Detection and Parameter Estimation of Multi-targets Based on Secondary Mixing Combined DPT Method in LFMCW Radar
基于二次混频DPT的LFMCW雷达多目标检测和参数估计

To solve the detection problem of high-speed accelerating targets in LFMCW (Linear Frequency- Modulated Continuous Wave) radar, a secondary mixing combined DPT (Discrete Polynomial-phase Transform) method is proposed. Utilizing the modulation symmetry of tri-LFMCW signals, up-sweep beat signal is secondary mixed with down-sweep one to eliminate MTRC (Migration Through Range Cell) induced by the high-speed. And DPT processing in terms of range cell leads to the estimation of acceleration and initial velocity. Furthermore, parameter estimation of multi-targets is emphasized. By analyzing the characteristics of the cross terms, the conditions for first order cross terms forming effective interfere and for second order cross terms emerging are derived, respectively. Resorting to Clean algorithm, multi-targets can be dealt with successfully, which detects and removes the strongest target for the current time. Processing steps of multi-targets cases are given. Simulation results testify the effectiveness of the method and the conclusions.