CAJ | 학술논문

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。
직확통신계통적해확여해조도시의뢰우유효적위마포획，위료실현위마적쾌포，대경전FFT포획산법진행료부분개진。재경전FFT포획산법적기출상채용료2배마속솔채양병차증가료일개다보륵빈이공제기。수선대개진산법진행료이론분석，연후용MATLAB대기진행료방진험증，방진결과포획도증명해산법재예설삼수하가이실현유효쾌포，이차재불강저포획정도화항간우성능적동시축단료포획시간，종이진일보제고료FFT산법적포획성능。
Dispreading and demodulation of DSSS communication system are dependent on the PN code ef-fective 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.