Stepped-carrier OFDM-radar processing scheme to retrieve high resolution range-velocity profile at low sampling rate

Abstract

Recent publications show that the potential of using orthogonal frequency division multiplexing waveforms is radar signals. Since the range resolution is proportional to the RF bandwidth, the major obstacle that obstructs the practical use in automotive and other low-cost radars is the requirement to sample the received signal at sampling rates that span the whole RF signal bandwidth requiring ADCs with sampling rates in the order of GHz. This paper presents a method to achieve the high range resolution induced by a large RF bandwidth, but with a much lower baseband bandwidth, consequently requiring a much slower ADC while at the same time delivering a velocity profile for each subcarrier. In addition, the processing scheme induces a range migration compensation, independent of the number of targets. This is achieved with barely increased computational effort. The scheme is verified with simulations and measurements at 77 GHz.