Binary Phase Shift Keying (BPSK) on Orthogonal Carriers for Multi-Channel IM-CW CO2 Absorption or Lidar/Radar/Sonar Mapping Applications

摘要

Systems, methods, and devices of the present invention use a single Pseudo Noise (PN) code to modulate multiple orthogonal carriers by Binary Phase Shift Keying (BPSK) modulation. The various embodiments enable closely spaced carriers to be modulated with the same periodic PN sequence using BPSK modulation. In this manner, even though the carriers may almost entirely share bandwidth, orthogonality of the carriers may not be lost, enabling the various embodiments to be used with limited bandwidth Intensity Modulated Continuous Wave (IM-CW) Light detection and ranging (Lidar), Radio detection and ranging (Radar), or Sound Navigation and Ranging (Sonar) systems. Additionally, by using orthogonal carriers the various embodiments enable measurements to be made simultaneously, thereby reducing the error compared to systems that require sequential measurements, such as pulsed Lidar systems.

主权项

1. A method for generating a modulation waveform in a ranging system, comprising:
generating two or more orthogonal carrier waveforms; modulating the two or more orthogonal carrier waveforms with a Pseudo Noise (PN) code; transmitting the modulated two or more orthogonal carrier waveforms toward a target; receiving a reflected signal from the target; selecting a reference signal form; demodulating the reflected signal using the selected reference signal form; and determining at least one of a range and differential absorption of the target based on the demodulation.