CPC G01S 17/36 (2013.01) [G01S 7/4913 (2013.01); G01S 7/4915 (2013.01)] | 4 Claims |
1. A method for measuring a distance between a transmitter and an object based on a phase delay between a transmitting signal and a reflected and received signal by a receiver in N-phase correlations time-of-flight (ToF) ranging, where the receiver includes an N-phase correlation vector controller, a correlator array, a zero-force synthesizer, and a signal processor, the N-phase correlation vector controller generating N delay-tap signals that control N-phase correlators in the correlator array, and each of the N-phase correlators performing an integration by accumulating photons in image sensor pixels of the receiver, where N is an odd number greater than or equal to 3, the method comprising:
(a) setting, by the N-phase correlation vector controller of the receiver, an integration start time of each of the N-phase correlators, at which time the N-phase correlators start to accumulate photons in the image sensor pixels, where the integration start time of each of the N-phase correlators is sequentially and equally time delayed by one period of the transmitting signal divided by N;
(b) adjusting, by the N-phase correlation vector controller of the receiver, an integration time of the N-phase correlators, during which time the N-phase correlators accumulate the photons in the image sensor pixels, from one transmitting signal period to
of the one transmitting signal period;
(c) obtaining, by the N-phase correlators of the receiver, N correlation vectors over one or more periods of the transmitting signal, where each of the N correlation vectors is sequentially and equally time delayed by one period of the transmitting signal divided by N;
(d) synthesizing by the zero-force synthesizer of the receiver, two-phase orthogonal signals from the N correlation vectors, where the zero-force synthesizer uses pre-determined synthesis coefficients; and
(e) determining by the signal processor of the receiver, the phase delay or the distance from the two-phase orthogonal signals.
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