Multi-Carrier Noncontact Signal Detection with Noise Suppression Based on a Phase-Locked Loop

Abstract

A non-contact signal detection system for detecting movement associated with a subject. A carrier source is configured to generate a first carrier signal in phase coherence with a second carrier signal. A phase-locked loop includes noise pre-cancellation system for suppressing the noise associated with a beat signal and a controlled oscillation system. The noise pre-cancellation system can be configured to phase-lock the beat signal to a first reference signal in order to stabilize the phase of the beat signal and pre-cancel the noise associated with the beat signal. The controlled oscillation system can include a propagation pathway on which a transmission signal is phase-modulated with a vibratory signal of the subject. Once acquired, the vibratory signal can have suppressed noise.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. application Ser. No. 16 / 060,781 filed 8 Jun. 2018, which US Application is a US National Stage Entry of PCT / US2016 / 065871 filed on 9 Dec. 2016, which US National Stage Entry claims the benefit under 35 USC § 119(e) of U.S. Provisional Patent Application No. 62 / 265,446 filed 10 Dec. 2015, the entirety of each of which is incorporated herein by reference as if set forth herein in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableTHE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT[0003]Not ApplicableSEQUENCE LISTING[0004]Not ApplicableSTATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR[0005]Not ApplicableBACKGROUND OF THE DISCLOSURE1. Field of the Invention[0006]Aspects of the present disclosure relate to systems and methods for non-contact signal detection of movement associated with a subject.2. Description of Related Art[0007]Th...

AI Technical Summary

Benefits of technology

The present patent is about a system and method for non-contact signal detection of movement associated with a subject. The system includes a carrier source, a noise pre-cancellation system, and a controlled oscillation system. The carrier source generates two carrier signals that are phase-locked to a reference signal. The noise pre-cancellation system can suppress phase noise and path noise associated with a beat signal. The controlled oscillation system can frequency-modulate the carrier signals with the noise pre-cancellation system and transmit a transmission signal to a propagation pathway. The system can also include a demodulator to extract the beat signal from the carrier signals and a data acquisition device to acquire information associated with the movement of the subject. The technical effects of the invention include improved signal-to-noise ratios, reduced phase noise, and improved accuracy in detecting movement-related information.

Problems solved by technology

However, they pose high requirements on the frequency chirp linearity and bandwidth to accurately detect small displacements in sub-millimeters and even millimeters.

For instance, it can raise the background noise floor, deteriorate the performance of the signal, and impair the signal-to-noise ratio (SNR), which can decrease the detection accuracy and distance.

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