Study Of Adaptive Filtering Algorithm On Passive Radar Using FM Broadcast As Transmitter

Without radiating electromagnetic wave,Passive radar based on opportunity Transmitter (such as FM broadcast signal, mobile phone signal and other civilian signal) is not easy to be detected by electronic scouting systems. And it has potential superiority in ECCM(Electronic Counter-Countermeasure),AARM(Anti Anti-Radiation Missile),and anti-stealthy targets, thus a bright future. In this paper, clutter cancellation in passive radar signal processing with adaptive filtering technique is studied. The common adaptive algorithms include least mean square (LMS) algorithm, recursive least square (RLS), adaptive lattice algorithm and so on. Adaptive transversal filter can be mainly divided into LMS adaptive transversal filter and RLS adaptive transversal filter. Two improved LMS algorithms are analyzed involving normalized least mean square (NLMS) and variable step-size least mean square with errors nonlinearities (NVSS). These two algorithms are provided to enhance the trade-off between misadjustment and convergence rate. RLS is based on Newton algorithm, which has faster convergence and larger amount of calculation than LMS. In this condition, this paper develops an adaptive lattice joint processor to process passive radar signal. This algorithm has faster convergence and a smaller amount of calculation, and it is more effective than the other algorithms to detect the target when processing real-time data.