Phenomenology of mutual interference of FMCW and PMCW automotive radars

With the increasing use of automotive radars for assisted driving, future cars will typically be fitted with eight to ten radars, covering 360° around the car. LRR radars at 77GHz and MRR/SRR at 79GHz will create a significant amount of mutual interference, reducing the radar sensitivity or creating false alarms, both of these being undesirable. The frequency, bandwidth and power spectral density are subject to regulation but the radar waveforms are not. The question therefore arises as to whether some waveforms are more vulnerable or creating more interference than others. We consider the FMCW and PMCW waveforms in this paper and describe the phenomenology of the mutual interference between the four possible interferer-victim pairs. Simulations are used throughout the paper to assess the behavior of the mutual interference.