A novel waveform design for multi-target detection in automotive FMCW radar

FMCW (Frequency Modulation Continuous Wave) radar has been widely used in active safety systems recently. On account of range-velocity processing, ghost targets and missed targets exist in a multi-target situation. To address those issues, a two-step scheme as well as a novel FMCW waveform have been proposed in this paper. The proposed waveform contains four segments: fast up ramp, slow up ramp, flat frequency and slow down ramp in each period. The approximate range can be detected by using the fast up ramp in the first step, then the unambiguous velocity can be calculated during the flat frequency segment in the second step. The combination of the two independent measurements yields, finally, the real targets and eliminates the ghost targets. In addition, the computational complexity of our proposed scheme is 80% lower than ramps with different slopes method, and the effectiveness of our approach is demonstrated by simulation results.