Joint Design of Periodic Binary Probing Sequences and Receive Filters for PMCW Radar

Joint design of binary probing sequences and receive filters is critical to the performance of low-cost phase-modulated continuous wave (PMCW) radar, which can play an important role in autonomous driving applications to mitigate mutual interferences. For many existing PMCW radar systems, matched filters are employed at the receiver and binary sequences with good periodic auto-correlation properties within a low correlation zone (LCZ) are chosen as probing sequences. In this paper, we first introduce a cyclic algorithm to design binary sequences for the case of using matched filters at the receivers. To further decrease the sidelobes of the periodic correlations between the binary probing sequences and receive filters, at the cost of a small loss in signal-to-noise ratio (SNR), we propose an algorithm for the joint design of binary probing sequences and mismatched receive filters. The proposed algorithms are also extended to take into account the Doppler shifts caused by moving targets. Moreover, the efficient implementations of these algorithms utilizing the fast Fourier transform (FFT) operations are presented, making it possible to use them to design probing sequences and receive filters with long lengths. Finally, numerical examples are presented to demonstrate the effectiveness of the proposed algorithms.