Apparatus and method for performing passive sensing
First Claim
1. A method of performing passive sensing using wireless digital communications, wherein said wireless digital communications are frame-based with a predefined frame structure, and wherein said wireless digital communications are Wi-Fi communications from a wireless access point or WiMAX or LTE communications, said method comprising:
- receiving a reference signal into a reference channel, wherein said reference signal comprises a direct version of a radio frequency transmission as part of said wireless digital communications;
receiving a surveillance signal into a surveillance channel;
detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure;
extracting portions of the surveillance signal corresponding to the extracted portions of the reference signal;
performing a cross-correlation on the extracted portions of the reference signal and the surveillance signal to determine a range-Doppler surface;
and providing a real-time display of said range-Doppler surface and/or of information derived therefrom;
wherein the wireless digital communications comprise durations of active burst interspersed in the time domain with durations of idle bursts, and said method further comprises identifying and discarding from the reference signal the durations of the idle bursts prior to detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure.
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Abstract
A method and an apparatus are provided for performing passing sensing using wireless digital communications. The wireless digital communications are frame-based with a predefined frame structure. The method includes receiving a reference signal into to a reference channel, wherein the reference signal comprises a direct version of a radio frequency transmission as part of said wireless digital communications; receiving a surveillance signal into a surveillance channel; detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure; extracting portions of the surveillance signal corresponding to the extracted portions of the reference signal; performing a cross-correlation on the extracted portions of the reference signal and the surveillance signal to determine a range-Doppler surface; and providing a real-time display of said range-Doppler surface and/or of information derived therefrom.
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Citations
11 Claims
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1. A method of performing passive sensing using wireless digital communications, wherein said wireless digital communications are frame-based with a predefined frame structure, and wherein said wireless digital communications are Wi-Fi communications from a wireless access point or WiMAX or LTE communications, said method comprising:
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receiving a reference signal into a reference channel, wherein said reference signal comprises a direct version of a radio frequency transmission as part of said wireless digital communications; receiving a surveillance signal into a surveillance channel; detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure; extracting portions of the surveillance signal corresponding to the extracted portions of the reference signal; performing a cross-correlation on the extracted portions of the reference signal and the surveillance signal to determine a range-Doppler surface; and providing a real-time display of said range-Doppler surface and/or of information derived therefrom; wherein the wireless digital communications comprise durations of active burst interspersed in the time domain with durations of idle bursts, and said method further comprises identifying and discarding from the reference signal the durations of the idle bursts prior to detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for passive sensing using wireless digital communications, wherein said wireless digital communications are frame-based with a predefined frame structure, and wherein said wireless digital communications are Wi-Fi communications from a wireless access point or WiMAX or LTE communications, said method comprising:
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receiving a reference signal into a reference channel, wherein said reference signal comprises a direct version of a radio frequency transmission as part of said wireless digital communications; receiving a surveillance signal into a surveillance channel; detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure; extracting portions of the surveillance signal corresponding to the extracted portions of the reference signal; performing a cross-correlation on the extracted portions of the reference signal and the surveillance signal to determine a range-Doppler surface; and providing a real-time display of said range-Doppler surface and/or of information derived therefrom; wherein the wireless digital communications comprise durations of active burst interspersed in the time domain with durations of idle bursts, and said method further comprises identifying and discarding from the reference signal the durations of the idle bursts prior to detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure.
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11. A system for passive sensing using wireless digital communications, wherein said wireless digital communications are frame-based with a predefined frame structure, and wherein said wireless digital communications are Wi-Fi communications from a wireless access point or WiMAX or LTE communications, said system comprising a circuit that:
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receives a reference signal into a reference channel, wherein said reference signal comprises a direct version of a radio frequency transmission as part of said wireless digital communications; receives a surveillance signal into a surveillance channel; detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure; extracts portions of the surveillance signal corresponding to the extracted portions of the reference signal; performs a cross-correlation on the extracted portions of the reference signal and the surveillance signal to determine a range-Doppler surface; and providing a real-time display of said range-Doppler surface and/or of information derived therefrom; wherein the wireless digital communications comprise durations of active burst interspersed in the time domain with durations of idle bursts, and said circuit further identifies and discards from the reference signal the durations of the idle bursts prior to detecting and extracting portions of the reference signal corresponding to data transmissions based on said predefined frame structure.
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Specification