A method and device for eliminating impulse noise in a power line scenario and an intelligent fusion terminal

Abstract

The present application relates to the technical field of communication signal processing, and relates to a power line scene impulse noise elimination method, device and intelligent fusion terminal. The power line scene impulse noise elimination method comprises: obtaining a received signal; performing discrete Fourier transform on the received signal to obtain a frequency domain received signal; constructing a noise subcarrier mapping matrix, and projecting the frequency domain received signal to a noise subspace according to the noise subcarrier mapping matrix to obtain a noise subspace projection signal; constructing a noise observation matrix according to the noise subcarrier mapping matrix; estimating an impulse noise support set based on the noise observation matrix and the noise subspace projection signal; reducing the dimension of the noise observation matrix through the impulse noise support set, and calculating an impulse noise estimate by using a least square algorithm; and eliminating the impulse noise in the received signal based on the impulse noise estimate to obtain a received signal after the impulse noise is eliminated. The present application reduces the calculation complexity without affecting the accuracy of the impulse noise estimate.

Description

Technical Field

[0001] This invention relates to the field of communication signal processing technology, and in particular to a method, device and intelligent fusion terminal for eliminating impulse noise in power line scenarios. Background Technology

[0002] Power line communication (PLC) is a technology that utilizes existing power line infrastructure for data transmission. PLC systems are widely used in smart grids, smart homes, and other fields because they require no additional wiring. However, impulse noise in power line channels has a significant impact on communication quality. Impulse noise mainly originates from transient interference generated by various electrical devices connected to power lines within the power network. Impulse noise has a short duration and a power spectral density much higher than background noise, sometimes exceeding it by more than 50 dB.

[0003] Traditional impulse noise suppression methods typically employ clipping or compressed sensing algorithms to eliminate impulse noise. Clipping usually has poor performance. Compressed sensing methods that utilize the sparsity of impulse noise are generally more complex, and some compressed sensing algorithms require prior information such as sparsity, which is difficult to obtain. Summary of the Invention

[0004] This application aims to at least solve the technical problems existing in the prior art, and to provide a method, device and intelligent fusion terminal for pulse noise cancellation in power line scenarios.

[0005] In a first aspect, the present invention provides a method for eliminating impulse noise in a power line scenario, the method comprising:

[0006] Acquire the received signal, which is a time-domain signal;

[0007] The frequency domain received signal is obtained by performing a discrete Fourier transform on the received signal.

[0008] A noise subcarrier mapping matrix is ​​constructed based on the noise subcarriers corresponding to the noise subspace, and the frequency domain received signal is projected onto the noise subspace according to the noise subcarrier mapping matrix to obtain the noise subspace projection signal.

[0009] Construct the noise observation matrix based on the noise subcarrier mapping matrix;

[0010] The impulse noise support set is estimated based on the noise observation matrix and the noise subspace projection signal. The impulse noise support set is a set composed of the position indices of the non-zero elements of the impulse noise.

[0011] The noise observation matrix is ​​reduced in dimensionality using an impulse noise support set, and the impulse noise estimate is obtained by processing the dimensionality-reduced noise observation matrix using a least squares algorithm. ;

[0012] Based on impulse noise estimation Impulse noise in the frequency domain received signal is eliminated to obtain the frequency domain received signal after impulse noise elimination.

[0013] By adopting the above technical solution, a noise subspace is constructed by selecting subcarriers in OFDM symbols (Orthogonal Frequency Division Multiplexing signals) that are not used by the useful signal. Based on the orthogonality between the signal subspace and the noise subspace, the received signal is projected onto the noise subspace to obtain a projected signal that does not contain the useful signal part, thereby eliminating the influence of the useful signal part in the received signal on the impulse noise estimation. Finally, the impulse noise in the projected signal of the noise subspace is filtered out using the noise observation matrix and the impulse noise is eliminated. This application does not require setting prior information such as impulse noise sparsity, and reduces the computational complexity without affecting the accuracy of impulse noise estimation.

[0014] Optionally, the expression for the noise observation matrix is: ,in, For the noise observation matrix, For the noise subcarrier mapping matrix, Represents the field of complex numbers. It is the number of subcarriers in an OFDM symbol. This represents the number of noise subcarriers corresponding to the noise subspace. Noise subcarrier mapping matrix The conjugate transpose of the matrix. It is the discrete Fourier transform matrix.

[0015] By adopting the above technical solution, the method for constructing the noise observation matrix was clarified.

[0016] Optionally, the number of subcarriers not used by the useful signal is Select A subcarrier that is not used by a useful signal creates a noise subspace. satisfy:

[0017] ;

[0018] This indicates rounding down. The value of is a power of 2.

[0019] Optionally, the estimation of the impulse noise support set based on the noise observation matrix and the noise subspace projection signal includes:

[0020] The column vectors of the noise observation matrix are divided into There are 3 clusters, and a column vector from each cluster is selected as the basis vector;

[0021] The noise subspace projection signal is projected onto the basis vectors of each cluster to obtain the basis projection signal;

[0022] The first comparison result is obtained by comparing the projection value of the base projection signal with the preset first reference threshold value;

[0023] Based on the first comparison result, determine the cluster where the non-zero elements of the impulse noise are located, and record the cluster where the non-zero elements of the impulse noise are located as the target cluster.

[0024] The cluster projection signal is obtained by projecting the noise subspace projection signal onto the column vector of the noise observation matrix corresponding to the noise subcarriers covered by the target cluster.

[0025] The second comparison result is obtained by comparing the projection value of the cluster projection signal with the preset second reference threshold value;

[0026] Based on the second comparison result, the position information of the non-zero pulse noise elements in the cluster projection signal is determined, and the position information of the non-zero pulse noise elements is added to the pulse noise support set.

[0027] By adopting the above technical solution, based on the semi-orthogonality of the noise observation matrix, the noise subspace projection signal is projected onto the basis vectors of each cluster to obtain the basis projection signal. The basis vectors whose projection values ​​exceed the first reference threshold are selected. The basis vectors whose projection values ​​exceed the first reference threshold are the clusters where the non-zero elements of the impulse noise are located, called the target clusters. The target clusters of the non-zero elements of the impulse noise are coarsely located using the above method, and then the positions of the non-zero elements of the impulse noise are finely located from the target clusters: the received signal is projected onto the column vectors of the observation matrix corresponding to the target cluster, and the column vectors whose projection values ​​exceed the second reference threshold are selected. The positions of the column vectors whose projection values ​​exceed the second reference threshold are the positions corresponding to the non-zero elements of the impulse noise. By first coarsely locating the positions of the non-zero elements of the impulse noise within the target clusters, and then finely locating the positions of the non-zero elements of the impulse noise from the target clusters, the range of impulse noise support set estimation can be narrowed, thereby reducing the computational complexity.

[0028] Optionally, the noise observation matrix is ​​reduced in dimensionality using the impulse noise support set, and the impulse noise is estimated using a least squares algorithm. .

[0029] Optionally, the received signal is denoted as The frequency domain received signal is denoted as Frequency domain received signal The expression is

[0030] ;

[0031] in, This represents the useful signal portion of the received signal. This indicates the impulse noise component in the received signal. This represents the Gaussian white noise component in the received signal; ,in, This means expanding the vector into a diagonal matrix. The number of subcarriers for an OFDM symbol. The discrete Fourier transform matrix is... Channel impulse response; The signal subcarrier mapping matrix, The number of subcarriers used for the useful signal in the received signal. This refers to the modulation symbol carried by the subcarrier used for the useful signal in an OFDM symbol. Represents time-domain complex Gaussian white noise; This represents time-domain impulse noise.

[0032] By adopting the above technical solution, the specific calculation method for frequency domain received signals has been clarified.

[0033] Optionally, the noise subspace projection signal The expression is

[0034] ;

[0035] in, For the noise subcarrier mapping matrix, Noise subcarrier mapping matrix The conjugate transpose of the matrix. This represents the number of noise subcarriers corresponding to the noise subspace.

[0036] By adopting the above technical solution, the specific calculation method of the noise subspace projection signal was clarified.

[0037] Optionally, impulse noise estimation Noise subvectors corresponding to non-zero elements The expression is

[0038] ;

[0039] in, Represents the impulse noise support set in the noise observation matrix. The submatrix formed by the column vectors corresponding to the positions of the inner elements. Represents the impulse noise support set. This indicates the conjugate transpose. This represents finding the inverse of a matrix. This represents the projection signal of the noise subspace.

[0040] By adopting the above technical solution, the impulse noise estimation method was clarified. Noise subvectors corresponding to non-zero elements The calculation method.

[0041] Optionally, estimation is performed using impulse noise. Eliminate frequency domain received signal The effect of impulse noise is eliminated to obtain the received signal. :

[0042] ;

[0043] in, This represents the frequency domain received signal after eliminating impulse noise. This represents the error in impulse noise cancellation. This represents the actual time-domain impulse noise. This represents the estimated time-domain impulse noise.

[0044] By adopting the above technical solution, the specific method for eliminating impulse noise has been clarified.

[0045] In a second aspect, the present invention provides an electronic device, the electronic device comprising:

[0046] At least one processor; and,

[0047] A memory communicatively connected to the at least one processor; wherein,

[0048] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the impulse noise cancellation method in the power line scenario described above.

[0049] Thirdly, the present invention also provides an intelligent fusion terminal, comprising:

[0050] The interface module is used to receive initial power line data;

[0051] The control module is used to control the exchange and communication of initial power line data;

[0052] The communication module is used to process the received initial power line data according to the aforementioned impulse noise cancellation method in the power line scenario, so as to obtain denoised power line data;

[0053] The storage module is used to temporarily store initial power line data, denoised power line data, and / or software programs for impulse noise cancellation methods in power line scenarios.

[0054] In summary, this application includes the following beneficial technical effects:

[0055] A noise subspace is constructed by selecting subcarriers in the OFDM (Orthogonal Frequency Division Multiplexing) symbol that are not used by the useful signal. Based on the orthogonality between the signal subspace and the noise subspace, the received signal is projected onto the noise subspace to obtain a noise subspace projection signal that does not contain the useful signal part. This eliminates the influence of the useful signal part in the received signal on the impulse noise estimation. Then, the impulse noise in the noise subspace projection signal is estimated using the noise observation matrix, and the impulse noise is eliminated from the frequency domain received signal. This application does not require setting prior information such as impulse noise sparsity, and reduces the computational complexity without affecting the accuracy of impulse noise estimation. Attached Figure Description

[0056] Figure 1 This is a flowchart illustrating a method for eliminating impulse noise in a power line scenario according to an embodiment of the present invention.

[0057] Figure 2 The waveform of the received signal in the time domain with impulse noise;

[0058] Figure 3 The received constellation diagram of the time-domain received signal with impulse noise without impulse noise cancellation;

[0059] Figure 4 For time-domain received signals with impulse noise, a pulse noise cancellation method in a power line scenario provided by an embodiment of the present invention is used to generate a received constellation diagram after impulse noise cancellation;

[0060] Figure 5 This is a schematic diagram of the structure of an electronic device for implementing the impulse noise cancellation method in a power line scenario, according to an embodiment of the present invention.

[0061] Reference numerals: 10, processor; 11, memory; 12, communication bus; 13, communication interface.

[0062] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0063] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0064] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0065] Reference Figure 1 The diagram shown is a flowchart illustrating a method for eliminating impulse noise in a power line scenario according to an embodiment of the present invention. In this embodiment, the method for eliminating impulse noise in a power line scenario includes:

[0066] S1. Acquire the received signal.

[0067] Specifically, the received signal is a time-domain signal. In this embodiment, the received signal is power line data, which refers to data information transmitted through power lines. The received signal includes carrier communication signals (e.g., high-frequency modulation signals, which are used to transmit data, voice, or control commands), equipment status signals, user-side data signals, remote configuration commands, and / or demand response signals. Equipment status signals include telemetry / telecommunication signals (e.g., circuit breaker open / close status, transformer oil temperature, residual current value, and other equipment operating parameters) and protection signals (e.g., relay protection action signals). User-side data signals include electricity meter data (e.g., electricity, voltage, current, and other parameters collected by the electricity meter) and smart home control signals (e.g., internet data, audio and video streams transmitted by powerline adapters or modems).

[0068] Received signals include useful signals and noise signals. In Power Line Communication (PLC) systems, the useful signal refers to the raw data or modulated signal carrying the information needed by the user or triggering preset actions. Noise signals refer to unnecessary signals that negatively impact the transmission or reception of the useful signal. The transmitted signal is transmitted using OFDM symbols. OFDM stands for Orthogonal Frequency Division Multiplexing. OFDM symbols are the core transmission unit in Orthogonal Frequency Division Multiplexing (OFDM) technology. OFDM symbols divide a high-speed data stream into multiple low-speed subcarriers for parallel transmission, with each subcarrier carrying independently modulated data. Because the subcarriers maintain orthogonality, no guard band is required, significantly improving spectrum utilization.

[0069] The number of subcarriers in an OFDM symbol is In power line communication systems, useful signals are typically transmitted in the frequency band range corresponding to the signal subcarriers. The signal subspace is the subspace corresponding to the signal subcarriers, and the signal subcarriers are subcarriers that contain useful signals.

[0070] In this embodiment, the actual set of subcarriers used when transmitting useful signals is as follows: ,gather The number of elements in the middle is The signal subcarrier mapping matrix is , Representing the complex field, the signal subcarrier mapping matrix has only 0 and 1 elements, and each column has only one element with a value of 1. The row index of an element with a value of 1 corresponds to the actual set of subcarriers used. .

[0071] S2. Perform a discrete Fourier transform on the received signal to obtain the frequency domain received signal.

[0072] Specifically, define 3D Discrete Fourier Transform Matrix The full name of the Discrete Fourier Transform is Discrete Fourier Transform, abbreviated as DFT; the Discrete Fourier Transform matrix... OK Column elements Represented as:

[0073] ;

[0074] in, Represents the first element in the discrete Fourier transform matrix. Line number Column elements, For the row index of the discrete Fourier transform matrix, ; For the column index of the discrete Fourier transform matrix, ; For imaginary units, The fundamental period is the angular frequency.

[0075] The discrete inverse Fourier transform matrix is The full name of the Inverse Discrete Fourier Transform is Inverse Fourier Transform, abbreviated as IFDT. This indicates the conjugate transpose. , express A 3D identity matrix. The modulation symbols carried by the subcarriers in actual use are... The modulation symbols are taken from the constellation diagram. In this embodiment, the time-domain baseband OFDM sampled signal transmitted by the transmitter is denoted as... Sampling signal The expression is:

[0076] ;

[0077] in, The signal subcarrier mapping matrix, The number of subcarriers used for the useful signal in the received signal. This refers to the modulation symbol carried by the subcarrier corresponding to the useful signal in an OFDM symbol.

[0078] The impulse noise cancellation method in the power line scenario proposed in this invention is applicable to the scenario where the transmitted signal passes through a frequency-flat fading multipath channel, and is also applicable to the scenario where the transmitted signal passes through a frequency-selective fading multipath channel. For the sake of brevity, this embodiment uses the scenario where the transmitted signal passes through a frequency-flat fading multipath channel as an example to describe the impulse noise cancellation method in the power line scenario.

[0079] In the scenario where the transmitted signal passes through a frequency-flat fading multipath channel, the time-domain baseband OFDM sampled signal received by the receiver after removing the cyclic prefix is: The expression for the received signal is:

[0080] ;

[0081] in, Indicates the number of paths. Indicates the path index. Representing a path The channel coefficient, To represent the field of complex numbers, in general , Indicates modulo; Represents the path after removing the cyclic prefix. The number of cyclic prefix points preceding the received sampled signal is typically: It should be added that, subscript The smaller the value, the shorter the transmission time from the sender to the receiver. Therefore, the smaller the signal attenuation, the better. .

[0082] According to the path Channel coefficients Determine the channel impulse response Channel impulse response Central Africa The channel coefficients are filled with 0. This indicates that the identity matrix Circular shift down The elementary matrix obtained after the row. It is time-domain complex Gaussian white noise. satisfy ,Right now:

[0083] ,

[0084] express A column vector of all zeros. Expressing expectations; It is actual time-domain impulse noise, impulse noise All elements in the set are independent and identically distributed, and each element follows a Bernoulli-complex Gaussian mixture distribution, i.e., for impulse noise... The Middle element It follows a complex Gaussian distribution. The probability is The probability that the impulse noise value is 0 is , It follows a complex normal distribution. Define the support set. Impulse noise The set of indices of non-zero elements; the support set Number of elements Follows a binomial distribution. Indicates support set The number of elements, denoted as , To represent the binomial distribution, describe in The probability distribution of the number of successes in a series of independent, repeated Bernoulli trials. The intensity of impulse noise is typically much greater than that of Gaussian noise, i.e. .

[0085] Utilizing the properties of cyclic matrices, the receiver can obtain the time-domain baseband OFDM sampled signal after removing the cyclic prefix. It can be written in matrix form:

[0086]

[0087] in It is a circular matrix, and the first column of the circular matrix is ​​the channel impulse response. The second column to the third column of the circular matrix Each column is shifted one row down relative to the column to its left. (Circular matrix) It can be decomposed into:

[0088] ,

[0089] in This means expanding the vector into a diagonal matrix. , The number of subcarriers for an OFDM symbol. The discrete Fourier transform matrix is... This is the channel impulse response.

[0090] The frequency domain received signal is denoted as Frequency domain received signal The expression is

[0091] ;

[0092] in, This represents the useful signal portion of the received signal. This indicates the impulse noise component in the received signal. This represents the Gaussian white noise component in the received signal; The signal subcarrier mapping matrix, The number of subcarriers used for the useful signal in the received signal. This refers to the modulation symbol carried by the subcarrier used for the useful signal in an OFDM symbol. Represents time-domain complex Gaussian white noise; This represents time-domain impulse noise.

[0093] S3. Construct a noise subcarrier mapping matrix based on the noise subcarriers corresponding to the noise subspace, and project the frequency domain received signal onto the noise subspace according to the noise subcarrier mapping matrix to obtain the noise subspace projection signal.

[0094] In this embodiment, the noisy subcarrier is a subcarrier of some OFDM symbols that is not used by the useful signal, and the noise subspace is the subspace corresponding to the noisy subcarrier.

[0095] Specifically, the number of subcarriers not used by the useful signal is Select A subcarrier that is not used by a useful signal creates a noise subspace. satisfy:

[0096] ;

[0097] This indicates rounding down. The value of is a power of 2, for example .

[0098] like To avoid spectral leakage in the signal subspace, the middle unused subcarrier is selected from a sequence of unused subcarriers. Each subcarrier creates a noise subspace as a noise subcarrier, ensuring that at least one subcarrier exists in both the signal subspace and the noise subspace to reduce the impact of spectral leakage from the signal subspace on the impulse noise estimation results; if Unused subcarriers were not arranged consecutively; lower numbers were selected. Each subcarrier creates a noise subspace (i.e., starting from position 0, selects unused subcarriers of OFDM symbols as noise subcarriers).

[0099] Selected The set of subcarriers is denoted as According to the subcarrier set Constructing the noisy subcarrier mapping matrix This matrix contains only 0 and 1 elements, and each column contains only one element with a value of 1. The set corresponding to the row index of the element with a value of 1 .

[0100] Noise subspace projection signal The expression is

[0101] ;

[0102] in, For the noise subcarrier mapping matrix, Noise subcarrier mapping matrix The conjugate transpose of the matrix. This represents the number of noise subcarriers corresponding to the noise subspace.

[0103] S4. Construct the noise observation matrix based on the noise subcarrier mapping matrix.

[0104] The expression for the noise observation matrix is: ,in, For the noise observation matrix, For the noise subcarrier mapping matrix, Represents the field of complex numbers. It is the number of subcarriers in an OFDM symbol. This represents the number of noise subcarriers corresponding to the noise subspace. Noise subcarrier mapping matrix The conjugate transpose of the matrix. It is the discrete Fourier transform matrix.

[0105] The relationship between the noise subspace projection signal and the noise observation matrix is ​​as follows:

[0106] ;

[0107] According to the formula Estimating impulse noise ,in, It is the discrete Fourier transform matrix A submatrix composed of a subset of rows. Consider the sparsity of impulse noise:

[0108] ;

[0109] in Representation matrix column vectors, Representation matrix Column vector index, Indicates impulse noise elements, Indicates support set The number of elements, Indicates support set elements, Indicates support set The element index.

[0110] S5. Estimating the impulse noise support set based on the noise observation matrix and the noise subspace projection signal. The impulse noise support set is a set of indexes of the non-zero elements in the impulse noise. Specifically, estimating the impulse noise support set based on the noise observation matrix and the noise subspace projection signal includes:

[0111] S51. Divide the column vectors of the noise observation matrix into... There are 3 clusters, and a column vector from each cluster is selected as the basis vector.

[0112] In this embodiment, the column vectors of the noise observation matrix are divided into the following order: Each cluster, from the noise observation matrix of Select from each column ... The columns are used as basis vectors; the meaning of a basis vector lies in any noise observation matrix. Each column can be represented by a linear combination of basis vectors.

[0113] S52. Project the noise subspace projection signal onto the basis vectors of each cluster to obtain the basis projection signal.

[0114] The expression for the base projection signal is:

[0115] ;

[0116] in, Indicates the base projection signal. This is the first noise detection submatrix, which is composed of the basis vectors of each cluster in the noise observation matrix. , Denotes the conjugate transpose of the first noise detection submatrix. Represents the noise observation matrix. This represents time-domain complex Gaussian white noise.

[0117] From the noise observation matrix The semi-orthogonality property of the base projection signal indicates that: Elements with larger projection values ​​in the middle mean that there are support sets near the corresponding basis vectors. The elements, namely the base projection signal The cluster containing the basis vectors of elements with larger projection values ​​has impulse noise.

[0118] S53. The first comparison result is obtained by comparing the projection value of the base projection signal with the preset first reference threshold value.

[0119] S54. Determine the cluster where the non-zero elements of the impulse noise are located based on the first comparison result, and record the cluster where the non-zero elements of the impulse noise are located as the target cluster.

[0120] Define the first reference threshold as: If the base projection signal The first in element satisfy Then determine the first element The cluster of corresponding basis vectors contains non-zero elements of impulse noise, resulting in the first comparison result.

[0121] In this expression, This indicates taking the absolute value of each element within the parentheses. This indicates taking the average.

[0122] In this embodiment, the first element The subcarrier range covered by the corresponding basis vector cluster is arrive ,in, Indicates rounding down. Indicates rounding up. Valid subcarrier numbers start from... arrive If the calculated subcarrier range exceeds the valid subcarrier range (if and only if basis vector 0 is selected), the subcarrier range is adjusted accordingly. For periodicity, subcarrier with subcarriers Equivalent, and so on.

[0123] S55. Project the noise subspace projection signal onto the column vector of the noise observation matrix corresponding to the noise subcarrier covered by the target cluster to obtain the cluster projection signal;

[0124] The expression for the cluster projection signal is:

[0125] ;

[0126] in, Indicates cluster projection signal, This represents the second noise detection submatrix, which is constructed based on the column vectors of the noisy subcarriers covered by the target cluster. The number of rows is The column number represents the number of noisy subcarriers covered by the target cluster. Denotes the conjugate transpose of the second noise detection submatrix. Represents the noise observation matrix. This represents time-domain complex Gaussian white noise.

[0127] S56. Compare the projection value of the cluster projection signal with the preset second reference threshold value to obtain the second comparison result;

[0128] Based on the second comparison result, the position information of the non-zero pulse noise elements in the cluster projection signal is determined, and the position information of the non-zero pulse noise elements is added to the pulse noise support set.

[0129] Define the second reference threshold as: Cluster projection signal The first in element satisfy Then determine the first element The corresponding subcarrier has impulse noise, resulting in the second comparison result; the cluster projection signal is then used to obtain the second comparison result. element The corresponding subcarrier position information is added to the impulse noise support set. middle.

[0130] S6. Reduce the dimensionality of the noise observation matrix using the impulse noise support set, and then use the least squares algorithm to process the dimensionality-reduced noise observation matrix to obtain the impulse noise estimate. .

[0131] Support set by impulse noise noise observation matrix Dimensionality reduction yields the dimensionality-reduced noise observation matrix, which is the impulse noise support set within the noise observation matrix. Submatrix composed of column vectors corresponding to the positions of the inner elements .

[0132] In this embodiment, impulse noise estimation Noise subvectors corresponding to non-zero elements The expression is

[0133] ;

[0134] in, Represents the impulse noise support set in the noise observation matrix. The submatrix formed by the column vectors corresponding to the positions of the inner elements. Represents the impulse noise support set. This indicates the conjugate transpose. This represents finding the inverse of a matrix. This represents the projection signal of the noise subspace.

[0135] Based on the semi-orthogonality of the noise observation matrix, the noise subspace projection signal is projected onto the basis vectors of each cluster to obtain the basis projection signal. The basis vectors whose projection values ​​exceed the first reference threshold are selected. The basis vectors whose projection values ​​exceed the first reference threshold are the clusters where the non-zero elements of the impulse noise are located, and are called the target clusters. The target clusters of the non-zero elements of the impulse noise are coarsely located using the above method. Then, the positions of the non-zero elements of the impulse noise are finely located from the target clusters: the received signal is projected onto the column vectors of the observation matrix corresponding to the target cluster. The column vectors whose projection values ​​exceed the second reference threshold are selected. The positions of the column vectors whose projection values ​​exceed the second reference threshold are the positions corresponding to the non-zero elements of the impulse noise.

[0136] First, the positions of the non-zero elements of the impulse noise are coarsely located within the target cluster, and then the positions of the non-zero elements of the impulse noise are finely located within the target cluster. This can narrow the range of impulse noise support set estimation, thereby reducing computational complexity.

[0137] S7, Based on impulse noise estimation Eliminate impulse noise in the received signal to obtain the received signal after impulse noise elimination.

[0138] Estimation of impulse noise Eliminate frequency domain received signal The effect of pulse noise is investigated to obtain the received signal after pulse noise cancellation. :

[0139] ;

[0140] in, This represents the received signal after eliminating impulse noise. This represents the error in impulse noise cancellation. Represents time-domain impulse noise. This represents impulse noise estimation.

[0141] The performance of the impulse noise cancellation method in the power line scenario of this application is verified below. Figure 2 The waveform of the received signal in the time domain with impulse noise is shown. Figure 3 The received constellation diagram is shown for a time-domain received signal with impulse noise without impulse noise cancellation. Without impulse noise cancellation, the received constellation diagram will be significantly affected. Figure 4 The received constellation diagram after pulse noise cancellation using the power line scenario pulse noise cancellation method of this application is shown to be a time-domain received signal with impulse noise. It can be seen that the power line scenario pulse noise cancellation method proposed in this application has a significant improvement on the received constellation diagram.

[0142] Based on the same inventive concept, an embodiment of the present invention provides an intelligent fusion terminal, comprising:

[0143] The interface module can receive initial power line data;

[0144] The control module is capable of controlling the exchange and communication of initial power line data;

[0145] The communication module can process the received initial power line data according to the aforementioned impulse noise cancellation method in the power line scenario to obtain denoised power line data;

[0146] The storage module can temporarily store initial power line data, denoised power line data, and / or software programs for impulse noise cancellation methods in power line scenarios.

[0147] This application also discloses an electronic device, such as Figure 5The diagram shown is a schematic representation of an electronic device for a method of eliminating impulse noise in a power line scenario according to an embodiment of the present invention. The electronic device may include at least one processor 10, a memory 11 communicatively connected to the at least one processor, a communication bus 12, and a communication interface 13. It may also include a computer program, such as a method program for eliminating impulse noise in a power line scenario, stored in the memory 11 and executable on the processor 10.

[0148] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., methods for pulse noise cancellation in power line scenarios) and calls data stored in the memory 11 to perform various functions of the electronic device and process data.

[0149] The memory 11 includes at least one type of readable storage medium, including flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of an electronic device, such as a portable hard drive. In other embodiments, the memory 11 can be an external storage device of the electronic device, such as a plug-in portable hard drive, smart media card (SMC), secure digital (SD) card, flash card, etc. Furthermore, the memory 11 can include both internal and external storage units of the electronic device. The memory 11 can be used not only to store application software and various types of data installed on the electronic device, such as the code for a method of pulse noise cancellation in a power line scenario, but also to temporarily store data that has been output or will be output.

[0150] The communication bus 12 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. The bus is configured to enable communication between the memory 11 and at least one processor 10, etc.

[0151] Communication interface 13 is used for communication between the aforementioned electronic device and other devices, including a network interface and a user interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, Bluetooth interface, etc.), typically used to establish communication connections between the electronic device and other electronic devices. The user interface may be a display, an input unit (such as a keyboard), or optionally, a standard wired or wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device and to display a visual user interface.

[0152] Figure 5 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 5 The structure shown does not constitute a limitation on the electronic device and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0153] For example, although not shown, the electronic device may also include a power supply (such as a battery) to power various components. Preferably, the power supply can be logically connected to at least one processor 10 via a power management device, thereby enabling functions such as charging management, discharging management, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0154] It should be understood that the embodiments are for illustrative purposes only and are not limited to this structure in the scope of the patent application.

[0155] Furthermore, if the modules / units integrated into the electronic device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile.

[0156] This application also provides a computer-readable storage medium, such as any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM). The computer-readable storage medium stores a computer program that can be loaded by a processor and execute the power line scene impulse noise cancellation method of the above embodiments.

[0157] In the description of this specification, the references to terms such as "an embodiment," "some embodiments," "example," "specific example," "a implementation," "a preferred implementation," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0158] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for eliminating impulse noise in a power line scenario, characterized in that, The method includes: Acquire the received signal, which is a time-domain signal; The frequency domain received signal is obtained by performing a discrete Fourier transform on the received signal; A noise subcarrier mapping matrix is ​​constructed based on the noise subcarriers corresponding to the noise subspace, and the frequency domain received signal is projected onto the noise subspace according to the noise subcarrier mapping matrix to obtain the noise subspace projection signal. Construct the noise observation matrix based on the noise subcarrier mapping matrix; The impulse noise support set is estimated based on the noise observation matrix and the noise subspace projection signal. The impulse noise support set is a set composed of the position indices of the non-zero elements of the impulse noise. The noise observation matrix is ​​reduced in dimensionality using an impulse noise support set, and the impulse noise estimate is obtained by processing the dimensionality-reduced noise observation matrix using a least squares algorithm. ; Based on impulse noise estimation Eliminate impulse noise in the frequency domain received signal to obtain the frequency domain received signal after impulse noise elimination; The expression for the noise observation matrix is: ,in, For the noise observation matrix, For the noise subcarrier mapping matrix, Represents the field of complex numbers. It is the number of subcarriers in an OFDM symbol. This represents the number of noise subcarriers corresponding to the noise subspace. Noise subcarrier mapping matrix The conjugate transpose of the matrix. It is the discrete Fourier transform matrix; The estimation of the impulse noise support set based on the noise observation matrix and the noise subspace projection signal includes: The column vectors of the noise observation matrix are divided into There are 3 clusters, and a column vector from each cluster is selected as the basis vector; The noise subspace projection signal is projected onto the basis vectors of each cluster to obtain the basis projection signal; The first comparison result is obtained by comparing the projection value of the base projection signal with the preset first reference threshold value; Based on the first comparison result, determine the cluster where the non-zero elements of the impulse noise are located, and record the cluster where the non-zero elements of the impulse noise are located as the target cluster. The cluster projection signal is obtained by projecting the noise subspace projection signal onto the column vector of the noise observation matrix corresponding to the noise subcarriers covered by the target cluster. The second comparison result is obtained by comparing the projection value of the cluster projection signal with the preset second reference threshold value; Based on the second comparison result, the position information of the non-zero pulse noise elements in the cluster projection signal is determined, and the position information of the non-zero pulse noise elements is added to the pulse noise support set.

2. The method for eliminating impulse noise in a power line scenario as described in claim 1, characterized in that, The number of subcarriers not used by the useful signal is Select A subcarrier that is not used by a useful signal creates a noise subspace. satisfy: ； Indicates rounding down. The value of is a power of 2.

3. The method for eliminating impulse noise in a power line scenario as described in claim 1 or 2, characterized in that, The received signal is denoted as The frequency domain received signal is denoted as Frequency domain received signal The expression is ； in, This represents the useful signal portion of the received signal. This indicates the impulse noise component in the received signal. This represents the Gaussian white noise component in the received signal; ,in, This means expanding the vector into a diagonal matrix. The number of subcarriers for an OFDM symbol. It is the discrete Fourier transform matrix. Channel impulse response; The signal subcarrier mapping matrix, The number of subcarriers used for the useful signal in the received signal. This refers to the modulation symbol carried by the subcarrier used for the useful signal in an OFDM symbol. Represents time-domain complex Gaussian white noise; This represents time-domain impulse noise.

4. The method for eliminating impulse noise in a power line scenario as described in claim 3, characterized in that, Noise subspace projection signal The expression is ； in, For the noise subcarrier mapping matrix, Noise subcarrier mapping matrix The conjugate transpose of the matrix. This represents the number of noise subcarriers corresponding to the noise subspace.

5. The method for eliminating impulse noise in a power line scenario as described in claim 3, characterized in that, Impulse noise estimation Noise subvectors corresponding to non-zero elements The expression is ； in, Represents the impulse noise support set in the noise observation matrix. The submatrix formed by the column vectors corresponding to the positions of the inner elements. Represents the impulse noise support set. This indicates the conjugate transpose. This represents finding the inverse of a matrix. This represents the projection signal of the noise subspace.

6. The method for eliminating impulse noise in a power line scenario as described in claim 5, characterized in that, Impulse noise estimation Eliminate frequency domain received signal The effect of impulse noise is eliminated to obtain the received signal. : ； in, This represents the frequency domain received signal after eliminating impulse noise. This represents the error in impulse noise cancellation. This represents the actual time-domain impulse noise. This represents the estimated time-domain impulse noise.

7. An electronic device, characterized in that, The electronic device includes: At least one processor (10); and, A memory (11) communicatively connected to the at least one processor (10); The memory (11) stores a computer program that can be executed by the at least one processor (10) to enable the at least one processor (10) to perform the impulse noise cancellation method in a power line scenario as described in any one of claims 1 to 6.

8. A smart converged terminal, characterized in that, include: The interface module is used to receive initial power line data; The control module is used to control the exchange and communication of initial power line data; The communication module is used to process the received initial power line data in the power line scenario according to any one of claims 1 to 6, so as to obtain the denoised power line data. ‌ The storage module is used to temporarily store initial power line data, denoised power line data, and / or software programs for impulse noise cancellation methods in power line scenarios.

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