Communication method and apparatus for impulse noise suppression based on outlier detection

Abstract

The application relates to the technical field of wireless communication, and discloses a communication method and device for impulse noise suppression based on abnormal point detection, wherein at a receiving end, the method receives a transmission signal, divides the transmission signal into four parts according to a quartile algorithm, determines upper quartiles, a median and lower quartiles, then determines a normal value interval according to the upper quartiles, the median and the lower quartiles, detects abnormal signals disturbed by impulse noise in the transmission signal based on the normal value interval, repairs the abnormal signals, and obtains a de-noised signal.In the embodiment of the application, the transmission signal features and the quartile algorithm are comprehensively utilized to more accurately locate the impulse noise disturbance and improve the suppression effect.In addition, through the quartile-based algorithm, the calculation amount is small, the abnormal signals can be quickly and accurately detected and repaired, the operation is simple, the impulse noise disturbance can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to a communication method and device for impulse noise suppression based on outlier detection. BACKGROUND

[0002] Orthogonal frequency division multiplexing (OFDM) is a form of multicarrier communication system. As an effective means to solve intersymbol interference, OFDM has been widely used in various wireless and wired communication standards, such as digital audio broadcasting (DAB), digital video broadcasting (DVB), digital television terrestrial broadcasting (DTMB), wireless regional area network (WRAN) and PLC communication standard IEEE 1901.2, etc.

[0003] Impulse noise is a kind of noise with burst, high amplitude and low probability. From the spectrum, impulse noise usually has a wide spectrum, and the harm to communication is mainly concentrated in the medium, short wave and below the wave band, and generally has little effect on the above high frequency band. Impulse noise is one of the main interferences in OFDM systems. The impulse noise with very short duration contains the spectral components of all subchannels, which will affect the decision of the transmitted symbols on all subchannels. Therefore, the influence of impulse noise is still an important problem that limits the application of OFDM technology.

[0004] At present, the widely used impulse noise suppression methods in OFDM systems include nonlinear method, minimum mean square error algorithm, compressed sensing algorithm and blanking method, etc. Among them, some impulse noise suppression methods (such as nonlinear method and blanking method) depend on the selection of some preset parameters or thresholds. The accurate setting of these parameters is crucial to the effect of impulse noise suppression. However, the adjustment of parameters may require experience or trial and error, and if not properly selected, it may lead to poor suppression effect or negative impact on normal signals; some impulse noise suppression methods (such as compressed sensing algorithm and blanking method) need to introduce additional processing steps or time windows in order to detect and suppress impulse noise, which may introduce a certain system delay. For real-time applications, it may bring certain challenges; some impulse noise suppression methods require complex algorithms and signal processing techniques, involving a large number of calculations and processing steps, so in practical applications, it may require high computing resources and time. SUMMARY

[0005] The embodiments of the present application provide a communication method for impulse noise suppression based on outlier detection, to solve the problems of high computational complexity, difficult parameter adjustment and impact on system delay of existing impulse noise suppression methods.

[0006] Correspondingly, the embodiments of the present application also provide a communication device for impulse noise suppression based on outlier detection, to ensure the implementation and application of the above method.

[0007] To solve the above technical problems, the embodiment of the application discloses a communication method for pulse noise suppression based on abnormal point detection, which comprises the following steps at a receiving end:

[0008] receiving a transmission signal;

[0009] dividing the transmission signal into four parts according to a quartile algorithm and determining upper quartiles, median and lower quartiles;

[0010] determining a normal value interval according to the upper quartiles, median and lower quartiles;

[0011] detecting abnormal signals disturbed by pulse noise in the transmission signal based on the normal value interval;

[0012] repairing the abnormal signals to obtain a de-noised signal.

[0013] Preferably, the method further comprises:

[0014] performing serial-parallel conversion on the de-noised signal and removing a guard interval to obtain a discrete time domain signal;

[0015] performing discrete Fourier transform on the discrete time domain signal to obtain N rows and M columns of binary data; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals;

[0016] performing parallel-serial conversion on the binary data and performing OFDM mapping to obtain a target signal.

[0017] Preferably, the step of dividing the transmission signal into four parts according to a quartile algorithm and determining upper quartiles, median and lower quartiles comprises:

[0018] arranging the transmission signal according to signal amplitude from small to large to obtain a signal ordering sequence;

[0019] dividing the signal ordering sequence into four parts and determining three limit points for dividing the signal ordering sequence into four parts, wherein the three limit points are the upper quartiles, median and lower quartiles, respectively;

[0020] wherein each part of the four parts contains the same number of transmission signals.

[0021] Preferably, the step of determining a normal value interval according to the upper quartiles, median and lower quartiles comprises:

[0022] calculating a minimum estimated value and a maximum estimated value according to the upper quartiles, median and lower quartiles;

[0023] determine the normal value interval according to the minimum estimated value and the maximum estimated value.

[0024] Preferably, the detecting the abnormal signal disturbed by the impulse noise in the transmission signal based on the normal value interval comprises:

[0025] determining that the signal amplitude of the transmission signal does not belong to the normal value interval, and determining the transmission signal as the abnormal signal.

[0026] Preferably, the communication method for impulse noise suppression based on the abnormal point detection comprises:

[0027] repairing the abnormal signal by a preset denoising method to obtain a denoised signal; the preset denoising method comprises a zero setting method, a mean filtering method and a median filtering method.

[0028] The embodiment of the application further discloses a communication method for impulse noise suppression based on abnormal point detection, which comprises the following steps at a sending end:

[0029] performing OFDM mapping and serial-parallel conversion on the target signal to obtain binary data in N rows and M columns; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals;

[0030] performing inverse discrete Fourier transform on the binary data to obtain a discrete time domain signal;

[0031] inserting a guard interval into the discrete time domain signal and performing parallel-serial conversion to obtain a transmission signal.

[0032] The embodiment of the application further discloses a communication device for impulse noise suppression based on abnormal point detection, which comprises the following steps at a receiving end:

[0033] a signal receiving module configured to receive a transmission signal;

[0034] a data processing module configured to divide the transmission signal into four parts according to a quartile algorithm and determine an upper quartile, a median and a lower quartile;

[0035] a normal interval determining module configured to determine a normal value interval according to the upper quartile, the median and the lower quartile;

[0036] an abnormal signal detecting module configured to detect an abnormal signal disturbed by impulse noise in the transmission signal based on the normal value interval;

[0037] a signal repairing module configured to repair the abnormal signal to obtain a denoised signal.

[0038] Preferably, at the receiving end, the device further comprises:

[0039] The anti-interference removal module is configured to perform serial-parallel conversion on the de-noised signal and remove the guard interval to obtain a discrete time domain signal.

[0040] The discrete processing module is configured to perform inverse discrete Fourier transform on the binary data to obtain a discrete time domain signal.

[0041] The signal inverse mapping module is configured to perform parallel-serial conversion on the binary data and OFDM mapping to obtain a target signal.

[0042] The application further discloses a communication device for pulse noise suppression based on abnormal point detection, which comprises the following at the sending end:

[0043] The signal mapping module is configured to perform OFDM mapping and serial-parallel conversion on the target signal to obtain N rows of M columns of binary data; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals.

[0044] The discrete processing module is configured to perform inverse discrete Fourier transform on the binary data to obtain a discrete time domain signal.

[0045] The anti-interference module is configured to insert a guard interval into the discrete time domain signal and perform parallel-serial conversion to obtain a transmission signal.

[0046] In the application, at the receiving end, a transmission signal is received, and the transmission signal is divided into four parts according to the quartile algorithm to determine the upper quartile, the median, and the lower quartile. Then, the normal value interval is determined according to the upper quartile, the median, and the lower quartile. Based on the normal value interval, the abnormal signal disturbed by pulse noise in the transmission signal is detected, the abnormal signal is repaired, and a de-noised signal is obtained. In the application, the method of comprehensively utilizing the characteristics of the transmission signal and the statistical theory (quartile) can more accurately locate the pulse noise disturbance and improve the suppression effect. In addition, through the algorithm based on the quartile, the calculation amount is small, the abnormal signal can be quickly and accurately detected and repaired, the operation is simple, the pulse noise disturbance can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

[0047] Additional aspects and advantages of the application will be given in the following description section, which will become apparent from the following description or be understood through practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0048] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0049] Figure 1 A flow chart of a communication method based on abnormal point detection for impulse noise suppression provided by an embodiment of the present application;

[0050] Figure 2 A flow chart of a communication method based on abnormal point detection for impulse noise suppression at a receiving end provided by an embodiment of the present application;

[0051] Figure 3 A graph showing the variation of the error rate of the FC segment under different signal-to-noise ratios for the method and blanking method provided by an embodiment of the present application;

[0052] Figure 4 A graph showing the variation of the error rate of the PL segment under different signal-to-noise ratios for the method and blanking method provided by an embodiment of the present application;

[0053] Figure 5 A structural schematic diagram of a communication device based on abnormal point detection for impulse noise suppression as a transmitting end provided by an embodiment of the present application;

[0054] Figure 6 A structural schematic diagram of a communication device based on abnormal point detection for impulse noise suppression as a receiving end provided by an embodiment of the present application. DETAILED DESCRIPTION

[0055] Embodiments of the present application are described in detail below with reference to examples illustrated in the accompanying drawings, in which the same or similar elements or elements having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended only for explanation of the present application, and cannot be interpreted as limiting the present application.

[0056] Those skilled in the art can understand that, unless specifically stated, the singular forms "a", "an" and "the" used herein also include the plural forms. It should be further understood that the use of the term "include" in the specification of the present application means that a feature, integer, step, operation, element and / or component exists, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intermediate elements. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any single unit and all combinations of the associated listed items.

[0057] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0058] The scheme provided by the embodiments of the present application can be executed by any electronic device, which can be a terminal device or a server. The server can be a physical server, a server cluster composed of multiple physical servers, a distributed system, or a cloud server providing cloud computing services. The terminal can be a smartphone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, etc., but is not limited thereto. The terminal and the server can be connected directly or indirectly through wired or wireless communication, which is not limited in the present application. For the technical problems existing in the prior art, the communication method and device for pulse noise suppression based on abnormal point detection provided by the present application aim to solve at least one of the technical problems of the prior art.

[0059] The technical scheme of the present application and how the technical scheme of the present application solves the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0060] The embodiments of the present application provide a possible implementation manner, as shown in Figure 1 A flowchart of a communication method for pulse noise suppression based on abnormal point detection is provided, which can be executed by any electronic device, and can be executed on a server side or a terminal device.

[0061] As shown in Figure 1 At the sending end, the method can include the following steps:

[0062] Step 101: Perform OFDM mapping and serial-parallel conversion on the target signal to obtain binary data of N rows and M columns; wherein N is the number of parallel transmission subcarriers, and M is the number of OFDM signals.

[0063] The embodiment of the present application can realize communication between a sending end and a receiving end based on an OFDM communication system. In the sending end of the OFDM communication system, the initial target signal can be mapped by OFDM and converted from serial to parallel to obtain binary data of N rows and M columns. The target signal is a binary sequence; the serial-to-parallel conversion is advantageous to reduce the rate of data flow; N is the number of subcarriers in parallel transmission; and M is the number of OFDM signals in a frame structure.

[0064] In step 102, inverse discrete Fourier transform is performed on the binary data to obtain a discrete time domain signal.

[0065] In step 103, a guard interval is inserted into the discrete time domain signal, and serial-to-parallel conversion is performed to obtain a transmission signal.

[0066] The insertion of the guard interval into the discrete time domain signal can prevent inter-symbol interference. Then, the serial-to-parallel conversion, i.e., superposition of N subcarrier signals, can obtain the transmission signal to be sent.

[0067] In the embodiment of the present application, the OFDM signal transmitted in the nth OFDM symbol interval can be written as where f c is a carrier frequency, s l (t) is an equivalent low-pass of the transmission signal, where t satisfies (n-1)T q ≤t<nT q , K is the number of subcarriers, S n,k is a data symbol of the subcarrier k transmitted in the nth OFDM symbol interval, T q =T G +T u is an OFDM symbol period, the frequency interval between two adjacent subcarriers is 1 / T u , and T G is a guard time interval.

[0068] The embodiment of the present application also provides a communication method for impulse noise suppression based on abnormal point detection, as shown in Figure 1 The method comprises the following steps at the receiving end:

[0069] In step 104, a transmission signal is received.

[0070] In the embodiment of the present application, after the transmission signal passes through a channel of the OFDM communication system, Gaussian white noise and impulse noise can cause interference to the transmission signal, and the transmission signal received by the receiving end is where h j is a channel coefficient of path j, τ j is a channel delay of path j, P is the number of paths, w(t) is a Gaussian white noise process, and i(t) is an impulse noise part.

[0071] In the n-th symbol interval, the received signal sample at subcarrier k in the frequency domain can be written as R n,k = H n,k S n,k + W n,k + I n,k , where H n,k is the channel frequency response at subcarrier k, S n,k is the transmitted data symbol at subcarrier k, W n,k is the Gaussian white noise with mean zero and variance N0 at subcarrier k, and I n,k is the impulse noise at subcarrier k in the n-th OFDM symbol.

[0072] In step 105, the transmission signal is divided into four parts according to the quartile algorithm, and the upper quartile, the median, and the lower quartile are determined.

[0073] In statistics, the quartile is to divide all data into four equal parts, each part including 25% of the data, and the value at each quartile point is the quartile.

[0074] In step 106, the normal value interval is determined according to the upper quartile, the median, and the lower quartile.

[0075] In the embodiments of the present application, the signal characteristics and statistical theory are combined, the upper and lower quartiles are calculated through the division of the quartiles, and the abnormal value interval is determined. This method of comprehensively using signal characteristics and statistical theory can more accurately locate the impulse noise interference and improve the suppression effect.

[0076] In step 107, the abnormal signal disturbed by the impulse noise in the transmission signal is detected based on the normal value interval.

[0077] In step 108, the abnormal signal is repaired to obtain a de-noised signal.

[0078] Compared with the complex impulse noise suppression method, the method in the embodiments of the present application has a smaller calculation amount. Through the algorithm based on the quartiles, the normal value interval is defined to find the signal seriously disturbed by the impulse noise (i.e., the signal not belonging to the normal value interval), which can quickly and accurately detect the abnormal signal and repair it, thereby reducing the calculation complexity and implementation difficulty. In addition, the impulse noise interference can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

[0079] In the embodiment of the present application, at the receiving end, a transmission signal is received, the transmission signal is divided into four parts according to a quartile algorithm, the upper quartile, the median and the lower quartile are determined, then the normal value interval is determined according to the upper quartile, the median and the lower quartile, based on the normal value interval, the abnormal signal disturbed by the impulse noise in the transmission signal is detected, the abnormal signal is repaired, and a de-noised signal is obtained. In the embodiment of the present application, the method of comprehensively utilizing the transmission signal characteristics and the statistical theory (quartile) can more accurately locate the impulse noise disturbance and improve the suppression effect. In addition, through the algorithm based on the quartile, the calculation amount is small, the abnormal signal can be quickly and accurately detected and repaired, the operation is simple, the impulse noise disturbance can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

[0080] In an optional embodiment, the transmission signal is divided into four parts according to the quartile algorithm, and the upper quartile, the median and the lower quartile are determined, including:

[0081] The transmission signal is arranged according to the order of signal amplitude from small to large to obtain a signal sorting sequence;

[0082] The signal sorting sequence is divided into four parts, and three limit points for dividing the signal sorting sequence into four parts are determined, the three limit points are the upper quartile, the median and the lower quartile respectively;

[0083] In the four parts, the number of transmission signals contained in each part is the same.

[0084] After the receiving end receives the transmission signal, the detection and processing of the impulse noise are performed as shown in Figure 2 First, the signal is arranged according to the order of signal amplitude from small to large, then the transmission signal is divided into four parts, each part contains 25% of the data, and the three limit points for dividing the data into four parts are the upper quartile Q1, the median Q2 and the lower quartile Q3.

[0085] In an optional embodiment, the normal value interval is determined according to the upper quartile, the median and the lower quartile, including:

[0086] The minimum estimated value and the maximum estimated value are calculated according to the upper quartile, the median and the lower quartile;

[0087] The normal value interval is determined according to the minimum estimated value and the maximum estimated value.

[0088] In the embodiment of the present application, as shown in Figure 2, according to Q1-k*(Q3-Q1) to calculate the minimum estimate, according to Q3+k*(Q3-Q1) to calculate the maximum estimate, then the normal value interval is [Q1-k*(Q3-Q1), Q3+k*(Q3-Q1)], wherein the influence coefficient k is to define the range of normal signals.

[0089] In an optional embodiment, the detecting of the abnormal signal in the transmission signal disturbed by the impulse noise based on the normal value interval comprises:

[0090] If the signal amplitude of the transmission signal does not belong to the normal value interval, the transmission signal is determined as the abnormal signal.

[0091] Specifically, as Figure 2 , judging whether the signal amplitude is less than the minimum estimate or greater than the maximum estimate, if yes, determining as the abnormal signal and performing the de-noising processing, if not, determining as the normal signal and not needing processing.

[0092] In the embodiment of the application, when the signal amplitude is less than the minimum estimate or greater than the maximum estimate, the signal is considered to be seriously disturbed by the impulse noise, and the signal is repaired after the abnormal signal is detected, and the experience value k can be 1.5-3. Through the setting of the experience value k, the normal signal and the impulse noise can be distinguished without knowing the signal characteristics in advance.

[0093] In an optional embodiment, the repairing of the abnormal signal to obtain the de-noised signal comprises:

[0094] The abnormal signal is repaired by a preset de-noising method to obtain the de-noised signal, and the preset de-noising method comprises a zeroing method, a mean filtering method and a median filtering method.

[0095] As Figure 2 shown, if the signal amplitude is less than the minimum estimate or greater than the maximum estimate, the abnormal signal is processed by zeroing, and then the signal after the impulse noise suppression (i.e. the de-noised signal) is output. In the embodiment of the application, the mean filtering method and the median filtering method can also be used to process the abnormal signal, and then the signal after the impulse noise suppression is output.

[0096] The mean filtering is a simple and effective method for smoothing signals and reducing the influence of noise. It is realized by calculating the average value of adjacent samples. By adjusting the size of the filtering window, the signal smoothness and the noise suppression effect can be balanced.

[0097] The median filtering is a nonlinear filtering method, which replaces the value of each sample in the signal with the median value of adjacent samples. It is very effective for eliminating impulse noise, because noise is usually regarded as an abnormal value. The median filtering can preserve the edge and detail information of the signal.

[0098] In an optional embodiment, the method further comprises:

[0099] Step 109, serial-parallel conversion is performed on the de-noised signal, and a guard interval is removed to obtain a discrete time domain signal;

[0100] Step 110, a discrete Fourier transform is performed on the discrete time domain signal to obtain N rows of M columns of binary data; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals;

[0101] Step 111, parallel-serial conversion is performed on the binary data, and OFDM mapping is performed to obtain a target signal.

[0102] Figure 3 Figures showing the changes of the FC segment error rate under different signal-to-noise ratios according to the method and the blanking method provided in the embodiments of the present application are given. In the figures, the abscissa represents the signal-to-noise ratio (SNR), and the ordinate represents the FC segment error rate (FCBRE). It can be seen from the figures that Figure 3 as the signal-to-noise ratio increases, the FC segment error rates of the two methods gradually decrease, and the method in the embodiments of the present application (i.e., the method of the present application in Figure 3 compared with the blanking method has a lower error rate under different signal-to-noise ratios.

[0103] Figure 4 Figures showing the changes of the PL segment error rate under different signal-to-noise ratios according to the method and the blanking method provided in the embodiments of the present application are given. In the figures, the abscissa represents the signal-to-noise ratio (SNR), and the ordinate represents the PL segment error rate (PLBRE). It can be seen from the figures that Figure 4 as the signal-to-noise ratio increases, the PL segment error rates of the two methods gradually decrease, and the method in the embodiments of the present application (i.e., the method of the present application in Figure 4 compared with the blanking method has a lower error rate under different signal-to-noise ratios.

[0104] Based on the same principle as the method provided in the embodiments of the present application, the embodiments of the present application also provide a communication device for suppressing impulse noise based on abnormal point detection, as shown in Figure 5 As a sending end, the device comprises:

[0105] A signal mapping module 501 is configured to perform OFDM mapping and serial-parallel conversion on a target signal to obtain N rows of M columns of binary data; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals.

[0106] A discrete processing module 502 is configured to perform an inverse discrete Fourier transform on the binary data to obtain a discrete time domain signal.

[0107] The anti-interference module 503 is configured to insert a guard interval into the discrete time domain signal and perform parallel-to-serial conversion to obtain a transmission signal.

[0108] The insertion of the guard interval into the discrete time domain signal can prevent inter-signal interference. Then, parallel-to-serial conversion is performed, i.e., the N sub-carrier signals are superimposed, to obtain the transmission signal to be sent.

[0109] In the embodiment of the present application, the OFDM signal transmitted in the nth OFDM symbol interval can be written as where f c is a carrier frequency, s l (t) is an equivalent low-pass of the transmission signal, where t satisfies (n-1)T q ≤t<nT q , K is the number of sub-carriers, S n,k is a data symbol of the sub-carrier k transmitted in the nth OFDM symbol interval, T q =T G +T u is an OFDM symbol period, the frequency interval between two adjacent sub-carriers is 1 / T u , and T G is a guard time interval.

[0110] The communication device based on abnormal point detection for impulse noise suppression provided in the embodiment of the present application can implement the method embodiment Figure 1 The various processes implemented in the method embodiment are not described again here to avoid repetition.

[0111] The communication device based on abnormal point detection for impulse noise suppression as the sending end in the embodiment of the present application can execute the communication method based on abnormal point detection for impulse noise suppression of the sending end provided in the embodiment of the present application, and the implementation principles are similar. The actions performed by each module and unit in the communication device based on abnormal point detection for impulse noise suppression in the embodiments of the present application are corresponding to the steps in the communication method based on abnormal point detection for impulse noise suppression in the embodiments of the present application. The detailed function description of each module of the communication device based on abnormal point detection for impulse noise suppression can be found in the description of the corresponding communication method based on abnormal point detection for impulse noise suppression shown in the foregoing, which will not be described again here.

[0112] Based on the same principles as the method provided in the embodiments of the present application, the embodiments of the present application further provide a communication device based on abnormal point detection for impulse noise suppression. As shown in Figure 6 the device as the receiving end includes:

[0113] The signal receiving module 601 is configured to receive a transmission signal.

[0114] In the embodiment of the present application, after the transmission signal passes through the channel of the OFDM communication system, Gaussian white noise and impulse noise will cause interference to the transmission signal, and the transmission signal received by the receiving end In the formula, h j is the channel coefficient of path j, τ j is the channel delay of path j, P is the path number, w(t) is a Gaussian white noise process, and i(t) is an impulse noise part.

[0115] In the nth symbol interval, the received signal sample at the subcarrier k in the frequency domain can be written as R n,k = H n,k S n,k + W n,k + I n,k , wherein H n,k is the channel frequency response at the subcarrier k, S n,k is the transmission data symbol at the subcarrier k, W n,k is Gaussian white noise with a mean of zero and a variance of N0 at the subcarrier, and I n,k is the impulse noise at the subcarrier in the nth OFDM symbol.

[0116] The data processing module 602 is configured to divide the transmission signal into four parts according to the quartile algorithm, and determine the upper quartile, the median, and the lower quartile.

[0117] In statistics, the quartile is to divide all data into four equal parts, each part including 25% of the data, and the value at each quartile point is the quartile.

[0118] The normal interval determination module 603 is configured to determine a normal value interval according to the upper quartile, the median, and the lower quartile.

[0119] In the embodiment of the present application, the signal characteristics and statistical theory are combined, the upper and lower quartiles are calculated through the division of the quartiles, and thus the abnormal value interval is determined. This method of comprehensively utilizing the signal characteristics and statistical theory can more accurately locate the impulse noise interference and improve the suppression effect.

[0120] The abnormal signal detection module 604 is configured to detect abnormal signals in the transmission signal interfered by the impulse noise based on the normal value interval.

[0121] The signal repair module 605 is configured to repair the abnormal signals to obtain a de-noised signal.

[0122] Compared with a complex pulse noise suppression method, the method in the embodiment of the application has a small amount of calculation. By using the quartile-based algorithm, the normal value interval is defined to find the signal severely disturbed by the pulse noise (i.e., the signal not belonging to the normal value interval), so that the abnormal signal can be quickly and accurately detected and repaired, thereby reducing the calculation complexity and implementation difficulty. In addition, the pulse noise interference can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

[0123] In the embodiment of the application, the signal receiving module receives a transmission signal, divides the transmission signal into four parts according to the quartile algorithm, and determines the upper quartile, the median, and the lower quartile. The normal interval determining module determines a normal value interval according to the upper quartile, the median, and the lower quartile. The abnormal signal detecting module detects an abnormal signal disturbed by pulse noise in the transmission signal based on the normal value interval. The signal repairing module repairs the abnormal signal to obtain a de-noised signal. In the embodiment of the application, the method of comprehensively utilizing the characteristics of the transmission signal and the statistical theory (quartile) can more accurately locate the pulse noise interference and improve the suppression effect. In addition, by using the quartile-based algorithm, the amount of calculation is small, the abnormal signal can be quickly and accurately detected and repaired, the operation is simple, the pulse noise interference can be effectively suppressed, the error rate of the system is reduced, and the reliability of data transmission is improved.

[0124] In an optional embodiment, the apparatus further includes:

[0125] The anti-interference removal module 606 is configured to perform serial-parallel conversion on the de-noised signal and remove a guard interval to obtain a discrete time domain signal.

[0126] The discrete inverse processing module 607 is configured to perform discrete Fourier transform on the discrete time domain signal to obtain N rows of M columns of binary data; where N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals.

[0127] The signal inverse mapping module 608 is configured to perform parallel-serial conversion on the binary data and perform OFDM mapping to obtain a target signal.

[0128] In an optional embodiment, the data processing module 602 includes:

[0129] The first data processing submodule is configured to receive the transmission signal, arrange the transmission signal according to the order of signal amplitude from small to large to obtain a signal sorting sequence.

[0130] The second data processing submodule is configured to divide the signal sorting sequence into four parts and determine three limit points for dividing the signal sorting sequence into four parts, where the three limit points are the upper quartile, the median, and the lower quartile, respectively.

[0131] Each of the four parts contains the same number of transmission signals.

[0132] In an optional embodiment, the normal interval determination module 603 comprises:

[0133] A first abnormal interval determination submodule is configured to calculate a minimum estimated value and a maximum estimated value according to the upper quartile, the median, and the lower quartile.

[0134] A second abnormal interval determination submodule is configured to determine the normal value interval according to the minimum estimated value and the maximum estimated value.

[0135] In an optional embodiment, the abnormal signal detection module 604 comprises:

[0136] A first abnormal signal detection submodule is configured to determine that the signal amplitude of the transmission signal does not belong to the normal value interval, and determine the transmission signal as the abnormal signal.

[0137] In an optional embodiment, the signal repair module 605 comprises:

[0138] A first signal repair submodule is configured to repair the abnormal signal by a preset denoising method to obtain a denoised signal; the preset denoising method comprises a zeroing method, a mean filtering method, and a median filtering method.

[0139] The communication device for pulse noise suppression based on abnormal point detection provided by the embodiments of the present application can achieve the advantages of Figures 1 to 4 The processes achieved in the method embodiments are not described herein again to avoid repetition.

[0140] The communication device for pulse noise suppression based on abnormal point detection of the embodiments of the present application as a receiving end can execute the communication method for pulse noise suppression based on abnormal point detection of the receiving end provided by the embodiments of the present application, and the implementation principles are similar. The actions performed by each module and unit in the communication device for pulse noise suppression based on abnormal point detection in the embodiments of the present application are corresponding to the steps in the communication method for pulse noise suppression based on abnormal point detection in the embodiments of the present application. The detailed function description of each module of the communication device for pulse noise suppression based on abnormal point detection can be referred to the description of the corresponding communication method for pulse noise suppression based on abnormal point detection in the foregoing, which will not be described herein again.

[0141] The above description is merely exemplary of the application and of the application of the principles thereof and the application is not limited to the disclosed technical features or combinations thereof. It is intended to be apparent to one skilled in the art that the scope of the disclosure is not limited to the technical solutions formed by the specific combinations of the technical features disclosed above, and also includes other technical solutions formed by the combinations of the technical features disclosed above or their equivalent features without departing from the above disclosed concept. For example, technical solutions formed by the mutual replacement of the above features and technical features with similar functions disclosed in the application (but not limited to) are also included.

Claims

1. A communication method for impulse noise suppression based on outlier detection, characterized by, The method comprises: receiving a transmission signal; dividing the transmission signal into four parts according to a quartile algorithm, and determining upper quartiles, median, and lower quartiles; determining a normal value interval according to the upper quartiles, median, and lower quartiles; detecting abnormal signals disturbed by impulse noise in the transmission signal based on the normal value interval; repairing the abnormal signals to obtain a de-noised signal; after obtaining the de-noised signal, the method further comprises: performing serial-parallel conversion on the de-noised signal and removing a guard interval to obtain a discrete time domain signal; performing discrete Fourier transform on the discrete time domain signal to obtain N rows of M columns of binary data; wherein N is the number of subcarriers for parallel transmission, and M is the number of OFDM signals; performing parallel-serial conversion on the binary data and OFDM mapping to obtain a target signal; the dividing the transmission signal into four parts according to a quartile algorithm, and determining upper quartiles, median, and lower quartiles, comprises: receiving the transmission signal, and arranging the transmission signal according to the order of signal amplitude from small to large to obtain a signal ordering sequence; dividing the signal ordering sequence into four parts, each part containing 25% of the data; and determining three limit points for dividing the signal ordering sequence into four parts, the three limit points being upper quartiles Q1, median Q2, and lower quartiles Q3, respectively; wherein each part of the four parts contains the same number of transmission signals; the determining a normal value interval according to the upper quartiles, median, and lower quartiles, comprises: calculating a minimum estimated value and a maximum estimated value according to the upper quartiles, median, and lower quartiles; determining the normal value interval according to the minimum estimated value and the maximum estimated value; calculating the minimum estimated value according to Q1-k*(Q3-Q1), calculating the maximum estimated value according to Q3+k*(Q3-Q1), and the normal value interval being: [Q1-k*(Q3-Q1), Q3+k*(Q3-Q1)], wherein the influence coefficient k is used to define the range of normal signals.

2. The communication method of impulse noise suppression based on outlier detection according to claim 1, characterized in that, the detecting abnormal signals disturbed by impulse noise in the transmission signal based on the normal value interval, comprises: determining that the signal amplitude of the transmission signal does not belong to the normal value interval, and then determining the transmission signal as the abnormal signal.

3. The communication method of impulse noise suppression based on outlier detection according to claim 1, characterized in that, the repairing the abnormal signals to obtain a de-noised signal, comprises: repairing the abnormal signals by a preset de-noising method to obtain a de-noised signal; the preset de-noising method comprises zeroing method, mean filtering method, and median filtering method.

4. A communication apparatus for impulse noise suppression based on outlier detection, the apparatus configured to implement the method for impulse noise suppression based on outlier detection according to any one of claims 1 to 3, characterized in that, The device comprises: a signal receiving module for receiving a transmission signal; a data processing module for dividing the transmission signal into four parts according to a quartile algorithm, and determining upper quartiles, median, and lower quartiles; a normal interval determining module for determining a normal value interval according to the upper quartiles, median, and lower quartiles; an abnormal signal detecting module for detecting abnormal signals disturbed by impulse noise in the transmission signal based on the normal value interval; a signal repairing module for repairing the abnormal signals to obtain a de-noised signal; the device further comprises: The anti-interference release module is configured to perform serial-parallel conversion on the de-noised signal and remove a guard interval to obtain a discrete time domain signal. The discrete inverse processing module is configured to perform a discrete Fourier transform on the discrete time domain signal to obtain N rows of M columns of binary data; N is a number of subcarriers for parallel transmission, and M is a number of OFDM signals. The signal inverse mapping module is configured to perform serial-parallel conversion on the binary data and perform OFDM mapping to obtain a target signal.

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