Broadband interferrence suppression in DS-SS system with modified chirp Fourier transform

Abstract

This paper presents the application of the discrete chirp Fourier transform for interference excision in DS-SS systems. Detailed analysis on the undesirable influence of side-lobes due to windowing operation is provided through both theoretical deviation and experimental results. A new efficient excision method is proposed by using modified DCFT to minimize the distortion from the side-lobes. With a computational complexity in the order of O(Nlog 2 N), the proposed method is shown to achieve a much better performance in terms of bit error rates in the presence of white noise and linear chirp-like interference within a large range of interference to sig nal ratios(ISR).