Method for Resisting Spoofing Attacks in Radio Frequency Sensing, Initiating Node and Responding Node

Abstract

The present application provides a method for resisting spoofing attacks in radio frequency sensing, an initiating node and a responding node. The method includes: the responding node receives a Null Data Packet Announcement (NDPA) frame, and extracts a first composite feature parameter including in-phase / quadrature (I / Q) imbalance characteristics and multipath channel characteristics from the pilot subcarriers in the NDPA frame; the responding node receives a Null Data Packet (NDP) frame for performing the current NDP measurement, and extracts a second composite feature parameter including I / Q imbalance characteristics and multipath channel characteristics from multiple non-linearly correlated Long Training Fields (LTFs) in the NDP frame; when the first composite feature parameter and the second composite feature parameter do not match, it means that the NDP frame received by the responding node may be a tampered or forged pseudo-NDP frame. Therefore, the responding node can determine that there is an attacker and recognize that the current NDP detection or measurement is invalid, thus avoiding the attacker from intervening in the subsequent transmission process.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method, an initiating node, and a responding node for resisting spoofing attacks in radio frequency sensing in a wireless local area network. Background Art

[0002] As the mainstream technology of current wireless communication, wireless local area network (WLAN) technology has penetrated all aspects of social production, business activities, and daily life. On the one hand, the widely distributed WLAN devices greatly facilitate the transmission of data information, and on the other hand, they are also suitable as a sensing infrastructure. The wireless signal reaches the receiver after being reflected by surrounding objects during propagation, and the receiver infers information such as the position, speed, and orientation of surrounding objects by analyzing the physical characteristics of the wireless signal.

[0003] The main purpose of wireless local area network sensing (WLAN Sensing) is to perform passive target sensing within the WLAN range. Different from the target sensing in 11az, the targets to be sensed in WLAN Sensing do not need to carry any devices (device free), and the related technologies can be widely applied to scenarios such as intrusion detection, action recognition, breathing / heartbeat detection, etc., and have great commercial value.

[0004] As WLAN sensing applications become more and more widespread, the devices for performing WLAN sensing are also likely to become targets of spoofing attacks by attackers. Spoofing attacks can cause the system to malfunction, such as being unable to recognize real actions, unable to calculate the correct distance, etc.; at the same time, it may also cause security problems, such as frequently triggering the switching of devices by false gestures, being deceived by attackers at a long distance to open the door lock, etc. Therefore, providing a defense mechanism to ensure the normal operation of the radio frequency-based sensing system has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a defense mechanism to ensure the normal operation of the radio frequency-based sensing system, including a method for resisting spoofing attacks in radio frequency sensing, an initiating node, a responding node, a chip system, a computer-readable storage medium, a computer program product, etc.

[0006] In a first aspect of this application, a method for resisting spoofing attacks in radio frequency sensing, which is applied to a responding node, includes:

[0007] The response node receives a null data packet announcement NDPA frame and extracts a first composite feature parameter including in-phase / quadrature I / Q imbalance features and multipath channel features from the pilot subcarriers in the NDPA frame;

[0008] The response node receives an NDP frame for performing the current null data packet NDP measurement and extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly correlated long training fields LTFs in the NDP frame;

[0009] The response node compares the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards the current NDP measurement as invalid.

[0010] A second aspect of the present application provides a response node, including:

[0011] A transceiver, configured to receive a null data packet announcement NDPA frame and an NDP frame for performing the current null data packet NDP measurement;

[0012] A processor, configured to extract a first composite feature parameter including in-phase / quadrature I / Q imbalance features and multipath channel features from the pilot subcarriers in the NDPA frame; and extract a second composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly correlated long training fields LTFs in the NDP frame;

[0013] The processor is further configured to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regard the current NDP measurement as invalid.

[0014] In the first aspect or the second aspect of the present application, when the first composite feature parameter and the second composite feature parameter do not match, it means that the NDP frame received by the response node may be a forged or imitated pseudo-NDP frame. Therefore, the second composite feature parameter extracted therefrom does not match the first composite feature parameter extracted from the pilot subcarriers of the NDPA frame. Therefore, the response node can determine that there is an attacker and recognize that the current NDP detection or measurement is invalid, thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node.

[0015] In the first design of the first aspect or the second aspect of the present application, it is determined whether the first composite feature parameter and the second composite feature parameter match according to a preset threshold.

[0016] In the second design of the first or second aspect of the present application, it is determined whether the operation result of the first composite feature parameter and the second composite feature parameter is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

[0017] In the third design of the first or second aspect of the present application, the non-linearly related LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

[0018] In the fourth design of the first or second aspect of the present application, the non-linearly related LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0019] In the fifth design of the first or second aspect of the present application, the NDPA frame received by the response node carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

[0020] The third aspect of the present application provides a method for resisting spoofing attacks in radio frequency sensing, which is applied to an initiating node and includes:

[0021] The initiating node sends an empty data packet to pre-announce the NDPA frame to the response node;

[0022] The initiating node sends an NDP frame to the response node, and the NDP frame includes a plurality of non-linearly related long training fields LTF.

[0023] The fourth aspect of the present application provides an initiating node, including:

[0024] A transceiver, configured to send an empty data packet to pre-announce the NDPA frame to the response node;

[0025] The transceiver is further configured to send an NDP frame to the response node, and the NDP frame includes a plurality of non-linearly related long training fields LTF.

[0026] In the third or fourth aspect of the present application, by processing the LTF in the NDP frame sent by the initiating node to make it satisfy the non-linearly related characteristics, the response node can extract composite feature parameters therefrom, so that the response node can determine whether the received NDP frame is a forged or imitated pseudo-NDP frame, whether there is an attacker, etc., thereby preventing the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node.

[0027] In the first design of the third or fourth aspect of the present application, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

[0028] In the second design of the third or fourth aspect of the present application, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

[0029] In the third design of the third or fourth aspect of the present application, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0030] The fifth aspect of the present application provides a method for resisting spoofing attacks in radio frequency sensing, which is applied to an initiating node and includes:

[0031] The initiating node sends an empty data packet to pre-announce the NDPA frame to the response node;

[0032] The initiating node receives the empty data packet NDP frame sent by the response node to it, and the NDP frame includes a plurality of non-linearly correlated long training fields LTF;

[0033] The initiating node extracts a first composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated LTFs;

[0034] The initiating node receives the sounding measurement report SMR sent by the response node to it, and obtains a second composite feature parameter including I / Q imbalance features and multipath channel features;

[0035] The initiating node compares the first composite feature parameter with the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards this NDP measurement as invalid.

[0036] The sixth aspect of the present application provides an initiating node, including:

[0037] A transceiver, configured to send an empty data packet to pre-announce the NDPA frame to the response node;

[0038] The transceiver is further configured to receive the empty data packet NDP frame sent by the response node to it; the NDP frame includes a plurality of non-linearly correlated long training fields LTF;

[0039] A processor, configured to extract a first composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated LTFs;

[0040] The transceiver is further configured to receive a sounding measurement report (SMR) sent by the response node thereto;

[0041] The processor is further configured to obtain, from the SMR, a second composite feature parameter including I / Q imbalance features and multipath channel features;

[0042] The processor is further configured to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regard the current NDP measurement as invalid.

[0043] In the fifth or sixth aspect of the present application, by extracting composite feature parameters from the NDP frame and SMR sent by the response node, the initiating node can determine whether there is a forged or counterfeited NDP frame that has been tampered with, whether there is an attacker, etc., thereby preventing the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node.

[0044] In the first design of the fifth or sixth aspect of the present application, the obtaining of the second composite feature parameter including I / Q imbalance features and multipath channel features includes:

[0045] The initiating node extracts the second composite feature parameter from the pilot subcarriers of the SMR.

[0046] In the second design of the fifth or sixth aspect of the present application, the obtaining of the second composite feature parameter including I / Q imbalance features and multipath channel features includes:

[0047] The initiating node directly obtains the second composite feature parameter from the SMR, and the second composite feature parameter included in the SMR is extracted by the response node from the NDPA frame or the NDP frame.

[0048] In the third design of the fifth or sixth aspect of the present application, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in the current NDP measurement to defend against attackers.

[0049] In the fourth design of the fifth or sixth aspect of the present application, determining whether the first composite feature parameter and the second composite feature parameter match includes:

[0050] Determining whether the first composite feature parameter and the second composite feature parameter satisfy any one of the conjugate or inverse relationship.

[0051] In the fifth design of the fifth or sixth aspect of the present application, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same, but the phases are different.

[0052] In the sixth design of the fifth or sixth aspect of the present application, the non-linearly correlated LTF is an LTF sequence that has undergone cyclic shift processing in the frequency domain.

[0053] The seventh aspect of the present application provides a method for resisting spoofing attacks in radio frequency sensing, which is applied to a responder node and includes:

[0054] The responder node receives an empty data packet preamble NDPA frame sent by the initiator node to it or an NDP frame used for this empty data packet NDP measurement, where the NDP frame includes multiple non-linearly correlated long training fields LTF;

[0055] The responder node extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from the multiple non-linearly correlated LTFs of the NDPA frame or NDP frame;

[0056] The responder node sends a probe measurement report SMR to the initiator node, and the SMR includes the second composite feature parameter.

[0057] The eighth aspect of the present application provides a responder node, including:

[0058] A transceiver, configured to receive an empty data packet preamble NDPA frame sent by the initiator node to it or an NDP frame used for this empty data packet NDP measurement; where the NDP frame includes multiple non-linearly correlated long training fields LTF;

[0059] A processor, configured to extract a second composite feature parameter including I / Q imbalance features and multipath channel features from the multiple non-linearly correlated LTFs of the NDPA frame or NDP frame;

[0060] The transceiver is further configured to send a probe measurement report SMR to the initiator node, and the SMR includes the second composite feature parameter.

[0061] In the third or eighth aspect of the present application, by processing the LTF in the NDP frame sent by the responder node to the sender node to make it satisfy the non-linearly correlated characteristic, the initiator node can extract the composite feature parameter from it, so that the initiator node can determine whether the received NDP frame is a forged or imitated pseudo-NDP frame, whether there is an attacker, etc., thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiator node and the responder node.

[0062] In the first design of the seventh or eighth aspect of the present application, the NDPA frame received by the response node carries defense indication information, and the defense indication information is used to instruct the response node to extract and feedback composite feature parameters in this NDP measurement to defend against attackers.

[0063] In the second design of the seventh or eighth aspect of the present application, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

[0064] In the third design of the seventh or eighth aspect of the present application, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0065] The ninth aspect of the present application provides a chip system, including: at least one processor and an interface;

[0066] The processor is used to run a computer program to execute the method described in any one of the foregoing first aspect, third aspect, fifth aspect, and seventh aspect.

[0067] In the first design of the ninth aspect of the present application, the chip system further includes a memory coupled to the processor, which is used to store a computer program for implementing the method described in any one of the foregoing first aspect, third aspect, fifth aspect, and seventh aspect.

[0068] The tenth aspect of the present application provides a computer-readable storage medium, which is used to store a computer program. When the computer program is executed, the method described in any one of the foregoing first aspect, third aspect, fifth aspect, and seventh aspect is implemented.

[0069] The eleventh aspect of the present application provides a computer program product, which is used to store a computer program. When the computer program is executed, the method described in any one of the foregoing first aspect, third aspect, fifth aspect, and seventh aspect is implemented.

[0070] The twelfth aspect of the present application provides a sensing system, including a response node described in any one of the foregoing second aspect and eighth aspect and an initiating node described in any one of the foregoing fourth aspect and sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic diagram of a passive sensing scenario provided by an embodiment of the present application;

[0072] Figure 2 It is a schematic diagram of an active sensing scenario provided by an embodiment of the present application;

[0073] Figure 3 Structural schematic diagram of the data transmission device provided by an embodiment of the present application;

[0074] Figure 4 Structural schematic diagram of the initiating node provided by an embodiment of the present application;

[0075] Figure 5 Structural schematic diagram of the response node provided by an embodiment of the present application;

[0076] Figure 6 Structural schematic diagram of the chip system provided by an embodiment of the present application;

[0077] Figure 7 Structural schematic diagram of the NDP frame provided by an embodiment of the present application;

[0078] Figure 8 A process schematic diagram of the method for resisting spoofing attacks in radio frequency sensing provided by an embodiment of the present application;

[0079] Figure 9 Another scenario schematic diagram of the method for resisting spoofing attacks in radio frequency sensing provided by an embodiment of the present application;

[0080] Figure 10 Another process schematic diagram of the method for resisting spoofing attacks in radio frequency sensing provided by an embodiment of the present application;

[0081] Figure 11 Another scenario schematic diagram of the method for resisting spoofing attacks in radio frequency sensing provided by an embodiment of the present application;

[0082] Figure 12 Another scenario schematic diagram of the method for resisting spoofing attacks in radio frequency sensing provided by an embodiment of the present application. Detailed implementation manners

[0083] Next, the technical solutions in the present application will be described with reference to the accompanying drawings.

[0084] The method of the embodiment of the present application involves a scenario of sensing between an initiating node and a response node, and can be applied to a wireless local area network (WLAN) system, especially to WLAN systems complying with the 802.11ad standard, the 802.11ay standard, and subsequent improved standards of these standards.

[0085] Based on the sensing of Wireless Fidelity (WiFi) signals, it can be divided into two types: sensing of passive objects and sensing of active objects.

[0086] Such as Figure 1As shown, passive objects affect the signal amplitude, time delay, and Doppler frequency shift of the receiver signal by reflecting WiFi signals. The WiFi receiver infers the state of surrounding passive objects from these characteristics. Based on WiFi signal-based passive object sensing, applications such as gesture recognition, motion recognition, and respiration monitoring can be developed.

[0087] As Figure 2 shown, active objects calculate the distance between each other through the timestamps of the transmitted frames sent to each other. Using active object sensing based on WiFi signals, functions such as automatic door opening when a wireless car key / door lock approaches can be developed.

[0088] Whether it is the sensing of active objects or the sensing of passive objects, these sensing applications are vulnerable to spoofing attacks by attackers.

[0089] Spoofing attacks can cause the system to malfunction, such as being unable to recognize real actions, unable to calculate the correct distance, etc.; at the same time, it may also cause security problems, such as being frequently triggered to switch devices by false gestures, being spoofed by attackers at a distance to open the door lock, etc.

[0090] Therefore, this application provides a defense mechanism to ensure the normal operation of the radio frequency-based sensing system.

[0091] The embodiments of this application can be applied to Figure 1 the passive sensing scenario shown, and can also be applicable to Figure 2 the active sensing scenario shown.

[0092] In the embodiments of this application, the initiating node of WLAN sensing or WiFi sensing can also be called the transmitting node. As Figure 1 shown, it can be represented as WiFi Tx. As Figure 2 shown, it can be represented as the initiator;

[0093] The responding node of WLAN sensing or WiFi sensing can also be called the receiving node. As Figure 1 shown, it can be represented as WiFi Rx; as Figure 2 shown, it can be represented as the responder.

[0094] In specific implementation, the initiating node or transmitting node can be a non-station access point (non-STA AP), and the corresponding responding node or receiving node can be a station (STA) or an AP.

[0095] Or, the initiating node or transmitting node can be a STA, and the corresponding responding node or receiving node can be an AP or a STA.

[0096] In the embodiments of the present application, the transmitting node is mainly taken as an AP and the responding node is taken as an STA for illustration. Other scenarios are similar and will not be exemplified one by one.

[0097] Among them, the access point can be an access point for a terminal device (such as a mobile phone) to access a wired (or wireless) network, mainly deployed inside homes, buildings, and campuses. The typical coverage radius is dozens of meters to hundreds of meters. Of course, it can also be deployed outdoors. The access point is equivalent to a bridge connecting a wired network and a wireless network. Its main function is to connect various wireless network clients together and then connect the wireless network to the Ethernet. Specifically, the access point can be a terminal device (such as a mobile phone) or a network device (such as a router) with a wireless-fidelity (WiFi) chip. The access point can be a device supporting the 802.11be standard. The access point can also be a device supporting multiple wireless local area network (WLAN) standards of the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. The access point in the present application can be a high efficient (HE) AP or an extremely high throughput (EHT) AP, and can also be an access point applicable to a future generation of WiFi standard.

[0098] The station can be a wireless communication chip, a wireless sensor, a wireless communication terminal, etc., and can also be called a user. For example, the station can be a mobile phone supporting WiFi communication function, a tablet computer supporting WiFi communication function, a set-top box supporting WiFi communication function, a smart TV supporting WiFi communication function, a smart wearable device supporting WiFi communication function, a vehicle-mounted communication device supporting WiFi communication function, and a computer supporting WiFi communication function, etc. Optionally, the station can support the 802.11be standard. The station can also support multiple wireless local area network (WLAN) standards of the 802.11 family, such as 802.11be, 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0099] The station in the present application can be a high efficient (HE) STA or an extremely high throughput (EHT) STA, and can also be an STA applicable to a future generation of WiFi standard.

[0100] For example, the access point and the station can be devices applied to the vehicle networking, IoT (Internet of Things) nodes, sensors in the Internet of Things, smart cameras in the smart home, smart remote controls, smart water meters and electricity meters, and sensors in the smart city, etc.

[0101] Although the embodiments of this application mainly take the network deployed with IEEE 802.11 as an example for illustration, those skilled in the art can easily understand that all aspects involved in this application can be extended to other networks adopting various standards or protocols. For example, BLUETOOTH, high performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard, mainly used in Europe), and wide area network (WAN), wireless local area network (WLAN), personal area network (PAN), or other networks known now or developed in the future. Therefore, regardless of the coverage range and wireless access protocol used, all aspects provided by this application can be applicable to any suitable wireless network.

[0102] Figure 4 It is a schematic structural diagram of a data transmission device provided by the embodiments of this application. It can illustrate the initiating node in the embodiments of this application, or can also illustrate the responding node in this application.

[0103] As Figure 4 shown, the data transmission device 200 may include: a processor 201, a transceiver 205, and optionally a memory 202.

[0104] The transceiver 205 can be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., for implementing the transceiver function. The transceiver 205 can include a receiver and a transmitter. The receiver can be referred to as a receiver or a receiving circuit, etc., for implementing the receiving function; the transmitter can be referred to as a transmitter or a transmitting circuit, etc., for implementing the transmitting function.

[0105] A computer program, software code, or instructions 204 can be stored in the memory 202, and the computer program, software code, or instructions 204 can also be referred to as firmware. The processor 201 can control the MAC layer and the PHY layer by running the computer program, software code, or instructions 203 therein, or by calling the computer program, software code, or instructions 204 stored in the memory 202, so as to implement the following embodiments of the present application. Among them, the processor 201 can be a central processing unit (CPU), and the memory 202 can be, for example, a read-only memory (ROM) or a random access memory (RAM).

[0106] The processor 201 and the transceiver 205 described in the present application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit RFIC, a mixed-signal IC, an application-specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc.

[0107] The above data transmission device 200 may further include an antenna 206. The modules included in the data transmission device 200 are only for illustrative purposes, and the present application does not limit this.

[0108] Please refer to Figure 5 , Figure 5 which is a schematic structural diagram of an initiating node provided by an embodiment of the present application. The initiating node can be used to implement any method and function related to the initiating node in the embodiments of the present application. The initiating node may include a processing module 301 and a sending module 302. Optionally, the sending module 302 corresponds to a baseband circuit and a radio frequency circuit included in the initiating node. The initiating node serves as the sending end of radio frequency sensing. The detailed descriptions of each module are as follows.

[0109] In one embodiment, the initiating node includes:

[0110] A processing module 301, configured to generate an NDPA frame and an NDP frame to be sent;

[0111] In one possible implementation, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

[0112] Among them, the NDP frame includes a plurality of non-linearly correlated LTFs.

[0113] In one implementation, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

[0114] In another implementation, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0115] The sending module 302 is configured to send an NDPA frame and an NDP frame to the receiving end device.

[0116] In this embodiment, by processing the LTF in the NDP frame sent by the initiating node to make it satisfy the non-linearly correlated characteristic, the responding node can extract composite feature parameters therefrom, so that the responding node can determine whether the received NDP frame is a forged or imitated pseudo-NDP frame, whether there is an attacker, etc., thereby avoiding an attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the responding node.

[0117] In another embodiment, the initiating node includes:

[0118] The transceiver module 302 is configured to send an NDPA frame of an empty data packet to the responding node; optionally, the defense indication information is used to instruct the responding node to extract and feedback composite feature parameters in this NDP measurement to defend against attackers.

[0119] The transceiver module 302 is further configured to receive an NDP frame of an empty data packet sent by the responding node; the NDP frame includes a plurality of non-linearly correlated long training fields LTF;

[0120] The processing module 301 is configured to extract a first composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated LTFs;

[0121] In one implementation, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

[0122] In another implementation, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0123] The transceiver module 302 is further configured to receive a sounding measurement report SMR sent by the responding node to it;

[0124] The processing module 301 is further configured to obtain a second composite feature parameter including I / Q imbalance features and multipath channel features from the SMR;

[0125] In one implementation, the processing module 301 extracts the second composite feature parameter from the pilot subcarriers of the SMR.

[0126] In another implementation, the processing module 301 directly obtains the second composite feature parameter from the SMR, and the second composite feature parameter included in the SMR is extracted by the response node from the NDPA frame or the NDP frame.

[0127] The processing module 301 is further configured to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regard the current NDP measurement as invalid.

[0128] In a specific implementation, the processing module 301 determines whether the first composite feature parameter and the second composite feature parameter satisfy any one of the conjugate or inversion relationships.

[0129] In this embodiment, by processing the LTF in the NDP frame sent by the response node to the sending node to make it satisfy the non-linear correlation characteristic, the initiating node can extract the composite feature parameter therefrom, so that the initiating node can determine whether the received NDP frame is a forged or imitated pseudo-NDP frame, whether there is an attacker, etc., thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node.

[0130] Please refer to Figure 6 , Figure 6 FIG. is a schematic structural diagram of a response node provided by an embodiment of the present application. The response node can be used to implement any method and function related to the response node in any embodiment of the present application. The response node may include a receiving module 401 and a processing module 402. Among them, the response node is the receiving end of radio frequency sensing, and the detailed description of each module is as follows.

[0131] In one implementation manner,

[0132] The receiving module 401 is configured to receive the null data packet preamble NDPA frame and the NDP frame for performing the current null data packet NDP measurement; optionally, the NDPA frame received by the receiving module 401 carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in the current NDP measurement to defend against attackers.

[0133] Among them, the non-linearly correlated LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

[0134] Alternatively, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0135] A processing module 402, configured to extract a first composite feature parameter including in-phase / quadrature I / Q imbalance features and multipath channel features from pilot subcarriers in the NDPA frame; and extract a second composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly correlated long training fields LTFs of the NDP frame;

[0136] The processing module 402 is further configured to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regard the current NDP measurement as invalid. In a specific implementation, the processing module 402 determines whether the first composite feature parameter and the second composite feature parameter match according to a preset threshold. For example, the processing module 402 determines whether the operation result of the first composite feature parameter and the second composite feature parameter is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

[0137] In this embodiment, by processing the LTF in the NDP frame sent by the initiating node to make it satisfy the non-linearly correlated characteristic, the responding node can extract the composite feature parameter therefrom, so as to determine whether the received NDP frame is a forged or imitated pseudo NDP frame, whether there is an attacker, etc., thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the responding node.

[0138] In another implementation, the responding node includes:

[0139] A receiving module 401, configured to receive an empty data packet preview NDPA frame sent by the initiating node to it or an NDP frame for performing the current empty data packet NDP measurement; optionally, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the responding node to perform extraction and feedback of composite feature parameters in the current NDP measurement to defend against attackers.

[0140] Wherein, the NDP frame includes multiple non-linearly correlated long training fields LTFs.

[0141] In one implementation, the non-linearly correlated LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

[0142] In another implementation, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

[0143] A processing module 402, configured to extract a second composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly correlated LTFs of the NDPA frame or the NDP frame;

[0144] The receiving module 401 is further configured to send a probe measurement report SMR to the initiating node, where the SMR includes the second composite feature parameter.

[0145] In this embodiment, by processing the LTF in the NDP frame sent by the response node to the sending node to make it satisfy the non-linearly correlated characteristic, the initiating node can extract the composite feature parameter from it, so that the initiating node can determine whether the received NDP frame is a forged or imitated pseudo-NDP frame, whether there is an attacker, etc., thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the perception and transmission between the initiating node and the response node.

[0146] It should be noted that the implementation of each module can also correspond to the corresponding description of the method embodiment of the present application, and execute the methods and functions performed by the receiving end device in the above embodiments.

[0147] An embodiment of the present application further provides a processor, configured to be coupled to a memory and execute the methods and functions involved in any one of the embodiments of the present application.

[0148] An embodiment of the present application further provides a computer program product containing instructions, which when running on a computer, causes the computer to execute the methods and functions involved in any one of the embodiments of the present application.

[0149] An embodiment of the present application further provides a device for executing any method and function involved in any one of the embodiments of the present application described above.

[0150] An embodiment of the present application further provides a wireless communication system, which includes at least one initiating node and at least one response node involved in any one of the embodiments of the present application.

[0151] As mentioned above, the data transmission device described in the above embodiments can be an access point or a station, but the scope of the data transmission device described in the present application is not limited thereto, and the structure of the data transmission device can be Figures 4 to 6 not limited. The data transmission device can be an independent device or can be a part of a larger device. For example, the implementation form of the data transmission device can be:

[0152] (1) An independent integrated circuit IC, or chip, or chip system or subsystem; (2) A set having one or more ICs, optionally, the IC set may also include a storage component for storing data and instructions; (3) A module that can be embedded in other devices; (4) A receiver, smart terminal, wireless device, handset, mobile unit, vehicle-mounted device, cloud device, artificial intelligence device, etc.; (5) Others, etc.

[0153] For the case where the implementation form of the data transmission device is a chip or a chip system, reference can be made to Figure 7 The schematic structural diagram of the chip shown. Figure 7 The chip shown includes a processor 501 and an interface 502. Among them, the number of processors 501 can be one or more, and the number of interfaces 502 can be multiple. Optionally, the chip or chip system may include a memory 503.

[0154] The embodiments of the present application do not limit the protection scope and applicability of the claims. Those skilled in the art can make adaptive changes to the functions and deployments of the elements involved in the present application without departing from the scope of the embodiments of the present application, or omit, substitute or add various processes or components as appropriate.

[0155] Before introducing the technical solutions provided by the present application to resist spoofing attacks in radio frequency sensing, the following explanations are made for the technical terms and related concepts in the embodiments of the present application.

[0156] 1. Orthogonal frequency division multiplexing (OFDM): Orthogonal frequency division multiplexing is a multi-carrier transmission technology that uses a large number of adjacent orthogonal subcarriers, where each subcarrier is modulated using a traditional modulation technique, enabling the technology to have the ability of high-rate transmission and effectively combat frequency selective fading. Therefore, many wireless transmission protocols adopt orthogonal frequency division multiplexing.

[0157] 2. Pilot subcarrier / Data subcarrier: In the WIFI protocol, except for the preamble, each OFDM symbol generally includes pilot subcarriers and data subcarriers. A pilot subcarrier is a subcarrier in an OFDM symbol that carries a preset sequence, and a data subcarrier is a subcarrier that carries transmission data. In a communication system, pilot subcarriers are generally used to help detect and correct subcarrier phase offsets, thereby improving the accuracy of data subcarrier parsing.

[0158] 3. Null Data Packet (NDP) sounding: Null Data Packet sounding is a way to obtain channel state information or beamforming information. A null data packet only contains a preamble and no data. In the sounding process, the initiating node first sends a null data packet, and the responding node detects the null data packet and calculates the channel state information / beamforming information and returns it to the sending initiating node. The initiating node can adjust the subsequent transmitted packets accordingly based on the feedback information. NDP sounding can also be referred to as NDP measurement.

[0159] 4. LTF (Long training field): The long training field is located at the head of the transmission packet. This LTF sequence is generally used for channel measurement. The LTF symbol mentioned in the embodiments of this application refers to the OFDM symbol occupied by the transmitted LTF sequence in the time domain; the LTF sequence refers to the LTF sequence transmitted on the subcarriers corresponding to the LTF symbol.

[0160] As Figure 7 shown, it is a schematic diagram of a possible NDP frame in 802.11be. This NDP frame is a transmission packet that does not include a data field. The functions of each field are shown in Table 1, where the LTF is divided into two categories: L-LTF (legacy-LTF) and Extremely High Throughput Long Training Field (EHT-LTF).

[0161] Table 1

[0162]

[0163] 5. Composite feature parameters of I (in-phase) / Q (quadrature) imbalance characteristics and multipath channel characteristics: In an OFDM symbol, if the transmitted signal S and the received signal Z are known, then the received signals of the i-th OFDM symbol and the (i + 1)-th OFDM symbol are respectively:

[0164]

[0165]

[0166] In this application, and are called composite feature parameters. When the matrix is full rank, the above two equations (1) and (2) have a unique solution, that is, the composite feature parameters and This composite feature parameter has two features: I / Q imbalance feature and multipath channel feature.

[0167] The I / Q imbalance feature includes I / Q gain imbalance and I / Q phase mismatch. During signal transmission, the signal will be affected by the I / Q imbalance of the transmitter and the I / Q imbalance of the receiver.

[0168] The multipath channel feature means that during signal transmission, the signal will be affected by the channel.

[0169] The parameter that comprehensively characterizes the I / Q imbalance feature and the multipath channel feature is called the composite feature parameter, and the specific representation is as follows: H k represents the channel coefficient of subcarrier k in the frequency domain. β R =-β T , representing the I / Q imbalance feature.

[0170] This composite feature parameter can be used to characterize the device features and channel features of the transmitter and the receiver. Therefore, it can be used to determine whether the transmitter is legal.

[0171] Next, the specific implementation process of resisting spoofing attacks in RF sensing in the WLAN system will be described.

[0172] See Figure 8 , which is the flowchart of the method for resisting spoofing attacks in RF sensing provided by this application; in this embodiment, the function of resisting RF sensing is mainly implemented at the response node.

[0173] Step 100, the initiating node sends an NDPA frame to the response node; in an optional implementation manner, when the initiating node sends an NDPA frame to the response node, it further includes defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

[0174] Step 101, after receiving the NDPA frame, the response node extracts the first composite feature parameter including the in-phase / quadrature I / Q imbalance feature and the multipath channel feature from the pilot subcarriers of the NDPA frame.

[0175] Step 102, the initiating node sends an NDP frame to the response node; where the NDP frame includes multiple LTFs, and these multiple LTFs are non-linearly correlated.

[0176] Specifically, in the embodiment of this application, phase rotation or cyclic shift processing is performed on the LTFs of the NDP frame, so that the multiple LTFs are non-linearly correlated.

[0177] In one implementation: The non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different. Specifically, different phase rotation values are introduced for the positive and negative subcarriers corresponding to adjacent LTF symbols, so that the corresponding matrix is full rank, and thus the second composite feature parameter can be extracted from the LTF of the NDP frame. An example is to normally transmit the first LTF symbol. When transmitting the second LTF symbol, the sequence values of the subcarriers at k>0 in the original LTF sequence are all multiplied by -1 or ±j, so that the sequence values corresponding to the same subcarrier on adjacent symbols have the same amplitude and different phases. Here, k represents the index of the subcarrier, and ±j is the unit imaginary number.

[0178] In the second implementation: The non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain. Specifically, different circular shifts are performed on each transmitted LTF sequence in the frequency domain, so that the training values on the same subcarrier of different symbols are different. In one example, the relationship between the new sequence training value after circular shift and the original training sequence value S(k) is as follows: where k represents the index of the subcarrier and offset is the offset.

[0179] The attacker copies the normal NDP frame sent by the initiating node, simply referred to as a pseudo-NDP frame, and acts as a legitimate initiating node in the subsequent transmission process to transmit between the initiating node and the responding node, so as to interfere with the ranging between the initiating node and the responding node;

[0180] Step 103, the responding node extracts the second composite feature parameter including the I / Q imbalance feature and the multipath channel feature from multiple non-linearly correlated long training fields LTF of the received NDP frame;

[0181] Since the attacker copies the NDP frame sent by the initiating node at this time, the NDP frame received by the responding node at this time will include the normal NDP frame sent by the initiating node and also the pseudo-NDP frame sent by the attacker.

[0182] The responding node can also extract the composite feature parameter from the NDPA frame after receiving the NDP frame, that is, the above step 101 can also be performed after step 102.

[0183] Step 104, the responding node compares the first composite feature parameter and the second composite feature parameter. When the first composite feature parameter and the second composite feature parameter do not match, the current NDP measurement is regarded as invalid. At this time, the responding node determines that there is an attacker at this time.

[0184] In a specific implementation, the response node may determine whether the first composite feature parameter and the second composite feature parameter match according to a preset threshold;

[0185] Specifically, it is determined whether the operation result of the first composite feature parameter and the second composite feature parameter is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

[0186] The first composite feature parameter is and The second composite feature parameter is and It is determined that the first composite feature parameter is and and the second composite feature parameter is and The following implementation methods are available for determining whether the operation result of

[0187] In one example, it is determined whether the operation result of is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

[0188] In another example, it is determined whether the absolute value of or the absolute value of is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

[0189] Among them, the threshold T may be the value with the largest absolute value among the first composite feature parameter and the second composite feature parameter; or the value with the smallest absolute value; or the threshold T is zero.

[0190] The aforementioned step 100 and step 102 can be implemented by the transceiver 205 in the data transmission device (as the initiating node) shown in Figure 3 or by the sending module 302 in the sending node shown in Figure 4 or by the interface 502 shown in Figure 6 ;

[0191] Regarding the receiving operation performed by the response node in step 101 and step 103, it can be implemented by the transceiver 205 in the data transmission device (as the response node) shown in Figure 3 or by Figure 5The receiving module 401 in the response node shown is implemented, or implemented by Figure 6 the interface 502 shown;

[0192] The processing operations performed by the response node in steps 101, 103, and 104 can be executed by the processor 201 of the data transmission device (as the response node) shown as Figure 3 , or implemented by the processing module 402 of the response node shown as Figure 5 , or implemented by the processor 501 shown as Figure 6 .

[0193] Since the physical locations of the initiating node and the attacker are different, the composite characteristic parameters of the NDPA frame sent by the initiating node and the NDP frame sent by the attacker are different. Based on this, the embodiments of the present application identify the attacker.

[0194] One example is as Figure 9 shown:

[0195] The initiating node first sends NDPA1 to the response node, and then sends NDP1 to the response node; at this time, the attacker copies and generates a pseudo NDP1 by interfering with the physical layer header of NDP1 and sends it to the response node with a stronger transmission power, intending to attack or interfere with the initiating node and the response node in the subsequent sensing process.

[0196] The initiating node sends NDPA2 and NDP2 to the response node again for sensing with the response node; when the attacker sends the pseudo NDP1 with a stronger transmission power, the response node receives the pseudo NDP1 and extracts the second composite characteristic parameter from it, and this second composite characteristic parameter does not match the first composite characteristic parameter extracted from the NDPA frame sent by the initiating node; or when the initiating node sends NDP2 and the power of the pseudo NDP1 sent by the attacker is approximately the same, the NDP frame received by the response node contains NDP2 sent by the initiating node and the tampered or imitated pseudo NDP1 sent by the attacker. Therefore, the second composite characteristic parameter extracted by the response node from the multipath signal composed of NDP2 and the pseudo NDP1 definitely does not match the first composite characteristic parameter extracted from the NDPA frame sent by the initiating node. Therefore, the response node can determine that there is an attacker and determine that this NDP detection or measurement is invalid, thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node. Moreover, implementing the present application increases the difficulty for the attacker to attack WLAN sensing, but the additional system overhead is very small.

[0197] Optionally, the response node can continue to send NDP2 and SMR to the initiating node.

[0198] Such as Figure 8 and Figure 9In the illustrated embodiment, the method for resisting spoofing attacks in radio frequency sensing is implemented by the interaction of NDPA frames and NDP frames between the initiating node and the responding node. In addition, in the embodiments of the present application, the responding node or the initiating node can also extract composite feature parameters from the pilot subcarriers of ordinary data frames for matching to identify whether there is an attacker.

[0199] In one example, on the side of the responding node, composite feature parameters are extracted from the pilot subcarriers corresponding to adjacent OFDM symbols in the PPDU received from the initiating node for matching. The matching method can be as described above. It is determined whether the composite feature parameters extracted from the pilot subcarriers corresponding to adjacent OFDM symbols are greater than the threshold T. If so, it indicates that there is an attacker at this time. If it is not greater than the threshold, the PPDU sent by the initiating node is trusted.

[0200] In another example, on the side of the initiating node, composite feature parameters are extracted from the pilot subcarriers corresponding to adjacent OFDM symbols in the PPDU received from the responding node for matching. The matching method can be as described above. It is determined whether the composite feature parameters extracted from the pilot subcarriers corresponding to adjacent OFDM symbols are greater than the threshold T. If so, it indicates that there is an attacker at this time. If it is not greater than the threshold, the PPDU sent by the initiating node is trusted.

[0201] See Figure 10 , which is the flowchart of the method for resisting spoofing attacks in radio frequency sensing provided by the present application. In this embodiment, the function of resisting radio frequency sensing is mainly implemented at the initiating node.

[0202] Step 200, the initiating node sends an NDPA frame to the responding node; in an optional implementation manner, the initiating node further includes defense indication information in the NDPA frame sent to the responding node, and the defense indication information is used to instruct the responding node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

[0203] Step 201, the initiating node sends an empty data packet NDP frame to the responding node, and the NDP frame includes a plurality of non-linearly correlated long training fields LTF;

[0204] Step 202, the responding node receives at least one of the NDPA frame and the NDP frame sent from the initiating node, and extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from the pilot subcarriers of the NDPA frame or multiple LTFs of the NDP frame respectively; alternatively, the second composite feature parameter including I / Q imbalance features and multipath channel features can also be extracted from the pilot subcarriers of the NDPA frame and multiple LTFs of the NDP frame simultaneously; then, the responding node carries the second composite feature parameter in a sounding measurement report (SMR) and sends it to the initiating node;

[0205] Step 203, the initiating node receives the null data packet NDP frame sent by the responding node to it, and the NDP frame includes multiple non-linearly correlated long training fields LTF;

[0206] Step 204, the initiating node extracts a first composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly correlated LTFs in the NDP frame from the responding node;

[0207] Step 205, the initiating node receives the sounding measurement report SMR sent by the responding node to it, and directly obtains the second composite feature parameter from it;

[0208] Step 206, the initiating node compares the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards this NDP measurement as invalid.

[0209] In a specific implementation, it can be determined whether the first composite feature parameter and the second composite feature parameter match by determining whether the first composite feature parameter and the second composite feature parameter satisfy any one of the conjugate or inverse relationship.

[0210] The detailed details of the first composite feature parameter and the second composite feature parameter have been described in detail in the foregoing embodiments, and will not be elaborated here.

[0211] The foregoing steps 200 and 201 can be implemented by Figure 3 the transceiver 205 in the data transmission device (as the initiating node) shown, or by Figure 4 the sending module 302 in the sending node shown, or by Figure 6 the interface 502 shown;

[0212] The operations of the initiating node in steps 203 and 205 can be implemented by the transceiver 205 in the data transmission device (as the initiating node) shown in 3, or by Figure 4The receiving module 303 in the sending node shown is implemented, or implemented by Figure 6 the interface 502 shown;

[0213] The processing operations of step 204, step 205, and step 206 can be implemented by the processor 201 in the data transmission device (as the initiating node) shown in 3, or by Figure 4 the processing module 302 in the sending node shown, or by Figure 6 the processor 501 shown;

[0214] Regarding the receiving operation performed by the response node in step 202, it can be implemented by Figure 3 the transceiver 205 in the data transmission device (as the response node) shown, or by Figure 5 the receiving module 401 in the response node shown, or by Figure 6 the interface 502 shown;

[0215] Regarding the processing operation performed by the response node in step 202, it can be executed by the processor 201 of the data transmission device (as the response node) as shown in Figure 3 , or implemented by Figure 5 the processing module 402 of the response node shown, or by Figure 6 the processor 501 shown.

[0216] Since the physical locations of the initiating node and the attacker are different, the composite characteristic parameters of the NDP frames sent by the initiating node and the attacker are different. Based on this, the embodiments of the present application identify the attacker.

[0217] An example is as Figure 11 shown:

[0218] The initiating node first sends NDPA1 to the response node, and then sends NDP1 to the response node;

[0219] The response node sends NDP1 to the initiating node. At this time, the attacker copies and generates a pseudo-NDP1 by interfering with the physical layer header of the NDP1 sent by the response node and sends it to the initiating node with a stronger transmission power, intending to attack or interfere with the initiating node and the response node in the subsequent sensing process.

[0220] The response node then extracts the composite characteristic parameters from NDPA1 and / or NDP1 and sends them to the sending node in the SMR;

[0221] The initiating node sends NDPA2 and NDP2 to the response node again to perform sensing with the response node;

[0222] The responding node sends NDP2 to the initiating node; the attacker sends fake NDP1 to the initiating node; when the attacker sends fake NDP1 with a stronger transmission power, the responding node receives the fake NDP1 and extracts the second composite feature parameter therefrom, and this second composite feature parameter does not match the first composite feature parameter extracted from the NDPA frame sent by the initiating node; or when the power of the NDP2 sent by the initiating node is approximately the same as the power of the fake NDP1 sent by the attacker, the NDP frame received by the initiating node contains the NDP2 sent by the responding node and the tampered or imitated fake NDP1 sent by the attacker. Therefore, the second composite feature parameter extracted by the initiating node from the multipath signal composed of NDP2 and fake NDP1 definitely does not match the first composite feature parameter carried in the SMR sent by the responding node. Therefore, the initiating node can determine that there is an attacker and determine that this NDP detection or measurement is invalid, thus avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the responding node. Moreover, by implementing this application, the difficulty for the attacker to attack the WLAN sensing is increased, but the additional system overhead is very small.

[0223] Optionally, the responding node can continue to send the SMR to the initiating node.

[0224] In the embodiment of this application, the responding node receives the NDPA frame or NDP frame of the initiating node, extracts the second composite feature parameter at least based on one of them, and then sends it to the initiating node through the SMR. The initiating node can extract the first composite feature parameter from the NDP frame sent by the responding node to it. The initiating node determines whether there is an attacker and determines whether this NDP detection or measurement is invalid by judging whether the first composite feature parameter and the second composite feature parameter satisfy the conjugate or negation relationship, thus avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the responding node. Moreover, by implementing this application, the difficulty for the attacker to attack the WLAN sensing is increased, but the additional system overhead is very small.

[0225] See Figure 12 , which is the flowchart of the method for resisting spoofing attacks in radio frequency sensing provided by this application. In this embodiment, the function of resisting radio frequency sensing is mainly implemented at the initiating node.

[0226] Step 300, the initiating node sends an NDPA frame to the responding node; in an optional implementation manner, when the initiating node sends the NDPA frame to the responding node, it further includes defense indication information, and the defense indication information is used to instruct the responding node to perform composite feature parameter matching in this NDP measurement to defend against the attacker.

[0227] Step 301, the initiating node sends an empty data packet NDP frame to the responding node, and the NDP frame includes multiple non-linearly related long training fields LTF;

[0228] Step 302: The responding node sends an SMR to the initiating node.

[0229] Step 303: The initiating node receives the null data packet NDP frame sent by the responding node, and the NDP frame includes multiple non-linearly related long training fields LTF.

[0230] Step 304: The initiating node extracts a first composite feature parameter including I / Q imbalance features and multipath channel features from multiple non-linearly related LTFs in the NDP frame from the responding node.

[0231] Step 305: The initiating node receives the SMR sent by the responding node and extracts a second composite feature parameter from the pilot subcarriers of the SMR.

[0232] Step 306: The initiating node compares the first composite feature parameter and the second composite feature parameter. When the first composite feature parameter and the second composite feature parameter do not match, this NDP measurement is regarded as invalid.

[0233] In a specific implementation, it can be determined whether the first composite feature parameter and the second composite feature parameter match by determining whether the first composite feature parameter and the second composite feature parameter satisfy any one of the conjugate or negation relationships.

[0234] The detailed details of the first composite feature parameter and the second composite feature parameter have been described in detail in the foregoing embodiments and will not be elaborated herein.

[0235] The sending operations performed by the initiating node in the foregoing steps 300 and 301 can be implemented by the transceiver 205 in the data transmission device (acting as the initiating node) shown in Figure 3 or by the sending module 302 in the sending node shown in Figure 4 or by the interface 502 shown in Figure 6 ;

[0236] The receiving operations of the initiating node in steps 303 and 305 can be implemented by the transceiver 205 in the data transmission device (acting as the initiating node) shown in 3, or by Figure 4 the receiving module 303 in the sending node shown in Figure 6 or by the interface 502 shown in

[0237] The processing operations of steps 304, 305, and 306 can be implemented by the processor 201 in the data transmission device (acting as the initiating node) shown in 3, or by Figure 4 the processing module 302 in the sending node shown in Figure 6Implemented by the processor 501 shown;

[0238] Regarding the sending operation performed by the response node in step 302, it can be implemented by Figure 3 The transceiver 205 in the data transmission device (as the response node) shown, or by Figure 5 The sending module 403 in the response node shown, or by Figure 6 The interface 502 shown.

[0239] Different from the previous embodiment, in the embodiment of the present application, the response node receives the NDPA frame or NDP frame from the initiating node, but does not extract the second composite feature parameter. Instead, it sends an SMR to the initiating node. Also refer to Figure 11 , the initiating node can extract the first composite feature parameter from the NDP2 frame sent by the response node to it, and extract the second composite feature parameter from the pilot subcarriers in the SMR sent by the response node. Then, the initiating node determines whether there is an attacker, and determines whether this NDP detection or measurement is invalid by judging whether the first composite feature parameter and the second composite feature parameter satisfy the conjugate or negation relationship, thereby avoiding the attacker from intervening in the subsequent transmission process and interfering with the sensing and transmission between the initiating node and the response node. Moreover, implementing the present application increases the difficulty for the attacker to attack WLAN sensing, but the additional system overhead is very small.

[0240] Those skilled in the art can also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such a function is implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can use various methods to implement the described function for each specific application, but such implementation should not be construed as exceeding the scope protected by the embodiments of the present application.

[0241] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a high-density digital video disc (DVD)), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0242] Those of ordinary skill in the art can understand that the various digital numbers such as the first and second involved in this application are only for the convenience of description and are not used to limit the scope of the embodiments of this application, nor do they represent the order of precedence.

[0243] The corresponding relationships shown in the tables in this application can be configured or predefined. The values taken by the information in each table are only examples and can be configured as other values, which are not limited in this application. When configuring the corresponding relationships between the configuration information and each parameter, it is not necessarily required to configure all the corresponding relationships shown in the tables. For example, in the tables of this application, the corresponding relationships shown in some rows can also not be configured. Also, for example, appropriate deformation adjustments can be made based on the above tables, such as splitting, merging, etc. The names of the parameters shown in the titles of the above tables can also use other names that can be understood by the communication device, and the values taken or the representation methods of the parameters can also use other values or representation methods that can be understood by the communication device. When implementing the above tables, other data structures can also be used, such as arrays, queues, containers, stacks, linear lists, pointers, linked lists, trees, graphs, structures, classes, heaps, hash tables, or hash tables, etc.

[0244] The predefined in this application can be understood as definition, predefined, storage, prestorage, pre - negotiation, pre - configuration, solidification, or pre - firing.

[0245] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0246] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0247] As described above, it is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A method for resisting spoofing attacks in radio frequency sensing, which is applied to a responder node. Characterized in that, It includes: The responder node receives a Null Data Packet Announcement (NDPA) frame and extracts a first composite feature parameter including in-phase / quadrature (I / Q) imbalance characteristics and multipath channel characteristics from the pilot subcarriers of the NDPA frame; The responder node receives a Null Data Packet (NDP) frame for performing the current NDP measurement and extracts a second composite feature parameter including I / Q imbalance characteristics and multipath channel characteristics from multiple non-linearly correlated Long Training Fields (LTFs) of the NDP frame; The responder node compares the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards the current NDP measurement as invalid.

2. The method according to claim 1, Characterized in that, According to a preset threshold T, it is judged whether the first composite feature parameter and the second composite feature parameter match.

3. The method according to claim 2, Characterized in that, It is judged whether the operation result of the first composite feature parameter and the second composite feature parameter is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

4. The method according to claim 1, Characterized in that, The non-linearly correlated LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

5. The method according to claim 1, Characterized in that, The non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

6. The method according to claim 1, Characterized in that, The NDPA frame received by the responder node carries defense indication information, and the defense indication information is used to instruct the responder node to perform composite feature parameter matching in the current NDP measurement to defend against attackers.

7. A responder node, Characterized in that, It includes: A transceiver for receiving a Null Data Packet Announcement (NDPA) frame and an NDP frame for performing the current NDP measurement; A processor for extracting a first composite feature parameter including in-phase / quadrature (I / Q) imbalance characteristics and multipath channel characteristics from the pilot subcarriers in the NDPA frame; and extracting a second composite feature parameter including I / Q imbalance characteristics and multipath channel characteristics from multiple non-linearly correlated Long Training Fields (LTFs) of the NDP frame; The processor is further used to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards the current NDP measurement as invalid.

8. The responder node according to claim 7, Characterized in that, According to a preset threshold T, it is judged whether the first composite feature parameter and the second composite feature parameter match.

9. The responder node according to claim 8, Characterized in that, Determine whether the operation result of the first composite feature parameter and the second composite feature parameter is greater than the threshold T; if it is less than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter match; if it is greater than the threshold T, it is determined that the first composite feature parameter and the second composite feature parameter do not match.

10. The response node according to claim 7, wherein, the non-linearly correlated LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

11. The response node according to claim 7, wherein, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

12. The response node according to claim 7, wherein, the NDPA frame received by the response node carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

13. A method for resisting spoofing attacks in radio frequency sensing, applied to an initiating node, wherein, comprising: The initiating node sends an empty packet to pre-announce an NDPA frame to the response node, so that the response node extracts a first composite feature parameter including in-phase / quadrature I / Q imbalance features and multipath channel features from the pilot subcarriers of the NDPA frame; The initiating node sends an NDP frame for performing this empty packet NDP measurement to the response node, and the NDP frame includes a plurality of non-linearly correlated long training fields LTF, so that the response node extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated long training fields LTF of the NDP frame, so that the response node compares the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards this NDP measurement as invalid.

14. The method according to claim 13, wherein, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

15. The method according to claim 13, wherein, the non-linearly correlated LTF is an LTF sequence in which the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different after phase rotation processing.

16. The method according to claim 13, wherein, the non-linearly correlated LTF is an LTF sequence that has been circularly shifted in the frequency domain.

17. An initiating node, wherein, comprising: a transceiver, configured to send an empty packet to pre-announce an NDPA frame to the response node, so that the response node extracts a first composite feature parameter including in-phase / quadrature I / Q imbalance features and multipath channel features from the pilot subcarriers of the NDPA frame; The transceiver is further configured to send an NDP frame for performing the current null data packet (NDP) measurement to the response node, where the NDP frame includes a plurality of non-linearly correlated long training fields (LTFs), so that the response node extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated long training fields (LTFs) of the NDP frame, thereby enabling the response node to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regarding the current NDP measurement as invalid.

18. The initiating node according to claim 17, wherein, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in the current NDP measurement to defend against attackers.

19. The initiating node according to claim 17, wherein, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

20. The initiating node according to claim 17, wherein, the non-linearly correlated LTF is an LTF sequence that has undergone cyclic shift processing in the frequency domain.

21. A method for resisting spoofing attacks in radio frequency sensing, applied to an initiating node, wherein, it includes: The initiating node sends a null data packet preamble (NDPA) frame to the response node; The initiating node receives the null data packet (NDP) frame sent by the response node to it, and the NDP frame includes a plurality of non-linearly correlated long training fields (LTFs); The initiating node extracts a first composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated LTFs; The initiating node receives the sounding measurement report (SMR) sent by the response node to it, and obtains a second composite feature parameter including I / Q imbalance features and multipath channel features; The initiating node compares the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regards the current NDP measurement as invalid.

22. The method according to claim 21, wherein, the obtaining of the second composite feature parameter including I / Q imbalance features and multipath channel features includes: The initiating node extracts the second composite feature parameter from the pilot subcarriers of the SMR.

23. The method according to claim 21, wherein, the obtaining of the second composite feature parameter including I / Q imbalance features and multipath channel features includes: The initiating node directly obtains the second composite feature parameter from the SMR, and the second composite feature parameter included in the SMR is extracted by the response node from the NDPA frame or the NDP frame.

24. The method according to claim 21, wherein, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

25. The method according to claim 21, wherein, the non-linearly correlated LTF is an LTF sequence that has undergone cyclic shift processing in the frequency domain.

26. The method according to claim 21, wherein, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

27. The method according to claim 21, wherein, judging whether the first composite feature parameter and the second composite feature parameter match includes: judging whether the first composite feature parameter and the second composite feature parameter satisfy either the conjugate or the negation relationship.

28. An initiating node, wherein, comprising: a transceiver, configured to send an NDPA frame of an empty data packet to a response node; the transceiver is further configured to receive an NDP frame of an empty data packet sent by the response node; the NDP frame includes a plurality of non-linearly correlated long training fields LTF; a processor, configured to extract a first composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non-linearly correlated LTFs; the transceiver is further configured to receive a sounding measurement report SMR sent by the response node; the processor is further configured to obtain a second composite feature parameter including I / Q imbalance features and multipath channel features from the SMR; the processor is further configured to compare the first composite feature parameter and the second composite feature parameter, and when the first composite feature parameter and the second composite feature parameter do not match, regard this NDP measurement as invalid.

29. The initiating node according to claim 28, wherein, obtaining the second composite feature parameter including I / Q imbalance features and multipath channel features includes: the initiating node extracts the second composite feature parameter from the pilot subcarriers of the SMR.

30. The initiating node according to claim 28, wherein, obtaining the second composite feature parameter including I / Q imbalance features and multipath channel features includes: the initiating node directly obtains the second composite feature parameter from the SMR, and the second composite feature parameter included in the SMR is extracted by the response node from the NDPA frame or the NDP frame.

31. The initiating node according to claim 28, wherein, the non-linearly correlated LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same subcarrier on adjacent symbols are the same and the phases are different.

32. The initiating node according to claim 28, wherein, the non-linearly correlated LTF is an LTF sequence that has undergone cyclic shift processing in the frequency domain.

33. The initiating node according to claim 28, wherein, the NDPA frame carries defense indication information, and the defense indication information is used to instruct the response node to perform composite feature parameter matching in this NDP measurement to defend against attackers.

34. The initiating node according to claim 28, wherein, Determining whether the first composite feature parameter and the second composite feature parameter match includes: Determining whether the first composite feature parameter and the second composite feature parameter satisfy either a conjugate or an inversion relationship.

35. A method for resisting spoofing attacks in radio frequency sensing, applied to a response node, characterized in that, it includes: The response node receives an empty data packet pre - announcement NDPA frame sent by the initiating node or an NDP frame for performing the current empty data packet NDP measurement, where the NDP frame includes a plurality of non - linearly related long training fields LTFs; The response node extracts a second composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non - linearly related LTFs of the NDPA frame or the NDP frame; The response node sends a probe measurement report SMR to the initiating node, and the SMR includes the second composite feature parameter.

36. The method according to claim 35, characterized in that, The NDPA frame received by the response node carries defense indication information, and the defense indication information is used to instruct the response node to extract and feedback composite feature parameters during the current NDP measurement to defend against attackers.

37. The method according to claim 35, characterized in that, The non - linearly related LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same sub - carrier on adjacent symbols are the same, and the phases are different.

38. The method according to claim 35, characterized in that, The non - linearly related LTF is an LTF sequence that has been circularly shifted in the frequency domain.

39. A response node, characterized in that, it includes: A transceiver for receiving an empty data packet pre - announcement NDPA frame sent by the initiating node or an NDP frame for performing the current empty data packet NDP measurement; where the NDP frame includes a plurality of non - linearly related long training fields LTFs; A processor for extracting a second composite feature parameter including I / Q imbalance features and multipath channel features from the plurality of non - linearly related LTFs of the NDPA frame or the NDP frame; The transceiver is further configured to send a probe measurement report SMR to the initiating node, and the SMR includes the second composite feature parameter.

40. The response node according to claim 39, characterized in that, The NDPA frame received by the response node carries defense indication information, and the defense indication information is used to instruct the response node to extract and feedback composite feature parameters during the current NDP measurement to defend against attackers.

41. The response node according to claim 39, characterized in that, The non - linearly related LTF is an LTF sequence in which, after phase rotation processing, the amplitudes corresponding to the same sub - carrier on adjacent symbols are the same, and the phases are different.

42. The response node according to claim 39, characterized in that, The non - linearly related LTF is an LTF sequence that has been circularly shifted in the frequency domain.

43. A chip system, characterized in that, it includes: At least one processor and an interface; The processor is used to run a computer program to execute the method according to any one of claims 1-6, 13-16, 21-27, 35-38.

44. The chip system according to claim 43, wherein, the chip system further includes a memory coupled to the processor, for storing a computer program for implementing the method according to any one of claims 1-6, 13-16, 21-27, 35-38.

45. A computer-readable storage medium, wherein, the computer-readable storage medium is used to store a computer program, and when the computer program is executed, the method according to any one of claims 1-6, 13-16, 21-27, 35-38 is implemented.

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