基于FFT的高动态扩频信号快速捕获  

Rapid acquisition of high dynamic spread spectrum signals based on FFT

作　　者：袁梦云 张继娜 赵忠凯[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《应用科技》2016年第1期13-16,共4页Applied Science and Technology

基　　金：中央高校基本科研费专项基金资助项目(HEUCF140803)

摘　　要：在卫星通信系统中,卫星相对于地面有非常大的径向速度,这种相对运动使地面上的扩频应答机接收到的信号附加了较大的多普勒频移,捕获难度大。针对高动态扩频信号捕获问题,提出了一种基于快速傅里叶变换(FFT)的快速捕获方法,并完成了软件仿真和硬件实现。该方法用FFT的方法遍历了伪随机码的所有相位,并通过本地伪码做FFT运算后的左/右循环移位来遍历多普勒频率范围,能够在得到载波多普勒频移的同时捕获伪随机码相位偏移。仿真结果表明,该方法具有捕获效率高,占用资源少的优点,适用于高动态环境。In the satellite communication system,the satellite has a very large radial velocity relative to the ground,and the signal received by transponder on the ground is added with a larger Doppler shift,resulting in the difficulty of capturing. For the high dynamic spread spectrum signal acquisition problem,a rapid acquisition method based on fast Fourier transform（ FFT） is presented,and the software simulation and hardware implementation have been completed. The method uses FFT approach through all phases of the pseudo-random code,and using the local pseudo-code to left / right cyclic shift to traverse the Doppler frequency range after the FFT operation,it is possible to obtain the Doppler shift of the carrier while capturing pseudo-random code phase offset. Simulation results show that this method has high capture efficiency and small footprint advantages,very suitable for high dynamic environment.

关 键 词：快速傅里叶变换 扩频 快速捕获 多普勒频移 

分 类 号：TN914.42[电子电信—通信与信息系统]