A Fast-Processing Approach for Passive OFDM Radar Clutter Rejection

The pervasive clutter in passive radar poses a significant challenge to radar target detection. Passive radars utilizing pulse-to-pulse incoherent signals, such as those derived from civilian communication signals, are particularly susceptible to clutter interference. This interference significantly raises the pedestal level of the Range-Doppler (RD) map, thereby completely obscuring the target. While numerous approaches have been developed to address this issue, including those based on least-squares or compressed sensing, they often suffer from practical limitations, such as high computational complexity or limited clutter suppression capabilities. In this paper, we present enhancements to the Extensive Cancellation Algorithm (ECA) method, leveraging the Least Squares QR factorization(LSQR) approach, which significantly reduces the time complexity but still maintain the performance levels of the original method. Furthermore, the original method is constrained by the storage requirements of computing devices, and the selection of clutter suppression points is limited. The new method overcomes these limitations, enabling the suppression of more clutter points at once.