A novel FMCW waveform for multi-target detection and the corresponding algorithm

Frequency Modulation Continuous Wave (FMCW) as a quite practical radar modulation technique, is increasingly applied in the intelligent transportation field. A classical FMCW radar system has good performance of short-range applications. However, in multi-target detection situations, so-called ghost targets usually occur because of the Doppler effect in the echo signal, leading to the false alarm rate. For solving this problem, a novel FMCW waveform is proposed, which consists of two parts: a trapezoid wave and a triangle wave. In accordance to a trapezoid wave, the ambiguous ranges are calculated by the slow ramp and the unambiguous relative velocities are detected by the flat frequencies. Nevertheless, some ghost targets still remain owing to the mismatch of intersections in Velocity-Range (V-R) map. Thus, another triangular pairing algorithm is added. It helps that the rest of ghost targets are completely removed. The simulated results demonstrate that the proposed waveform of multiple chirp signals with different slopes behaves well.