1 Introduction

The most common FMCW radar to FMCW radar interference happens when the transmitted chirp from a radar (called an aggressor) crosses the chirp of another radar’s receiver (called the Victim). In this context, the term crossing is meant to indicate that the instantaneous RF frequencies of both the devices are equal at a certain point of time. In such a case, the Aggressor’s signal will not be rejected by any of the filters on the Victim’s receiver. The Aggressor's chirp will be down-converted, digitized and send out as part of ADC data.

In the ADC data, the duration during which the crossing occurs will have glitch – whose amplitude is related to the distance between the Aggressor and the Victim, as well as the antenna gain of both the Aggressor and the Victim. Unmitigated, this glitch can result in unacceptably higher noise floor after range and doppler processing – hence identifying the region of the glitch (referred to as the process of localization), and ‘healing’ the damage (referred to as mitigation) are both vital signal processing steps necessary to preserve the SNR and maintain robust performance.

The AWR294x transceiver is TI’s latest radar-on-a-chip which has, in addition to a C66x DSP (for proprietary signal processing) and a R5F Arm processor (tracking, communication, and control, and so forth), a radar signal process hardware accelerator (called the HWA). The HWA is equipped with hardware blocks to localize and mitigate interferers in-line during range processing.

This document discusses two topics, the mechanism of crossing interference and the methods to detect and mitigate such interference using the HWA. A more thorough introduction to FMCW radar interference can be seen in [1].