直扩通信系统中FFT捕获算法的改进  

Improved FFT Acquisition Algorithm for DSSS Communication System

作　　者：李璐[1] 赵建平[1] 朱伟[1] 杨真[1] 孟刚[1] 刘中梅[1] 

机构地区：[1]曲阜师范大学物理工程学院,山东曲阜273165

出　　处：《通信技术》2014年第8期860-864,共5页Communications Technology

基　　金：山东省自然科学基金项目(No.ZR2011AM018)~~

摘　　要：直扩通信系统的解扩与解调都是依赖于有效的伪码捕获,为了实现伪码的快捕,对经典FFT捕获算法进行了部分改进。在经典FFT捕获算法的基础上采用了2倍码速率采样并且增加了一个多普勒频移控制器。首先对改进算法进行了理论分析,然后用MATLAB对其进行了仿真验证,仿真结果捕获图证明该算法在预设参数下可以实现有效快捕,而且在不降低捕获精度和抗干扰性能的同时缩短了捕获时间,从而进一步提高了FFT算法的捕获性能。Dispreading and demodulation of DSSS communication system are dependent on the PN code effective acquisition. In order to realize the fast acquisition of PN code, the acquisition algorithm of classical FFT is partly improved. Based on the classic FFT acquisition algorithm, the improved algorithm uses 2 times the PN code rate sampling and adds a Doppler frequency shift controller. Firstly, the theory of the improved algorithm is analyzed, and then a simulation is carried on by MATLAB. The graph capture of the simulation results shows that the algorithm can achieve effective fast acquisition in the preset parameters. Without the reduction of the acquisition precision and anti-jamming performance, the acquisition time is shorten, and thus the performance of FFT algorithm is further improved.

关 键 词：FFT 捕获算法 自相关 多普勒频移 

分 类 号：TN914.42[电子电信—通信与信息系统]