直接序列扩频系统中线性调频干扰的抑制

针对直接序列(DS)扩频系统中线性调频干扰的抑制,本文提出了一种基于分数阶傅里叶变换的干扰抑制接收机的结构和相应的干扰抑制算法.根据线性调频信号在不同的分数阶傅里叶域呈现出不同的能量分布这一特性,利用分数阶傅里叶变换实现干扰信号的检测参数和估计,在此基础上,进行干扰分量的重建和抵消,从而实现对干扰的自适应抑制.性能分析和仿真实验表明,该方法不仅可以在较大的动态范围内有效地抑制线性调频干扰,而且计算简单,便于实现.

LINEAR FREQUENCY MODULATION INTERFERENCE SUPPRESSION IN DIRECT SEQUENCE SPREAD SPECTRUM SYSTEMS

For the suppression of linear frequency modulation interference in a direct sequence spread spectrum system, a direct sequence (DS) spread spectrum receiver with an interference exciser using fractional Fourier transform is presented. Based on the fact that the localization performance of a given LFM interference varies in different fractional Fourier domains, the detection and parameter estimation of the interference are implemented using the fractional Fourier transform. The interference can be reconstructed and excised adaptively. Performance analyses and simulation results have showed that the proposed method works effectively in a large dynamic range. It is easy in computation and simple in implementation.