扩频信号的一种快速捕获技术

Quickly Acquisition Technology of Spread Spectrum Signals

介绍了一种双频域并行捕获算法及其快速实现方法,该方法通过将时域的相关运算转换成频域傅里叶变换的乘法运算实现码相位的并行搜索,且基于频域圆周移位的原理,通过对傅里叶变换序列进行循环移位实现多普勒频率的并行搜索,大大减小了运算量和捕获时间。和其他算法相比,本算法捕获时间能缩小一个数量级,尤其适于宽范围高动态扩频信号的快速捕获。

An bi-frequency domain acquisition algorithm and its fast implementation method is given, which can realize the search of code phase and Doppler frequency in paral- lel. Instead of calculating correlation in time domain, the parallel search of code phase is car- ried out by executing multiplication in frequency domain. Meanwhile, based on the principle of circular shift of frequency domain, the fourier transform sequence is cyclic shifted with different offset to search Doppler frequency in parallel. As a result, the amount of computa- tion and the capture time is significantly reduced. Compared with other algorithms, the cap- ture time can be reduced greatly. So it is suitable for rapid acquisition of spread spectrum sig- nals under large deviation and high dynamic conditions.