Wi-Fi Sensing Measurement Exchange for Passive Target Speed Detection
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Solution Overview
Problem
Existing Wi-Fi devices can only locate passive targets and cannot determine their instantaneous speed, and existing radar technologies require line-of-sight conditions and have limited precision in measuring distances and speeds.
Innovation Solution
A sensing measurement method using bidirectional sensing measurements between two stations to determine the location and instantaneous speed of passive targets based on channel reciprocity, utilizing angle of arrival, relative time of flight, and Doppler frequency shift measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Wi-Fi device uses existing detection methods, then passive target location can be determined, but instantaneous speed cannot be measured
Solution Approach 1:
The patent segments the measurement process into multiple independent transmission paths (N paths) between two stations, with each path providing separate measurement results including angle of arrival, time of flight, and Doppler frequency shift. This segmentation enables comprehensive extraction of both location and speed information from passive targets through multiple measurement dimensions.
Solution Approach 2:
The patent implements a feedback mechanism where the second station measures and reports sensing measurement results back to the first station. This feedback loop enables the first station to obtain comprehensive measurement data including Doppler frequency shift information, which is essential for determining instantaneous speed of passive targets.
2Measurement precision
If radar technology is used for target detection, then distance and speed can be measured, but line-of-sight conditions are required and precision is limited
Solution Approach 1:
The patent makes the Wi-Fi device universal by enabling it to perform both communication functions and sensing measurement functions. The same Wi-Fi device can operate in different modes (communication mode and sensing mode), eliminating the need for dedicated radar equipment and expanding adaptability to various scenarios including non line-of-sight conditions.
Solution Approach 2:
The patent adds a new dimension to Wi-Fi functionality by integrating sensing measurement capabilities into the communication device. This dimensionality change allows the device to extract additional information (angle of arrival, time of flight, Doppler shift) from signal reflections, enabling passive target detection and speed measurement without requiring traditional radar hardware.
3Device complexity
If single station detection is used, then device complexity is reduced, but measurement capability is limited
Solution Approach 1:
The patent merges the detection capabilities of multiple stations into a unified measurement system. By combining measurements from both the first station and second station across N transmission paths, the system achieves comprehensive target detection capability while maintaining relatively simple individual station structures. The merging of measurement data from multiple sources enables simultaneous determination of location and speed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate location and speed determination of multiple passive targets with improved precision and robustness by leveraging angle and time measurements, overcoming limitations of existing technologies.
Implementation Method 1
A radar transmitting system transmits a specific electromagnetic wave signal. The electromagnetic wave signal is reflected by a target during propagation.
Implementation Method 2
A radar receiving system receives the reflected signal, compares the reflected signal with the transmitted signal, and calculates information such as a distance, a moving speed, and an orientation of the target
Data Source
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AI summary
This application provides a sensing measurement information exchange apparatus, applied to a first station. The apparatus includes: a transceiver unit, configured to receive sensing measurement report information sent by a second station, where the sensing measurement report information includes N groups of first measurement results, where the N groups of first measurement results are in a one-to-one correspondence with N first transmission paths between the first station and the second station, and each group of first measurement results includes an angle of arrival, relative time of flight, and a Doppler frequency shift of a corresponding first transmission path; and a processing unit, configured to obtain angles of arrival, relative time of flight, and Doppler frequency shifts of the N first transmission paths based on the sensing measurement report information. This application implements measurement of locations and instantaneous speeds of a plurality of passive targets.