New methodologies for analytically modelling and compensation of phase noise based distortions in continuous wave radar

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Critical radar parameters such as range and the probability of correctly resolving and detecting a targets and the uncertainty of measuring range and speed are greatly impacted by phase-noise-based interference in continuous wave radar such as Doppler and FMCW radar. Highly reflective targets, like reflections at the antenna radome and direct crosstalk between transmitter and receiver in conjunction with phase noise increase the noise level across the entire baseband signal. Phase noise also reduces and blurs the spectral power density at the target beat or target Doppler frequencies. The latter effect increases with the target distance. Despite the application of CW/FMCW radar at scale in industry and transportation and despite considerable research efforts, these issues, to date, have only been poorly modelled analytically based on simplified approximations. Very few methodologies have emerged as efficient solutions to the issues either. The proposed project will focus on these two research issues. The primary project objective is the fundamental investigation of a novel radar concept proposed by the applicant for compensating phase-noise-based interference in FMCW radar and its analytical verification, by simulation, as well as its empirical verification. In this ground-breaking radar concept, two opposing frequency modulated partial radar signals are transmitted simultaneously, which, when received, are converted in the mixer to two separate coherent baseband signals with phase-noise distortion components that are reverse phased. Phase-noise-based interference can be fully compensated by balancing both baseband signals, as exploratory research has indicated. This would be a game-changer in FMCW radar technology if successfully verified both analytically and experimentally. The secondary project objective is to further supplement and refine existing analytical phase noise disturbance models and simulation methodologies – indeed, the applicant has made important contributions in this regard in the past. Interference has heretofore been mainly modeled utilizing several simplifying assumptions, such as evenly distributed / white phase-noise models and small signal approximations, which were more theoretical than practical. The intention now is to consider the real colored phase-noise characteristic curves and their range-related correlation effects in the receiver mixing process. The aim is to close gaps in current radar phase noise theory. In addition, it will be possible for the first time to precisely predict and realistically simulate the interference effects in functional interfaces, which have not heretofore been well modelled. These advances will also aid the verification of the proposed new radar concept.