Recognition, Reconstruction, and Suppression of Range Overlapped Ghost Target Based on Dual Receiving Channels for LFMCW Radar

Linear frequency-modulated continuous-wave (LFMCW) radar has extensive applications in air defense and target measurements. Due to the rapid development of electronic countermeasures (ECMs) and the growing number of radars in autonomous driving, indistinguishable ghost target interference has become an increasingly critical challenge for LFMCW radar. Under conditions of intensive interference or dense targets, the ghost target may overlap with real targets, leading to erroneous detections. This study investigates the methods of recognizing, reconstructing, and suppressing interference when the ghost target overlaps with real targets in range. First, this work suggests a dual receiving channels scheme based on interpulse phase coding to distinguish the aliased ghost target. By modulating the initial phase of the transmitted pulse, and decoding and undecoding the received pulse phases, the real and ghost targets can be compressed separately in different receiving channels. Furthermore, to efficiently differentiate the aliased ghost target from real targets, this article develops a ghost target recognition strategy based on the statistical parameters of the Doppler signal in each range gate. More importantly, to further suppress the aliased ghost target, this work additionally proposes an interference reconstruction and suppression scheme in the range and Doppler (RD) domain. These proposed strategies can exactly identify, reconstruct, and eliminate the aliased interfering signals while preserving the desired signals of real targets. Finally, the effectiveness and performance of these proposed schemes are explicitly examined by experimental tests.