Method for reducing bit error rate of power line communication equipment and power line communication equipment

Abstract

The present invention discloses a method for reducing the bit error rate of a power line communication device and a power line communication device, the method comprising: S1, the power line communication device obtains channel measurement values ​​of multiple channels of a power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively; S2, based on the channel measurement value of each channel, respectively calculating the average gain of each channel; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel; S3, selecting a receiving mode of the power line communication device based on the average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to a method for reducing a bit error rate of a power line communication device and related power line communication device. Background Art

[0002] In a single-phase line system, the power line medium includes three conductors, namely, the phase line or live wire (L), the neutral line or neutral wire (N), and the protective ground wire (G). In a three-phase line system, the power line medium includes four conductors, namely, phase A, phase B, phase C, and neutral wire (N). Traditional power line communication equipment uses a pair of wires (e.g., live wire and neutral wire) to transmit signals. Such equipment only contains one communication port and is a single-input single-output (SISO) system. However, in a single-phase three-wire system and a three-phase four-wire system, more ports (e.g., live wire and neutral wire, live wire and ground wire) are allowed to be used to transmit signals, forming a multiple-input multiple-output (MIMO) system.

[0003] At present, most power line communication devices that use power line communication technology for remote meter reading services use a single-input single-output system. Although MIMO technology has been introduced into power line communication devices abroad, it is mainly aimed at home power line environments to improve the throughput of power line communication devices. The power line medium has serious frequency selective fading. At present, power line communication devices that receive single channel signals have a high bit error rate problem. Power line communication devices that use MIMO space division multiplexing technology improve the system throughput, but must use multiple ports to receive signals, which increases the complexity of the equipment. Therefore, it is necessary to make improvements to reduce the bit error rate and improve the communication stability of power line communication devices. Summary of the invention

[0004] In view of this, the present invention proposes a method for reducing a bit error rate of a power line communication device and a power line communication device, aiming at reducing the bit error rate of the power line communication device.

[0005] According to one aspect of the present invention, a method for reducing a bit error rate of a power line communication device is proposed, comprising the following steps: S1, the power line communication device obtains channel measurement values ​​of multiple channels of a power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively; S2, based on the channel measurement value of each channel, respectively calculating the average gain of each channel; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel; S3, selecting a receiving mode of the power line communication device based on the average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

[0006] Furthermore, the step S3 of selecting the receiving mode of the power line communication device based on the average gain of each channel includes: selecting the receiving mode of the power line communication device based on whether the ratio or difference of the average gain of each channel is within a given threshold range.

[0007] Furthermore, in step S3, when the ratio or difference of the average gains of each channel exceeds a given threshold range, the single SISO receiving mode is selected; when the ratio or difference of the average gains of each channel is within a given threshold range, the receiving mode based on transmit diversity is selected.

[0008] Furthermore, the single SISO receiving mode is to use a channel with the largest average gain among multiple channels of the power line medium for receiving, and the receiving mode based on transmit diversity is to use two or three channels among multiple channels of the power line medium for receiving.

[0009] Furthermore, when the power line communication device operates in a single-phase line system:

[0010] In step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium, including: obtaining channel measurement values ​​of two channels and Wherein, k is a subcarrier index; the power line medium of the single-phase line system includes three conductors, forming two effective communication channels;

[0011] In step S2, the average gain of each channel is calculated respectively, including: the average gain of two channels is calculated respectively.

[0012] Furthermore, the two channels are a direct channel and a crosstalk channel, and the corresponding average gains are denoted as G1 and G2 respectively;

[0013] In step S3, first compare the sizes of G1 and G2, and then calculate the ratio or difference between the larger and the smaller of G1 and G2. If the ratio or difference exceeds a given threshold range, the single SISO receiving mode is selected; if the ratio or difference is within a given threshold range, the receiving mode based on transmit diversity is selected.

[0014] Furthermore, when the power line communication device operates in a three-phase line system:

[0015] In step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium, including: obtaining channel measurement values ​​of three channels and Wherein, k is a subcarrier index; the power line medium of the three-phase line system includes four conductors, forming three effective communication channels;

[0016] In step S2, the average gain of each channel is calculated respectively, including: the average gain of three channels is calculated respectively.

[0017] Furthermore, the three channels are a direct channel, a first crosstalk channel and a second crosstalk channel, and the corresponding average gains are recorded as G1, G2 and G3 respectively;

[0018] In step S3, first compare the sizes of G1, G2 and G3, and then calculate the ratio or difference D1 between the largest and the second largest, and the ratio or difference D2 between the largest and the third largest respectively;

[0019] If D1 and D2 are both within a given threshold range, a reception mode based on transmit diversity is selected, and the power line communication device receives signals transmitted on the direct channel, the first crosstalk channel, and the second crosstalk channel;

[0020] If D1 is within a given threshold range and D2 exceeds a given threshold range, a receiving mode based on transmit diversity is selected, and the power line communication device receives signals transmitted on the channels corresponding to the channels with the largest average gain and the second largest average gain;

[0021] If both D1 and D2 exceed the given threshold range, the single SISO receiving mode is selected.

[0022] Furthermore, in step S2, the average gain of each channel is calculated using the following formula (1) or formula (2):

[0023]

[0024]

[0025] Among them, i is the effective communication channel index, G i is the average gain of the ith channel, and N is the number of subcarriers in each channel.

[0026] According to another aspect of the present invention, a power line communication device is proposed, comprising: a coupling device, through which the power line communication device receives a signal transmitted by a power line medium; a memory for storing instructions; a processor for executing the instructions, so that the power line communication device performs the following operations: determining channel measurement values ​​of multiple channels of the power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively; based on the channel measurement value of each channel, respectively calculating the average gain of each channel; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel; selecting a receiving mode of the power line communication device based on the average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

[0027] The beneficial effects of the technical solution of the present invention are embodied in that: compared with a single-input single-output system, the method and device of the present invention can use a single port at the receiving end to receive signals encoded using space-time coding technology for multi-path transmission, and these multi-path signals include signals on the same wire pair as the transmitting end and signals sent by the transmitting end on other wire pairs that are leaked to the receiving end wire pair due to crosstalk or energy leakage. The receiving end receives multi-path signals so that the power line communication device obtains the diversity gain of the system, improves the signal-to-noise ratio of the system, and then reduces the bit error rate of the power line communication device.

[0028] The power line communication device of the present invention compares the average gains of the transmission channels and selects the signal with the highest channel gain to communicate, thereby improving the stability of the power line device communication.

[0029] The power line communication device of the present invention can use a coupling device, especially a single coupling device, to receive multi-channel signals transmitted by the power line medium. Without increasing the complexity of the device, the receiving end only needs to perform simple linear processing to parse the received multi-channel signals, thereby obtaining the diversity gain of the system, improving the signal-to-noise ratio of the system, and reducing the bit error rate of the power line communication device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a flowchart of a method for reducing the bit error rate of a power line communication device according to an embodiment of the present invention.

[0031] Figure 2A It is a schematic diagram of multiple channels of a power line communication device working in a single-phase line system according to an embodiment of the present invention.

[0032] Figure 2B It is a multi-channel schematic diagram of a power line communication device working in a three-phase line system according to an embodiment of the present invention.

[0033] Figure 3 This is an example flow chart of selecting a receiving mode for a power line communication device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0035] An embodiment of the present invention discloses a method for reducing a bit error rate of a power line communication device, comprising the following steps:

[0036] An embodiment is:

[0037] In this embodiment, the power line communication device works in a single-phase line system. In the single-phase line system, the power line medium includes three conductors, namely, phase line (L), neutral line (N) and ground line (G). The transmitting end of the traditional power line communication device couples the signal to the wire pair (for example, the phase line and the neutral line, referred to as LN), and the receiving end of the power line communication device receives the signal of the wire pair through a coupling device. This system using a common wire pair is called a single SISO system, and the receiving method is called a single SISO reception; however, another wire can be used to combine into a new wire pair (for example: phase line and ground line, referred to as LG), and the signal on the wire pair is crosstalked or leaked to the wire pair LN, so the power line communication device that receives the signal through the wire pair LN can also receive the signal transmitted on the wire pair LG.

[0038] Figure 1 This is an example execution step of a method for reducing the bit error rate of a power line communication device according to the disclosure of the present invention, which specifically includes the following process:

[0039] Step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium;

[0040] Combination Figure 2A As shown, the receiving end of the power line communication device 10 only includes one receiving port RX1, which can receive the signal on the wire pair LN; the power line communication device 20 sends signals on the wire pair LN and the wire pair LG through the sending ports TX1 and TX2, the transmitting end wire pair LN and the power line communication device 10 receiving wire pair LN form a channel (which can be called a direct channel), the transmitting end wire pair LG and the power line communication device 10 receiving wire pair LN form another channel (which can be called a crosstalk channel), the direct channel corresponds to a transmission path LN-LN, and the crosstalk channel corresponds to a transmission path LN-LG; the power line communication device 10 can obtain channel measurement values ​​of the two channels, the direct channel measurement value and crosstalk channel measurements Wherein, k is the subcarrier index.

[0041] Step S2, calculating the average gain of the channel measurement values ​​of each channel. In this step, based on the channel measurement values ​​of the two channels, the average gains of the two channels are calculated respectively; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel.

[0042] In this embodiment, the power line communication device calculates the direct channel measurement value obtained and crosstalk channel measurements The average gain of the direct channel Average gain of the crosstalk channel Where N is the number of subcarriers.

[0043] Step S3: Select a receiving mode of the power line communication device based on the average gain of each channel.

[0044] In this embodiment, the receiving mode of the power line communication device 10 is selected based on the average gain G1 of the direct channel and the average gain G2 of the crosstalk channel;

[0045] The average gain of the direct channel and the average gain of the crosstalk channel can be sorted in order from large to small or from small to large to compare the size. In this embodiment, they are sorted from large to small. Assuming that G1>G2 in this embodiment, the ratio of the average gain of the direct channel G1>G2 to the average gain of the crosstalk channel G2 is calculated. That is to say, the larger one is divided by the smaller one to obtain the ratio R, and then the receiving mode is selected based on the ratio R.

[0046] Combination Figure 3 As shown, at the judgment point in the figure, it is determined whether the ratio R is within a given threshold range. If the ratio R is within the given threshold range, the power line communication device receives the signal transmitted on the direct channel and the signal transmitted on the crosstalk channel. This receiving of signals on two different transmission paths through one receiving port is called reception based on transmit diversity. If the ratio R exceeds the given threshold range, the channel with the largest average gain in the two channels of the power line medium is selected as the single SISO receiving mode. In combination with this embodiment, the signal transmitted on the direct channel is selected for reception.

[0047] Another embodiment is:

[0048] In this embodiment, the power line communication device works in a three-phase line system. In the three-phase line system, the power line medium includes four conductors, namely, phase A, phase B, phase C and neutral (N). The transmitting end of the traditional power line communication device couples the signal to the wire pair (for example, phase A and neutral, referred to as AN), and the receiving end of the power line communication device receives the signal of the wire pair through a coupling device. This system using a common wire pair is called a single SISO system, and the receiving method is called single SISO reception; however, other wires can be used to combine into a new wire pair (for example: phase B and neutral, referred to as BN; or phase C and neutral, referred to as CN), and the signal on the wire pair is crosstalked or leaked to the wire pair AN, so the power line communication device that receives the signal through the wire pair AN can also receive the signal transmitted on other wire pairs.

[0049] Figure 1 This is an example execution step of a method for reducing the bit error rate of a power line communication device according to the disclosure of the present invention, which specifically includes the following process:

[0050] Step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium;

[0051] Combination Figure 2B As shown, the receiving end of the power line communication device 100 includes only one receiving port RX1, which can receive the signal on the wire pair AN; the power line communication device 200 sends signals on the wire pair AN, the wire pair BN and the wire pair CN through the sending ports TX1, TX2 and TX3 respectively, the transmitting end wire pair AN and the power line communication device 100 receiving wire pair AN form a channel (which can be called a direct channel), the transmitting end wire pair BN and the power line communication device 100 receiving wire pair AN form another channel (which can be called a crosstalk channel 1), the transmitting end wire pair CN and the power line communication device 100 receiving wire pair AN form another channel (which can be called a crosstalk channel 2), the direct channel corresponds to a transmission path AN-AN, the crosstalk channel 1 corresponds to a transmission path AN-BN; the crosstalk channel 2 corresponds to a transmission path AN-CN; the power line communication device 100 can obtain channel measurement values ​​of the three channels, the direct channel measurement value Crosstalk channel 1 measured values and the measured values ​​of crosstalk channel 2 Wherein, k is the subcarrier index.

[0052] Step S2, calculating the average gain of the channel measurement values ​​of each channel. In this step, based on the channel measurement values ​​of the three channels, the average gain of the three channels is calculated respectively; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel.

[0053] In this embodiment, the power line communication device measures the value of the direct channel. Calculate the average gain of the direct channel, based on the measured value of crosstalk channel 1 Calculate the average gain of crosstalk channel 1 and, based on the measured value of crosstalk channel 2 Calculate the average gain of crosstalk channel 2; the average gain of the direct channel Average gain of crosstalk channel 1 Average gain of crosstalk channel 2 measurements Where N is the number of subcarriers in each channel.

[0054] Step S3: Select a receiving mode of the power line communication device based on the average gain of each channel.

[0055] In this embodiment, the receiving mode of the power line communication device 100 is selected based on the average gain G1 of the direct channel, the average gain G2 of the crosstalk channel 1, and the average gain G3 of the crosstalk channel 2;

[0056] The average gain of the direct channel, the average gain of crosstalk channel 1, and the average gain of crosstalk channel 2 can be sorted in descending order or ascending order. In this example, they are sorted in ascending order. Assume that in this embodiment, G2 < G3 < G1. Then calculate the difference D1 = G1 - G3 between the average gain G1 of the direct channel and the average gain G3 of crosstalk channel 2, and calculate the difference D2 = G1 - G2 between the average gain G1 of the direct channel and the average gain G2 of crosstalk channel 1. That is, first compare the magnitudes of G1, G2, and G3, and then calculate the difference D1 between the largest and the second largest, and the difference D2 between the largest and the third largest respectively;

[0057] Combined with Figure 3 As shown, at the decision point in the figure, determine whether the differences D1 and D2 are within the given threshold range, specifically as follows:

[0058] If both D1 and D2 are within the given threshold range, then select the reception mode based on transmit diversity, and the power line communication device receives the signals transmitted on the direct channel, the first crosstalk channel, and the second crosstalk channel;

[0059] If D1 is within the given threshold range while D2 exceeds the given threshold range, then select the reception mode based on transmit diversity, and the power line communication device receives the signals transmitted on the direct channel and the second crosstalk channel;

[0060] If both D1 and D2 exceed the given threshold range, then select the single SISO reception mode.

[0061] In summary, the method for reducing the bit error rate of a power line communication device provided by the embodiment of the present invention can select an appropriate reception mode according to the average gain of the channel. When using single SISO reception, select the channel with the largest average gain to receive; for reception based on transmit diversity, select to receive the signals transmitted on multiple channels, so that the power line communication device obtains diversity gain, improves the signal-to-noise ratio of the received signal, reduces the bit error rate, ensures the reliability of communication, and the receiving end only needs to perform simple linear processing to analyze the received multiple signals.

[0062] Another embodiment of the present invention also provides a power line communication device, including:

[0063] A coupling device, through which the power line communication device receives the signals transmitted on the power line medium;

[0064] A memory for storing instructions;

[0065] A processor for executing the instructions, so that the power line communication device performs the following operations:

[0066] Determine channel measurement values ​​of multiple channels of the power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively;

[0067] Based on the channel measurement value of each channel, the average gain of each channel is calculated respectively; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel;

[0068] A receiving mode of the power line communication device is selected based on an average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

[0069] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for reducing the bit error rate of a power line communication device, characterized in that: The following steps are involved: S1. A power line communication device obtains channel measurement values ​​of multiple channels of a power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively; S2. Calculate the average gain of each channel based on the channel measurement value of each channel; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel; S3. Selecting a receiving mode of the power line communication device based on an average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

2. The method for reducing the bit error rate of a power line communication device according to claim 1, characterized in that: The step S3 of selecting the receiving mode of the power line communication device based on the average gain of each channel includes: selecting the receiving mode of the power line communication device based on whether the ratio or difference of the average gain of each channel is within a given threshold range.

3. The method for reducing the bit error rate of a power line communication device according to claim 2, characterized in that: In step S3, when the ratio or difference of the average gains of each channel exceeds a given threshold range, the single SISO receiving mode is selected; when the ratio or difference of the average gains of each channel is within a given threshold range, the receiving mode based on transmit diversity is selected.

4. The method for reducing the bit error rate of a power line communication device according to claim 3, characterized in that: The single SISO receiving mode is to use a channel with the largest average gain among multiple channels of the power line medium for receiving, and the receiving mode based on transmit diversity is to use two or three channels among multiple channels of the power line medium for receiving.

5. The method for reducing the bit error rate of a power line communication device according to claim 4, characterized in that: When the power line communication device operates in a single-phase line system: In step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium, including: obtaining channel measurement values ​​of two channels and Wherein, k is a subcarrier index; the power line medium of the single-phase line system includes three conductors, forming two effective communication channels; In step S2, the average gain of each channel is calculated respectively, including: the average gain of two channels is calculated respectively.

6. The method for reducing the bit error rate of a power line communication device according to claim 5, characterized in that: The two channels are a direct channel and a crosstalk channel, and the corresponding average gains are denoted as G1 and G2 respectively; In step S3, first compare the sizes of G1 and G2, and then calculate the ratio or difference between the larger and the smaller of G1 and G2. If the ratio or difference exceeds a given threshold range, select the single SISO receiving mode. If the ratio or difference is within a given threshold range, a reception mode based on transmit diversity is selected.

7. The method for reducing the bit error rate of a power line communication device according to claim 4, characterized in that: When the power line communication device operates in a three-phase line system: In step S1, the power line communication device obtains channel measurement values ​​of multiple channels of the power line medium, including: obtaining channel measurement values ​​of three channels and Wherein, k is a subcarrier index; the power line medium of the three-phase line system includes four conductors, forming three effective communication channels; In step S2, the average gain of each channel is calculated respectively, including: the average gain of three channels is calculated respectively.

8. The method for reducing the bit error rate of a power line communication device according to claim 7, characterized in that: The three channels are a direct channel, a first crosstalk channel, and a second crosstalk channel, and the corresponding average gains are recorded as G1, G2, and G3 respectively; In step S3, first compare the sizes of G1, G2 and G3, and then calculate the ratio or difference D1 between the largest and the second largest, and the ratio or difference D2 between the largest and the third largest respectively; If D1 and D2 are both within a given threshold range, a reception mode based on transmit diversity is selected, and the power line communication device receives signals transmitted on the direct channel, the first crosstalk channel, and the second crosstalk channel; If D1 is within a given threshold range and D2 exceeds a given threshold range, a receiving mode based on transmit diversity is selected, and the power line communication device receives signals transmitted on the channels corresponding to the channels with the largest average gain and the second largest average gain; If both D1 and D2 exceed the given threshold range, the single SISO receiving mode is selected.

9. The method for reducing the bit error rate of a power line communication device according to claim 1, characterized in that: In step S2, the average gain of each channel is calculated using the following formula (1) or formula (2): Among them, i is the effective communication channel index, G i is the average gain of the ith channel, and N is the number of subcarriers in each channel.

10. A power line communication device, characterized in that: include: A coupling device, through which the power line communication device receives a signal transmitted by a power line medium; A memory for storing instructions; The processor is configured to execute the instruction so that the power line communication device performs the following operations: Determine channel measurement values ​​of multiple channels of the power line medium; wherein the multiple channels of the power line medium are associated with a transmission path of the power line medium, and the multiple channels correspond to different transmission paths respectively; Based on the channel measurement value of each channel, the average gain of each channel is calculated respectively; wherein the channel measurement value of each channel is the channel gain value of multiple subcarriers of the channel; A receiving mode of the power line communication device is selected based on an average gain of each channel; wherein the receiving mode is selected from a single SISO receiving mode and a receiving mode based on transmit diversity.

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