Signal sender identity authentication method and related device

Abstract

The application provides a signal sender identity authentication method and related equipment, and relates to the technical field of communication. The method comprises the following steps: acquiring a channel polarization response at a current moment according to a polarization state of a received signal, a polarization state of a sent signal, transmitter characteristics and receiver characteristics; estimating a difference value between the channel polarization response at the current moment and a channel polarization response at a previous moment; the channel polarization response at the previous moment corresponds to a legal sender; confirming that the signal sender is the legal sender in the case that the difference value is less than a threshold value; and confirming that the signal sender is an illegal sender in the case that the difference value is greater than the threshold value. The application realizes identity authentication of different senders at the same position by using the fact that the channel polarization response depends on the polarization state of a signal.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a method and related equipment for authenticating the identity of a signal sender. Background Technology

[0002] Current physical layer authentication schemes based on channel information mainly focus on using channel impulse response, channel frequency response, received signal power spectral density, and received signal strength to authenticate the signal sender.

[0003] The authentication process of these authentication schemes is as follows: First, the upper-layer encryption authentication mechanism is used to authenticate the signal sender at the initial moment. Then, taking advantage of the principle that the channel information of the same sender is highly correlated within the coherent time period, while the channel information of different senders is independent, the signal sender at subsequent moments is authenticated.

[0004] The use of massive MIMO (Multiple In Multiple Out) antennas and millimeter wave (mm wave) in 5G communication systems gives transmitted signals strong directionality. To ensure a successful attack, the malicious sender often needs to be close to or in the same location as the legitimate sender. However, when the malicious sender and the legitimate sender are close to or in the same location, the authentication performance of existing physical layer authentication schemes based on channel information drops sharply, making them ineffective against malicious senders.

[0005] Therefore, it is necessary to study the authentication of signal senders in scenarios where illegal senders and legitimate senders are close to each other or in the same location. Summary of the Invention

[0006] This invention provides a signal sender authentication method and related equipment to address the shortcomings of existing technologies where the authentication performance of signal senders drops sharply when illegal senders and legitimate senders are close to each other or in the same location, thereby enabling authentication of different senders in the same location.

[0007] This invention provides a method for authenticating the identity of a signal sender, comprising:

[0008] Based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics at the current moment, obtain the channel polarization response at the current moment;

[0009] Estimate the difference between the current channel polarization response and the previous channel polarization response; the previous channel polarization response corresponds to the legitimate sender;

[0010] If the difference value is less than the threshold, the signal sender is confirmed as a legitimate sender; if the difference value is greater than the threshold, the signal sender is confirmed as an illegitimate sender.

[0011] In some embodiments, obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, transmitter characteristics, and receiver characteristics includes:

[0012] Based on the polarization state of the received signal and the polarization state of the transmitted signal at the current moment, determine the first amplitude ratio component and the first phase difference component;

[0013] Determine the second amplitude ratio component and the second phase difference component; the second amplitude ratio component is the influence of the transmitter characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the transmitter characteristics on the phase difference component of the channel polarization response.

[0014] The third amplitude ratio component and the third phase difference component are determined; the third amplitude ratio component is the influence of the receiver characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the receiver characteristics on the phase difference component of the channel polarization response.

[0015] The amplitude ratio component of the channel polarization response at the current moment is obtained based on the first amplitude ratio component, the second amplitude ratio component, and the third amplitude ratio component.

[0016] Based on the first phase difference component, the second phase difference component, and the third phase difference component, the phase difference component of the channel polarization response at the current moment is obtained.

[0017] In some embodiments, estimating the difference between the channel polarization response at the current time and the channel polarization response at the previous time includes:

[0018] The difference between the current channel polarization response and the previous channel polarization response is estimated using the log-likelihood ratio.

[0019] In some embodiments, before estimating the difference between the channel polarization response at the current time and the channel polarization response at the previous time, the method further includes:

[0020] Extract the channel polarization response of the previous time step from the feature database that stores the channel polarization response of the legitimate sender.

[0021] In some embodiments, after confirming that the signal sender is a legitimate sender, the method further includes:

[0022] The channel polarization response at the current moment replaces the channel polarization response at the previous moment and is stored in the feature database.

[0023] In some embodiments, the method further includes:

[0024] During the initial identity authentication process, the identity of the signal sender is authenticated through an encrypted authentication mechanism;

[0025] If the signal sender is confirmed to be a legitimate sender, the initial channel polarization response is estimated and stored in the feature database.

[0026] The present invention also provides a signal sender authentication device, comprising:

[0027] The acquisition module is used to acquire the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics.

[0028] The difference estimation module is used to estimate the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment; the channel polarization response at the previous moment corresponds to the legitimate sender;

[0029] The identity verification module is used to verify that the signal sender is a legitimate sender when the difference value is less than a threshold, and to verify that the signal sender is an illegitimate sender when the difference value is greater than the threshold.

[0030] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the signal sender authentication method as described above.

[0031] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the signal sender authentication method as described above.

[0032] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the signal sender authentication method as described above.

[0033] The signal transmitter authentication method and related equipment provided by this invention utilize the different transmitter characteristics of different transmitters. The transmitter characteristics affect the polarization state of the transmitted signal, and the channel polarization response depends on the polarization state of the signal, resulting in different channel polarization responses for different transmitters. Based on the channel polarization response, the identity authentication of different transmitters at the same location is achieved. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a communication scenario provided by the present invention;

[0036] Figure 2 This is one of the flowcharts illustrating a signal sender authentication method provided in an exemplary embodiment of the present invention;

[0037] Figure 3 This is a second flowchart illustrating a signal sender authentication method provided in an exemplary embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the polarization deflection of the transmitter provided by the present invention;

[0039] Figure 5 This invention provides the channel polarization response differences between different transmitters at the same location;

[0040] Figure 6 This is a schematic diagram of the structure of the signal sender identity authentication device provided by the present invention;

[0041] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. It should be noted that, unless otherwise specified, the embodiments and features of the embodiments of this invention can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0044] It should be further noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0045] In this invention, "at least one" means one or more, and "more than one" means two or more. The terms "first," "second," "third," "fourth," etc. (if present) in this invention are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0046] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0047] A signal is determined by scalar information, such as amplitude and phase, and vector information, such as polarization. When a signal passes through a wireless channel, the channel affects not only the signal's amplitude and phase but also its polarization. Similar to the channel's influence on signal amplitude and phase, the channel's influence on polarization can also be used as channel information for physical layer authentication. The channel's influence on signal amplitude is called the Channel Impulse Response (CIR), its influence on signal phase is called the Channel Frequency Response (CFR), and its influence on signal polarization is called the Channel Polarization Response (CPR).

[0048] Unlike channel impulse response or channel frequency response, channel polarization response is polarization dependent, meaning that different transmit polarization states will have different channel polarization responses under the same wireless channel.

[0049] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a communication scenario provided by the present invention. For example... Figure 1As shown on the left, this scenario involves two entities: a legitimate sender (Alice) and a legitimate receiver (Bob). In the t-th time interval, the legitimate sender transmits a signal to the legitimate receiver via a legitimate communication link. A cluster of scatterers distributed along the legitimate communication link moves at a speed V, influencing the channel polarization response. Let H be the channel polarization response between the legitimate sender and the legitimate receiver. AB (t).

[0050] like Figure 1 As shown on the right, this scenario involves three entities: a legitimate sender, a legitimate receiver, and an illegitimate sender (Eve). In the (t+1)th time interval, the illegitimate sender eavesdrops on the authentication information used in the communication between the legitimate sender and receiver via the eavesdropping link, and then uses this authentication information to send a signal to the legitimate receiver. A cluster of scatterers distributed along both the legitimate and illegitimate communication links moves at a speed V, influencing the channel polarization response. Let H be the channel polarization response between the legitimate sender and receiver. AB (t+1). The channel polarization response between the illegal sender and the legitimate receiver is denoted as H. EB (t+1).

[0051] Therefore, a legitimate receiver needs to determine whether the signal originated from a legitimate sender in the presence of an illegitimate sender.

[0052] Figure 2 This is one of the flowcharts illustrating a signal sender authentication method provided in an exemplary embodiment of the present invention, such as... Figure 2 As shown, this embodiment provides a signal sender authentication method, where the executing entity can be a legitimate receiver. The method includes:

[0053] Step 210: Obtain the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics.

[0054] Specifically, transmitter characteristics include transmitter hardware defects and transmitter noise, while receiver characteristics include receiver hardware defects and noise. Transmitter hardware defects and noise can affect the polarization state of the transmitted signal. Receiver hardware defects and noise can affect the polarization state of the received signal. Therefore, both transmitter and receiver characteristics affect the channel polarization response.

[0055] Although the illegal sender expects the signal to have the same polarization state as the legitimate one, the hardware defects and noise of the transmitters of different senders are different, and the polarization state of the signals sent by different senders is also slightly different. Therefore, the channel polarization response is also different.

[0056] In some embodiments, the legitimate receiver determines the impact of transmitter characteristics on the polarization state of the transmitted signal at the current moment, determines the impact of receiver characteristics on the polarization state of the received signal at the current moment, and obtains the channel polarization response at the current moment based on the polarization state of the transmitted signal after the impact and the polarization state of the received signal after the impact.

[0057] In some embodiments, the legitimate receiver obtains a first channel polarization response based on the polarization state of the received signal and the polarization state of the transmitted signal at the previous time; determines the influence of transmitter and receiver characteristics on the channel polarization response; and obtains the channel polarization response at the current time based on the influence of transmitter and receiver characteristics on the channel polarization response and the first channel polarization response.

[0058] Step 220: Estimate the difference between the current channel polarization response and the previous channel polarization response; the previous channel polarization response corresponds to the legitimate sender.

[0059] Specifically, the legitimate receiver obtains the channel polarization response of the previous moment, which is generated by the signal sent by the legitimate sender.

[0060] The legitimate receiver compares the current channel polarization response with the channel polarization response of the previous time step and estimates the difference between the current channel polarization response and the channel polarization response of the previous time step.

[0061] Step 230: If the difference value is less than or equal to the threshold, the signal sender is confirmed as a legitimate sender; if the difference value is greater than the threshold, the signal sender is confirmed as an illegitimate sender.

[0062] Specifically, the legitimate receiver uses a binary hypothesis testing model to determine whether the signal sender is a legitimate sender. H0 hypothesis: If the difference value T is less than or equal to the threshold δ, the signal sender is a legitimate sender; H1 hypothesis: If the difference value T is greater than the threshold δ, the signal sender is an illegitimate sender. In some embodiments, the threshold δ can be flexibly set according to requirements.

[0063] After determining the difference value T, the legitimate receiver compares T with a threshold. If the difference value T is less than or equal to the threshold δ, the legitimate receiver accepts the H0 hypothesis, confirming the signal sender as a legitimate sender. If the difference value T is greater than the threshold δ, the legitimate receiver accepts the H1 hypothesis, confirming the signal sender as an illegitimate sender.

[0064] The signal transmitter authentication method provided in this embodiment utilizes the different transmitter characteristics of different transmitters. The transmitter characteristics affect the polarization state of the transmitted signal, and the channel polarization response depends on the polarization state, resulting in different channel polarization responses for different transmitters. Based on the channel polarization response, the method realizes the authentication of different transmitters at the same location.

[0065] Furthermore, this embodiment provides a signal sender authentication method. This embodiment is a further explanation of the foregoing embodiments, mainly illustrating the specific process of obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, and the transmitter characteristics. The method includes:

[0066] Based on the polarization state of the received signal and the polarization state of the transmitted signal at the current moment, determine the first amplitude ratio component and the first phase difference component;

[0067] Determine the second amplitude ratio component and the second phase difference component; the second amplitude ratio component is the influence of transmitter characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of transmitter characteristics on the phase difference component of the channel polarization response.

[0068] The third amplitude ratio component and the third phase difference component are determined; the third amplitude ratio component is the influence of receiver characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of receiver characteristics on the phase difference component of the channel polarization response.

[0069] The amplitude ratio components of the channel polarization response at the current moment are obtained based on the first amplitude ratio component, the second amplitude ratio component, and the third amplitude ratio component.

[0070] Based on the first phase difference component, the second phase difference component, and the third phase difference component, the phase difference component of the channel polarization response at the current moment is obtained.

[0071] Specifically, after receiving the received signal, the legitimate receiver uses the least squares method to estimate the channel polarization response.

[0072] The expression for the channel polarization response is shown below:

[0073]

[0074] in,

[0075]

[0076] In the formula, X represents the channel polarization response. J Indicates the polarization state of the transmitted signal. Indicates the polarization state of the received signal, |X v| represents the amplitude of the vertical component of the transmitted signal, |X h | represents the amplitude of the horizontal component of the transmitted signal, X P X represents the phase difference of the transmitted signal. F The amplitude ratio of the transmitted signal is represented by |X|. v | / |X h |, This indicates the amplitude of the vertical component of the received signal. This represents the amplitude of the horizontal component of the received signal. R represents the phase difference of the received signal. F This represents the amplitude ratio of the received signal.

[0077] Therefore, the expression for the channel polarization response can be transformed into:

[0078]

[0079] in,

[0080]

[0081] In the formula, R represents the channel polarization response. F X represents the amplitude ratio of the received signal. F This indicates the amplitude ratio of the transmitted signal. X represents the phase difference of the received signal. P Indicates the phase difference of the transmitted signal. The amplitude ratio component represents the channel polarization response. This represents the phase difference component of the channel polarization response.

[0082] X J For the ideal emission polarization state, This represents the ideal receiving polarization. In reality, the transmitting polarization is affected by transmitter characteristics and will deviate from the ideal transmitting polarization X. J The receiving polarization is affected by the receiver characteristics and will deviate from the ideal receiving polarization. Therefore, the amplitude ratio component of the channel polarization response is not equal to the amplitude ratio component under ideal polarization, and the phase difference component of the channel polarization response is not equal to the amplitude ratio component under ideal polarization.

[0083] Considering the influence of transmitter and receiver characteristics on the amplitude ratio component of the channel polarization response, the expression for the amplitude ratio component of the channel polarization response is as follows:

[0084]

[0085] In the formula, S represents the amplitude ratio component of the channel polarization response. F F represents the amplitude ratio component under ideal polarization. WX S indicates the characteristics of the transmitter. F Estimation error, F WR S indicates the characteristics of the receiver. F Estimation error.

[0086] Considering the influence of transmitter and receiver characteristics on the phase difference component of the channel polarization response, the expression for the phase difference component of the channel polarization response is as follows:

[0087]

[0088] In the formula, S represents the phase difference component of the channel polarization response. P P represents the phase difference component of the channel polarization response under ideal polarization conditions. WX S indicates the characteristics of the transmitter. P Estimation error, P WR S indicates the characteristics of the receiver. P Estimation error.

[0089] Because log(S) F ) and S P It follows a complex Gaussian distribution with a mean of zero; therefore, using log(S) F ) and S P The expression characterizing the channel polarization response, i.e., the expression for the channel polarization response, can also be shown below:

[0090]

[0091] In the formula, To represent the channel polarization response, for the sake of symbolic representation, we use S. lF Characterize log(S) F ), S lF S represents the amplitude ratio component of the channel polarization response. P This represents the phase difference component of the channel polarization response.

[0092] The expression for the actual amplitude of the channel polarization response as a fraction is shown below:

[0093]

[0094] In the formula, S represents the actual amplitude ratio component of the channel polarization response. lF F represents the amplitude ratio component of the channel polarization response under ideal polarization conditions. X S indicates the characteristics of the transmitter. lF Estimation error, FR S indicates the characteristics of the receiver. lF Estimation error.

[0095] The expression for the actual phase difference component of the channel polarization response is as follows:

[0096]

[0097] In the formula, S represents the actual phase difference component of the channel polarization response. P P represents the phase difference component of the channel polarization response under ideal polarization conditions. X S indicates the characteristics of the transmitter. P Estimation error, P R S indicates the characteristics of the receiver. P Estimation error.

[0098] As shown in the formulas above, a legitimate receiver can obtain the amplitude ratio and phase difference of the received signal at the current moment based on the polarization state of the received signal. Similarly, based on the polarization state of the transmitted signal at the current moment, it can obtain the amplitude ratio and phase difference of the transmitted signal at the current moment.

[0099] The legitimate receiver determines the first amplitude ratio component based on the amplitude ratio of the received signal at the current time and the amplitude ratio of the transmitted signal at the current time; and determines the first phase difference component based on the phase difference of the received signal at the current time and the phase difference of the transmitted signal at the current time.

[0100] The legitimate receiver determines the influence of transmitter characteristics on the amplitude ratio component of the channel polarization response, i.e., determines the second amplitude ratio component; it also determines the influence of transmitter characteristics on the phase difference component of the channel polarization response, i.e., determines the second phase difference component.

[0101] The legitimate receiver determines the influence of receiver characteristics on the amplitude ratio component of the channel polarization response, i.e., determines the third amplitude ratio component; it also determines the influence of receiver characteristics on the phase difference component of the channel polarization response, i.e., determines the third phase difference component.

[0102] The legitimate receiver uses the sum of the first amplitude ratio component, the second amplitude ratio component, and the third amplitude ratio component as the amplitude ratio component for obtaining the channel polarization response at the current moment. The legitimate receiver also uses the sum of the first phase difference component, the second phase difference component, and the third phase difference component as the phase difference component for the channel polarization response at the current moment.

[0103] In some embodiments, since the receiver of the illegal sender and the receiver of the legitimate sender are the same, the influence of receiver characteristics on the polarization state of the received signal can be disregarded, that is, the influence of receiver characteristics on the channel polarization response can be disregarded.

[0104] The legitimate receiver determines the influence of transmitter characteristics on the amplitude ratio component of the channel polarization response, i.e., determines the second amplitude ratio component; it also determines the influence of transmitter characteristics on the phase difference component of the channel polarization response, i.e., determines the second phase difference component.

[0105] The legitimate receiver uses the sum of the first amplitude ratio component and the second amplitude ratio component as the amplitude ratio component of the channel polarization response at the current moment. The legitimate receiver also uses the sum of the first phase difference component and the second phase difference component as the phase difference component of the channel polarization response at the current moment.

[0106] The signal transmitter authentication method provided in this embodiment obtains the channel polarization response under ideal polarization by using the polarization state of the received signal and the polarization state of the transmitted signal at the current moment, determines the influence of transmitter characteristics and receiver characteristics on the channel polarization response, thereby obtaining the actual channel polarization response, achieving accurate acquisition of the channel polarization response, and further realizing the authentication of the signal transmitter.

[0107] Furthermore, this embodiment provides a signal transmitter authentication method. This embodiment is a further explanation of the foregoing embodiments, mainly illustrating the specific process of estimating the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment. The method includes:

[0108] The difference between the current channel polarization response and the previous channel polarization response is estimated using the log-likelihood ratio.

[0109] Specifically, the legitimate recipient uses the log-likelihood ratio to estimate the difference value T, which is expressed as follows:

[0110]

[0111] in,

[0112]

[0113] In the formula, T represents the difference between the channel polarization responses at two adjacent time points. This represents the actual amplitude ratio component of the channel polarization response at time t+1. This represents the actual phase difference component of the channel polarization response at time t+1. This represents the actual amplitude ratio component of the channel polarization response at time t. α represents the actual phase difference component of the channel polarization response at time t. A These are the autoregressive coefficients of the channel polarization response between the legitimate sender and the legitimate receiver. The amplitude-to-component variance of the channel polarization response when the sender is a legitimate sender. The variance of the phase difference component of the channel polarization response when the sender is a legitimate sender. S indicates the characteristics of the transmitter. lF Estimate the variance of the error. S indicates the characteristics of the transmitter. P Estimate the variance of the error. S indicates the characteristics of the receiver. lF Estimate the variance of the error. S indicates the characteristics of the receiver. P Estimate the variance of the error. The amplitude ratio component variance of the channel polarization response when the sender is an illegal sender. The variance of the phase difference component of the channel polarization response when the sender is an illegal sender. S indicates the characteristics of the transmitter. lF Estimate the variance of the error. S indicates the characteristics of the transmitter. P Estimate the variance of the error.

[0114] Substituting the current channel polarization response and the previous channel polarization response into the expression for the difference value, we obtain the difference value between the current channel polarization response and the previous channel polarization response.

[0115] The signal transmitter authentication method provided in this embodiment improves the accuracy of the difference estimation by using the log-likelihood ratio to estimate the difference between the current channel polarization response and the previous channel polarization response, thereby further improving the accuracy of signal transmitter authentication.

[0116] Furthermore, based on the foregoing embodiments, this embodiment provides a signal transmitter authentication method, which, before estimating the difference between the current channel polarization response and the previous channel polarization response, further includes:

[0117] Extract the channel polarization response of the previous time step from the feature database that stores the channel polarization response of the legitimate sender.

[0118] Specifically, the feature database stores the channel polarization response corresponding to the signal sent by the legitimate sender, that is, it stores the features of the channel polarization response, such as the amplitude ratio component and the phase difference component.

[0119] In some embodiments, the feature database stores all channel polarization responses corresponding to legitimate senders over time.

[0120] In some embodiments, the feature database stores the latest channel polarization response corresponding to the legitimate sender. If the channel polarization response at the current time is not stored in the feature database, the latest channel polarization response in the feature database is the channel polarization response at the previous time step.

[0121] The legitimate receiver extracts the channel polarization response of the previous time step from the feature database, that is, it extracts the amplitude ratio component and phase difference component of the channel polarization response of the previous time step.

[0122] The signal transmitter authentication method provided in this embodiment stores the channel polarization response corresponding to the legitimate transmitter in a feature database. Extracting the channel polarization response of the previous moment from the feature database is beneficial for subsequent calculation of the difference between the channel polarization response of the current moment and the channel polarization response of the previous moment, which is further helpful for confirming the identity of the signal transmitter.

[0123] Furthermore, based on the foregoing embodiments, this embodiment provides a signal sender authentication method. After confirming that the signal sender is a legitimate sender, the method further includes:

[0124] The current channel polarization response replaces the previous channel polarization response and is stored in the feature database.

[0125] Specifically, after confirming that the signal sender is legitimate, the legitimate receiver stores the current channel polarization response in the feature database, replacing the channel polarization response from the previous moment in the feature database. This saves storage space in the feature database and ensures that the channel polarization response stored in the feature database is the most recent one, further facilitating the estimation of the difference value and improving its accuracy.

[0126] Furthermore, based on the foregoing embodiments, this embodiment provides a signal sender authentication method, which further includes:

[0127] During the initial identity authentication process, the identity of the signal sender is authenticated through an encrypted authentication mechanism.

[0128] Once the signal sender is confirmed to be a legitimate sender, the initial channel polarization response is estimated and stored in the feature database.

[0129] Specifically, Figure 3 This is a second flowchart illustrating a signal sender authentication method provided in an exemplary embodiment of the present invention, as shown below. Figure 3 As shown, the method includes:

[0130] During the initial authentication process, the legitimate recipient authenticates the signal sender through an encrypted authentication mechanism. If the authentication is successful, the signal sender is confirmed as a legitimate sender; if the authentication fails, the signal sender is confirmed as an illegitimate sender.

[0131] In some embodiments, authentication is considered successful if the legitimate receiver successfully decrypts the received signal, and unsuccessful if the legitimate receiver fails to decrypt the received signal. Upon confirming that the signal sender is legitimate, the legitimate receiver performs CPR estimation to obtain the initial channel polarization response. and the initial channel polarization response Stored in the feature database. An alarm is triggered if the signal sender is confirmed to be an unauthorized sender.

[0132] In the subsequent identity authentication process, the legitimate recipient uses the physical layer authentication mechanism to determine whether the sender of the signal is still a legitimate sender.

[0133] The legitimate receiver first performs CPR estimation to obtain the channel polarization response at the current moment. Extract the channel polarization response of the previous time step from the feature database. Calculate the channel polarization response at the current moment. Channel polarization response compared to the previous time step The difference value T between them is used to determine whether the difference value T is less than or equal to the threshold δ. If the difference value T is less than or equal to the threshold δ, the signal sender is confirmed as a legitimate sender, and the channel polarization response at the current moment is recorded. Stored in the feature database; if the difference value T is not less than or equal to the threshold δ, the signal sender is confirmed to be an illegal sender, and an alarm is triggered.

[0134] The signal sender authentication method provided in this embodiment uses an encrypted authentication mechanism to determine whether the signal sender is a legitimate sender during the initial authentication process, thereby simplifying the initial authentication process. If the signal sender is confirmed to be a legitimate sender, the initial channel polarization response is estimated and stored in a feature database so that the initial channel polarization response can be used for subsequent signal sender authentication.

[0135] Assume the legitimate sender and the illegitimate sender are located at the same position, and the illegitimate sender can perfectly obtain the transmission polarization state that the legitimate sender wants to transmit. The legitimate sender and the illegitimate sender transmit information at time intervals t and t+1, respectively.

[0136] Since the receivers of legitimate and illegitimate senders are the same, the influence of receiver characteristics is not considered; only the influence of transmitter characteristics on channel polarization response needs to be analyzed. Figure 4This is a schematic diagram of the polarization deflection of the transmitter provided by the present invention, as shown below. Figure 4 As shown, the vertical polarization state of the illegal sender is the vertical polarization state of the legitimate sender deflected by an angle ζ, and the horizontal polarization state of the illegal sender is the horizontal polarization state of the legitimate sender deflected by an angle ζ-π / 2.

[0137] The expression for the channel polarization response when the sender is an illegal sender is shown below:

[0138]

[0139] In the formula, Let ζ(f) represent the channel polarization response between the legitimate sender and the legitimate receiver, and let ζ(f) represent the difference in polarization deflection caused by the different transmitter characteristics of the legitimate sender and the illegitimate sender. This indicates the channel polarization response between the illegal sender and the legitimate receiver.

[0140] The expression for the difference in channel polarization response between legitimate and illegitimate senders is as follows:

[0141]

[0142] In the formula, This represents the difference in channel polarization response between a legitimate and an illegitimate transmitter under a transmitter polarization deflection difference ζ(f). This represents the channel polarization response between a legitimate sender and a legitimate receiver. S represents the channel polarization response between the illegal sender and the legitimate receiver. FA S represents the amplitude component of the legitimate sender's channel polarization response. PA X represents the phase component of the legitimate transmitted channel polarization response. F X represents the amplitude of the signal transmitted by the transmitter. P This indicates the phase of the signal transmitted by the transmitter.

[0143] To simplify the analysis, we assume that the legitimate sender's transmit polarization is ideally vertical. The expression for the difference in channel polarization response between the legitimate and illegitimate senders can be simplified to:

[0144]

[0145] In the formula, S represents the difference in channel polarization response between a legitimate and illegitimate transmitter under the transmitter polarization deflection difference ζ(f). FA S represents the amplitude component of the legitimate sender's channel polarization response. PA This represents the phase component of the legitimate transmitted channel polarization response.

[0146] Figure 5 This invention provides the channel polarization response differences between different transmitters at the same location, such as... Figure 5 As shown, this illustrates the relationship between ξ and ζ and |ΔCPR| at a given frequency. 2 The influence of ξ and ζ on The effect of ξ is a three-dimensional surface, where the curves represent the authentication threshold. ξ represents the channel power imbalance, used to characterize the impact of channel polarization fading.

[0147] Depend on Figure 5 It can be seen that, The difference in channel polarization response increases with the increase of ξ and ζ. When ξ ≥ 3.25 and ζ ≥ 0.3, the difference exceeds the authentication threshold. In practice, ξ ≥ 3.25 and ζ ≥ 0.3 can always be obtained. Therefore, the scheme proposed in this invention can distinguish different senders at the same location.

[0148] The signal sender authentication device provided by the present invention is described below. The signal sender authentication device described below can be referred to in correspondence with the signal sender authentication method described above.

[0149] Figure 6 This is a schematic diagram of the structure of the signal sender authentication device provided by the present invention, as shown below. Figure 6 As shown, the signal sender authentication device provided by the present invention includes: an acquisition module 610, a difference estimation module 620, and an identity confirmation module 630, wherein:

[0150] The acquisition module 610 is used to acquire the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics at the current moment.

[0151] The difference estimation module 620 is used to estimate the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment; the channel polarization response at the previous moment corresponds to the legitimate sender;

[0152] The identity verification module 630 is used to verify that the signal sender is a legitimate sender when the difference value is less than a threshold, and to verify that the signal sender is an illegitimate sender when the difference value is greater than the threshold.

[0153] In some embodiments, the acquisition module 610 includes: a first determining submodule, a second determining submodule, a third determining submodule, a first acquisition submodule, and a second acquisition submodule; wherein:

[0154] The first determining submodule is used to determine the first amplitude ratio component and the first phase difference component based on the polarization state of the received signal and the polarization state of the transmitted signal at the current moment.

[0155] The second determining submodule is used to determine the second amplitude ratio component and the second phase difference component; the second amplitude ratio component is the influence of the transmitter characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the transmitter characteristics on the phase difference component of the channel polarization response.

[0156] The third determining submodule is used to determine the third amplitude ratio component and the third phase difference component; the third amplitude ratio component is the influence of the receiver characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the receiver characteristics on the phase difference component of the channel polarization response.

[0157] The first acquisition submodule is used to obtain the amplitude ratio component of the channel polarization response at the current moment based on the first amplitude ratio component, the second amplitude ratio component and the third amplitude ratio component;

[0158] The second acquisition submodule is used to obtain the phase difference component of the channel polarization response at the current moment based on the first phase difference component, the second phase difference component and the third phase difference component.

[0159] In some embodiments, the difference estimation module 620 is specifically used to: estimate the difference between the channel polarization response at the current time and the channel polarization response at the previous time using the log-likelihood ratio.

[0160] In some embodiments, the apparatus further includes: an extraction module; the extraction module is configured to extract the channel polarization response of the previous time step from a feature database storing the channel polarization response corresponding to a legitimate sender.

[0161] In some embodiments, the apparatus further includes a storage module; the storage module is configured to store the current channel polarization response in place of the previous channel polarization response in the feature database.

[0162] In some embodiments, the apparatus further includes: an initial authentication module; the initial authentication module is configured to authenticate the signal sender through an encryption authentication mechanism during the initial identity authentication process; and, if the signal sender is confirmed to be a legitimate sender, estimate the initial channel polarization response and store the initial channel polarization response in a feature database.

[0163] It should be noted that the signal sender authentication device provided by the present invention can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Therefore, the parts and beneficial effects that are the same as those in the method embodiments will not be described in detail here.

[0164] Figure 7This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 7 As shown, the electronic device may include a processor 710, a communications interface 720, a memory 730, and a communication bus 740. The processor 710, communications interface 720, and memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute a signal sender authentication method. This method includes: obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, transmitter characteristics, and receiver characteristics; estimating the difference between the current channel polarization response and the channel polarization response at the previous moment; the channel polarization response at the previous moment corresponding to a legitimate sender; confirming the signal sender as a legitimate sender if the difference is less than a threshold; and confirming the signal sender as an illegitimate sender if the difference is greater than the threshold.

[0165] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0166] On the other hand, the present invention also provides a computer program product, which includes a computer program that 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 signal sender authentication method provided by the above methods. The method includes: obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, transmitter characteristics, and receiver characteristics; estimating the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment; the channel polarization response at the previous moment corresponding to a legitimate sender; confirming the signal sender as a legitimate sender if the difference is less than a threshold; and confirming the signal sender as an illegitimate sender if the difference is greater than the threshold.

[0167] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements a signal transmitter authentication method provided by the methods described above. The method includes: obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, transmitter characteristics, and receiver characteristics; estimating the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment; the channel polarization response at the previous moment corresponding to a legitimate transmitter; confirming the signal transmitter as a legitimate transmitter if the difference is less than a threshold; and confirming the signal transmitter as an illegitimate transmitter if the difference is greater than the threshold.

[0168] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0169] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for authenticating the identity of a signal sender, characterized in that, include: Based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics at the current moment, obtain the channel polarization response at the current moment; Estimate the difference between the current channel polarization response and the previous channel polarization response; The channel polarization response at the previous moment corresponds to the legitimate sender; If the difference value is less than the threshold, the signal sender is confirmed as a legitimate sender; if the difference value is greater than the threshold, the signal sender is confirmed as an illegitimate sender. The step of obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics includes: Based on the polarization state of the received signal and the polarization state of the transmitted signal at the current moment, determine the first amplitude ratio component and the first phase difference component; Determine the second amplitude ratio component and the second phase difference component; the second amplitude ratio component is the influence of the transmitter characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the transmitter characteristics on the phase difference component of the channel polarization response. Determine the third amplitude ratio component and the third phase difference component; the third amplitude ratio component is the influence of the receiver characteristics on the amplitude ratio component of the channel polarization response; the third phase difference component is the influence of the receiver characteristics on the phase difference component of the channel polarization response. The amplitude ratio component of the channel polarization response at the current moment is obtained based on the first amplitude ratio component, the second amplitude ratio component, and the third amplitude ratio component. Based on the first phase difference component, the second phase difference component, and the third phase difference component, the phase difference component of the channel polarization response at the current moment is obtained.

2. The signal sender authentication method according to claim 1, characterized in that, The estimation of the difference between the current channel polarization response and the previous channel polarization response includes: The difference between the current channel polarization response and the previous channel polarization response is estimated using the log-likelihood ratio.

3. The signal sender authentication method according to claim 1, characterized in that, Before estimating the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment, the method further includes: Extract the channel polarization response of the previous time step from the feature database that stores the channel polarization response of the legitimate sender.

4. The signal sender authentication method according to claim 3, characterized in that, After confirming that the signal sender is a legitimate sender, the process further includes: The channel polarization response at the current moment replaces the channel polarization response at the previous moment and is stored in the feature database.

5. The signal sender authentication method according to claim 1, characterized in that, The method further includes: During the initial identity authentication process, the identity of the signal sender is authenticated through an encrypted authentication mechanism; If the signal sender is confirmed to be a legitimate sender, the initial channel polarization response is estimated and stored in the feature database.

6. A signal transmitter authentication device, characterized in that, include: The acquisition module is used to acquire the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics. The difference estimation module is used to estimate the difference between the channel polarization response at the current moment and the channel polarization response at the previous moment. The channel polarization response at the previous moment corresponds to the legitimate sender; The identity verification module is used to verify that the signal sender is a legitimate sender when the difference value is less than a threshold, and to verify that the signal sender is an illegitimate sender when the difference value is greater than the threshold. The step of obtaining the channel polarization response at the current moment based on the polarization state of the received signal, the polarization state of the transmitted signal, the transmitter characteristics, and the receiver characteristics includes: Based on the polarization state of the received signal and the polarization state of the transmitted signal at the current moment, determine the first amplitude ratio component and the first phase difference component; Determine the second amplitude ratio component and the second phase difference component; the second amplitude ratio component is the influence of the transmitter characteristics on the amplitude ratio component of the channel polarization response; the second phase difference component is the influence of the transmitter characteristics on the phase difference component of the channel polarization response. Determine the third amplitude ratio component and the third phase difference component; the third amplitude ratio component is the influence of the receiver characteristics on the amplitude ratio component of the channel polarization response; the third phase difference component is the influence of the receiver characteristics on the phase difference component of the channel polarization response. The amplitude ratio component of the channel polarization response at the current moment is obtained based on the first amplitude ratio component, the second amplitude ratio component, and the third amplitude ratio component. Based on the first phase difference component, the second phase difference component, and the third phase difference component, the phase difference component of the channel polarization response at the current moment is obtained.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the signal sender authentication method as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the signal sender authentication method as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the signal sender authentication method as described in any one of claims 1 to 5.

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