Fast Calculation of Cross Ambiguity Function for Passive Radar Based on SMGO

For passive radar system, the distance and speed of target can be determined by locating the peak of cross ambiguity function between the reference signal and the echo signal. However, the calculation of cross ambiguity function is expensive so that signal processing in real-time for passive radar system is challenging. To solve this problem, conventional traversal methods are mainly dedicated to reducing the calculation expense of cross ambiguity function. This paper proposes to utilize the Set Membership Global Optimal algorithm to reduce the evaluation number of cross ambiguity function needed for peak search. Then, the computational burden for determining the distance and speed of target is further lessened by combining the optimization method proposed and the conventional traversal methods. Feasibility and efficiency of this method are verified by numerical simulations.