Analytical Investigation of Non-Coherent Mutual FMCW Radar Interference

Radar sensors are increasingly utilized in today’s cars. This inevitably leads to increased mutual sensor interference and thus a performance decrease, potentially resulting in major safety risks. Understanding signal impairments caused by interference accurately helps to devise signal processing schemes to combat said performance degradation. For the frequency modulated continuous wave (FMCW) radars prevalent in automotive applications, it has been shown that so-called non-coherent interference occurs frequently and results in an increase of the noise floor. In this work we investigate the impact of interference analytically by focusing on its detailed description. We show, among others, that the spectrum of the typical interference signal has a linear phase and a magnitude that is strongly fluctuating with the phase parameters of the time domain interference signal. Analytical results are verified by simulation, highlighting the dependence on the specific phase terms that cause strong deviations from spectral whiteness.