WO2013056520A1

WO2013056520A1 - Power line communication method based on channel cognitive technology

Info

Publication number: WO2013056520A1
Application number: PCT/CN2012/070313
Authority: WO
Inventors: 陆超
Original assignee: 上海炜呈智能电力科技有限责任公司
Priority date: 2011-10-19
Filing date: 2012-01-13
Publication date: 2013-04-25
Also published as: CN102355313A; CN102355313B

Abstract

A power line communication method based on a channel cognitive technology comprises: performing cognition on a power line channel and obtaining a channel model; according to the obtained channel model, determining configuration parameters of a communication device; according to the determined configuration parameters, configuring a communication transceiver in the communication device; performing data transmission through the communication device configured with the configuration parameters. Compared with the prior art, the present invention can configure configuration parameters of the communication transceiver in the power line communication device, so as to make the whole power line communication system work in a most suitable state, thereby improving the reliability, stability, and communication rate of power line communication, and meanwhile improving the spectrum utilization and the power utilization.

Description

TECHNICAL FIELD The present invention relates to communication technologies, and in particular, to a power line communication method based on channel recognition technology. BACKGROUND OF THE INVENTION Power line carrier communication technology is a communication method for transmitting data information by using a power line as a communication medium, and generally includes: high-voltage power line carrier communication using a high-voltage transmission line of a voltage level of 35 kV or higher as a communication medium; with a voltage level of 10 kV Medium voltage power line carrier communication using medium voltage transmission line as communication medium; and low voltage power line carrier communication using 380V or 220V low voltage transmission line as communication medium. The traditional power line carrier communication mainly uses a high-voltage transmission line as a transmission channel of a high-frequency signal, and is limited to transmitting a remote control signal, etc., and has a narrow application range and a low transmission rate. At present, with the continuous development of power line carrier technology and the needs of society, power carrier communication is turning to low-voltage distribution network for carrier communication, which makes the development and application of low-voltage power line carrier communication appear in the ascendant situation. Compared with other communication technologies, the channel conditions that power line carrier communication needs to face have the following characteristics: strong time-varying, and exhibiting a cyclic smoothing characteristic that varies with the power frequency signal; large channel attenuation; strong intensity of the interference signal and the noise signal, The signal to noise ratio and the signal are relatively poor. Conventional power line carrier communication uses spread spectrum, narrowband modulation or phase modulation techniques, with fixed carrier frequency and communication bandwidth, and fixed communication time. In general, conventional power line carrier communication uses one or two fixed carrier frequencies and communication bandwidths to transmit and/or receive signals at all times in a fixed modulation method. This method will bring the following problems: On the one hand, because the topology of the power grid and the connected electrical equipment have great randomness and uncertainty, the multipath effect and attenuation characteristics of the channel are not Fixed, not only varies with the application scenario, but also has a strong time-varying. For traditional power line communication equipment, it is unrealistic to find a communication band that can perform optimally in all application scenarios. This makes it impossible for products using traditional communication methods to select the appropriate communication method for the current application, so that the reliability of communication is greatly affected. On the other hand, the traditional product design is based on the worst case as the reference design. If the current communication conditions are better than the worst case, the traditional products can not be adjusted accordingly, which will inevitably lead to the design of the ultra-margin, its spectrum utilization. Rate and power consumption The usage rate is relatively low. SUMMARY OF THE INVENTION An object of the present invention is to provide a power line communication method based on channel cognition technology, which is used to solve the problems of poor communication reliability, spectrum utilization, and low power consumption utilization of existing power line carrier communication. The present invention provides a power line communication method based on channel cognition technology, comprising: recognizing a power line channel and obtaining a channel model; determining a configuration parameter of the communication device according to the obtained channel model; and configuring the device according to the determined configuration parameter a communication transceiver in the communication device; performing data transmission by the communication device having the configuration parameters configured. Optionally, recognizing the power line channel and obtaining the channel model comprises: performing open-loop cognitive and/or closed-loop recognition on the power line channel to obtain a channel model. Optionally, performing open-loop awareness of the power line channel includes: measuring, by the sender or the receiver of the communication, frequency domain characteristics and time domain characteristics of the channel separately; the measuring includes: time domain of interference introduced in the channel Estimating characteristics and frequency domain characteristics; the interference includes narrowband interference or wideband interference; estimating time domain characteristics and frequency domain characteristics of noise introduced in the channel; the noise includes burst noise. Optionally, the closed loop awareness of the power line channel comprises: jointly measuring the frequency domain characteristics and the time domain characteristics of the channel by the sender and the receiver of the communication; the measuring comprises: performing the attenuation characteristic and the time variation of the channel Domain and frequency domain estimates. Optionally, determining configuration parameters of the communication device according to the channel model includes: determining configuration parameters of the communication device according to the obtained channel model and predetermined determination criteria. Optionally, the determining criterion includes a lowest bit error rate, a lowest packet loss rate, a signal to noise ratio threshold, or a signal to interference ratio threshold. Optionally, the configuration parameters include: a communication system, a frequency and bandwidth occupied by the signal, a scrambling code type and a modulation ratio parameter, a modulation mode, a type of the error correction code, a code rate, an interleaving manner, a generation matrix, and a network collaboration and organization One or more of the parameters of the form, digital to analog and analog to digital converter, and the frequency response of the communication transceiver. Optionally, the communication system is one or more of narrowband modulation, spread spectrum, and orthogonal frequency division multiplexing. Optionally, the scrambling code type includes a long code or a short code. Optionally, the type of the error correction code includes a BCH code, a cyclic code, a convolutional code, an RS coding, a Turbo coding, and a low Density parity check encodes one or more of LDPCs. The method for power line communication based on channel cognition technology of the present invention is capable of recognizing a current channel and obtaining a channel model; learning and analyzing according to the obtained channel model, selecting a most suitable communication mode for the power line communication device The configuration parameters of the communication transceiver are configured to operate the entire power line communication system in an optimum state, thereby improving the reliability, stability, and communication rate of the power line communication, and at the same time improving spectrum utilization and power consumption utilization. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic flow chart of a power line communication method based on channel cognition technology in an embodiment of the present invention. FIG. 2 is a schematic diagram of a power line communication method based on a channel cognition technology for identifying a power line channel and generating configuration parameters in an embodiment according to the present invention. 3 is a schematic diagram of the configuration of the frequency response of the communication transceiver. 4 is a structural block diagram of a power line communication device to which a power line communication method based on a channel cognitive technology is applied in one embodiment.

Component label description

201 narrowband interference

202 burst noise

203 attenuation

301 narrowband mode

302 broadband mode

401 parameter configurable power line communication transceiver

403 channel cognition module

405 Cognitive Control Module DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In view of the fact that the topology of the existing power grid and the accessing power equipment have great randomness and uncertainty, the power line channel has a strong time variation, and the existing communication equipment cannot achieve the current The application chooses the appropriate communication method, so that the reliability of its communication is greatly affected, and the spectrum utilization and power consumption are relatively low. Accordingly, the inventors of the present invention have improved the prior art, including: recognizing a power line channel and obtaining a channel model, determining configuration parameters of the communication device, thereby reconfiguring the communication transceiver in the communication device, by configuring The communication device performs data transmission, so that the entire power line communication system works in the most suitable state, thereby improving the reliability, stability and communication rate of the power line communication. The power line communication method based on the channel cognitive technology proposed by the present invention will be described in detail below through specific embodiments. FIG. 1 is a flow chart showing the power line communication method based on the channel cognition technology of the present invention in one embodiment. As shown in FIG. 1, the power line communication method includes:

Step S101: Cognizing a power line channel and obtaining a channel model;

Step S103: Determine, according to the obtained channel model, configuration parameters of the communication device.

Step S105, configuring a communication transceiver in the communication device according to the determined configuration parameter;

Step S107: Perform data transmission by using the communication device configured with the configuration parameter.

The above steps are described in detail below.

Step S101: Cognizing the power line channel and obtaining a channel model.

In practical applications, because the topology of the power grid and the connected electrical equipment have great randomness and uncertainty, the multipath effect and attenuation characteristics of the power line channel are not fixed, not only with the application. The scene varies from scene to scene and has a strong time-varying nature. Therefore, it is necessary to recognize the power line channel and obtain its channel characteristics.

In this embodiment, the knowledge of the power line channel and the resulting channel model can be achieved by open loop cognition and/or closed loop recognition.

Open-loop awareness of the power line channel includes: measuring the frequency domain characteristics and time domain characteristics of the channel by the sender or receiver of the communication. The measurements include, but are not limited to, estimating time domain patterns and frequency domain characteristics of interference introduced in the channel (e.g., narrowband interference or wideband interference), and time domain characteristics of noise (including burst noise) introduced in the channel. Estimated with frequency domain characteristics. Since the measurement of the frequency domain characteristics and the time domain characteristics by a communication terminal (sender or receiver) unidirectional channel is a prior art well known to those skilled in the art, it will not be described. Closed-loop awareness of the power line channel includes: The sender and receiver of the communication jointly measure the frequency domain characteristics and time domain characteristics of the channel. Specifically, a specific communication signal or a communication signal having a specific mode is transmitted by the sender of the communication, and the communication signal is received by the receiver of the communication after passing through the power line channel to be tested, and the receiver according to the received communication signal And a communication signal sent by the sender, analyzing the characteristics of the power line channel. The measurements include, but are not limited to: time and frequency domain estimation of the attenuation characteristics and time-varying of the channel. Since the frequency domain characteristics and the time domain characteristics of the channel are jointly measured by the sender and the receiver, the prior art is well known to those skilled in the art, and therefore will not be described.

Thus, by step S101, the power line channel can be measured to obtain a basic model of the power line channel characteristics. The channel characteristics include time domain and frequency domain distribution of interference signals such as channel (e.g., narrowband interference signals and burst noise), amplitude-frequency response of the channel, and time-varying characteristics thereof.

Step S103: Determine configuration parameters of the communication device according to the obtained channel model. Here, determining the configuration parameters of the communication device according to the channel model comprises: determining configuration parameters adopted by the communication device in the current communication according to the obtained channel model and predetermined determination criteria. The determining criterion includes the lowest bit error rate or the lowest packet loss rate, but is not limited thereto. In other embodiments, the determining criterion may also be other communication indicators. For example, in one embodiment, when the signal to interference ratio due to narrowband interference is within a certain range (e.g., the signal to interference ratio is less than 0 dB), the narrowband interference should be avoided when selecting an available communication band.

FIG. 2 is a schematic diagram showing the power line communication method based on the channel cognition technology provided by the present invention in an embodiment to recognize the power line channel and generate configuration parameters. As shown in Figure 2, the time and frequency resources that can be used for communication can be represented by a band-slotted grid map. In Figure 2, there are five frequency bands that can be used for communication, numbered 0, 1, 2, 3, and 4; there are six time slots that can be used for communication, numbered 0, 1, and 2 respectively. , 3, 4, 5. In the band-timeslot grid, the total number of time-frequency resource particles that can be used for communication is 5 X 6=30. It is assumed that after open-loop cognition and/or closed-loop cognition, the channel characteristic model as shown in Fig. 2 can be obtained: At the available band 1 (all time slots), there is a strong narrowband interference 201 in the channel; At 3 (all bands), there is burst noise 202 in the channel; at the available band 4 (all time slots), there is a strong attenuation 203 in the channel. After the channel characteristic model is obtained, the time-frequency resources used for communication can be determined to be available frequency bands 0, 2, 3 according to predetermined criteria, and punctured at available time slots 3.

Step S105, configuring a communication transceiver in the communication device according to the determined configuration parameter.

In this step, according to the configuration parameters determined in step S103, the configuration parameters of the communication transceiver in the communication device are changed accordingly, so that the communication device has a corresponding function.

The configuration parameters include: communication system, frequency and bandwidth occupied by the signal, scrambling code type and modulation ratio parameter, modulation The manner, the type of error correcting code, the code rate, the interleaving pattern, the generation matrix, the network cooperation and organization form, the parameters of the digital to analog and analog to digital converter, and one or more of the frequency response of the communication transceiver.

The following describes each of the above configuration parameters:

Communication system: The communication transceiver can be configured as one or more of narrowband modulation (such as binary frequency shift keying BFSK, etc.), spread spectrum (such as direct sequence spread spectrum DSSS, etc.), or orthogonal frequency division multiplexing (OFDM). Kind.

The frequency and bandwidth occupied by the signal: including the bandwidth occupied by the communication signal and the carrier frequency (communication signal center frequency). Scrambling code type and modulation ratio parameter: The scrambling code type means that the communication transceiver can be configured to use a long code or a short code as the scrambling code, and the generator polynomial of the scrambling code can be specified; the modulation ratio parameter refers to the scrambling code chip rate. The ratio to the symbol rate.

Modulation method: The modulation method of the communication signal can be configured as one or more of modulation methods such as amplitude modulation ASK, frequency modulation FSK, and quadrature amplitude modulation QAM.

Type of error correcting code, code rate, interleaving method, and generating matrix: The type of error correcting code means that the error correcting code used by the communication transceiver can be configured as BCH code, cyclic code, convolutional code, RS code, Turbo code or Low density parity check encoding one or more of encoding modes such as LDPC. The code rate means that the code rate of the channel coding used by the communication transceiver can be configured to one or more of 1/3, 1/2, 3/4, and the like.

Network collaboration and organization: Includes parameters such as the maximum order of the repeaters used for communication.

Parameters of digital-to-analog and analog-to-digital converters: Digital-to-analog converters used in communication transceivers, DACs, and analog-to-digital converters. ADC accuracy, dynamic range, and sampling rate.

Frequency response of the communication transceiver: The frequency response of the communication transceiver (including the amplitude-frequency response and the phase-frequency response) can be configured, such as the bandwidth, attenuation, and center frequency of the filter of the communication transceiver. The frequency response of the communication transceiver includes parameters of the notch filter for narrowband interference: For narrowband interference in the frequency domain, the communication transceiver can be eliminated using a notch filter. The notch frequency of the notch filter and the order of the notch filter can be configured to different values.

Taking the frequency response of the communication transceiver as an example, FIG. 3 shows a schematic diagram of the configuration of the frequency response of the communication transceiver. As shown in Figure 3, the frequency response of the configurable power line communication transceiver can be configured in two modes: a narrowband mode 301 with a corner frequency of fl and a notch filter with a corner frequency of f2 and a notch frequency of fn Broadband mode 302. Wherein, the wideband mode 302 corresponds to the channel condition shown in Fig. 2, and the notch frequency fn corresponds to the narrowband interference 201 at the available frequency band 1 in Fig. 2.

After the above step S105, the configuration parameters of the communication transceiver in the communication device are configured.

Since the configuration of the configuration parameters of the communication transceiver in the communication device has been completed after step S105, In step S107, the communication device can be used for data transmission. Compared with the conventional communication technology, the communication method adopted by the communication device at this time is obtained based on the current power line channel cognitive learning, so the method of the present invention can provide better communication stability and communication rate. As described above, the power line communication method based on the channel cognition technology of the present invention can recognize the current channel and obtain a channel model; learn and analyze according to the obtained channel model, and select the most suitable communication method for the power line The configuration parameters of the communication transceiver in the communication device are configured to make the entire power line communication system work in the most suitable state, thereby improving the reliability, stability and communication rate of the power line communication, and at the same time improving spectrum utilization and power consumption utilization. Referring to FIG. 4, a structural block diagram of a power line communication device applied in one embodiment of a power line communication method based on channel cognitive technology. As shown in FIG. 4, the power line communication device includes: a parameter configurable power line communication transceiver 401, a channel awareness module 403, and a cognitive control module 405. A parameter configurable power line communication transceiver 401.

The configuration parameters include: communication standard, frequency and bandwidth occupied by the signal, scrambling code type and modulation ratio parameter, modulation mode, type of error correction code, code rate, interleaving mode, generation matrix, network cooperation and organization form, digital mode And one or more of the parameters of the analog to digital converter and the frequency response of the communication transceiver.

The following describes each of the above configuration parameters:

Parameters of the digital-to-analog and analog-to-digital converter: The accuracy, dynamic range, and sampling rate of the digital-to-analog converter DAC and analog-to-digital converter ADC used in the communication transceiver. Frequency response of the communication transceiver: The frequency response of the communication transceiver (including the amplitude frequency response and the phase frequency response) can be configured, such as the bandwidth, attenuation, and wave parameters of the filter of the communication transceiver can be configured. The frequency response of the communication transceiver includes parameters of the notch filter for narrowband interference: For narrowband interference in the frequency domain, the communication transceiver can be eliminated using a notch filter. The notch frequency of the notch filter and the order of the notch filter can be configured to different values. The channel awareness module 403 is configured to recognize the power line channel and obtain a channel model.

In practical applications, because the topology of the power grid and the connected electrical equipment have great randomness and uncertainty, the multipath effect and attenuation characteristics of the power line channel are not fixed, not only with the application. The scene varies from scene to scene and has a strong time-varying nature. Therefore, it is necessary to recognize the power line channel to obtain its channel model.

The open-loop awareness of the power line channel includes: measuring the frequency domain characteristics and time domain characteristics of the channel by the sender or receiver of the communication. The measurements include, but are not limited to, estimating time domain patterns and frequency domain characteristics of interference introduced in the channel (e.g., narrowband interference or wideband interference), and time domain characteristics of noise (including burst noise) introduced in the channel. Estimated with frequency domain characteristics. Since the measurement of the frequency domain characteristics and the time domain characteristics by a communication terminal (sender or receiver) unidirectional channel is known in the art, it will not be described.

Closed-loop awareness of the power line channel includes: The sender and receiver of the communication jointly measure the frequency domain characteristics and time domain characteristics of the channel. Specifically, a specific communication signal or a communication signal having a specific mode is transmitted by the sender of the communication, and the communication signal is received by the receiver of the communication after passing through the power line channel to be tested, and the receiver according to the received communication signal And a communication signal sent by the sender, analyzing the characteristics of the power line channel. The measurements include, but are not limited to, time and frequency domain estimation of the attenuation characteristics and time-varying of the channel. Since the frequency domain characteristics and the time domain characteristics of the channel are jointly measured by the sender and the receiver, the prior art is well known to those skilled in the art, and therefore will not be described.

With the channel awareness module 403, the power line channel can be measured to obtain a basic model of the power line channel characteristics. The channel characteristics include time domain and frequency domain distribution of interference signals such as channel (e.g., narrowband interference signals and burst noise), amplitude-frequency response of the channel, and time-varying characteristics thereof. The cognitive control module 405 is configured to learn according to the channel model obtained by the channel cognitive module 403 to determine and configure configuration parameters of the communication transceiver in the communication device.

Determining configuration parameters of the communication device according to the channel model includes: determining configuration parameters adopted by the communication device in the current communication according to the obtained channel model and predetermined determination criteria. Wherein the criterion includes a bit error rate Minimum, lowest packet loss rate or signal to noise ratio (signal to interference ratio) threshold.

As described above, the power line communication device based on the channel cognition technology of the present invention can use the channel cognition module to recognize the current channel and obtain a channel model; and the cognitive control module is configured to obtain according to the channel cognition module The channel model is learned and analyzed to determine and configure the configuration parameters of the communication transceiver in the communication device, so that the entire power line communication system works in the most appropriate state, thereby improving the reliability, stability and communication rate of the power line communication. At the same time, it can improve spectrum utilization and power consumption.

Further, the communication device using the above-described channel cognitive technology-based power line communication method can also constitute a communication system. The communication system configures an uplink communication transceiver and a downlink communication transceiver by performing an uplink and downlink communication manner that best matches the current channel quality by identifying the current power line channel, so that the entire communication system works at the most Excellent state.

The above-described embodiments are merely illustrative of the principles and effects of the invention and are not intended to limit the invention. Any of the above-described embodiments may be modified by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, the scope of protection of the invention should be as set forth in the claims.

Claims

Claim

A power line communication method based on channel cognition technology, comprising:

Cognizing the power line channel and obtaining a channel model;

Determining configuration parameters of the communication device according to the obtained channel model;

Configuring a communication transceiver in the communication device according to the determined configuration parameter;

Data transmission is performed by the communication device that has been configured with the configuration parameters.

2. The power line communication method according to claim 1, wherein the cognitiveizing the power line channel and obtaining the channel model comprises: performing open-loop cognitive and/or closed-loop recognition on the power line channel to obtain a channel model.

3. The power line communication method according to claim 2, wherein the open loop awareness of the power line channel comprises:

The frequency domain characteristics and time domain characteristics of the channel are separately measured by the sender or receiver of the communication;

The measurements include:

Estimating time domain characteristics and frequency domain characteristics of interference introduced in the channel; the interference includes narrowband interference or broadband interference;

Estimating the time domain characteristics and frequency domain characteristics of the noise introduced in the channel; the noise includes burst noise.

4. The power line communication method according to claim 2, wherein the closed loop awareness of the power line channel comprises:

The frequency domain characteristic and the time domain characteristic of the channel are jointly measured by the sender and the receiver of the communication;

The measurements include:

The time domain and frequency domain are estimated for the attenuation characteristics and time-varying of the channel.

5. The power line communication method according to claim 1, wherein determining configuration parameters of the communication device according to the channel model comprises:

The configuration parameters of the communication device are determined based on the obtained channel model and predetermined determination criteria.

The power line communication method according to claim 5, wherein the determination criterion comprises a lowest bit error rate, a lowest packet loss rate, a signal to noise ratio threshold, or a signal to interference ratio threshold.

The power line communication method according to claim 1 or 5, wherein the configuration parameters include: a communication system, a frequency and bandwidth occupied by the signal, a scrambling code type and a modulation ratio parameter, a modulation mode, and an error correction code. One or more of the type, rate, interleaving pattern, generation matrix, network cooperation and organization form, parameters of the digital to analog and analog to digital converter, and the frequency response of the communication transceiver.

8. The power line communication method according to claim 7, wherein the communication system is one or more of narrowband modulation, spread spectrum, and orthogonal frequency division multiplexing.

9. The power line communication method according to claim 7, wherein the scrambling code type comprises a long code or a short code.

The power line communication method according to claim 7, wherein the type of the error correction code comprises a BCH code, a cyclic code, a convolutional code, an RS code, a Turbo code, and a low density parity check code in the LDPC. One or more.