Robust Adaptive Pulse Compression Method Based on Two-Stage Phase Compensation

Abstract

The conventional pulse compression method [i.e., matched filter (MF)] and adaptive pulse compression (APC) methods are based on the assumption that the echo sampling point is located in the target point which is in a range cell. If the echo sampling point is not located in the target point, it will result in sampling mismatch problem and the performance of MF and APC methods will be significantly reduced when using the continuous-time phase-modulated waveforms, such as linear frequency modulation (LFM) signal. Aiming at solving the sampling mismatch problem, an APC based on two-stage phase compensation (TPC-APC) and its dimensionality-reduced version-contiguous fast APC based on two-stage phase compensation (TPC-CFAPC) are proposed in this article. In TPC-APC/TPC-CFAPC method, the mismatch phase caused by the sampling mismatch is first compensated through the first-stage phase compensation, which suppresses the sampling-mismatch-induced range sidelobes; then the mismatch phase caused by the target’s Doppler frequency is compensated through the second-stage phase compensation to suppress the Doppler-mismatch-induced range sidelobes; finally, the APC is applied to suppress the range sidelobe. To further compensate the mismatch phases of different targets, this article proposes a reiterative TPC-APC method and its dimensionality-reduced version, which iteratively use TPC-APC or TPC-CFAPC to suppress the range sidelobes caused by the mismatch phases of different targets. The results of the experiments have shown that the proposed methods are more robust compared with MF and APC methods.