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CN119341695A - Blind recognition method and system of power carrier signal based on OFDM signal characteristics - Google Patents

Blind recognition method and system of power carrier signal based on OFDM signal characteristics Download PDF

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Publication number
CN119341695A
CN119341695A CN202411500538.9A CN202411500538A CN119341695A CN 119341695 A CN119341695 A CN 119341695A CN 202411500538 A CN202411500538 A CN 202411500538A CN 119341695 A CN119341695 A CN 119341695A
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power carrier
signal
carrier signal
array
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CN119341695B (en
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张宏亮
钱海锋
张石瑞
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Hangzhou Vango Technologies Inc
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Hangzhou Vango Technologies Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0036—Systems modifying transmission characteristics according to link quality, e.g. power backoff arrangements specific to the receiver
    • H04L1/0038—Blind format detection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/54—Systems for transmission via power distribution lines
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0012—Modulated-carrier systems arrangements for identifying the type of modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L43/00—Arrangements for monitoring or testing data switching networks
    • H04L43/18—Protocol analysers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
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  • Mobile Radio Communication Systems (AREA)

Abstract

本发明公开了一种基于OFDM信号特征的电力载波信号盲识别方法及系统，所述方法包括：步骤1，接收电力载波信号，所述电力载波信号通过OFDM调制；步骤2，盲估计所述电力载波信号的子载波数、信号中心频点和子载波间隔，获得电力载波信号的先验信息；步骤3，根据所述电力载波信号的先验信息解码接收的电力载波信号。该方法及系统根据OFDM调制信号的特征值，在不知道协议信息的情况下，估计出电力载波的子载波数、信号中心频点和子载波间隔，从而确定电力载波的协议和调制参数，给RX端和TX端建立链接提供便利，提高链接效率。

The present invention discloses a method and system for blindly identifying a power carrier signal based on OFDM signal characteristics, the method comprising: step 1, receiving a power carrier signal, the power carrier signal being modulated by OFDM; step 2, blindly estimating the number of subcarriers, the signal center frequency and the subcarrier spacing of the power carrier signal, and obtaining the prior information of the power carrier signal; step 3, decoding the received power carrier signal according to the prior information of the power carrier signal. The method and system estimate the number of subcarriers, the signal center frequency and the subcarrier spacing of the power carrier according to the characteristic value of the OFDM modulated signal without knowing the protocol information, thereby determining the protocol and modulation parameters of the power carrier, facilitating the establishment of a link between the RX end and the TX end, and improving the link efficiency.

Description

Power carrier signal blind identification method and system based on OFDM signal characteristics
Technical Field
The invention belongs to the technical field of power carrier communication, and particularly relates to a power carrier signal blind identification method and system based on OFDM signal characteristics.
Background
The power carrier communication technology has been rapidly developed with the continuous improvement of power automation and intelligence level. In this process, the power carrier protocol is used as a technical standard throughout, and is subject to development and evolution in multiple stages. In the evolution process, many standards and protocols are generated, including domestic and foreign, high speed, medium speed and low speed, etc. Before the receiving end RX and the transmitting end TX establish communication, the receiving end and the transmitting end do not know what power carrier protocol is used by the other end, so that the link needs to be established in a mode of polling to try various power carrier protocol modes to be matched and decoding is tried according to various protocols. Because of the various power carrier protocols, the connection time is wasted, errors are easy to occur, unrecognizable signals are encountered, the power carrier protocols are relatively confusing, and the difficulty is brought to station investigation and maintenance.
Disclosure of Invention
The invention aims to solve the technical problem of providing a power carrier signal blind identification method and a power carrier signal blind identification system based on OFDM signal characteristics aiming at the defects of the prior art.
In order to solve the technical problem, in a first aspect, a power carrier signal blind identification method based on OFDM signal characteristics is disclosed, including:
Step1, receiving a power carrier signal, wherein the power carrier signal is modulated by OFDM;
step 2, blindly estimating the subcarrier number, the signal center frequency point and the subcarrier interval of the power carrier signal to obtain prior information of the power carrier signal;
And step 3, decoding the received power carrier signal according to the prior information of the power carrier signal.
Further, blind estimating the subcarrier number of the power carrier signal in step 2 includes:
step 2-1, calculating an autocorrelation matrix R xx of the power carrier signal;
step 2-2, performing eigenvalue decomposition on the autocorrelation matrix R xx to obtain an eigenvalue diagonal matrix b and an eigenvector W;
and 2-3, taking an array with a large median value of the eigenvalue to form an array C, wherein the data in the array C is the blind estimation of the subcarrier number of the received power carrier signal.
Further, step 2-1 includes recording the received power carrier signal Y (i) =s T (i) +u (i), i e {1,2,., L X m }, L X m representing the data sample length; S T (i) represents a transmission signal, u (i) represents noise, Y (i) is divided into m groups according to the length of L according to the characteristics of power carriers and the consideration of calculated quantity, wherein L is greater than the maximum subcarrier number of all protocols of the power carriers, a vector array X,X＝{x1,x2,x3,…,xm}＝{xs1,xs2,xs3,…,xsm}+{xu1,xu2,xu3,…,xum}, is formed, wherein X s＝{xs1,xs2,xs3,…,xsm is a signal vector group, and X u＝{xu1,xu2,xu3,…,xum is a noise vector group;
the autocorrelation matrix R xx of the received power carrier signal is
Since the signal and noise are uncorrelated, obtain
Thereby obtaining
Further, step 2-2 includes recording a signal matrixAccording to the characteristics of OFDM signals, the rank p of the signal matrix S is the number of subcarriers;
Performing eigenvalue decomposition on the signal matrix S to obtain an eigenvalue diagonal matrix a and an eigenvector Q of the signal matrix S:
SQ=aQ
is the characteristic value of the power carrier signal when no noise exists;
Performing eigenvalue decomposition on the autocorrelation matrix R xx to obtain an eigenvalue diagonal matrix b and an eigenvector W of the autocorrelation matrix R xx:
RxxW=bW
Is a characteristic value of noise.
Further, the step 2-3 includes the characteristic value of the power carrier signal when no noise existsCharacteristic value of specific noiseThe eigenvalue of the autocorrelation matrix R xx is normalized to the diagonal matrix b, and an array with large internal value is taken to form a plurality of groupsAnd the data in the array C is blind estimation of the subcarrier number of the received power carrier signal, and the subcarrier number in all power carrier protocols is adapted according to the blind estimation subcarrier number, wherein the subcarrier number closest to the blind estimation subcarrier number is determined as the subcarrier number of the power carrier signal.
Further, the blind estimation of the signal center frequency point of the power carrier signal in step 2 includes:
The vector corresponding to the eigenvalue in the array C in the eigenvector W of the autocorrelation matrix R xx is taken to form an effective subcarrier space vector array W c＝[r1,r2,r3,…,rp;
Will be Is divided into L parts respectively corresponding toThe average L frequency points are used for obtaining an array F_list= [ F 1,F2,F3,…,Fp,Fp+1,…,FL ]The corresponding frequency point isWherein FS is signal sampling frequency, v represents frequency point index, and v is more than or equal to 1 and less than or equal to L.
And obtaining an angular frequency vector array S0=e 2*F_list*i*(0～L-1) corresponding to all the subcarriers according to the array F_list, wherein i represents an imaginary number.
Multiplying the effective subcarrier space vector array W c by the angular frequency vector array S0 corresponding to all subcarriers to obtain an array s1=w c ×s0, wherein the size of the array is p rows and L columns;
Adding each column of the array S1 to obtain an effective subcarrier space vector and a correlation value array S2 of all subcarriers, wherein the size of the array S2 is 1 row and L columns;
Sorting the absolute values of the arrays S2 from large to small, taking the p numbers in front of the arrays F_list according to the sorting rule, and obtaining F values in the arrays F_list corresponding to the p numbers in the arrays S2 to form an array FX_list= [ FX 1,FX2,FX3,…,FXp ];
And calculating an average value of the array FX_list, obtaining a blind estimation FX center =mean (FX_list) of the central frequency points, and adapting the central frequency points in all power carrier protocols according to the blind estimation central frequency points, wherein the central frequency points closest to the blind estimation central frequency points are determined to be the central frequency points of the power carrier signals.
The interference on the common power line is serious, and the signal to noise ratio is not ideal. The received signal Y (i) is subjected to autocorrelation calculation, so that vectors of corresponding effective subcarriers in signal subspaces W c,Wc and S0 of the effective subcarriers have better correlation, and vectors of corresponding ineffective subcarriers in W c and S0 have poorer correlation, and therefore the positions of the effective subcarriers in Y (i) can be estimated. When the signal-to-noise ratio of the received Y (i) signal is smaller than 0db, the effective subcarrier position of the Y (i) received signal can be distinguished more ideally when the sampling length of the Y (i) is increased and the value of m is relatively large. Thereby, the center frequency point is estimated according to the effective subcarrier position. Effective subcarrier position effective information provides necessary conditions for the next subcarrier spacing estimation, so that the estimation is more accurate.
Further, blind estimating the subcarrier spacing of the power carrier signal in step 2 includes:
Ordering the array FX_list= [ FX 1,FX2,FX3,…,FXp ] from small to large to obtain FX_list= [ FX 1,FXX2,FXX3,…,FXXp ]. Obtain ordering the effective subcarrier position from small to large.
The calculation array FSUB_list＝[FXX2,FXX3,…,FXXp]-[FXX1,FXX2,FXX3,…,FXXp-1], averages the arrays FSUB _list to obtain the subcarrier spacing blind estimation values.
The blind estimation values of the number of the subcarriers, the center frequency point and the carrier intervals are provided, so that the protocol of carrier communication can be traversed, the protocol with the best matching degree and configuration can be found, and the parameters of the received signals on the power line can be obtained.
In a second aspect, a power carrier signal blind identification system based on OFDM signal characteristics is disclosed, which comprises an RX end signal receiving module, an OFDM blind estimation module and an RX-OFDM baseband signal decoding module,
The RX end signal receiving module is used for receiving a power carrier signal, and the power carrier signal is modulated by OFDM;
The OFDM blind estimation module is used for blindly estimating the subcarrier number, the signal center frequency point and the subcarrier interval of the power carrier signal to obtain priori information of the power carrier signal;
The RX-OFDM baseband signal decoding module is used for decoding the received power carrier signal according to the prior information of the power carrier signal.
Further, the OFDM blind estimation module comprises a subcarrier number blind estimation unit, a signal center frequency point blind estimation unit and a subcarrier interval blind estimation unit,
The subcarrier number blind estimation unit is used for calculating the subcarrier number according to the autocorrelation matrix R xx of the power carrier signal;
the signal center frequency point blind estimation unit is used for calculating and obtaining a signal center frequency point according to the correlation between the effective subcarrier space vector array W c of the autocorrelation matrix R xx and the vector in the corresponding F_list of the subcarrier frequency point;
the subcarrier spacing blind estimation unit is used for calculating and obtaining subcarrier spacing according to the vector position in the corresponding F_list of the subcarrier frequency points.
Further, the calculating, by the subcarrier number blind estimation unit, the number of subcarriers according to the autocorrelation matrix R xx of the power carrier signal includes:
Calculating an autocorrelation matrix R xx of the power carrier signal;
Performing eigenvalue decomposition on the autocorrelation matrix R xx to obtain an eigenvalue diagonal matrix b and an eigenvector W;
and taking an array with a large value in the eigenvalue diagonal array b as a group C, wherein the data in the group C is the blind estimation of the subcarrier number of the received power carrier signal.
The method for blind identification of the power carrier signal with the OFDM signal characteristics has the beneficial effects that the method for blind identification of the power carrier signal with the OFDM signal characteristics can obtain some information of a communication protocol by blind estimation of the carrier number, the center frequency point and the subcarrier interval of the power carrier received OFDM signal under the condition that protocol information is not known, and the RX end selectively tries to establish a link with TX according to the information, so that the link efficiency is improved. When the power line is subjected to an ambiguous signal, corresponding information can be given, so that convenience is brought to station investigation and maintenance of a communication system and the station investigation and maintenance efficiency is improved.
Drawings
The foregoing and/or other advantages of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings and detailed description.
Fig. 1 is a plot of the rank of normalized eigenvalues from large to small for an OFDM modulated power carrier signal with an SNR of 5 db.
Fig. 2 shows the normalized S2 array value size arrangement for the case where L is 1024 and the snr is 5 db.
Fig. 3 is a schematic structural diagram of a power carrier signal blind identification system based on OFDM signal characteristics according to an embodiment of the present application.
Fig. 4 is a schematic structural diagram of an OFDM blind estimation module in a power carrier signal blind identification system based on OFDM signal characteristics according to an embodiment of the present application.
Detailed Description
Embodiments of the present invention will be described below with reference to the accompanying drawings.
The blind identification of the OFDM communication signal of the power carrier line ensures that before the communication is not linked, the RX end can have partial protocol information of the TX end, thereby providing convenience for the establishment of the link between the RX end and the TX end and improving the success rate. The blind identification of the OFDM signals of the power carrier line can also provide station investigation maintenance information for the situation that RX and TX cannot establish a link, and improves station investigation maintenance efficiency.
The invention aims to estimate the subcarrier number, the signal center frequency point and the subcarrier interval of a power carrier according to the characteristic value of an OFDM modulation signal under the condition that protocol information is not known, so as to determine the protocol and the modulation parameters of the power carrier. The link is directly established between the TX end and the RX end of the communication without polling to try various possible communication protocols, and when the signal is ambiguous on the power carrier line, the signal information can be given, thereby bringing convenience to the investigation and maintenance of the power carrier communication system station. The method can be applied to application scenes such as intelligent power grids, remote meter reading systems, intelligent home furnishings, industrial control, field operation and maintenance tests of power carrier communication systems, power carrier communication environment station investigation and the like.
The first embodiment of the application discloses a power carrier signal blind identification method based on OFDM signal characteristics, which comprises the following steps of 1, receiving a power carrier signal, wherein the power carrier signal is modulated by OFDM;
step 2, blindly estimating the subcarrier number, the signal center frequency point and the subcarrier interval of the power carrier signal to obtain prior information of the power carrier signal;
blind estimating the number of subcarriers of the power carrier signal includes:
step 2-1, calculating an autocorrelation matrix R xx of the power carrier signal;
the power carrier TX end transmits a signal, and the RX end receives a signal, where the received signal may be expressed as:
Y(i)=ST(i)+u(i) (1)
i e {1,2,., L x m }, L x m represents the data sample length. S T (i) represents a transmission signal, u (i) represents noise, and Y (i) represents a reception signal. According to the power carrier characteristics and the calculated amount, Y (i) is divided into m groups according to L length, wherein L is larger than the maximum subcarrier number of all the power carrier protocols, a vector array X,X＝{x1,x2,x3,…,xm}＝{xs1,xs2,xs3,…,xsm}+{xu1,xu2,xu3,…,xum}, is formed, wherein X s＝{xs1,xs2,xs3,…,xsm is a signal vector group, and X u＝{xu1,xu2,xu3,…,xum is a noise vector group. Meanwhile, considering the calculated amount, L cannot be too large, in the embodiment, L can be 1024, 2048 or 4096, and m can be 8-2048.
The autocorrelation matrix R xx of the received power carrier signal is
Since the signal and noise are uncorrelated, it is possible to
Thereby obtaining
Step 2-2, performing eigenvalue decomposition on the autocorrelation matrix R xx to obtain an eigenvalue diagonal matrix b and an eigenvector W;
Since X s is an OFDM signal, the signal matrix is known from the characteristics of the OFDM signal The rank p of (a) is the number of subcarriers. The eigenvalue decomposition is carried out on the signal matrix S, and the eigenvalue diagonal matrix a and the eigenvector Q of the signal matrix S can be obtained
SQ=aQ
Is a characteristic value of the power carrier signal when it is noise-free.
Autocorrelation matrixThe eigenvalue decomposition is carried out on the autocorrelation matrix R xx, and the eigenvalue diagonal matrix b and the eigenvector W of the autocorrelation matrix R xx can be obtained
RxxW=bW
Is a characteristic value of noise.
And 2-3, taking an array with a large median value of the eigenvalue to form an array C, wherein the data in the array C is the blind estimation of the subcarrier number of the received power carrier signal.
Characteristic value of power carrier signal without noiseThe value of (2) is compared with the characteristic value of noiseIs large. Normalizing the eigenvalue of the autocorrelation matrix R xx to the diagonal matrix b, and taking the array with large eigenvalue (with 0.7 as the value threshold) of the normalized eigenvalue to form a plurality of groups The number of data in the array C is blind estimation of the number of subcarriers of the received power carrier signal, the number of subcarriers in all power carrier protocols is adapted according to the number of subcarriers in the blind estimation, wherein the number of subcarriers closest to the number of subcarriers in the blind estimation is determined as the number of subcarriers of the power carrier signal.
Blind estimation of the signal center frequency point of the power carrier signal includes:
The vector corresponding to the eigenvalue in the array C in the eigenvector W of the autocorrelation matrix R xx is taken to form an effective subcarrier space vector array W c＝[r1,r2,r3,…,rp;
Will be Is divided into L parts respectively corresponding toThe average L frequency points are used for obtaining an array F_list= [ F 1,F2,F3,…,Fp,Fp+1,…,FL ]The corresponding frequency point isWherein FS is signal sampling frequency, v represents frequency point index, and v is more than or equal to 1 and less than or equal to L.
And obtaining an angular frequency vector array S0=e 2*F_list*i*(0～L-1) corresponding to all the subcarriers according to the array F_list, wherein i represents an imaginary number.
Multiplying the effective subcarrier space vector array W c by the angular frequency vector array S0 corresponding to all subcarriers to obtain an array s1=w c ×s0, wherein the size of the array is p rows and L columns;
Adding each column of the array S1 to obtain an effective subcarrier space vector and a correlation value array S2 of all subcarriers, wherein the size of the array S2 is 1 row and L columns;
Sorting the absolute values of the arrays S2 from large to small, taking the p numbers in front of the arrays F_list according to the sorting rule, and obtaining F values in the arrays F_list corresponding to the p numbers in the arrays S2 to form an array FX_list= [ FX 1,FX2,FX3,…,FXp ];
And calculating an average value of the array FX_list, obtaining a blind estimation FX center =mean (FX_list) of the central frequency points, and adapting the central frequency points in all power carrier protocols according to the blind estimation central frequency points, wherein the central frequency points closest to the blind estimation central frequency points are determined to be the central frequency points of the power carrier signals.
Blind estimating the subcarrier spacing of the power carrier signal includes:
The array fx_list= [ FX 1,FX2,FX3,…,FXp ] is sorted from small to large to obtain fxx_list= [ FXX 1,FXX2,FXX3,…,FXXp ]. A small to large ordering of the effective subcarrier locations is obtained. Then, the calculation array FSUB_list＝[FXX2,FXX3,…,FXXp]-[FXX1,FXX2,FXX3,…,FXXp-1], averages the arrays FSUB _list to obtain the blind estimation value of the subcarrier spacing.
And step 3, decoding the received power carrier signal according to the prior information of the power carrier signal.
Fig. 1 is a graph showing the order of normalized eigenvalues from large to small in the case of an OFDM modulated power carrier signal Y (i) with an SNR of 5 db. It can be seen that the first 191 eigenvalues are significantly larger than the latter. From the figure, the number of subcarriers from which the OFDM signal was obtained was blind estimated to be 191. Fig. 2 shows the normalized S2 array value size arrangement for the case where L is 1024 and the snr is 5 db. The center frequency point and subcarrier spacing can be calculated.
The second embodiment of the application discloses a power carrier signal blind identification system based on OFDM signal characteristics, which comprises an RX end signal receiving module, an OFDM blind estimation module and an RX-OFDM baseband signal decoding module,
The RX end signal receiving module is used for receiving a power carrier signal, and the power carrier signal is modulated by OFDM;
The OFDM blind estimation module is used for blind estimation of the subcarrier number, the signal center frequency point and the subcarrier interval of the power carrier signal to obtain prior information of the power carrier signal, and concretely, as shown in fig. 4, comprises a subcarrier number blind estimation unit, a signal center frequency point blind estimation unit and a subcarrier interval blind estimation unit,
The blind estimation unit of subcarrier number is used for calculating the subcarrier number according to an autocorrelation matrix R xx of a power carrier signal, and concretely comprises the steps of calculating an autocorrelation matrix R xx of the power carrier signal, carrying out eigenvalue decomposition on the autocorrelation matrix R xx to obtain an eigenvalue diagonal matrix b and an eigenvector W, and taking an array with a large median of the eigenvalue diagonal matrix b as a group C, wherein the data number in the group C is blind estimation of the subcarrier number of the received power carrier signal.
The signal center frequency point blind estimation unit is used for calculating and obtaining a signal center frequency point according to the correlation between the effective subcarrier space vector array W c of the autocorrelation matrix R xx and the vector in the corresponding F_list of the subcarrier frequency point;
the subcarrier spacing blind estimation unit is used for calculating and obtaining subcarrier spacing according to the vector position in the corresponding F_list of the subcarrier frequency points.
The RX-OFDM baseband signal decoding module is used for decoding the received power carrier signal according to the prior information of the power carrier signal.
Fig. 3 is a block diagram of an entire power carrier communication system, where the TX end includes an OFDM baseband signal generating module for generating an OFDM baseband signal and a TX end signal transmitting module for transmitting the OFDM baseband signal to the RX end through a power line.
The RX-OFDM baseband signal decoding module can directly select a protocol mode corresponding to the OFDM estimation information to receive and decode an RX signal according to the OFDM estimation information obtained by the blind estimation module. It is not necessary to poll all possible protocol patterns of the power carrier protocol to find a matching protocol pattern.
The subcarrier number, the center frequency point and the subcarrier interval of the OFDM signal are obtained through blind identification of the OFDM carrier signal of the power carrier line, and prior information of the OFDM signal can be obtained according to the information. In the case that the TX and RX do not establish a link, the RX end does not have any information on the TX end, and the RX calculates the protocol on the TX end from these blind identification information according to various protocols of the power carrier communication. Thus, RX can establish a link with TX directly according to the deduced protocol. RX does not need various protocols to poll the matches to establish a link with the TX end.
The power carrier signal blind identification system based on the OFDM signal characteristics further comprises a station investigation information display module, wherein the station investigation information display module is used for receiving subcarrier number, signal center frequency point and subcarrier interval information of the power carrier signal sent by the OFDM blind estimation module. When the power line is subjected to an ambiguous signal, the system can also give out corresponding information, thereby bringing convenience to station investigation and maintenance of the communication system and improving the station investigation and maintenance efficiency.
In a specific implementation, the application provides a computer storage medium and a corresponding data processing unit, wherein the computer storage medium can store a computer program, and the computer program can run the application content of the power carrier signal blind identification method based on the OFDM signal characteristics and part or all of the steps in each embodiment when being executed by the data processing unit. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), a random-access memory (random access memory, RAM), or the like.
It will be apparent to those skilled in the art that the technical solutions in the embodiments of the present invention may be implemented by means of a computer program and its corresponding general hardware platform. Based on such understanding, the technical solutions in the embodiments of the present invention may be embodied essentially or in the form of a computer program, i.e. a software product, which may be stored in a storage medium, and include several instructions to cause a device (which may be a personal computer, a server, a single-chip microcomputer, MUU or a network device, etc.) including a data processing unit to perform the methods described in the embodiments or some parts of the embodiments of the present invention.
The invention provides a power carrier signal blind identification method and a system based on OFDM signal characteristics, and the method and the way for realizing the technical scheme are numerous, the above description is only a preferred embodiment of the invention, and it should be noted that, for a person skilled in the art, a plurality of improvements and modifications can be made without departing from the principle of the invention, and the improvements and modifications are also considered as the protection scope of the invention. The components not explicitly described in this embodiment can be implemented by using the prior art.

Claims (10)

1.一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，包括：1. A method for blindly identifying a power carrier signal based on OFDM signal characteristics, comprising: 步骤1，接收电力载波信号，所述电力载波信号通过OFDM调制；Step 1, receiving a power carrier signal, wherein the power carrier signal is modulated by OFDM; 步骤2，盲估计所述电力载波信号的子载波数、信号中心频点和子载波间隔，获得电力载波信号的先验信息；Step 2, blindly estimating the number of subcarriers, the signal center frequency and the subcarrier spacing of the power carrier signal to obtain prior information of the power carrier signal; 步骤3，根据所述电力载波信号的先验信息解码接收的电力载波信号。Step 3: Decode the received power carrier signal according to the prior information of the power carrier signal. 2.根据权利要求1所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2中盲估计所述电力载波信号的子载波数包括：2. A method for blindly identifying a power carrier signal based on OFDM signal characteristics according to claim 1, characterized in that the blind estimation of the number of subcarriers of the power carrier signal in step 2 comprises: 步骤2-1，计算所述电力载波信号的自相关矩阵Rxx；Step 2-1, calculating the autocorrelation matrix R xx of the power carrier signal; 步骤2-2，对自相关矩阵Rxx进行特征值分解，获得特征值对角阵b和特征向量W；Step 2-2, perform eigenvalue decomposition on the autocorrelation matrix R xx to obtain the eigenvalue diagonal matrix b and eigenvector W; 步骤2-3，取特征值对角阵b中值大的数组成数组C，数组C中数据个数即为接收到的电力载波信号的子载波个数盲估计。Step 2-3, take the numbers with large values in the eigenvalue diagonal array b to form an array C, and the number of data in array C is the blind estimate of the number of subcarriers of the received power carrier signal. 3.根据权利要求2所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2-1包括：记接收的电力载波信号Y(i)＝ST(i)+u(i)，i∈{1,2,…,L*m}，L*m表示数据采样长度；ST(i)代表发射信号，u(i)表示噪声，根据电力载波特征和考虑计算量，将Y(i)按L长度分成m组，其中L大于电力载波所有协议的最大子载波数，形成一个向量数组X，X＝{x1,x2,x3,…,xm}＝{xs1,xs2,xs3,…,xsm}+{xu1,xu2,xu3,…,xum}，其中Xs＝{xs1,xs2,xs3,…,xsm}为信号向量组，Xu＝{xu1,xu2,xu3,…,xum}为噪声向量组；3. According to claim 2, a blind identification method for power carrier signals based on OFDM signal characteristics is characterized in that step 2-1 comprises: recording the received power carrier signal Y(i)= ST (i)+u(i), i∈{1,2,…,L*m}, L*m represents the data sampling length; ST (i) represents the transmitted signal, u(i) represents the noise, and according to the power carrier characteristics and considering the amount of calculation, Y(i) is divided into m groups of length L, where L is greater than the maximum number of subcarriers of all power carrier protocols, to form a vector array X, X={ x1 , x2 , x3 ,…, xm }={ xs1 , xs2 , xs3 ,…, xsm }+{ xu1 , xu2 , xu3 ,…, xum }, where Xs ={ xs1 , xs2 , xs3 ,…, xsm } is the signal vector group, Xu ={x u1 ,x u2 ,x u3 ,…,x um } is a noise vector group; 接收的电力载波信号的自相关矩阵Rxx为The autocorrelation matrix R xx of the received power carrier signal is: 由于信号和噪声不相关，获得Since the signal and noise are uncorrelated, we get 从而得到 Thus we get 4.根据权利要求3所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2-2包括：记信号矩阵根据OFDM信号特点，信号矩阵S的秩p为子载波个数；4. A method for blindly identifying power carrier signals based on OFDM signal characteristics according to claim 3, characterized in that step 2-2 comprises: recording the signal matrix According to the characteristics of OFDM signals, the rank p of the signal matrix S is the number of subcarriers; 对信号矩阵S做特征值分解，获得信号矩阵S的特征值对角阵a和特征向量Q：Perform eigenvalue decomposition on the signal matrix S to obtain the eigenvalue diagonal matrix a and eigenvector Q of the signal matrix S: SQ＝aQSQ＝aQ 是电力载波信号无噪声时的特征值； It is the characteristic value of the power carrier signal when there is no noise; 对自相关矩阵Rxx做特征值分解，获得自相关矩阵Rxx的特征值对角阵b和特征向量W：Perform eigenvalue decomposition on the autocorrelation matrix R xx to obtain the eigenvalue diagonal matrix b and eigenvector W of the autocorrelation matrix R xx : RxxW＝bWR xx W＝bW 是噪声的特征值。 is the characteristic value of the noise. 5.根据权利要求4所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2-3包括：电力载波信号无噪声时的特征值比噪声的特征值的值大，对自相关矩阵Rxx的特征值对角阵b归一化，取里面值大的数组成数组数组C中数据个数就是接收到的电力载波信号的子载波数盲估计，根据盲估计的子载波数适配所有电力载波协议中子载波数，其中与盲估计的子载波数最接近的，确定为所述电力载波信号的子载波数。5. A method for blindly identifying a power carrier signal based on OFDM signal characteristics according to claim 4, characterized in that step 2-3 comprises: the characteristic value of the power carrier signal when there is no noise Eigenvalue of noise The value of is large, normalize the eigenvalue diagonal matrix b of the autocorrelation matrix R xx , and take the numbers with large values to form an array The number of data in array C is a blind estimate of the number of subcarriers of the received power carrier signal. The number of subcarriers in all power carrier protocols is adapted according to the blind estimated number of subcarriers, and the one closest to the blind estimated number of subcarriers is determined as the number of subcarriers of the power carrier signal. 6.根据权利要求5所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2中盲估计所述电力载波信号的信号中心频点包括：6. A method for blindly identifying a power carrier signal based on OFDM signal characteristics according to claim 5, characterized in that the blindly estimating the signal center frequency of the power carrier signal in step 2 comprises: 取自相关矩阵Rxx的特征向量W中与数组C中特征值对应的向量，组成有效子载波空间向量数组Wc＝[r1,r2,r3,…,rp]；Take the vectors corresponding to the eigenvalues in the array C from the eigenvector W of the autocorrelation matrix R xx to form an effective subcarrier space vector array W c = [r 1 , r 2 , r 3 , …, r p ]; 将平均分成L份，分别对应平均分的L个频点，获得数组F_list＝[F1,F2,F3,…,Fp,Fp+1,…,FL]；其中对应的频点为其中，FS为信号采样频率，v表示频点索引，1≤v≤L；Will Divide into L equal parts, corresponding to The L frequency points are averaged to obtain an array F_list = [F 1 , F 2 , F 3 , ..., F p , F p+1 , ..., F L ]; where The corresponding frequency is Where FS is the signal sampling frequency, v represents the frequency index, 1≤v≤L; 根据数组F_list获得所有子载波对应的角频率向量数组S0＝e2*F_list*i*(0～L-1)，其中i表示虚数；Obtain the angular frequency vector array S0=e 2*F_list*i*(0～L-1) corresponding to all subcarriers according to the array F_list, where i represents an imaginary number; 将有效子载波空间向量数组Wc和所有子载波对应的角频率向量数组S0相乘获得数组S1＝Wc*S0，这个数组大小为p行L列；Multiply the effective subcarrier space vector array W c and the angular frequency vector array S0 corresponding to all subcarriers to obtain an array S1 = W c * S0, the size of this array is p rows and L columns; 将数组S1的每列数相加，获得有效子载波空间向量和所有子载波的相关值数组S2，数组S2大小是1行L列；Add the numbers of each column of array S1 to obtain the effective subcarrier space vector and the correlation value array S2 of all subcarriers. The size of array S2 is 1 row and L columns. 对数组S2的绝对值进行从大到小排序，数组F_list也按这个排序规则，取F_list的前面p个数，获得数组S2里面最大的p个数对应的数组F_list里面的F值，组成数组FX_list＝[FX1,FX2,FX3,…,FXp]；The absolute values of array S2 are sorted from large to small. Array F_list is also sorted according to this rule. The first p numbers of F_list are taken to obtain the F values in array F_list corresponding to the largest p numbers in array S2, forming array FX_list = [FX 1 , FX 2 , FX 3 , …, FX p ]; 对数组FX_list计算平均值，获得中心频点盲估计FXcenter＝mean(FX_list)，根据盲估计的中心频点适配所有电力载波协议中中心频点，其中与盲估计的中心频点最接近的，确定为所述电力载波信号的中心频点。The average value of the array FX_list is calculated to obtain a blind estimate of the center frequency FX center =mean(FX_list), and the center frequencies of all power carrier protocols are adapted according to the blind estimated center frequency, and the one closest to the blind estimated center frequency is determined as the center frequency of the power carrier signal. 7.根据权利要求6所述的一种基于OFDM信号特征的电力载波信号盲识别方法，其特征在于，步骤2中盲估计所述电力载波信号的子载波间隔包括：7. A method for blindly identifying a power carrier signal based on OFDM signal characteristics according to claim 6, characterized in that the blind estimation of the subcarrier spacing of the power carrier signal in step 2 comprises: 对数组FX_list＝[FX1,FX2,FX3,…,FXp]进行从小到大排序，获得FXX_list＝[FXX1,FXX2,FXX3,…,FXXp]；得到有效子载波位置的从小到大的排序；The array FX_list = [FX 1 , FX 2 , FX 3 , ..., FX p ] is sorted from small to large to obtain FXX_list = [FXX 1 , FXX 2 , FXX 3 , ..., FXX p ]; the effective subcarrier positions are sorted from small to large; 计算数组FSUB_list＝[FXX2,FXX3,…,FXXp]-[FXX1,FXX2,FXX3,…,FXXp-1]，对数组FSUB_list做平均，获得子载波间隔盲估计值。Calculate array FSUB_list = [FXX 2 , FXX 3 , ..., FXX p ] - [FXX 1 , FXX 2 , FXX 3 , ..., FXX p-1 ], average the array FSUB_list to obtain a blind subcarrier spacing estimation value. 8.一种基于OFDM信号特征的电力载波信号盲识别系统，其特征在于，包括RX端信号接收模块、OFDM盲估计模块和RX-OFDM基带信号解码模块，8. A power carrier signal blind recognition system based on OFDM signal characteristics, characterized by comprising an RX-end signal receiving module, an OFDM blind estimation module and an RX-OFDM baseband signal decoding module, 所述RX端信号接收模块，用于接收电力载波信号，所述电力载波信号通过OFDM调制；The RX-end signal receiving module is used to receive a power carrier signal, and the power carrier signal is modulated by OFDM; 所述OFDM盲估计模块，用于盲估计所述电力载波信号的子载波数、信号中心频点和子载波间隔，获得电力载波信号的先验信息；The OFDM blind estimation module is used to blindly estimate the number of subcarriers, the signal center frequency and the subcarrier spacing of the power carrier signal to obtain prior information of the power carrier signal; 所述RX-OFDM基带信号解码模块，用于根据所述电力载波信号的先验信息解码接收的电力载波信号。The RX-OFDM baseband signal decoding module is used to decode the received power carrier signal according to the prior information of the power carrier signal. 9.根据权利要求8所述的一种基于OFDM信号特征的电力载波信号盲识别系统，其特征在于，所述OFDM盲估计模块包括子载波数盲估计单元、信号中心频点盲估计单元和子载波间隔盲估计单元，9. A power carrier signal blind identification system based on OFDM signal characteristics according to claim 8, characterized in that the OFDM blind estimation module includes a subcarrier number blind estimation unit, a signal center frequency blind estimation unit and a subcarrier spacing blind estimation unit, 所述子载波数盲估计单元，用于根据电力载波信号的自相关矩阵Rxx计算获得子载波个数；The subcarrier number blind estimation unit is used to calculate the number of subcarriers according to the autocorrelation matrix R xx of the power carrier signal; 所述信号中心频点盲估计单元，用于根据自相关矩阵Rxx的有效子载波空间向量数组Wc和子载波频点对应F_list中向量的相关性，计算获得信号中心频点；The signal center frequency blind estimation unit is used to calculate the signal center frequency according to the correlation between the effective subcarrier space vector array W c of the autocorrelation matrix R xx and the vectors in F_list corresponding to the subcarrier frequency; 所述子载波间隔盲估计单元，用于根据子载波频点对应F_list中向量位置计算获得子载波间隔。The subcarrier spacing blind estimation unit is used to calculate and obtain the subcarrier spacing according to the vector position in F_list corresponding to the subcarrier frequency point. 10.根据权利要求9所述的一种基于OFDM信号特征的电力载波信号盲识别系统，其特征在于，所述子载波数盲估计单元根据电力载波信号的自相关矩阵Rxx计算获得子载波个数包括：10. A power carrier signal blind identification system based on OFDM signal characteristics according to claim 9, characterized in that the subcarrier number blind estimation unit calculates the number of subcarriers according to the autocorrelation matrix R xx of the power carrier signal, comprising: 计算所述电力载波信号的自相关矩阵Rxx；Calculating the autocorrelation matrix R xx of the power carrier signal; 对自相关矩阵Rxx进行特征值分解，获得特征值对角阵b和特征向量W；Perform eigenvalue decomposition on the autocorrelation matrix R xx to obtain the eigenvalue diagonal matrix b and eigenvector W; 取特征值对角阵b中值大的数组成数组C，数组C中数据个数为接收到的电力载波信号的子载波个数盲估计。The numbers with the largest values in the eigenvalue diagonal matrix b are taken to form an array C. The number of data in the array C is a blind estimate of the number of subcarriers of the received power carrier signal.
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