US-20260129410-A1 - WIRELESS SENSING METHOD AND APPARATUS

Abstract

A wireless sensing method and apparatus are disclosed. An example method includes: A first node outputs a first signal, where the first signal is a signal that has undergone randomization processing. The first node receives a second signal, where the second signal is a fourth signal after channel transmission, the fourth signal includes a signal obtained by transforming a third signal, the fourth signal includes a signal output by a first antenna corresponding to a second node and a signal output by a second antenna corresponding to the second node, and the third signal is the first signal after channel transmission. The first node processes the second signal to determine a wireless sensing result.

Inventors

• Li Sun
• Yuwei WANG
• Peng Liu
• Wenhui Wang
• Yiyan ZHANG

Assignees

• HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date

20260507

Application Date

20251219

Claims (20)

1. 1 . A wireless sensing method, comprising: outputting, by a first node, a first signal, wherein the first signal is a signal that has undergone randomization processing; receiving, by the first node, a second signal, wherein the second signal is a fourth signal after channel transmission and is received by the first node, the fourth signal comprises a signal obtained by transforming a third signal, the third signal is the first signal after channel transmission and is received by a second node, and the fourth signal comprises a signal output by a first antenna corresponding to the second node and a signal output by a second antenna corresponding to the second node; and processing, by the first node, the second signal to determine a wireless sensing result.
2. 2 . The method according to claim 1 , wherein the outputting, by the first node, the first signal comprises: jointly sending, by the first node, the first signal to the second node through a plurality of antennas, wherein the first signal comprises a first sensing signal flow and a second sensing signal flow, the first sensing signal flow is a random signal flow, and the second sensing signal flow is determined based on the first sensing signal flow and a lowpass function.
3. 3 . The method according to claim 2 , wherein a modulus value of the first sensing signal flow is equal to a modulus value of the second sensing signal flow.
4. 4 . The method according to claim 1 , wherein the fourth signal is obtained by performing conjugate transpose on the third signal; or the fourth signal is obtained by sequentially performing fast Fourier transform (FFT), conjugation, and inverse fast Fourier transform IFFT on the third signal.
5. 5 . The method according to claim 1 , wherein the outputting, by the first node, the first signal comprises: sending, by the first node, the first signal to the second node through a single antenna, wherein the first signal is a random signal flow.
6. 6 . The method according to claim 5 , wherein the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by performing conjugate transpose on the fifth signal, and the eighth signal is obtained by sequentially performing conjugate transpose and addition of a time domain offset n 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal; or the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, and inverse fast Fourier transform IFFT on the fifth signal, and the eighth signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, multiplication by a phase rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 , and inverse fast Fourier transform IFFT on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers; or the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by estimating a frequency-domain synthetic channel based on the fifth signal and performing conjugation on the fifth signal, and the eighth signal is obtained by estimating a frequency-domain synthetic channel based on the sixth signal and sequentially performing conjugation and multiplication by a rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers.
7. 7 . The method according to claim 6 , wherein a value range of n 0 is between two constants greater than zero, and the two constants are determined based on N and k.
8. 8 . A communication apparatus comprising at least one processor coupled to at least one memory storing a computer program including instructions that, when executed by the processor, cause the communication apparatus to: receive, a third signal, wherein the third signal is a first signal after channel transmission and is received by the second node, and the first signal is a signal that has undergone randomization processing and that is output by a first node; and output, a fourth signal, wherein the fourth signal comprises a signal obtained by transforming the third signal, and the fourth signal comprises a signal output by a first antenna corresponding to the second node and a signal output by a second antenna corresponding to the second node.
9. 9 . The communication apparatus according to claim 8 , wherein the third signal is a signal is a first sensing signal flow and a second sensing signal flow after channel transmission, the first signal is jointly sent by the first node to the second node through a plurality of antennas, the first signal comprises the first sensing signal flow and the second sensing signal flow, the first sensing signal flow is a random signal flow, and the second sensing signal flow is determined based on the first sensing signal flow and a lowpass function.
10. 10 . The communication apparatus according to claim 8 , wherein a modulus value of the first sensing signal flow is equal to a modulus value of the second sensing signal flow.
11. 11 . The communication apparatus according to claim 8 , wherein the fourth signal is obtained by performing conjugate transpose on the third signal; or the fourth signal is obtained by sequentially performing fast Fourier transform FFT, conjugation, and inverse fast Fourier transform IFFT on the third signal.
12. 12 . The communication apparatus according to claim 8 , wherein the first signal is sent by the first node to the second node through a single antenna, and the first signal is a random signal flow.
13. 13 . The communication apparatus according to claim 12 , wherein the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by performing conjugate transpose on the fifth signal, and the eighth signal is obtained by sequentially performing conjugate transpose and addition of a time domain offset n 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal; or, the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, and inverse fast Fourier transform IFFT on the fifth signal, and the eighth signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, multiplication by a phase rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 , and inverse fast Fourier transform IFFT on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers; or the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by estimating a frequency-domain synthetic channel based on the fifth signal and performing conjugation on the fifth signal, and the eighth signal is obtained by estimating a frequency-domain synthetic channel based on the sixth signal and sequentially performing conjugation and multiplication by a rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers.
14. 14 . The communication apparatus according to claim 13 , wherein a value range of n 0 is between two constants greater than zero, and the two constants are determined based on N and k.
15. 15 . A communication apparatus comprising at least one processor coupled to at least one memory storing a computer program including instructions that, when executed by the processor, cause the communication apparatus to: output a first signal, wherein the first signal is a signal that has undergone randomization processing; receive a second signal, wherein the second signal is a fourth signal after channel transmission and is received by the first node, the fourth signal comprises a signal obtained by transforming a third signal, the third signal is the first signal after channel transmission and is received by a second node, and the fourth signal comprises a signal output by a first antenna corresponding to the second node and a signal output by a second antenna corresponding to the second node; and process the second signal to determine a wireless sensing result.
16. 16 . The communication apparatus according to claim 15 , wherein the instructions specifically cause the communication apparatus to: jointly send the first signal to the second node through a plurality of antennas, wherein the first signal comprises a first sensing signal flow and a second sensing signal flow, the first sensing signal flow is a random signal flow, and the second sensing signal flow is determined based on the first sensing signal flow and a lowpass function.
17. 17 . The communication apparatus according to claim 16 , wherein a modulus value of the first sensing signal flow is equal to a modulus value of the second sensing signal flow.
18. 18 . The communication apparatus according to claim 15 , wherein the fourth signal is obtained by performing conjugate transpose on the third signal; or the fourth signal is obtained by sequentially performing fast Fourier transform (FFT), conjugation, and inverse fast Fourier transform IFFT on the third signal.
19. 19 . The communication apparatus according to claim 15 , wherein the outputting, by the first node, the first signal comprises: sending, by the first node, the first signal to the second node through a single antenna, wherein the first signal is a random signal flow.
20. 20 . The communication apparatus according to claim 19 , wherein the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by performing conjugate transpose on the fifth signal, and the eighth signal is obtained by sequentially performing conjugate transpose and addition of a time domain offset n 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal; or the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, and inverse fast Fourier transform IFFT on the fifth signal, and the eighth signal is obtained by sequentially performing fast Fourier transform FFT, conjugation in frequency domain, multiplication by a phase rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 , and inverse fast Fourier transform IFFT on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers; or the third signal comprises a fifth signal and a sixth signal, the fourth signal comprises a seventh signal and an eighth signal, the seventh signal is obtained by estimating a frequency-domain synthetic channel based on the fifth signal and performing conjugation on the fifth signal, and the eighth signal is obtained by estimating a frequency-domain synthetic channel based on the sixth signal and sequentially performing conjugation and multiplication by a rotation factor e - j ⁢ 2 ⁢ π N ⁢ kn 0 on the sixth signal, wherein n 0 is a sampling value of a lowpass function in a time unit for sending the first signal, k represents a subcarrier sequence number, and N represents a quantity of subcarriers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2023/101545, filed on Jun. 20, 2023, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the communication field, and more specifically, to a wireless sensing method and an apparatus. BACKGROUND Sensing is one of important applications of a 6th generation (6th generation, 6G) mobile communication technology and next-generation wireless connectivity (wireless-fidelity, Wi-Fi). The fundamental principle of sensing is to use radio signals to measure channels, to obtain channel state information (channel state information, CSI) or a channel impulse response (channel impulse response, CIR), thereby inferring information related to the environment or a sensed object (for example, an object in the environment) based on the channel state information or the channel impulse response. Special “measurement” signals (such as pilots) in wireless systems can be used for sensing, but such signals have a publicly known signal structure, which may lead to privacy exposure. Unauthorized users could potentially eavesdrop the aforementioned measurement signals, and infer positions, trajectories, behavior features, and the like of authorized users. This results in privacy leakage. Therefore, how to protect user privacy during sensing is an urgent problem to be resolved currently. SUMMARY Embodiments of this application provide a wireless sensing method and an apparatus, to protect user privacy during sensing. To achieve the foregoing objective, the following technical solutions are used in this application. According to a first aspect, a wireless sensing method is provided. The method may be performed by a first node, or may be performed by a component of the first node, for example, a processor, a chip, or a chip system of the first node, or may be implemented by a logic module or software that can implement all or a part of functions of the first node. For example, the method may be performed by the first node. The method includes: The first node outputs a first signal, where the first signal is a signal that has undergone randomization processing. The first node receives a second signal, where the second signal a fourth signal after channel transmission and is received by the first node, the fourth signal includes a signal obtained by transforming a third signal, the third signal is the first signal after channel transmission, and the fourth signal includes a signal output by a first antenna corresponding to a second node and a signal output by a second antenna corresponding to the second node. The first node processes the second signal to determine a wireless sensing result. Based on this solution, the first signal is randomized, and authorized users do not need to share a randomization parameter, so that unauthorized users cannot obtain the randomization parameter and cannot determine a sensing result. This improves privacy of the authorized user, and reduces overheads caused by parameter sharing. Further, in comparison with a solution of sending a jamming signal, a channel obfuscation solution, or the like, in this solution, the wireless sensing result can be determined based on the second signal received by the first node, only through round-trip signal receiving and sending and signal processing, and an additional device other than the first node and the second node does not need to be added. Therefore, implementation complexity is low. In conclusion, in embodiments of this application, when wireless sensing is performed, privacy of the authorized user can be protected, system overheads can be reduced, and implementation complexity is low. In a possible implementation, that the first node outputs the first signal includes: The first node jointly sends the first signal to the second node through a plurality of antennas. The first signal includes a first sensing signal flow and a second sensing signal flow, the first sensing signal flow is a random signal flow, and the second sensing signal flow is determined based on the first sensing signal flow and a lowpass function. In this solution, because of a lowpass feature of the lowpass function, the unauthorized users cannot determine the wireless sensing result. This further protects privacy of the authorized user. Optionally, the fourth signal is obtained by performing conjugate transpose on the third signal. In this solution, processing is performed in time domain, a processing procedure is simple, and implementation complexity is low. Optionally, the fourth signal is obtained by sequentially performing fast Fourier transform FFT, conjugation, and inverse fast Fourier transform IFFT on the third signal. In this solution, processing is performed in frequency domain, and a signal processing process in an existing communication system also involves FFT and IFFT. Therefore, compatibility is high. I