CN107800491B - Wireless sensing anti-interference method and device based on channel state information - Google Patents
Wireless sensing anti-interference method and device based on channel state information Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
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- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2691—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation involving interference determination or cancellation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2692—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver
Abstract
A wireless sensing anti-interference method and device based on channel state information are provided. Wherein the method comprises the following steps: detecting each received data packet to obtain the data packet subjected to radio frequency interference; extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; and correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier. The device is used for executing the method. According to the wireless sensing anti-interference method and device based on the channel state information, each received data packet can be detected, the data packet subjected to radio frequency interference is obtained, distorted subcarriers are extracted, subcarriers to be processed are obtained, then the subcarriers to be processed are corrected, and distortion of the distorted subcarriers is eliminated, so that the anti-interference capability of wireless sensing application based on Wi-Fi signals is enhanced, and the accuracy of wireless sensing is improved.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a wireless sensing anti-interference method and device based on channel state information.
Background
In recent years, Wi-Fi technology gradually becomes an important 'perception' platform, namely applications such as Wi-Fi-based indoor positioning, personnel detection, fall detection, sleep monitoring, activity recognition and the like are in the future.
Among many features of Wi-Fi, Channel State Information (CSI) characterizes the amplitude and phase Information of a plurality of subcarriers, so that it can resist the common indoor multipath effect to some extent and is widely used for high-precision sensing applications. However, at present, the work of using CSI for environment sensing is based on the premise of no radio frequency interference indoors, but as is well known, the frequency band of Wi-Fi work is a frequency band which does not need to be authorized, especially in the 2.4GHz ISM frequency band, and there are a large number of other radio frequency devices which can work simultaneously with Wi-Fi devices, such as bluetooth, ZigBee, microwave oven, cordless phone, and the like. Therefore, radio frequency interference is inevitable when the CSI is used for environment sensing. Although previous researches verify that radio frequency interference can have an important effect on the collected CSI and the CSI-based sensing application, a classifier which can tolerate the radio frequency interference is provided only for a special case of activity identification. The classifier is not only not suitable for other non-machine learning sensing applications, such as indoor positioning and personnel tracking, but also has extremely high calculation amount and cannot meet the real-time performance of sensing requirements. At present, a wireless sensing radio frequency interference resisting processing method does not exist, so that the performance of sensing application based on CSI is further improved.
Therefore, how to provide a method to improve the radio frequency interference resistance of CSI-based sensing applications becomes an important issue to be solved in the industry.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a wireless sensing radio frequency interference resisting method and device based on channel state information.
On one hand, the invention provides a wireless sensing radio frequency interference resisting method based on channel state information, which comprises the following steps:
detecting each received data packet to obtain the data packet subjected to radio frequency interference;
extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; wherein the subcarriers to be processed comprise the distorted subcarriers;
and correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier.
In another aspect, the present invention provides a wireless sensing anti-jamming device based on channel state information, including:
the detection unit is used for detecting each received data packet to obtain the data packet subjected to radio frequency interference;
the extraction unit is used for extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed;
and the processing unit is used for correcting the to-be-processed subcarrier and eliminating the radio frequency interference on the distorted subcarrier.
In yet another aspect, the present invention provides an electronic device comprising: a processor, a memory, and a communication bus, wherein:
the processor and the memory are communicated with each other through the communication bus;
the memory stores program instructions executable by the processor, and the processor invokes the program instructions to perform the method for wireless sensing and radio frequency interference rejection based on channel state information as provided in the embodiments.
In yet another aspect, the present invention provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the channel state information-based wireless sensing anti-radio frequency interference method provided in the above embodiments.
According to the wireless sensing anti-interference method and device based on the channel state information, each received data packet can be detected, the data packet subjected to radio frequency interference is obtained, distorted subcarriers are extracted, subcarriers to be processed are obtained, then the subcarriers to be processed are corrected, and distortion of the distorted subcarriers is eliminated, so that the anti-interference capability of wireless sensing based on Wi-Fi signals in a wireless sensing process is enhanced, and the accuracy of communication data is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is a schematic flowchart of a wireless sensing anti-interference method based on channel state information according to an embodiment of the present invention;
fig. 2 is a schematic flowchart of a wireless sensing anti-interference method based on channel state information according to another embodiment of the present invention;
FIG. 3 is a diagram illustrating the spectral dependence of CSI without RF interference according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating a spectral correlation function of CSI subjected to radio frequency interference according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of a wireless perceptual anti-interference method based on channel state information according to another embodiment of the present invention;
FIG. 6 is a graph comparing the magnitude of CSI with and without RF interference according to an embodiment of the present invention;
FIG. 7 is a comparison of the CSI correction process before and after being interfered according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a wireless sensing anti-jamming device based on channel state information according to an embodiment of the present invention;
FIG. 9 is a schematic structural diagram of a wireless perceptual anti-jamming device based on channel state information according to another embodiment of the present invention;
FIG. 10 is a schematic structural diagram of a wireless perceptual anti-jamming device based on channel state information according to yet another embodiment of the present invention;
fig. 11 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Due to the fact that the rate of sending the Wi-Fi data packets and the time of sending the Wi-Fi data packets of different devices are different, the CSI corresponding to each Wi-Fi data packet is not affected by radio frequency interference existing in a working environment. Therefore, the solution proposed by the present invention is to identify and process the distorted CSI, while not processing the CSI that is not subject to radio frequency interference. Therefore, the radio frequency interference resistance of different devices during wireless sensing by utilizing Wi-Fi signals is enhanced, and the accuracy of wireless sensing is improved.
Fig. 1 is a schematic flowchart of a wireless sensing anti-interference method based on channel state information according to an embodiment of the present invention, and as shown in fig. 1, the wireless sensing anti-interference method based on channel state information provided by the present invention includes:
s101, detecting each received data packet to obtain the data packet subjected to radio frequency interference;
it should be noted that the execution main body of the wireless sensing anti-interference method based on the channel state information provided by the embodiment of the present invention is a wireless sensing anti-interference device (hereinafter referred to as an anti-interference device) based on the channel state information, and the wireless sensing anti-interference device has a Wi-Fi communication function, and the anti-interference device may be an existing touch screen mobile phone, a tablet computer, or an intelligent bracelet, etc.
Specifically, when Wi-Fi communication is performed, the anti-jamming device may detect each received data packet, and if any data packet is subjected to radio frequency interference, the anti-jamming device may obtain the data packet subjected to the radio frequency interference, so as to perform subsequent processing.
S102, extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; wherein the subcarriers to be processed comprise the distorted subcarriers;
specifically, when the data packet is subjected to radio frequency interference, the amplitude of the sub-carrier subjected to radio frequency interference becomes extremely high or extremely low, an abnormal peak or trough occurs, and the sub-carrier including the abnormal peak or trough is a distorted sub-carrier. The anti-jamming device can extract distorted subcarriers in the data packet subjected to radio frequency interference, and select a plurality of subcarriers adjacent to the distorted subcarriers and the distorted subcarriers as subcarriers to be processed by taking the position of the distorted subcarriers as a center. It can be understood that if there are multiple distorted subcarriers in the data packet subjected to radio frequency interference, there may be multiple subcarriers to be processed. The number of the subcarriers included in the subcarriers to be processed is set according to actual experience, and the embodiment of the present invention is not limited.
S103, correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier.
Specifically, after obtaining the subcarrier to be processed, the anti-jamming device corrects the subcarrier to be processed, eliminates radio frequency interference on the distorted subcarrier, and restores channel state information of the distorted subcarrier.
For example, the anti-jamming device judges the working environment, if the working environment is stable, the anti-jamming device acquires the data packet which is not subjected to the radio frequency interference within the preset time range of the receiving time according to the receiving time of the data packet which is subjected to the radio frequency interference, and replaces the channel state information of the data packet which is not subjected to the radio frequency interference with the channel state information of the data packet which is not subjected to the radio frequency interference, so that the radio frequency interference on the distorted subcarrier is eliminated. If the working environment changes dynamically, the anti-jamming device can adopt a pilot frequency auxiliary channel estimation algorithm, namely, part of known channel state information of subcarriers which are not subjected to radio frequency interference is defined as pilot frequency, the channel state information of the subcarriers to be processed is calculated according to the known pilot frequency, and the channel state information of the distorted subcarriers is restored, so that the radio frequency interference on the distorted subcarriers is eliminated.
According to the wireless sensing anti-interference method based on the channel state information, provided by the invention, each received data packet can be detected, the data packet subjected to radio frequency interference is obtained, the distorted subcarrier is extracted, the subcarrier to be processed is obtained, then the subcarrier to be processed is corrected, and the distortion of the distorted subcarrier is eliminated, so that the anti-interference capability of the wireless sensing based on Wi-Fi signals in the wireless sensing process is enhanced, and the accuracy of the wireless sensing is improved.
Fig. 2 is a schematic flow chart of a wireless sensing anti-interference method based on channel state information according to another embodiment of the present invention, and as shown in fig. 2, based on the above embodiment, further detecting each received data packet to obtain a data packet subjected to radio frequency interference includes:
s1011, obtaining channel state information of a data packet;
specifically, when Wi-Fi communication is performed, the anti-interference device acquires CSI of a data packet every time the anti-interference device receives the data packet.
For example, the data packet includes N of the subcarriers. The CSI for the packet is represented as:
H＝[H(1),H(2),…H(k),…H(N)],k∈[1,N]
wherein the content of the first and second substances,
i H (k) I and phikRespectively representing the amplitude and phase information of the k-th subcarrier.
S1012, calculating a spectrum correlation function of the data packet according to the channel state information;
specifically, after acquiring the CSI of the data packet, the anti-interference device calculates a spectrum correlation function of the data packet according to the CSI of the data packet.
Since the Preamble sequence of each data packet is fixed, the anti-interference apparatus usually estimates the channel state information according to the following formula:
wherein, X represents Preamble sequence original information, Y representsThe Preamble information received by the anti-interference device is represented,
representing estimated channel state information.
When the interference rejection apparatus is subjected to radio frequency interference of other devices, the CSI received by the interference rejection apparatus may actually be expressed by the following formula:
wherein, H represents channel state information of the Wi-Fi signal, H 'represents channel state information of the interference signal, and X' represents original information of the interference signal. As can be known from the above two mathematical formulas and fig. 6, for the CSI of the Wi-Fi signal, the radio frequency interference only affects the subcarriers of the Wi-Fi signal corresponding to the working frequency band of the interference signal, and the effect on other subcarriers is very small and can be ignored.
To find out the effect of the radio frequency interference on the channel state information, a spectral correlation function of the data packet is calculated as follows:
wherein the content of the first and second substances,
represents the value of the spectral correlation function, H, for the k-th subcarrier at a particular cyclic frequency α*Is the conjugate of H, H is the expression of H in the time domain, L represents the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols in the data packet, L represents the L-th OFDM symbol, and L and n are positive integers. For the vast majority of wireless signals, they can be modeled as "cyclostationary signals" because of the frame structure of the wireless signalSince different kinds of wireless signals have different repetition periods, the cyclostationarity is not completely cancelled even if the two signals are divided when estimating the CSI, so that the CSI subjected to radio frequency interference can be considered to have the cyclostationarity that the spectral correlation function has a peak at a certain cycle frequency, which is the specific cycle frequency α.
For example, fig. 3 is a graph of the spectral correlation function of CSI without radio frequency interference, and as shown in fig. 3, the graph of the spectral correlation function of CSI without radio frequency interference is relatively smooth; fig. 4 is a graph of a spectral correlation function of CSI subjected to radio frequency interference according to an embodiment of the present invention, and as shown in fig. 4, the graph of the spectral correlation function of CSI subjected to radio frequency interference generates a peak at a location subjected to radio frequency interference.
S1013, obtaining a gradient matrix according to the spectrum correlation function;
specifically, after obtaining the spectrum correlation function, the anti-interference device obtains a complex matrix of the spectrum correlation function according to the spectrum correlation function, obtains an amplitude matrix according to the complex matrix, and obtains a gradient matrix according to the amplitude matrix.
S1014, performing singular value decomposition on the gradient matrix to obtain a maximum singular value;
specifically, after obtaining the gradient matrix, the anti-interference apparatus performs singular value decomposition on the gradient matrix, so as to obtain a plurality of singular values. Since the gradient matrix corresponding to the CSI of the data packet affected by the radio frequency interference has a very large gradient in a partial region, the maximum singular value obtained is correspondingly larger than the maximum singular value corresponding to the data packet without the radio frequency interference.
And S1015, if it is judged that the maximum singular value is greater than or equal to a preset threshold value, the data packet is a data packet subjected to radio frequency interference.
Specifically, after obtaining the maximum singular value, the anti-jamming device compares the maximum singular value with a preset threshold, and if the maximum singular value is greater than or equal to the preset threshold, the data packet is subjected to radio frequency interference, that is, the data packet is a data packet subjected to radio frequency interference. The preset threshold is set according to an actual situation, and the embodiment of the present invention is not limited.
Fig. 5 is a schematic flowchart of a wireless sensing anti-interference method based on channel state information according to another embodiment of the present invention, and as shown in fig. 5, on the basis of the foregoing embodiments, further extracting distorted subcarriers in the data packet subjected to radio frequency interference to obtain subcarriers to be eliminated includes:
s1021, acquiring the position of the distorted subcarrier according to the channel state information of the data packet subjected to the radio frequency interference;
specifically, the anti-interference apparatus may obtain channel state information of the data packet subjected to radio frequency interference, that is: h ═ H (1), H (2), … H (k), … H (n)],k∈[1,N]Wherein, in the step (A),
i H (k) I and phikRespectively representing the amplitude and phase information of the kth subcarrier, wherein N is the number of the subcarriers; and then calculating a magnitude difference value of the adjacent subcarriers, the magnitude difference value p(s) | H (s +1) | - | H(s) |, where s ∈ [1, N-1 ∈ 1 |)]Obtaining a sequence of amplitude differences, i.e. P ═ P (1), P (2), … P(s), … P (N-1)](ii) a Taking absolute value of each amplitude difference value to obtain new amplitude difference value sequence | P | [ | P (1) |, | P (2) |, … | P(s) |, … | P (N-1) |]And searching a local maximum value in the new amplitude difference value sequence, comparing the local maximum value with a preset value, and if the local maximum value is greater than the preset value, determining the position of the subcarrier corresponding to the local maximum value in the CSI as the position of the distorted subcarrier. Wherein the preset value is set according to practical experience, such as the above
The embodiments of the present invention are not limited.
For example, fig. 6 is a comparison graph of amplitudes of CSI subjected to radio frequency interference and CSI not subjected to radio frequency interference according to an embodiment of the present invention, as shown in fig. 6, amplitudes of CSI not subjected to radio frequency interference are relatively smooth, and amplitudes of distorted subcarriers of CSI subjected to radio frequency interference have peaks and valleys.
And S1022, extracting a preset number of subcarriers as the subcarriers to be processed according to the positions of the distorted subcarriers.
Specifically, after obtaining the position of the distorted subcarrier, the anti-interference device selects a preset number of subcarriers as the to-be-processed subcarriers with the position of the distorted subcarrier as a center. For example, the first three subcarriers and the last three subcarriers of the distorted subcarrier may be selected, and seven subcarriers in total may be used as the subcarriers to be processed. The preset number is set according to actual conditions, and the embodiment of the invention is not limited.
On the basis of the foregoing embodiments, further, the performing correction processing on the to-be-processed subcarrier, where eliminating radio frequency interference suffered by the distorted subcarrier includes:
and if the working environment is judged to be stable, selecting the channel state information of the data packet which is not subjected to the radio frequency interference within the preset time range of the receiving time to replace the channel state information of the data packet which is subjected to the radio frequency interference according to the receiving time of the data packet which is subjected to the radio frequency interference.
Specifically, the anti-jamming device judges a working environment, and if the working environment of the anti-jamming device is stable, the anti-jamming device obtains the receiving time of the data packet subjected to the radio frequency interference, searches the data packet not subjected to the radio frequency interference within a preset time range of the receiving time, obtains the subcarriers not subjected to the radio frequency interference corresponding to the position of the subcarrier to be processed in the data packet not subjected to the radio frequency interference, obtains channel state information of each corresponding subcarrier not subjected to the radio frequency interference, and uses the channel state information to replace the channel state information of the subcarrier to be processed, so as to eliminate the radio frequency interference on the distorted subcarrier.
The working environment of the anti-interference device is judged as follows: firstly, the anti-interference device acquires CSI of M data packets within preset time, if each data packet comprises 30 subcarriers, the subcarriers of the M data packets can form a 30-by-M two-dimensional matrix, and an absolute value is taken for each element in the two-dimensional matrix, so that an amplitude matrix of the two-dimensional matrix within the preset time can be acquired; secondly, calculating correlation coefficients among all columns in the amplitude matrix to obtain a correlation coefficient matrix of the amplitude matrix; and performing singular value decomposition on the correlation coefficient matrix to obtain the maximum singular value of the correlation coefficient matrix, dividing the maximum singular value by M to be used as the characteristic value of the correlation coefficient matrix, and if the characteristic value is greater than a preset value, stabilizing the working environment. The preset time and the M are selected according to actual conditions, and the embodiment of the invention is not limited. The preset value is set according to actual experience, and the embodiment of the invention is not limited.
On the basis of the foregoing embodiments, further, the performing correction processing on the to-be-processed subcarrier, where eliminating radio frequency interference suffered by the distorted subcarrier includes:
and if the dynamic change of the working environment is judged and obtained, processing the subcarrier to be processed by using a channel estimation method based on linear interpolation to eliminate the radio frequency interference on the distorted subcarrier.
Specifically, the anti-jamming device judges the working environment, and if the working environment of the anti-jamming device changes dynamically, the anti-jamming device processes the to-be-processed subcarriers by using a channel estimation method based on linear interpolation. The channel estimation based on linear interpolation is a common method with low complexity, wherein the channel state information of a part of known subcarriers is defined as pilot frequency, the channel state information of other subcarriers can be derived from the channel state information of the pilot frequency, that is, the channel state information of the interfered subcarrier can be derived from the channel state information of the non-interfered subcarrier, when the subcarrier to be processed is processed according to a channel estimation method based on linear interpolation, the channel state information of the non-interfered subcarrier only needs to be regarded as the pilot frequency, and the channel state information of the distorted subcarrier can be derived according to the pilot frequency, so that the radio frequency interference suffered by the distorted subcarrier is eliminated. The process of estimating the channel state information of the distorted subcarriers according to the channel state information of the subcarriers that are not interfered is the prior art, and is not described herein again.
For example, fig. 7 is a comparison between before and after CSI correction processing according to an embodiment of the present invention, and as shown in fig. 7, the subcarriers in two gray vertical dashed lines include subcarriers determined to be distorted, and after linear interpolation is performed, the influence caused by the radio frequency interference can be effectively eliminated.
Fig. 8 is a schematic structural diagram of a wireless sensing anti-jamming device based on channel state information according to an embodiment of the present invention, and as shown in fig. 8, the wireless sensing anti-jamming device based on channel state information provided by the present invention includes: a detection unit 801, an extraction unit 802, and a processing unit 803, wherein:
the detecting unit 801 is configured to detect each received data packet, and acquire a data packet subjected to radio frequency interference; the extracting unit 802 is configured to extract distorted subcarriers in the data packet subjected to radio frequency interference, so as to obtain subcarriers to be processed; wherein the subcarriers to be processed comprise the distorted subcarriers; the processing unit 803 is configured to perform correction processing on the to-be-processed subcarriers, so as to eliminate radio frequency interference on the distorted subcarriers.
Specifically, during Wi-Fi communication, the detection unit 801 may detect each received data packet, and if which data packet is subjected to radio frequency interference, the anti-interference apparatus may acquire the data packet subjected to radio frequency interference, so as to perform subsequent processing.
When the data packet is subjected to radio frequency interference, the amplitude of the sub-carrier waves subjected to the radio frequency interference becomes extremely high or extremely low, abnormal wave peaks or wave troughs appear, and the sub-carrier waves containing the abnormal wave peaks or wave troughs are distorted sub-carrier waves. The extracting unit 802 may extract a distorted subcarrier in the data packet subjected to radio frequency interference, and select a plurality of subcarriers adjacent to the distorted subcarrier as subcarriers to be processed together with the distorted subcarrier by taking the position of the distorted subcarrier as a center. It can be understood that if there are multiple distorted subcarriers in the data packet subjected to radio frequency interference, there may be multiple subcarriers to be processed. The number of the subcarriers included in the subcarriers to be processed is set according to actual experience, and the embodiment of the present invention is not limited.
After obtaining the subcarriers to be processed, the processing unit 803 may perform correction processing on the subcarriers to be processed, eliminate radio frequency interference received by the distorted subcarriers, and restore channel state information of the distorted subcarriers.
According to the wireless sensing anti-jamming device based on the channel state information, provided by the invention, each received data packet can be detected, the data packet subjected to radio frequency interference is obtained, the distorted subcarrier is extracted, the subcarrier to be processed is obtained, then the subcarrier to be processed is corrected, and the distortion of the distorted subcarrier is eliminated, so that the anti-jamming capability of the wireless sensing based on Wi-Fi signals in the wireless sensing process is enhanced, and the accuracy of the wireless sensing is improved.
Fig. 9 is a schematic structural diagram of a wireless perceptual-anti-jamming apparatus based on channel state information according to another embodiment of the present invention, and as shown in fig. 9, a detecting unit 801 includes a first obtaining subunit 8011, a calculating subunit 8012, an obtaining subunit 8013, a decomposing subunit 8014, and a determining subunit 8015, where:
the first obtaining subunit 8011 is configured to obtain channel state information of a packet; the computing subunit 8012 is configured to compute a spectrum correlation function of the data packet according to the channel state information; the obtaining subunit 8013 is configured to obtain a gradient matrix according to the spectral correlation function; the decomposition subunit 8014 is configured to perform singular decomposition on the gradient matrix to obtain a maximum singular value; the determining subunit 8015 is configured to determine that the data packet is a data packet subjected to radio frequency interference if it is determined that the maximum singular value is greater than or equal to a preset threshold.
Specifically, when performing Wi-Fi communication, the first obtaining subunit 8011 obtains CSI of each data packet received by the data packet.
After acquiring the CSI of the data packet, the calculating subunit 8012 calculates the spectrum correlation function of the data packet according to the CSI of the data packet.
After obtaining the spectrum correlation function, the obtaining subunit 8013 obtains a complex matrix of the spectrum correlation function according to the spectrum correlation function, obtains an amplitude matrix according to the complex matrix, and obtains a gradient matrix according to the amplitude matrix.
After obtaining the gradient matrix, the decomposition subunit 8014 performs singular value decomposition on the gradient matrix to obtain a plurality of singular values. Since the gradient matrix corresponding to the CSI of the data packet affected by the radio frequency interference has a very large gradient in a partial region, the maximum singular value obtained is correspondingly larger than the maximum singular value corresponding to the data packet without the radio frequency interference.
After obtaining the maximum singular value, the determining subunit 8015 compares the maximum singular value with a preset threshold, and if the maximum singular value is greater than the preset threshold, the data packet is subjected to radio frequency interference, that is, the data packet is a data packet subjected to radio frequency interference. The preset threshold is set according to an actual situation, and the embodiment of the present invention is not limited.
Fig. 10 is a schematic structural diagram of a wireless sensing anti-jamming device based on channel state information according to another embodiment of the present invention, as shown in fig. 10, an extracting unit 802 includes a second obtaining subunit 8021 and an extracting subunit 8022, where:
the second obtaining subunit 8021 is configured to obtain, according to the channel state information of the data packet subjected to the radio frequency interference, a position of the distorted subcarrier; the extracting sub-unit 8022 is configured to extract a preset number of sub-carriers as the to-be-processed sub-carriers according to the positions of the distorted sub-carriers.
Specifically, the second obtaining subunit 8021 may obtain channel state information of the data packet subjected to radio frequency interference, that is: h ═[H(1),H(2),…H(k),…H(N)],k∈[1,N]Wherein, in the step (A),
i H (k) I and phikRespectively representing the amplitude and phase information of the kth subcarrier, wherein N is the number of the subcarriers; and then calculating a magnitude difference value of the adjacent subcarriers, the magnitude difference value p(s) | H (s +1) | - | H(s) |, where s ∈ [1, N-1 ∈ 1 |)]Obtaining a sequence of amplitude differences, i.e. P ═ P (1), P (2), … P(s), … P (N-1)](ii) a Taking absolute value of each amplitude difference value to obtain new amplitude difference value sequence | P | [ | P (1) |, | P (2) |, … | P(s) |, … | P (N-1) |]And searching a local maximum value in the new amplitude difference value sequence, comparing the local maximum value with a preset value, and if the local maximum value is greater than the preset value, determining the position of the subcarrier corresponding to the local maximum value in the CSI as the position of the distorted subcarrier. Wherein the preset value is set according to practical experience, such as the above
The embodiments of the present invention are not limited.
After obtaining the position of the distorted subcarrier, the extracting subunit 8022 selects a preset number of subcarriers as the to-be-processed subcarriers with the position of the distorted subcarrier as a center. For example, the first three subcarriers and the last three subcarriers of the distorted subcarrier may be selected, and seven subcarriers in total may be used as the subcarriers to be processed. The preset number is set according to actual conditions, and the embodiment of the invention is not limited.
The embodiment of the anti-interference apparatus provided by the present invention may be specifically configured to execute the processing flow of each of the method embodiments, and the functions of the embodiment are not described herein again, and refer to the detailed description of the method embodiments.
Fig. 11 is a schematic entity structure diagram of an electronic device according to an embodiment of the present invention, and as shown in fig. 6, the electronic device includes a processor (processor)1101, a memory (memory)1102, and a communication bus 1103;
the processor 1101 and the memory 1102 complete communication with each other through a communication bus 1103;
the processor 1101 is configured to call the program instructions in the memory 1102 to execute the methods provided by the above-mentioned method embodiments, for example, including: detecting each received data packet to obtain the data packet subjected to radio frequency interference; extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; and correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier.
The present embodiment discloses a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the method provided by the above-mentioned method embodiments, for example, comprising: detecting each received data packet to obtain the data packet subjected to radio frequency interference; extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; and correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier.
The present embodiments provide a non-transitory computer-readable storage medium storing computer instructions that cause the computer to perform the methods provided by the above method embodiments, for example, including: detecting each received data packet to obtain the data packet subjected to radio frequency interference; extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; and correcting the to-be-processed subcarrier to eliminate the radio frequency interference on the distorted subcarrier.
In addition, the logic instructions in the memory may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer (which may be a personal computer, an apparatus, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. A wireless perception anti-interference method based on channel state information is characterized by comprising the following steps:
detecting each received data packet to obtain the data packet subjected to radio frequency interference;
extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed; wherein the subcarriers to be processed comprise the distorted subcarriers;
correcting the to-be-processed subcarriers to eliminate radio frequency interference on the distorted subcarriers;
wherein, the correcting the to-be-processed sub-carrier, and the eliminating the radio frequency interference suffered by the distorted sub-carrier includes:
if the working environment is judged to be stable, selecting the channel state information of the data packet which is not subjected to the radio frequency interference within the preset time range of the receiving time to replace the channel state information of the data packet which is subjected to the radio frequency interference according to the receiving time of the data packet which is subjected to the radio frequency interference;
and if the dynamic change of the working environment is judged and obtained, processing the subcarrier to be processed by using a channel estimation method based on linear interpolation to eliminate the radio frequency interference on the distorted subcarrier.
2. The method of claim 1, wherein the detecting each received data packet and obtaining the data packet subjected to radio frequency interference comprises:
acquiring channel state information of a data packet;
calculating a spectrum correlation function of the data packet according to the channel state information;
obtaining a gradient matrix according to the spectrum correlation function;
performing singular value decomposition on the gradient matrix to obtain a maximum singular value;
and if the maximum singular value is judged to be larger than or equal to a preset threshold value, the data packet is subjected to radio frequency interference.
3. The method of claim 1, wherein the extracting distorted subcarriers from the data packet subjected to radio frequency interference to obtain to-be-processed subcarriers comprises:
acquiring the position of the distorted subcarrier according to the channel state information of the data packet subjected to the radio frequency interference;
and extracting a preset number of subcarriers as the subcarriers to be processed according to the positions of the distorted subcarriers.
4. A wireless perception anti-jamming device based on channel state information, comprising:
the detection unit is used for detecting each received data packet to obtain the data packet subjected to radio frequency interference;
the extraction unit is used for extracting distorted subcarriers in the data packet subjected to the radio frequency interference to obtain subcarriers to be processed;
the processing unit is used for correcting the subcarriers to be processed and eliminating radio frequency interference suffered by the distorted subcarriers;
the processing unit is specifically configured to, if it is determined that the working environment is stable, select, according to the reception time of the data packet subjected to radio frequency interference, channel state information of a data packet not subjected to radio frequency interference within a preset time range of the reception time to replace the channel state information of the data packet subjected to radio frequency interference;
and the processing unit is further specifically configured to, if the dynamic change of the working environment is determined to be known, process the to-be-processed subcarrier by using a channel estimation method based on linear interpolation, and eliminate radio frequency interference on the distorted subcarrier.
5. The apparatus of claim 4, wherein the detection unit comprises:
a first obtaining subunit, configured to obtain channel state information of a data packet;
a calculating subunit, configured to calculate a spectrum correlation function of the data packet according to the channel state information;
an obtaining subunit, configured to obtain a gradient matrix according to the spectrum correlation function;
the decomposition subunit is used for performing singular value decomposition on the gradient matrix to obtain a maximum singular value;
and the judging subunit is configured to determine that the data packet is a data packet subjected to radio frequency interference if it is judged that the maximum singular value is greater than or equal to a preset threshold.
6. The apparatus of claim 4, wherein the extraction unit comprises:
the second obtaining subunit is configured to obtain, according to the channel state information of the data packet subjected to the radio frequency interference, a position of the distorted subcarrier;
and the extraction sub-unit is used for extracting a preset number of sub-carriers as the sub-carriers to be processed according to the positions of the distorted sub-carriers.
7. An electronic device, comprising: a processor, a memory, and a communication bus, wherein:
the processor and the memory are communicated with each other through the communication bus;
the memory stores program instructions executable by the processor, the processor invoking the program instructions to perform the method of any of claims 1 to 3.
8. A non-transitory computer-readable storage medium storing computer instructions that cause a computer to perform the method of any one of claims 1 to 3.
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