Motion Detection via Channel Response Decomposition
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Solution Overview
Problem
Existing motion detection systems face challenges in accurately distinguishing between motion caused by objects and variations induced by interference, leading to false-positive detections, especially in environments with significant out-of-band or out-of-channel interference.
Innovation Solution
The system employs channel response analysis in the frequency vector domain to differentiate between interference and motion by defining axes based on channel vector projections, allowing for the isolation of motion-related variations and filtering out interference effects, enabling accurate motion detection without clear line-of-sight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If channel response analysis is performed in environments with out-of-band or out-of-channel interference, then motion detection capability is maintained, but false-positive detections increase due to interference-induced variations
Solution Approach 1:
The patent segments the channel response variations into distinct components: interference-induced variations and motion-induced variations. By decomposing the total channel response into separate interference and motion components, the system can independently analyze and differentiate between these two types of variations, thereby maintaining motion detection accuracy in interference-prone environments
Solution Approach 2:
The patent extracts and isolates the interference-induced variations from the total channel response variations. By separating the interference component from the motion component, the system can filter out the harmful interference effects while preserving the motion detection capability, thus reducing false-positive detections
2Device complexity
If traditional motion detection methods are used without interference filtering, then detection simplicity is maintained, but false-positive rates increase due to inability to distinguish interference from motion
Solution Approach 1:
The patent introduces a new dimension of analysis by examining channel responses across multiple frequency subcarriers simultaneously. By transforming the detection problem from a single-frequency analysis to a multi-frequency vector analysis, the system gains the ability to differentiate between interference and motion patterns that are not distinguishable in traditional single-frequency methods
Solution Approach 2:
The patent employs dynamic thresholding and adaptive filtering that adjusts detection parameters based on the observed channel conditions. The system dynamically adapts to varying interference levels and characteristics, maintaining detection simplicity while improving precision by automatically adjusting to environmental conditions
Data Source
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AI summary
In a general aspect, motion is detected using vector representations of channel responses. In some aspects, a first set of channel responses are obtained based on wireless signals transmitted through a space during a first time period. From the first set of channel responses, a set of orthogonal axes in a frequency vector domain are determined. A second channel response is obtained based on a wireless signal transmitted through the space during a second time period, and a channel vector representing the second channel response in the frequency vector domain is determined. Motion of an object in the space is detected based on a projection of the channel vector onto one of the set of orthogonal axes.