signal, and the differential mode signal is coupled to the power line through the differential mode coupling circuit 3, thereby realizing the use of the live wire and the neutral wire to transmit the differential mode signal. , and use the live wire, neutral wire and ground wire to send differential mode signals (the differential mode signal composed of the common mode signal on the live wire and neutral wire and the ground wire), and then the signal sent by the electronic device 3 is transmitted through the power line. On the signal receiving side, the signal is received through the electronic device 4, which includes a differential mode coupling circuit 4 and a common mode coupling circuit. Specifically, the signals on the three lines of the power line first pass through the common mode transformer. The common mode transformer couples the common mode signals on the live line, neutral line and ground line. The common mode signal is received through the common mode signal receiving circuit, and then the three lines of the power line The signal on the power line is then input into the differential mode coupling circuit 4 to couple the differential mode signal on the power line to the fourth transceiver circuit and the fifth transceiver circuit of the differential mode coupling circuit 4. The fourth transceiver circuit and the fifth transceiver circuit of the differential mode coupling circuit 4 are The circuit receives differential mode signals, thereby receiving differential mode signals on the live and neutral lines, and receiving differential mode signals on the live, neutral and ground lines (differential mode composed of common mode signals on the live and neutral lines and the ground line). Signal).

Referring to Figure 5b, Figure 5b is a schematic diagram of the differential mode coupling circuit 4 and the common mode coupling circuit included in the electronic device 4 in Figure 5a. As shown in Figure 5b, the differential mode coupling circuit 4 includes a fourth coupling transformer 501, a fourth transceiver circuit 502, a fifth coupling transformer 503 and a fifth transceiver circuit 504. The common mode coupling circuit includes a common mode transformer 505 and a common mode signal. Receive circuit 506. Among them, the fourth coupling transformer 501 is connected to the live wire and the neutral wire, the fourth coupling transformer 501 is coupled to the fourth transceiver circuit 502, the input terminal TX0 of the fourth transceiver circuit 502 is used to send signals, and the output terminal RX0 of the fourth transceiver circuit 502 used to receive signals. The fifth coupling transformer 503 is connected to the live wire, the neutral wire and the ground wire. The fifth coupling transformer 503 is coupled to the fifth transceiver circuit 504. The input terminal TX1 of the fifth transceiver circuit 504 is used to send signals, and the output terminal of the fifth transceiver circuit 504 is RX1 is used to receive signals. The common mode transformer 505 is connected to the live wire, the neutral wire and the ground wire. The common mode transformer 505 is coupled to the common mode signal receiving circuit 506. The output terminal RX2 of the common mode signal receiving circuit 506 is used to receive signals.

Specifically, when receiving signals on the power line, the signals on the live line and the neutral line are input to the fourth coupling transformer 501, and the fourth coupling transformer 501 couples the fourth differential mode signal received from the live line and the neutral line to the fourth The transceiver circuit 502 receives the fourth differential mode signal through the output terminal RX0 of the fourth transceiver circuit 502 . The signals on the live wire, neutral wire and ground wire are input to the fifth coupling transformer 503. The fifth coupling transformer 503 receives the fifth differential mode signal (the common mode on the live wire and neutral wire) from the live wire, neutral wire and ground wire. A differential mode signal composed of a signal and a ground wire) is coupled to the fifth transceiver circuit 504 and is received through the output terminal RX1 of the fifth transceiver circuit 504 . The signals on the live wire, neutral wire and ground wire are respectively input to the common mode transformer 505. The common mode transformer 505 couples the common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit 506, and passes through the common mode transformer 505. The output terminal RX2 of the mode signal receiving circuit 506 receives the common mode signal.

Among them, in the differential mode coupling circuit 4 as shown in Figure 5b, the fourth differential mode signal is received through the output terminal RX0 of the fourth transceiver circuit 502, and the fifth differential mode signal is received through the output terminal RX1 of the fifth transceiver circuit 504. Since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise. That is to say, both the fourth differential mode signal and the fifth differential mode signal include differential mode electrical appliance noise. At the same time, since electrical appliance noise has strong common-mode characteristics, the common-mode signal (including common-mode electrical appliance noise) on the power line can be coupled by introducing the common-mode transformer 505, which is received through the output terminal RX2 of the common-mode signal receiving circuit 506. the common mode signal. Since the electrical noise in the fourth differential mode signal and the fifth differential mode signal is correlated with the common mode electrical noise, the received three signals (the fourth differential mode signal, the fifth differential mode signal) can be processed later through the digital terminal algorithm. signals and common-mode signals) to eliminate electrical noise in differential-mode signals, thereby improving the performance of power line communications.

In a possible example, the differential mode coupling circuit 4 further includes a sixth coupling transformer 507 and a sixth transceiver circuit 508. The schematic diagram of the differential mode coupling circuit 4 and the common mode coupling circuit is shown in Figure 5c. The sixth coupling transformer 507 is connected to the live wire and the ground wire. The sixth coupling transformer 507 is coupled to the sixth transceiver circuit 508. The output terminal RX3 of the sixth transceiver circuit 508 is used to receive signals.

Specifically, the signals on the live wire and the ground wire are input to the sixth coupling transformer 507. The sixth coupling transformer 507 couples the sixth differential mode signal received from the live wire and the ground wire to the sixth transceiver circuit 508, and passes through the sixth differential mode signal. The output terminal RX3 of the sixth transceiver circuit 508 receives the sixth differential mode signal.

Among them, in the differential mode coupling circuit 4 as shown in Figure 5c, the fourth differential mode signal is received through the output terminal RX0 of the fourth transceiver circuit 502, and the fifth differential mode signal is received through the output terminal RX1 of the fifth transceiver circuit 504. The sixth differential mode signal is received through the output terminal RX3 of the sixth transceiver circuit 508. Since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise, that is to say, the fourth differential mode signal and the fifth differential mode signal are Both the differential mode signal and the sixth differential mode signal include differential mode electrical noise. At the same time, since electrical appliance noise has strong common-mode characteristics, the common-mode signal (including common-mode electrical appliance noise) on the power line can be coupled by introducing the common-mode transformer 505, which is received through the output terminal RX2 of the common-mode signal circuit 506. common mode signal. Since the electrical noise in the fourth differential mode signal, the fifth differential mode signal and the sixth differential mode signal is correlated with the electrical noise in the common mode, the received four signals (the fourth differential mode signal) can subsequently be processed through the digital terminal algorithm. signal, fifth differential mode signal, sixth differential mode signal and common mode signal) are processed to eliminate electrical noise in the differential mode signal, thereby improving the performance of power line communication.

Referring to Figure 6, Figure 6 is a schematic diagram of a noise processing circuit provided by an embodiment of the present application. As shown in Figure 6, the noise processing circuit includes an analog interface 601, an analog front end (analog front end) 602, a digital interface 603 and a digital front end (digital front end) 604.

Wherein, the analog front end 602 is connected to the differential mode coupling circuit and the common mode coupling circuit in the above embodiment through the analog interface 601, the digital front end 604 is connected to the analog front end 602 through the digital interface 603, and the analog front end 602 Including a programmable-gain amplifier 6021 and an analog-to-digital converter 6022.

The analog interface 601 is used to receive differential mode signals and common mode signals obtained through the differential mode coupling circuit and common mode coupling circuit. Among them, the differential mode signal and the common mode signal obtained through the differential mode coupling circuit and the common mode coupling circuit include the following combination: the two differential mode signals obtained through the differential mode coupling circuit 2 shown in Figure 4b and the common mode signal obtained through the differential mode coupling circuit 2 shown in Figure 4b The common mode signal obtained by the coupling circuit, the three differential mode signals obtained by the differential mode coupling circuit 2 shown in Figure 4c and the common mode signal obtained by the common mode coupling circuit are obtained by the differential mode coupling circuit 4 shown in Figure 5b The two differential mode signals and the common mode signal obtained through the common mode coupling circuit, the three differential mode signals obtained through the differential mode coupling circuit 4 shown in Figure 5c and the common mode signal obtained through the common mode coupling circuit.

The adjustable amplifier 6021 is used to amplify the differential mode signals and common mode signals received by the analog interface 601 to obtain amplified differential mode signals and common mode signals.

The analog-to-digital converter 6022 is used to sample the amplified differential mode signal and common mode signal to obtain a digital signal.

Digital interface 603 is used to receive the digital signal.

The digital front end 604 is used to process the digital signals received by the digital interface 603 to eliminate noise.

Optionally, the above-mentioned analog interface 601 also includes a line driver, which is used to drive the signal power on the amplification line.

Optionally, the analog front end 602 and the digital front end 604 are located on the same chip, or the analog front end 602 and the digital front end 604 are located on two separate chips, or the analog-to-digital converter 6022 and the digital front end 604 in the analog front end 602 are located on On one chip, the adjustable amplifier 6021 and line driver in the analog front end 602 are located on another chip.

Optionally, the digital front-end 604 includes a noise elimination module. The digital front-end 604 processes the received digital signal to implement reception and demodulation of the signal. As mentioned above, common-mode noise and differential-mode noise are correlated. Therefore, digital processing can be used to utilize the noise characteristics of common-mode signals to eliminate electrical noise in differential-mode signals, thereby improving the performance of power line communications. On the premise that a noise characteristic is known, there are already many solutions in the industry to eliminate the noise. In the embodiment of the present invention, it can be processed through digital algorithms, such as minimum mean square error-interference suppression. Merge (minimum mean square error-interference rejection combining, MMSE-IRC) algorithm. The MMSE-IRC algorithm is a commonly used MIMO receiver technology. When the interference in the received signal is mainly colored interference (the interference has a certain correlation on multiple receiving lines and is not completely independent), it can use specific weighting to make The interference on the combined received signal cancels each other out, thereby achieving the effect of suppressing interference, that is, eliminating the noise in the received signal.

Specifically, when the MMSE-IRC algorithm is used to perform noise elimination processing on the received signal, the process of the digital front end 604 performing noise elimination processing on the received signal is as follows:

The signal received by the digital front end 604 is expressed as:

Y(k)＝H(k)S(k)+N(k)

Among them, Y(k) is the N _r ×1-dimensional received signal on the k-th carrier, S(k) is the N _t ×1-dimensional transmitted signal, and N(k) is the noise plus interference on the k-th carrier. Let S(k) have a mean value of 0 and a variance of 1.

The received signal is equalized, and the equalized received signal is expressed as:

R(k)=W(k)Y(k)=W(k)H(k)S(k)+W(k)N(k)

Among them, let W(k) be an equalization matrix, and W(k) be an N _t ×N _r -dimensional matrix.

Taking the minimum mean square error and the maximum signal-to-interference-noise ratio as the criteria, there are:

That is:

J=E[||W(k)Y(k)-S(k)|| ² ]=E[tr((W(k)Y(k)-S(k))(W(k)Y( k)-S(k)) ^H )]

=E[tr(W(k)Y(k)Y(k) ^H W(k) ^H +S(k)S(k) ^H -W(k)Y(k)S(k) ^H -S( k)Y(k) ^H W(k) ^H )]

Calculate the partial derivatives of W(k) ^H in the above formula term by term, we can get:

W(k)E[Y(k)Y(k) ^H ]＝E[S(k)Y(k) ^H ]

That is:

W(k)E[(H(k)S(k)+N(k))(H(k)S(k)+N(k)) ^H ]＝E[S(k)(H(k) S(k)+N(k)) ^H ]

That is:

W(k)E[H(k)S(k)S(k) ^H H(k) ^H +H(k)S(k)N(k) ^H +N(k)S(k) ^H H( k) ^H +N(k)N(k) ^H ]

=E[S(k)S(k) ^H H(k) ^H +S(k)N(k) ^H ]

According to the mean value of S(k) is 0 and the variance is 1, then there is:

W(k)(H(k)H(k) ^H +E[N(k)N(k) ^H ])=H(k) ^H

Assuming that the noise covariance matrix E[N(k)N(k) ^H ] is R _uu (k), the equalization matrix can be obtained:

Among them, R _uu is the noise covariance matrix. When the interference in the multi-channel received signal is uncorrelated, the off-diagonal elements of R _uu are 0, and the interference rejection combining (IRC) algorithm degenerates into maximum ratio combining. (maximal ratio combining, MRC) algorithm. The MRC algorithm corrects the phase of each received signal to be consistent, and uses the signal-to-noise ratio as the weight and weighted sum. The combined received signal has the largest signal-to-noise ratio, but has no interference suppression effect and cannot achieve the maximum signal-to-interference-to-noise ratio. . The interference in the multi-channel signals received through the signal transceiver circuit provided by the embodiment of the present application is correlated, that is, R _uu is a non-diagonal matrix. Therefore, the signal-to-interference-to-noise ratio can be achieved by using the MMSE-IRC algorithm to process the received signal. Maximize, that is, eliminate electrical noise in the received signal.

The following introduces the system implementation of the signal transceiver circuit for power line communication.

Referring to FIG. 7 , FIG. 7 is a schematic diagram of another signal transceiver circuit for power line communication provided by an embodiment of the present application. As shown in Figure 7, the signal transceiver circuit is located on a single board. The signal transceiver circuit includes a differential mode coupling circuit 7011, a common mode coupling circuit 7012, a first analog interface 7021, a second analog interface 7022, a third analog interface 7023, The first analog front end 7031, the second analog front end 7032, the third analog front end 7033, the first digital interface 7041, the second digital interface 7042, the third digital interface 7043 and the digital front end 705.

Among them, the differential mode coupling circuit 7011 and the common mode coupling circuit 7012 are located outside the chip and are respectively connected to the power lines. The power lines include at least one line among the live line, the neutral line and the ground line. The differential mode coupling circuit 7011 and the common mode coupling circuit 7012 can be the differential mode coupling circuit 2 and the common mode coupling circuit shown in Figure 4b, or the differential mode coupling circuit 7011 and the common mode coupling circuit 7012 can be the differential mode coupling circuit 7011 and the common mode coupling circuit 7012 shown in Figure 5b. The differential mode coupling circuit 4 and the common mode coupling circuit are shown.

The first analog interface 7021, the second analog interface 7022 and the third analog interface 7023 are connected to the differential mode coupling circuit 7011 and the common mode coupling circuit 7012 respectively, and are used to receive three signals obtained through the differential mode coupling circuit 7011 and the common mode coupling circuit 7012. analog signals (including two differential mode signals and one common mode signal). Among them, the first analog interface 7021 and the second analog interface 7022 are respectively connected to the differential mode coupling circuit 7011. The first analog interface 7021 is used to receive the first path differential mode signal, and the second analog interface 7022 is used to receive the second path differential mode signal. Signal. The third analog interface 7023 is connected to the common mode coupling circuit 7012, and the third analog interface 7023 is used to receive the third common mode signal. Optionally, the first analog interface 7021, the second analog interface 7022, and the third analog interface 7023 include line drivers, and the line drivers are used to drive the signal power on the amplification line when sending signals.

The first analog front end 7031 is connected to the first analog interface 7021, the second analog front end 7032 is connected to the second analog interface 7022, and the third analog front end 7033 is connected to the third analog interface 7023. Among them, the first analog front end 7031, the second analog front end 7032 and the third analog front end 7033 all include an adjustable amplifier and an analog-to-digital converter. The adjustable amplifier is used to amplify the analog signal, and the analog-to-digital converter is used to amplify the analog signal. sampling. The first analog front end 7031 is used to amplify and sample the first differential mode signal received by the first analog interface 7021 to obtain the first digital signal, and the second analog front end 7032 is used to amplify and sample the first differential mode signal received by the second analog interface 7022 The second differential mode signal is amplified and sampled to obtain the second digital signal. The third analog front end 7033 is used to amplify and sample the third common mode signal received by the third analog interface 7023 to obtain the third common mode signal. Three digital signals.

The first digital interface 7041 is connected to the first analog front end 7031, the second digital interface 7042 is connected to the second analog front end 7032, and the third digital interface 7043 is connected to the third analog front end 7033. Among them, the first digital interface 7041 is used to receive the first digital signal obtained through the first analog front end 7031, the second digital interface 7042 is used to receive the second digital signal obtained through the second analog front end 7032, and the third digital interface 7043 is used to receive the third digital signal obtained through the third analog front end 7033.

The digital front end 705 is connected to the first digital interface 7041, the second digital interface 7042 and the third digital interface 7043. The digital front end 705 includes a noise cancellation module 7051. Among them, the digital front end 705 is used to process three digital signals received through the first digital interface 7041, the second digital interface 7042, and the third digital interface 7043 to realize signal reception and demodulation. Among them, the noise elimination module 7051 is used to perform noise elimination processing on the received three digital signals, thereby improving the performance of power line communication. Specifically, noise elimination processing can be performed on the three digital signals through a digital end algorithm. The digital end algorithm can be, for example, the MMSE-IRC algorithm.

Referring to Figure 8, Figure 8 is a schematic diagram of a signal transceiving method for power line communication provided by an embodiment of the present application. As shown in Figure 8, the signal transceiving method is applied to the signal transceiving circuit of power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. The differential mode coupling circuit and the common mode coupling circuit are respectively connected to the power line. The noise processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit. The power line includes at least one of the following: live line, neutral line and ground line. The signal transceiving method includes steps S801-S803, specifically as follows:

S801, the differential mode coupling circuit couples and receives the differential mode signal on the power line.

Among them, the differential mode signals on the power line include differential mode signals on two lines of the power line or differential mode signals on three lines of the power line. The differential mode signals on the two lines in the power line include differential mode signals on the live and neutral lines, differential mode signals on the live and ground lines, or differential mode signals on the neutral and ground lines. The differential mode signals on the three lines of the power line include the differential mode signal composed of the common mode signal on the live and neutral wires and the ground wire, the differential mode signal composed of the common mode signal on the live and ground wires and the neutral wire, or the differential mode signal composed of the neutral wire and the ground wire. The common mode signal on the line and the differential mode signal composed of the live wire.

S802, the common mode coupling circuit couples and receives the common mode signal on the power line.

Among them, the common mode signals on the power line are the common mode signals on the live wire, neutral wire and ground wire.

S803. The noise processing circuit processes the common mode signal and the differential mode signal to eliminate the noise in the differential mode signal.

Among them, in the power line communication system, signals are transmitted through power lines. Since various electrical appliances are added to the power lines, the signals transmitted on the power lines include electrical appliance noise. In the above signal transceiver method of power line communication, the differential mode signal on the power line received by the differential mode coupling circuit includes differential mode electrical noise. At the same time, because the electrical noise has strong common mode characteristics, the common mode coupling circuit couples and receives the signal. The common-mode signal arriving on the power line includes common-mode electrical noise. The electrical appliance noise in the differential mode signal is correlated with the common mode electrical appliance noise. Therefore, the noise processing circuit processes the common mode signal and the differential mode signal to eliminate the electrical appliance noise in the differential mode signal, thereby improving the performance of power line communication.

Referring to FIG. 9 , FIG. 9 is a schematic diagram of another signal transceiving method for power line communication provided by an embodiment of the present application. As shown in Figure 9, this signal transceiving method is applied to the signal transceiving circuit of power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. Wherein, the differential mode coupling circuit includes a first coupling transformer, a first transceiver circuit, a second coupling transformer and a second transceiver circuit, and the common mode coupling circuit includes a common mode transformer and a common mode signal receiving circuit. The first coupling transformer is connected to the live wire and the neutral wire, and the first coupling transformer is coupled to the first transceiver circuit. The second coupling transformer is connected to the live wire and the ground wire, and the second coupling transformer is coupled to the second transceiver circuit. The common mode transformer is connected to the live wire, the neutral wire and the ground wire, and the common mode transformer is coupled to the common mode signal receiving circuit. The noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end. The analog front end is connected to the differential mode coupling circuit and the common mode coupling circuit through the analog interface. The digital front end is connected to the analog front end through the digital interface. , the analog front-end includes an adjustable amplifier and an analog-to-digital converter. The signal sending and receiving method includes steps S901-S911, specifically as follows:

S901. The first coupling transformer couples the first differential mode signal received from the live line and the neutral line to the first transceiver circuit.

S902. The first transceiver circuit receives the first differential mode signal coupled to the first transceiver circuit by the first coupling transformer.

S903. The second coupling transformer couples the second differential mode signal received from the live wire and the ground wire to the second transceiver circuit.

S904. The second transceiver circuit receives the second differential mode signal coupled to the second transceiver circuit by the second coupling transformer.

S905, the common mode transformer couples the common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit.

S906. The common-mode signal receiving circuit receives the common-mode signal coupled to the common-mode signal receiving circuit by the common-mode transformer.

S907. The analog interface receives the first differential mode signal, the second differential mode signal and the common mode signal.

S908. The adjustable amplifier amplifies the first differential mode signal, the second differential mode signal and the common mode signal received by the analog interface to obtain amplified differential mode signals and common mode signals.

S909. The analog-to-digital converter samples the amplified differential mode signal and common mode signal to obtain a digital signal.

S910, digital interface receives digital signals.

S911. The digital front end processes the digital signals received by the digital interface to eliminate noise.

Specifically, noise elimination processing can be performed on the digital signal through a digital end algorithm, and the digital end algorithm can be, for example, the MMSE-IRC algorithm.

In the above signal sending and receiving method, since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise. That is to say, the two coupled differential mode signals received include differential mode electrical appliance noise. At the same time, since electrical noise has strong common-mode characteristics, the common-mode signal received by the coupling includes common-mode electrical noise. Since the electrical appliance noise in the two-way differential mode signal is correlated with the common mode electrical appliance noise, the received digital signal is processed through the digital terminal algorithm to eliminate the electrical appliance noise, thereby improving the performance of power line communication.

Referring to Figure 10, Figure 10 is a schematic diagram of another signal transceiving method for power line communication provided by an embodiment of the present application. As shown in Figure 10, this signal transceiver method is applied to the signal transceiver circuit of power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. Wherein, the differential mode coupling circuit includes a fourth coupling transformer, a fourth transceiver circuit, a fifth coupling transformer and a fifth transceiver circuit, and the common mode coupling circuit includes a common mode transformer and a common mode signal receiving circuit. The fourth coupling transformer is connected to the live wire and the neutral wire, and the fourth coupling transformer is coupled to the fourth transceiver circuit. The fifth coupling transformer is connected to the live wire, the neutral wire and the ground wire, and the fifth coupling transformer is coupled to the fifth transceiver circuit. The common mode transformer is connected to the live wire, the neutral wire and the ground wire, and the common mode transformer is coupled to the common mode signal receiving circuit. The noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end. The analog front end is connected to the differential mode coupling circuit and the common mode coupling circuit through the analog interface. The digital front end is connected to the analog front end through the digital interface. , the analog front-end includes an adjustable amplifier and an analog-to-digital converter. The signal sending and receiving method includes steps S1001-S1011, specifically as follows:

S1001. The fourth coupling transformer couples the fourth differential mode signal received from the live line and the neutral line to the fourth transceiver circuit.

S1002. The fourth transceiver circuit receives the fourth differential mode signal coupled to the fourth transceiver circuit by the fourth coupling transformer.

S1003. The fifth coupling transformer couples the fifth differential mode signal received from the live wire, neutral wire and ground wire to the fifth transceiver circuit.

Among them, the fifth differential mode signal is a differential mode signal composed of the common mode signal on the live wire and the neutral wire and the ground wire.

S1004. The fifth transceiver circuit receives the fifth differential mode signal coupled to the fifth transceiver circuit by the fifth coupling transformer.

S1005, the common mode transformer couples the common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit.

S1006. The common-mode signal receiving circuit receives the common-mode signal coupled to the common-mode signal receiving circuit by the common-mode transformer.

S1007. The analog interface receives the fourth differential mode signal, the fifth differential mode signal and the common mode signal.

S1008. The adjustable amplifier amplifies the fourth differential mode signal, the fifth differential mode signal and the common mode signal received by the analog interface to obtain amplified differential mode signals and common mode signals.

S1009. The analog-to-digital converter samples the amplified differential mode signal and common mode signal to obtain a digital signal.

S1010, the digital interface receives digital signals.

S1011. The digital front end processes the digital signals received by the digital interface to eliminate noise.

Specifically, noise elimination processing can be performed on the digital signal through a digital end algorithm, and the digital end algorithm can be, for example, the MMSE-IRC algorithm.

In the above signal sending and receiving method, since various electrical appliances are added to the power line, the signal transmitted on the power line includes electrical appliance noise. That is to say, the two coupled differential mode signals received include differential mode electrical appliance noise. At the same time, since electrical noise has strong common-mode characteristics, the common-mode signal received by the coupling includes common-mode electrical noise. Since the electrical appliance noise in the two-way differential mode signal is correlated with the common mode electrical appliance noise, the received digital signal is processed through the digital terminal algorithm to eliminate the electrical appliance noise, thereby improving the performance of power line communication.

Referring to Figure 11, Figure 11 is a schematic diagram of the performance gain achieved by receiving signals through the signal transceiver circuit provided in the embodiment of the present application. As shown in Figure 11, the white bar graph is a schematic diagram of the performance gain achieved by receiving three signals through a conventional T-shaped coupling circuit, and the black bar graph is a common mode introduced on the basis of a T-shaped coupling circuit provided by the embodiment of the present application. Schematic diagram of the performance gains achieved by a coupling circuit receiving three signals, including one common-mode signal. The line diagram is a schematic diagram of the performance gain achieved by receiving signals through the signal transceiver circuit provided in the embodiment of the present application compared with receiving signals through a conventional circuit. It can be seen that under the interference of various electrical noise, the performance gain provided by the signal transceiver circuit provided by the embodiment of the present application The signal transceiver circuit can achieve 5-78% performance improvement when receiving signals.

The embodiments of the present application have been introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and the core idea of the present application; at the same time, for Those of ordinary skill in the art will have changes in the specific implementation and application scope based on the ideas of the present application. In summary, the contents of this description should not be understood as limiting the present application.

Claims (16)

1. A signal transceiver circuit for power line communication, characterized in that the circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit, and the differential mode coupling circuit and the common mode coupling circuit are respectively connected to the power line. , the noise processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit, the common mode coupling circuit includes a common mode transformer, and the power line includes at least one of the following: live line, neutral line and ground line, in, The differential mode coupling circuit is used to couple and receive differential mode signals on the power line; The common mode coupling circuit is used to couple and receive common mode signals on the power line, wherein the common mode transformer is connected in series on the power line; The noise processing circuit is used to process the common mode signal and the differential mode signal to eliminate noise in the differential mode signal. 2. The circuit of claim 1, wherein the differential mode coupling circuit includes at least one coupling transformer and at least one transceiver circuit, and each of the at least one coupling transformers is connected to one of the power lines. At least two lines are connected, each of the at least one coupling transformer is coupled to one of the at least one transceiver circuit, wherein, Each of the at least one coupling transformers is configured to couple a differential mode signal received from at least two of the power lines to one of the at least one transceiver circuit; Each transceiver circuit in the at least one transceiver circuit is configured to receive the differential mode signal coupled to each transceiver circuit by the coupling transformer. 3. The circuit according to claim 1, characterized in that the common mode coupling circuit further includes a common mode signal receiving circuit, the common mode transformer is connected to the live wire, the neutral wire and the ground wire, and the common mode transformer couples to the common mode signal receiving circuit, where, The common mode transformer is used to couple common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit; The common mode signal receiving circuit is configured to receive the common mode signal coupled to the common mode signal receiving circuit by the common mode transformer. 4. The circuit of claim 1, wherein the differential mode coupling circuit includes a first coupling transformer, a first transceiver circuit, a second coupling transformer and a second transceiver circuit, and the first coupling transformer is connected to the first transceiver circuit. Two lines in the power line are connected, the first coupling transformer is coupled to the first transceiver circuit, the second coupling transformer is connected to two lines in the power line, and the second coupling transformer is coupled to the first transceiver circuit. In the second transceiver circuit, the two lines of the power line are two lines of the live line, the neutral line and the ground line, and the two lines of the power line connected to the first coupling transformer are connected to the second coupling line. Two of the power lines connected by the transformer are different, where, The first coupling transformer is used to couple the first differential mode signal received from two lines in the power line to the first transceiver circuit; The first transceiver circuit is configured to receive the first differential mode signal coupled to the first transceiver circuit by the first coupling transformer; The second coupling transformer is used to couple the second differential mode signal received from two lines of the power line to the second transceiver circuit; The second transceiver circuit is configured to receive the second differential mode signal coupled to the second transceiver circuit by the second coupling transformer. 5. The circuit according to claim 4, wherein the differential mode coupling circuit further includes a third coupling transformer and a third transceiver circuit, the third coupling transformer is connected to two of the power lines, The third coupling transformer is coupled to the third transceiver circuit, and two of the power lines connected to the third coupling transformer are different from two of the power lines connected to the first coupling transformer, And two of the power lines connected to the second coupling transformer are different, wherein, The third coupling transformer is used to couple the third differential mode signal received from two lines of the power line to the third transceiver circuit; The third transceiver circuit is configured to receive the third differential mode signal coupled to the third transceiver circuit by the third coupling transformer. 6. The circuit of claim 1, wherein the differential mode coupling circuit includes a fourth coupling transformer, a fourth transceiver circuit, a fifth coupling transformer, and a fifth transceiver circuit, and the fourth coupling transformer is connected to the fourth transceiver circuit. At least two of the power lines are connected, the fourth coupling transformer is coupled to the fourth transceiver circuit, the fifth coupling transformer is connected to at least two of the power lines, and the fifth coupling transformer is coupled to To the fifth transceiver circuit, at least two of the power lines are two of the live line, the neutral line and the ground line or the live line, the neutral line and the ground line, the fourth coupling transformer and the fifth At least one of the coupling transformers is connected to the live wire, neutral wire and ground wire, where, The fourth coupling transformer is used to couple a fourth differential mode signal received from at least two of the power lines to the fourth transceiver circuit; The fourth transceiver circuit is configured to receive the fourth differential mode signal coupled to the fourth transceiver circuit by the fourth coupling transformer; The fifth coupling transformer is used to couple a fifth differential mode signal received from at least two of the power lines to the fifth transceiver circuit; The fifth transceiver circuit is configured to receive the fifth differential mode signal coupled to the fifth transceiver circuit by the fifth coupling transformer. 7. The circuit according to claim 6, wherein the differential mode coupling circuit further includes a sixth coupling transformer and a sixth transceiver circuit, the sixth coupling transformer is connected to at least two of the power lines. , the sixth coupling transformer is coupled to the sixth transceiver circuit, wherein, The sixth coupling transformer is used to couple a sixth differential mode signal received from at least two of the power lines to the sixth transceiver circuit; The sixth transceiver circuit is configured to receive the sixth differential mode signal coupled to the sixth transceiver circuit by the sixth coupling transformer. 8. The circuit according to any one of claims 1 to 7, characterized in that the noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end, and the analog front end communicates with the analog interface through the analog interface. The differential mode coupling circuit is connected to the common mode coupling circuit, and the digital front end is connected to the analog front end through the digital interface. The analog front end includes an adjustable amplifier and an analog-to-digital converter, wherein, The analog interface is used to receive the differential mode signal and the common mode signal; The adjustable amplifier is used to amplify the differential mode signal and the common mode signal received by the analog interface to obtain amplified differential mode signals and common mode signals; The analog-to-digital converter is used to sample the amplified differential mode signal and common mode signal to obtain a digital signal; The digital interface is used to receive the digital signal; The digital front end is used to process the digital signal received by the digital interface to eliminate noise. 9. A signal transceiving method for power line communication, characterized in that it is applied to a signal transceiving circuit for power line communication. The circuit includes a differential mode coupling circuit, a common mode coupling circuit and a noise processing circuit. The differential mode coupling circuit and the The common mode coupling circuit is connected to the power line respectively, the noise processing circuit is connected to the differential mode coupling circuit and the common mode coupling circuit, the common mode coupling circuit includes a common mode transformer, and the power line includes at least one of the following : live wire, neutral wire and ground wire, the method includes: The differential mode coupling circuit is coupled to receive the differential mode signal on the power line; The common mode coupling circuit is coupled to receive the common mode signal on the power line, wherein the common mode transformer is connected in series to the power line; The noise processing circuit processes the common mode signal and the differential mode signal to eliminate noise in the differential mode signal. 10. The method of claim 9, wherein the differential mode coupling circuit includes at least one coupling transformer and at least one transceiver circuit, and each of the at least one coupling transformer is connected to a circuit in the power line. At least two lines are connected, each of the at least one coupling transformer is coupled to one of the at least one transceiver circuit, and the differential mode coupling circuit coupled to receive the differential mode signal on the power line includes: Each of the at least one coupling transformers couples differential mode signals received from at least two of the power lines to one of the at least one transceiver circuits; Each of the at least one transceiver circuit receives the differential mode signal coupled to the each transceiver circuit by the coupling transformer. 11. The method according to claim 9, characterized in that the common mode coupling circuit further includes a common mode signal receiving circuit, the common mode transformer is connected to the live wire, the neutral wire and the ground wire, and the common mode transformer couples To the common mode signal receiving circuit, the common mode coupling circuit coupled to receive the common mode signal on the power line includes: The common mode transformer couples common mode signals received from the live wire, neutral wire and ground wire to the common mode signal receiving circuit; The common mode signal receiving circuit receives the common mode signal coupled to the common mode signal receiving circuit by the common mode transformer. 12. The method of claim 9, wherein the differential mode coupling circuit includes a first coupling transformer, a first transceiver circuit, a second coupling transformer and a second transceiver circuit, and the first coupling transformer is connected to the first transceiver circuit. Two lines in the power line are connected, the first coupling transformer is coupled to the first transceiver circuit, the second coupling transformer is connected to two lines in the power line, and the second coupling transformer is coupled to the first transceiver circuit. In the second transceiver circuit, the two lines of the power line are two lines of the live line, the neutral line and the ground line, and the two lines of the power line connected to the first coupling transformer are connected to the second coupling line. Two of the power lines connected by the transformer are different, and the differential mode coupling circuit coupled to receive the differential mode signal on the power line includes: the first coupling transformer couples a first differential mode signal received from two of the power lines to the first transceiver circuit; The first transceiver circuit receives the first differential mode signal coupled to the first transceiver circuit by the first coupling transformer; the second coupling transformer couples a second differential mode signal received from two of the power lines to the second transceiver circuit; The second transceiver circuit receives the second differential mode signal coupled to the second transceiver circuit by the second coupling transformer. 13. The method according to claim 12, wherein the differential mode coupling circuit further includes a third coupling transformer and a third transceiver circuit, the third coupling transformer is connected to two of the power lines, The third coupling transformer is coupled to the third transceiver circuit, and two of the power lines connected to the third coupling transformer are different from two of the power lines connected to the first coupling transformer, And different from the two lines in the power line connected to the second coupling transformer, the differential mode coupling circuit coupled to receive the differential mode signal on the power line further includes: the third coupling transformer couples a third differential mode signal received from two of the power lines to the third transceiver circuit; The third transceiver circuit receives the third differential mode signal coupled to the third transceiver circuit by the third coupling transformer. 14. The method of claim 9, wherein the differential mode coupling circuit includes a fourth coupling transformer, a fourth transceiver circuit, a fifth coupling transformer, and a fifth transceiver circuit, and the fourth coupling transformer is connected to the fourth transceiver circuit. At least two of the power lines are connected, the fourth coupling transformer is coupled to the fourth transceiver circuit, the fifth coupling transformer is connected to at least two of the power lines, and the fifth coupling transformer is coupled to To the fifth transceiver circuit, at least two of the power lines are two of the live line, the neutral line and the ground line or the live line, the neutral line and the ground line, the fourth coupling transformer and the fifth At least one of the coupling transformers is connected to the live wire, the neutral wire and the ground wire, and the differential mode coupling circuit coupled to receive the differential mode signal on the power line includes: the fourth coupling transformer couples a fourth differential mode signal received from at least two of the power lines to the fourth transceiver circuit; The fourth transceiver circuit receives the fourth differential mode signal coupled to the fourth transceiver circuit by the fourth coupling transformer; the fifth coupling transformer couples a fifth differential mode signal received from at least two of the power lines to the fifth transceiver circuit; The fifth transceiver circuit receives the fifth differential mode signal coupled to the fifth transceiver circuit by the fifth coupling transformer. 15. The method of claim 14, wherein the differential mode coupling circuit further includes a sixth coupling transformer and a sixth transceiver circuit, the sixth coupling transformer is connected to at least two of the power lines. , the sixth coupling transformer is coupled to the sixth transceiver circuit, and the differential mode coupling circuit coupled to receive the differential mode signal on the power line further includes: the sixth coupling transformer couples a sixth differential mode signal received from at least two of the power lines to the sixth transceiver circuit; The sixth transceiver circuit receives the sixth differential mode signal coupled to the sixth transceiver circuit by the sixth coupling transformer. 16. The method according to any one of claims 9 to 15, characterized in that the noise processing circuit includes an analog interface, an analog front end, a digital interface and a digital front end, and the analog front end communicates with the analog interface through the analog interface. The differential mode coupling circuit is connected to the common mode coupling circuit, the digital front end is connected to the analog front end through the digital interface, the analog front end includes an adjustable amplifier and an analog-to-digital converter, and the noise processing circuit is Processing the common mode signal and the differential mode signal to eliminate noise in the differential mode signal includes: The analog interface receives the differential mode signal and the common mode signal; The adjustable amplifier amplifies the differential mode signal and the common mode signal received by the analog interface to obtain amplified differential mode signals and common mode signals; The analog-to-digital converter samples the amplified differential mode signal and common mode signal to obtain a digital signal; The digital interface receives the digital signal; The digital front end processes the digital signal received by the digital interface to eliminate noise.