Anti-eavesdropping communication method and device

Abstract

The invention provides an anti-eavesdropping communication method and device, and relates to the technical field of wireless endogenous security, and the method comprises the steps: carrying out the channel estimation based on a received SRS measurement signal transmitted by a legal terminal, and obtaining an RB-level channel estimation value; determining the incoming wave direction of the legal terminal based on the RB-level channel estimation value; and on the basis of the incoming wave direction of the legal terminal, random beamforming is carried out on a downlink PDSCH signal transmitted to the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise which is transparent to the legal terminal and opaque to the illegal terminal. According to the invention, anti-eavesdropping is realized, and the communication rate of the legal user is ensured.

Description

Technical Field

[0001] The present invention relates to the field of wireless intrinsic security technology, and in particular to an anti-eavesdropping communication method and device. Background Art

[0002] Wireless communication, due to its broadcasting characteristics, allows legitimate users to receive signals anytime and anywhere, but it also makes it easier for potential eavesdroppers to intercept and steal signals. Based on Shannon's research, perfect encryption can only be achieved when the key entropy is not less than the plaintext entropy and "one-time one-pad" is used. Achieving perfect encryption is the main challenge in wireless communication anti-eavesdropping.

[0003] Today's wireless communication anti-eavesdropping schemes use quantum key distribution schemes, but the scheme that uses physical channel information to generate keys will be affected by the slow rate of channel changes in the natural environment, resulting in the inability to guarantee the communication rate of legitimate users. Summary of the invention

[0004] The present invention provides an anti-eavesdropping communication method and device, which are used to solve the defect that the communication rate of legitimate users cannot be guaranteed in the prior art, and realize the guarantee of the communication rate of legitimate users while preventing eavesdropping.

[0005] The present invention provides an anti-eavesdropping communication method, comprising: Perform channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; Determining the direction of arrival of the legitimate terminal based on the RB-level channel estimation value; Based on the incoming direction of the legal terminal, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

[0006] In some embodiments, the performing random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the direction of the wave of the legal terminal includes: Calculating a signal shaping factor and a noise shaping factor in beamforming based on the direction of the wave of the legal terminal; Performing random beamforming on a downlink PDSCH signal transmitted to the legitimate terminal according to the signal shaping factor and the noise shaping factor; The signal shaping factors are a group of multiplicative factors used to shape the downlink PDSCH signal, and the noise shaping factors are a group of additive factors used to shape the downlink PDSCH signal.

[0007] In some embodiments, the calculating the signal shaping factor and the noise shaping factor in beamforming based on the direction of the wave of the legitimate terminal includes: Generate the signal shaping factor and array factor according to the wave direction of the legitimate terminal; According to the array factor, within the range of the incoming wave direction, a zero point is selected as the noise angle; The noise shaping factor is generated according to the noise angle.

[0008] In some embodiments, the determining the direction of arrival of the legitimate terminal based on the RB-level channel estimation value includes: Calculating a covariance matrix of the RB-level channel estimation value; Performing eigenvalue decomposition on the covariance matrix of the RB-level channel estimation value to obtain a noise subspace; According to the noise subspace, a spectral function is calculated using a MUSIC algorithm; The incoming wave direction corresponding to the peak value of the spectrum function is determined as the incoming wave direction of the legitimate terminal.

[0009] In some embodiments, performing channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain the RB-level channel estimation value includes: Based on the LS algorithm, the SRS local sequence and the SRS measurement signal are calculated to obtain a frequency domain LS channel estimation value; Performing IDFT transformation on the frequency domain LS channel estimation value to obtain the time domain CIR; Based on the time domain CIR, the RB level channel estimation value is obtained.

[0010] In some embodiments, obtaining the RB-level channel estimation value based on the time domain CIR includes: Determine the signal window and the noise window; In the noise window, based on the time domain CIR, calculate the noise average power; Determining a sampling threshold of the signal window according to the noise average power; In the signal window, sampling is performed based on the time domain CIR and the sampling threshold of the signal window to obtain a sampling result; Perform DFT transformation on the sampling result to obtain the RB level channel estimation value.

[0011] The present invention also provides an anti-eavesdropping communication device, comprising: A channel estimation module, used to perform channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; A determination module, used to determine the direction of arrival of a legitimate terminal based on the RB-level channel estimation value; The beamforming module is used to perform random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the incoming wave direction of the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

[0012] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the anti-eavesdropping communication method described above is implemented.

[0013] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the anti-eavesdropping communication method as described in any one of the above is implemented.

[0014] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned anti-eavesdropping communication methods.

[0015] The anti-eavesdropping communication method and device provided by the present invention firstly perform channel estimation based on the SRS measurement signal sent by the received legal terminal to obtain the RB-level channel estimation value, thereby reducing the number of data of the channel estimation value; then, based on the RB-level channel estimation value, determine the incoming wave direction of the legal terminal, greatly reduce the amount of algorithm calculation, speed up the algorithm processing speed, and save hardware resources; finally, by using the technical means of configuring interference noise, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal based on the incoming wave direction of the legal terminal, so as to create artificial noise that is transparent to the legal terminal and opaque to the illegal terminal, thereby reducing the receiving signal-to-noise ratio of the eavesdropper, and the artificial noise does not affect the receiving channel of the legal user, and is not affected by the slow channel change rate in the natural environment, that is, it does not affect the communication rate of the legal user, thereby achieving the goal of ensuring the communication rate of the legal user while preventing eavesdropping. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is one of the flow charts of the anti-eavesdropping communication method provided by the present invention; Figure 2is a schematic diagram of a uniform linear array of antennas; Figure 3 This is the second flow chart of the anti-eavesdropping communication method provided by the present invention; Figure 4 It is a schematic structural diagram of the anti-eavesdropping communication device provided by the present invention; Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] With the rapid development of mobile communication technology, wireless communication security has become the focus of attention of all countries. While the industry continues to develop traditional information encryption as a bottom-line technology, it has also gradually begun to pay attention to wireless intrinsic security technologies represented by channel fingerprints. Combining the characteristics of large bandwidth and multiple antennas of the fifth generation mobile communication technology (5th Generation Mobile Communication Technology, 5G), the "fingerprint" of the wireless channel is extracted using large-scale antenna technology, which can generate a random sequence that can be quickly updated in real time to disrupt the signal. Without affecting the communication of legitimate terminals, the reception of the eavesdropping terminal is degraded, and the "location stamp" of the channel is verified, that is, the security based on the user's spatial location characteristics.

[0020] In 5G communications, the main functions of the channel sounding reference signal (SRS) are to obtain uplink channel state information, downlink channel state information, and beam management, and to measure the signal-noise ratio (SNR). SRS channel estimation can obtain uplink channel information. The base station uses a large-scale antenna array to search the angle spectrum of the SRS channel estimation of the target terminal, calculate the null angle, and add interference beam noise to the downlink physical downlink shared channel (PDSCH) signal based on the mutual difference between the uplink and downlink channels. The interference beam noise does not affect the demodulation of the useful signal position of the target terminal, but affects the demodulation of useful signals at other positions.

[0021] The superimposed interference beam noise is calculated based on the wireless channel information. The interference beam noise is transparent to the target terminal. The signal received by the terminal does not contain the interference beam noise but only contains useful information. Therefore, the channel quality (channel capacity) of the target terminal is not affected. However, for potential eavesdropping terminals, the interference beam noise is not transparent. The signal it receives is the superposition of useful information and interference noise. The interference noise and background noise together constitute equivalent noise, and the power of the interference noise is usually much larger than that of the background noise. Therefore, the channel quality (channel capacity) of the potential eavesdropping terminal will be greatly reduced under the influence of the interference noise.

[0022] Figure 1 It is one of the flow charts of the anti-eavesdropping communication method provided by the present invention, such as Figure 1 As shown, the present invention provides an anti-eavesdropping communication method, the execution subject is a base station, including: Step 110, performing channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; Step 120, determining the direction of arrival of the legitimate terminal based on the RB-level channel estimation value; Step 130: Based on the direction of the incoming wave of the legal terminal, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal. The downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to the illegal terminal.

[0023] First, the base station receives the SRS measurement signal sent by the legitimate terminal, performs channel estimation based on the received SRS measurement signal, and obtains the frequency domain resource block (RB) level channel estimation value. Then, the base station determines the direction of the legitimate terminal based on the RB level channel estimation value. .

[0024] In the related art, channel estimation is performed on the received SRS measurement signal, and usually a single resource element (RE) is output, resulting in a large number of data of the channel estimation value. In the present invention, channel estimation is performed on the received SRS measurement signal, and RB-level channel estimation is output, which reduces the number of data of the channel estimation value. When calculating the terminal incoming wave direction based on the RB-level channel estimation value, the amount of algorithm calculation can be greatly reduced, the algorithm processing speed can be accelerated, and hardware resources can be saved.

[0025] Finally, based on the direction of the legitimate terminal , random beamforming is performed on the downlink PDSCH signal transmitted to the legitimate terminal, and random beamforming is used to replace the existing beamforming algorithm to transmit the downlink PDSCH signal to create artificial noise that is transparent to the legitimate terminal and opaque to the illegal terminal, preventing the signal from being eavesdropped.

[0026] The anti-eavesdropping communication method provided by the present invention firstly performs channel estimation based on an SRS measurement signal sent by a received legal terminal to obtain an RB-level channel estimation value, thereby reducing the number of data of the channel estimation value; then, based on the RB-level channel estimation value, determines the incoming wave direction of the legal terminal, greatly reduces the amount of algorithm calculation, speeds up the algorithm processing speed, and saves hardware resources; finally, by using the technical means of configuring interference noise, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal based on the incoming wave direction of the legal terminal, so as to create artificial noise that is transparent to the legal terminal and opaque to the illegal terminal, thereby reducing the receiving signal-to-noise ratio of the eavesdropper, and the artificial noise does not affect the receiving channel of the legal user and is not affected by the slow channel change rate in the natural environment, that is, it does not affect the communication rate of the legal user, thereby achieving the goal of ensuring the communication rate of the legal user while preventing eavesdropping.

[0027] In some embodiments, based on the direction of the incoming wave of the legal terminal, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal, including: Based on the direction of the legitimate terminal’s incoming wave, the signal shaping factor and noise shaping factor in beamforming are calculated; According to the signal shaping factor and the noise shaping factor, random beamforming is performed on the downlink PDSCH signal transmitted to the terminal; The signal shaping factors are a group of multiplicative factors used to shape the downlink PDSCH signal, and the noise shaping factors are a group of additive factors used to shape the downlink PDSCH signal.

[0028] Specifically, based on the direction of the legitimate terminal’s incoming signal, the signal shaping factor (downlink precoding factor) in beamforming is calculated. and noise shaping factor (downlink noise factor) The signal shaping factor is a set of multiplicative factors used to shape the downlink PDSCH signal, and the noise shaping factor is a set of additive factors used to shape the downlink PDSCH signal.

[0029] Assume that there is a legitimate terminal UE and an eavesdropper Eave in the environment. When random beamforming is not performed on the downlink PDSCH signal, the signals received by the legitimate terminal UE and the eavesdropper Eave can be expressed as:

[0030] in, Indicates the signal received by the legitimate terminal UE, represents the downlink channel between the base station and the legal terminal UE, A vector of, N represents the number of antennas in the base station receiving antenna array, It represents the signal received by the eavesdropper Eave. represents the downlink channel between the base station and the eavesdropper Eave, which is The vector of Indicates the downlink PDSCH signal sent by the base station. The vector, superscript T means transpose, Represents background noise.

[0031] According to the signal shaping factor and the noise shaping factor, random beamforming is performed on the transmitted downlink PDSCH signal. The expression is as follows:

[0032] In the formula, Indicates the downlink PDSCH signal sent by the base station. The vector, superscript T means transpose, represents the signal shaping factor, which is The vector of It is the symbol sent by the base station to the legitimate terminal UE. represents the noise shaping factor, which is The vector of Represents a random number.

[0033] After random beamforming is performed on the downlink PDSCH signal, the signals received by the legitimate terminal UE and the eavesdropper Eave can be expressed as:

[0034] in, Indicates the signal received by the legitimate terminal UE, Represents the downlink channel between the base station and the legal terminal UE, It represents the signal received by the eavesdropper Eave. represents the downlink channel between the base station and the eavesdropper Eave, which is The vector, superscript T indicates transpose, represents the background noise, represents the signal shaping factor, which is The vector of It is the symbol sent by the base station to the legitimate terminal UE. represents the noise shaping factor, which is The vector of Represents a random number.

[0035] Since the beam at the noise angle has no energy to form a null at the location of the useful signal, that is:

[0036] Therefore,

[0037] As can be seen from the above formula, for the signals received by the legitimate terminal UE, random noise has no effect on it, and random noise only acts on the eavesdropper Eave. In this way, the anti-eavesdropping transmission function for the legitimate terminal UE can be realized.

[0038] When implementing in engineering, the signal shaping factor and noise shaping factor corresponding to different incoming wave directions can be pre-calculated and stored in a table. In the application, according to the actually estimated incoming wave direction, the signal shaping factor and noise shaping factor can be quickly obtained by looking up the table. This method can greatly speed up the processing speed and improve the operation efficiency.

[0039] The anti-eavesdropping communication method provided by the present invention calculates the signal shaping factor and noise shaping factor in beamforming based on the incoming wave direction of the legitimate terminal, and then performs random beamforming on the downlink PDSCH signal transmitted to the legitimate terminal according to the signal shaping factor and noise shaping factor. Since the signal shaping factor and noise shaping factor are determined based on the incoming wave direction of the legitimate terminal, after performing random beamforming on the downlink PDSCH signal transmitted to the legitimate terminal using the signal shaping factor and noise shaping factor, it can be ensured that the artificial noise contained in the downlink PDSCH signal after random beamforming does not affect the receiving channel of the legitimate user and will not affect the communication rate of the legitimate user, further realizing ensuring the communication rate of the legitimate user while preventing eavesdropping.

[0040] In some embodiments, calculating the signal shaping factor and noise shaping factor in beamforming based on the incoming wave direction of the legitimate terminal includes: Generating a signal shaping factor and an array factor according to the incoming wave direction of the legitimate terminal; Selecting the zero point as the noise angle within the range of change of the incoming wave direction according to the array factor; Generating a noise shaping factor according to the noise angle.

[0041] Specifically, by way of example, Figure 2 is a schematic diagram of a uniform linear antenna array, as Figure 2 shown, for the current environment, there is M = 1 terminal UE, the base station receiving array uses an N = 8 antenna uniform linear array, the number of signals M < N, and the interval between adjacent antenna elements is ( is the wavelength), Indicates the direction of incoming waves in the plane.

[0042] According to the direction of the wave from the legal terminal Generate signal shaping factor and the array factor Signal shaping factor The expression is as follows:

[0043] Array Factor The expression is as follows:

[0044] in, represents the array factor, N represents the number of antennas in the base station receiving antenna array, Indicates the spacing between adjacent antenna elements. Indicates the direction of the wave coming from the legal terminal. Indicates the direction of incoming waves in the plane.

[0045] According to the array factor (i.e. spatial spectrum), the direction of the incoming wave in the plane The range of changes (e.g. ), the zero point of the spatial spectrum is selected as the noise angle.

[0046] For example, the noise angle is recorded as , the number is recorded as L. Then according to the noise angle, the noise shaping factor matrix is ​​generated , , , the noise shaping factor matrix The expression is as follows:

[0047] in, Represents an imaginary unit.

[0048] The noise shaping factor matrix Accumulate and get the noise shaping factor , the expression is as follows:

[0049] The noise shaping factor matrix generated by the noise angle The directional diagram is in the direction of arrival (Direction of the Angle, DoA), that is, the direction of the legitimate terminal UE There is no energy on the DoA, and the value is 0, so it is transparent to the legal terminal UE located in the DoA direction.

[0050] The anti-eavesdropping communication method provided by the present invention generates a signal shaping factor and an array factor according to the wave direction of a legitimate terminal, selects a zero point as a noise angle within the variation range of the wave direction according to the array factor, and generates a noise shaping factor according to the noise angle, so that the noise shaping factor is transparent to the legitimate terminal UE located in the DoA direction, which facilitates the subsequent random beamforming of the downlink PDSCH signal, and further realizes the guarantee of the communication rate of the legitimate user while preventing eavesdropping.

[0051] In some embodiments, determining the direction of arrival of a legitimate terminal based on the RB-level channel estimation value includes: Calculate the covariance matrix of RB-level channel estimates; Perform eigenvalue decomposition on the covariance matrix of the RB-level channel estimation value to obtain the noise subspace; According to the noise subspace, the spectral function is calculated using the MUSIC algorithm; The incoming wave direction corresponding to the peak value of the spectrum function is determined as the incoming wave direction of the legitimate terminal.

[0052] Specifically, according to the RB-level channel estimation value , calculate the RB-level channel estimate The covariance matrix R of the channel estimation data is decomposed by eigenvalues ​​according to the knowledge of matrix theory to obtain the signal subspace and noise subspace. The eigenvalue decomposition of the covariance matrix R is as follows:

[0053] in, represents the covariance matrix, the superscript H represents the transposed conjugate, Indicates matrix eigenvalues, Indicates the corresponding The normalized eigenvector of , N represents the number of antennas in the base station receiving antenna array.

[0054] Sort the N eigenvalues ​​from large to small, and form the signal subspace with the eigenvectors corresponding to the large eigenvalues ​​equal to the number of signal sources M. , use the eigenvectors corresponding to the remaining NM small eigenvalues ​​to form the noise subspace . Signal subspace and the noise subspace The expression is as follows:

[0055] According to the noise subspace , the spectral function is calculated using the MUSIC algorithm. The MUSIC algorithm is defined as:

[0056] in, Indicates that the incoming wave direction is The corresponding spectral function value is represents the noise subspace, Indicates the spacing between adjacent antenna elements. Indicates the incoming wave direction.

[0057] Make the incoming wave direction exist The peak value of the spectrum function is found, and the incoming wave direction corresponding to the peak value of the spectrum function is determined as the incoming wave direction of the legitimate terminal. , that is, the DOA estimation angle is .

[0058] The anti-eavesdropping communication method provided by the present invention calculates the covariance matrix of the RB-level channel estimation value, performs eigenvalue decomposition on the covariance matrix of the RB-level channel estimation value to obtain a noise subspace, calculates the spectral function according to the noise subspace using the MUSIC algorithm, determines the incoming wave direction corresponding to the peak value of the spectral function as the incoming wave direction of the legitimate terminal, and realizes rapid determination of the incoming wave direction of the legitimate terminal.

[0059] In some embodiments, performing channel estimation based on an SRS measurement signal received from a legitimate terminal to obtain an RB-level channel estimation value includes: Based on the LS algorithm, the SRS local sequence and the SRS measurement signal are calculated to obtain the frequency domain LS channel estimation value; Perform IDFT transformation on the frequency domain LS channel estimation value to obtain the time domain CIR; Based on the time domain CIR, an RB-level channel estimation value is obtained.

[0060] Specifically, the SRS local sequence Generated by the base station according to the 3GPP protocol and configured parameters; Indicates the transmit antenna port index, Indicates the subcarrier index of the received SRS signal, Indicates an Orthogonal Frequency Division Multiplexing (OFDM) symbol. In this embodiment, the SRS signal adopts a single port configuration, the configuration parameter cyclic shift is 0, and the SRS local sequence is recorded as .

[0061] The base station receives the SRS measurement signal transmitted by the legitimate terminal through the wireless channel, and extracts the SRS measurement signal from the received frequency domain data. ; Wherein, k is the subcarrier index of the received SRS signal, represents OFDM symbol, Indicates the receiving antenna.

[0062] Based on the least mean square error (LS), the SRS local sequence and the received SRS measurement signal Calculate and obtain the frequency domain LS channel estimation value. The expression of the frequency domain LS channel estimation value is as follows:

[0063] in, represents the frequency domain LS channel estimation value, Represents the SRS measurement signal, Indicates the SRS local sequence.

[0064] Perform an Inverse Discrete Fourier Transform (IDFT) on the frequency domain LS channel estimate to obtain the time domain channel impulse response (CIR). After obtaining the time domain CIR, the RB level channel estimate is obtained based on the time domain CIR.

[0065] The expression of time domain CIR is as follows:

[0066] in, represents the time domain CIR, Represents the frequency domain LS channel estimation value.

[0067] The anti-eavesdropping communication method provided by the present invention calculates the SRS local sequence and the received SRS measurement signal based on the LS algorithm to obtain the frequency domain LS channel estimation value, performs IDFT transformation on the frequency domain LS channel estimation value to obtain the time domain CIR, and obtains the RB level channel estimation value based on the time domain CIR, so as to achieve accurate acquisition of the RB level channel estimation value, thereby ensuring that the number of channel estimation value data is reduced.

[0068] In some embodiments, obtaining an RB-level channel estimation value based on the time domain CIR includes: Determine the signal window and the noise window; In the noise window, the average noise power is calculated based on the time domain CIR; Determine the sampling threshold of the signal window according to the average power of the noise; In the signal window, sampling is performed based on the time domain CIR and the sampling threshold of the signal window to obtain a sampling result; Perform DFT transformation on the sampling result to obtain the RB level channel estimation value.

[0069] Specifically, a denoising filter is used in the time domain to reduce noise, and a signal window and a noise window are selected. The selected signal window is the energy concentration area. The definition of the signal window is:

[0070] in, represents the sampling point, represents the cutoff point of the time domain filter, Represents IDFT points, , The combing configuration of the SRS signal is 2 or 4 according to the protocol; is the number of PRBs occupied by the SRS signal in the frequency domain.

[0071] Cutoff point of time domain filter Defined as:

[0072] For 5GNR, configuration parameters When the system bandwidth is 100M, , represents the number of cyclic prefix points, , is the configured cyclic shift. hour, ,when hour, .

[0073] The noise window is defined as:

[0074] The noise window cutoff point is Defined as:

[0075] For 5G NR, When the system bandwidth is 100M, is the total number of resource blocks RB, is the number of subcarriers in a resource block RB.

[0076] In the noise window, calculate the average noise power based on the time domain CIR . Noise average power The expression is as follows:

[0077] in, represents the average noise power, Indicates brackets Take the average of the contents in represents the time domain channel impulse response, represents the sampling point, Represents the noise window.

[0078] According to the average noise power , determine the threshold of the signal window as In the signal window, based on the time domain CIR and the sampling threshold of the signal window Sampling is performed, and the signal that is greater than the sampling threshold is sampled within the signal window. The time domain channel impulse response Sampling will be less than the sampling threshold The time domain channel impulse response Set to 0 to obtain the sampling results Sampling results The expression is as follows:

[0079] in, Indicates the sampling results, represents the time domain channel impulse response, represents the sampling point, Represents the signal window, Indicates the sampling threshold of the signal window.

[0080] The sampling results Perform Discrete Fourier Transform (DFT) to obtain RB-level channel estimation. RB-level channel estimation The expression is as follows:

[0081] in, represents the RB-level channel estimation value, Indicates the sampling result.

[0082] The anti-eavesdropping communication method provided by the present invention calculates the noise average power based on the time domain CIR in the noise window, determines the sampling threshold of the signal window according to the noise average power, performs sampling in the signal window based on the time domain CIR and the sampling threshold of the signal window, obtains the sampling result, performs DFT transformation on the sampling result, obtains the RB level channel estimation value, and further realizes the accurate acquisition of the RB level channel estimation value, thereby further ensuring the reduction of the number of data of the channel estimation value.

[0083] Figure 3 FIG. 2 is a flow chart of the anti-eavesdropping communication method provided by the present invention. Figure 3 As shown, the anti-eavesdropping communication method includes the following steps: Step 310, receiving an SRS measurement signal; Step 320, generating an SRS local sequence; Step 330, calculating a frequency domain LS channel estimation value according to the received SRS measurement signal and the SRS local sequence; Step 340, performing IDFT transformation on the LS channel estimation value to obtain a time domain CIR; Step 350, obtaining an RB-level channel estimation value based on the time domain CIR; Step 360, performing DOA estimation according to the RB-level channel estimation value to obtain the direction of arrival of the terminal; Step 370, calculating a signal shaping factor and a noise shaping factor according to the direction of the incoming wave of the terminal; Step 380: Perform random beamforming on the downlink PDSCH signal according to the signal shaping factor and the noise shaping factor.

[0084] The anti-eavesdropping communication device provided by the present invention is described below. The anti-eavesdropping communication device described below and the anti-eavesdropping communication method described above can be referred to each other.

[0085] Figure 4 Schematic diagram of the structure of the anti-eavesdropping communication device provided by the present invention, such as Figure 4 As shown, the present invention provides an anti-eavesdropping communication device, comprising: The channel estimation module 410 is used to perform channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; A determination module 420, configured to determine the direction of arrival of the legitimate terminal based on the RB-level channel estimation value; The beamforming module 430 is used to perform random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the incoming direction of the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

[0086] In some embodiments, the beamforming module 430 includes: A first calculation submodule, configured to calculate a signal shaping factor and a noise shaping factor in beamforming based on the direction of the wave of the legal terminal; A beamforming submodule, configured to perform random beamforming on a downlink PDSCH signal transmitted to the legitimate terminal according to the signal shaping factor and the noise shaping factor; The signal shaping factors are a group of multiplicative factors used to shape the downlink PDSCH signal, and the noise shaping factors are a group of additive factors used to shape the downlink PDSCH signal.

[0087] In some embodiments, the beamforming submodule is specifically used to: Generate the signal shaping factor and array factor according to the wave direction of the legitimate terminal; According to the array factor, within the range of the incoming wave direction, a zero point is selected as the noise angle; The noise shaping factor is generated according to the noise angle.

[0088] In some embodiments, the determination module 420 includes: A second calculation submodule, used for calculating the covariance matrix of the RB level channel estimation value; A decomposition submodule, used for performing eigenvalue decomposition on the covariance matrix of the RB-level channel estimation value to obtain a noise subspace; A third calculation submodule is used to calculate the spectral function using the MUSIC algorithm according to the noise subspace; The determination submodule is used to determine the incoming wave direction corresponding to the peak value of the spectrum function as the incoming wave direction of the legitimate terminal.

[0089] In some embodiments, the channel estimation module 410 includes: A fourth calculation submodule, configured to calculate the SRS local sequence and the SRS measurement signal based on an LS algorithm to obtain a frequency domain LS channel estimation value; A transformation submodule, configured to perform IDFT transformation on the frequency domain LS channel estimation value to obtain the time domain CIR; A processing submodule is used to obtain the RB-level channel estimation value based on the time domain CIR.

[0090] In some embodiments, the processing submodule is specifically used for: Determine the signal window and the noise window; In the noise window, based on the time domain CIR, calculate the noise average power; Determining a sampling threshold of the signal window according to the noise average power; In the signal window, sampling is performed based on the time domain CIR and the sampling threshold of the signal window to obtain a sampling result; Perform DFT transformation on the sampling result to obtain the RB level channel estimation value.

[0091] Figure 5 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 5 As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520 and the memory 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 530 to execute the anti-eavesdropping communication method, which includes: performing channel estimation based on the SRS measurement signal sent by the received legal terminal to obtain the RB-level channel estimation value; determining the direction of the wave of the legal terminal based on the RB-level channel estimation value; performing random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the direction of the wave of the legal terminal, wherein the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to the illegal terminal.

[0092] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0093] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the anti-eavesdropping communication method provided by the above methods, which includes: performing channel estimation based on the SRS measurement signal sent by the received legal terminal to obtain an RB-level channel estimation value; determining the incoming direction of the legal terminal based on the RB-level channel estimation value; and performing random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the incoming direction of the legal terminal, wherein the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

[0094] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the anti-eavesdropping communication method provided by the above-mentioned methods is implemented, and the method includes: performing channel estimation based on the SRS measurement signal sent by the received legal terminal to obtain an RB-level channel estimation value; determining the direction of arrival of the legal terminal based on the RB-level channel estimation value; and performing random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the direction of arrival of the legal terminal, wherein the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

[0095] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0096] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A communication method for preventing eavesdropping, characterized in that: include: Perform channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; Determining the direction of arrival of the legitimate terminal based on the RB-level channel estimation value; Based on the incoming direction of the legal terminal, random beamforming is performed on the downlink PDSCH signal transmitted to the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

2. The anti-eavesdropping communication method according to claim 1, characterized in that: The performing random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the direction of the wave of the legal terminal includes: Calculating a signal shaping factor and a noise shaping factor in beamforming based on the direction of the wave of the legal terminal; Performing random beamforming on a downlink PDSCH signal transmitted to the legitimate terminal according to the signal shaping factor and the noise shaping factor; The signal shaping factors are a group of multiplicative factors used to shape the downlink PDSCH signal, and the noise shaping factors are a group of additive factors used to shape the downlink PDSCH signal.

3. The anti-eavesdropping communication method according to claim 2, characterized in that: The calculating, based on the direction of arrival of the legitimate terminal, a signal shaping factor and a noise shaping factor in beamforming includes: Generate the signal shaping factor and array factor according to the wave direction of the legitimate terminal; According to the array factor, within the range of the incoming wave direction, a zero point is selected as the noise angle; The noise shaping factor is generated according to the noise angle.

4. The anti-eavesdropping communication method according to claim 1, characterized in that: The determining the direction of arrival of the legitimate terminal based on the RB-level channel estimation value includes: Calculating a covariance matrix of the RB-level channel estimation value; Performing eigenvalue decomposition on the covariance matrix of the RB-level channel estimation value to obtain a noise subspace; According to the noise subspace, a spectral function is calculated using a MUSIC algorithm; The incoming wave direction corresponding to the peak value of the spectrum function is determined as the incoming wave direction of the legitimate terminal.

5. The method according to claim 1, characterized in that The performing channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain the RB-level channel estimation value includes: Based on the LS algorithm, the SRS local sequence and the SRS measurement signal are calculated to obtain a frequency domain LS channel estimation value; Performing IDFT transformation on the frequency domain LS channel estimation value to obtain the time domain CIR; Based on the time domain CIR, the RB level channel estimation value is obtained.

6. The method according to claim 5, characterized in that The obtaining the RB-level channel estimation value based on the time domain CIR includes: Determine the signal window and the noise window; In the noise window, based on the time domain CIR, calculate the noise average power; Determining a sampling threshold of the signal window according to the noise average power; In the signal window, sampling is performed based on the time domain CIR and the sampling threshold of the signal window to obtain a sampling result; Perform DFT transformation on the sampling result to obtain the RB level channel estimation value.

7. A communication device for preventing eavesdropping, characterized in that: include: A channel estimation module, used to perform channel estimation based on the received SRS measurement signal sent by the legitimate terminal to obtain an RB-level channel estimation value; A determination module, used to determine the direction of arrival of the legitimate terminal based on the RB-level channel estimation value; The beamforming module is used to perform random beamforming on the downlink PDSCH signal transmitted to the legal terminal based on the incoming wave direction of the legal terminal, and the downlink PDSCH signal after random beamforming contains artificial noise that is transparent to the legal terminal and opaque to illegal terminals.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the anti-eavesdropping communication method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the anti-eavesdropping communication method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the anti-eavesdropping communication method according to any one of claims 1 to 6 is implemented.

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