  In this paper, the interference mitigation for Frequency Modulated Continuous
Wave (FMCW) radar system with a dechirping receiver is investigated. After
dechirping operation, the scattered signals from targets result in beat
signals, i.e., the sum of complex exponentials while the interferences lead to
chirp-like short pulses. Taking advantage of these different time and frequency
features between the useful signals and the interferences, the interference
mitigation is formulated as an optimization problem: a sparse and low-rank
decomposition of a Hankel matrix constructed by lifting the measurements. Then,
an iterative optimization algorithm is proposed to tackle it by exploiting the
Alternating Direction of Multipliers (ADMM) scheme. Compared to the existing
methods, the proposed approach does not need to detect the interference and
also improves the estimation accuracy of the separated useful signals. Both
numerical simulations with point-like targets and experiment results with
distributed targets (i.e., raindrops) are presented to demonstrate and verify
its performance. The results show that the proposed approach is generally
applicable for interference mitigation in both stationary and moving target
scenarios.
