The side peaks of the ambiguity function of the passive radar will lead to false alarms in detection and the mask of weak targets.We proposed a method to suppress the side peaks of the ambiguity function based on generalized sidelobe canceller(GSC)and derived the closed form expression of the GSC-based filter.Moreover

we analyzed the signal to noise ratio(SNR)loss of the proposed filter as well as the relationship between the heights of the side peaks and the SNR loss.In order to avoid the inversion of high dimensional matrices

we also proposed a fast implementation of the proposed filter design.Both theoretical and numerical results based on real data show that

the proposed method can suppress the side peaks to arbitrary level with minimum SNR loss.