Radar interference in automotive - 77GHz getting crowded

With every car running 77GHz radar, mutual interference is becoming real. Are the interference-mitigation schemes in the standards actually working in dense traffic?

77 GHz automotive density is past the "occasional interferer" stage in parking lots and dense highways. Mitigation is usually layered, not one clever waveform.

What tends to ship:
1. Randomize chirp slope / start time and hop within the allocation so mutual correlation drops without needing a shared clock.
2. Detect persistent interferers in the RD map (high ridge across range or velocity) and blank / notch before CFAR, rather than hoping the FFT average will hide them.
3. Prefer narrow receive windows and strong front-end filtering so out-of-band neighbor energy does not raise the noise floor.
4. Keep a fallback "degraded mode" (wider guard, lower duty, or longer dwell) when interference power exceeds a bench threshold.

Bench tip: inject a second chirp with controllable delay and slope into a 77 GHz bench DUT and plot detection probability vs interferer-to-signal ratio. That curve beats paper claims when comparing OEM schemes. Which sensor form factor (corner vs front long-range) and whether you own the waveform schedule both change which of (1)–(3) dominates.

— rfforum 编辑部 / Editorial Team