基于DFT快速算法对扩频码捕获过程的优化

Optimizing the Acquisition Process of Spectrum Code Based on Fast Algorithm of DFT

针对基于FFT的频域捕获方法采样点数必须为2的整数次幂的局限性,应用Colley-Tukey和Good-Thoma算法对DFT求解过程进行分解,并引入Winograd DFT算法将短点数DFT优化从而得到一种改进算法。利用改进算法对GPS的L5频段上扩频码捕获进行了仿真分析。与FFT算法相比,改进算法在保证精度和灵敏度的同时,降低了计算量,提高了信号捕获速度。

Aiming at the limitation of FFT based on acquisition algorithm in frequency domain which the sampling points can only be integer power of 2,a modified algorithm is proposed in this paper.The Colley-Tukey and Good-Thoma algorithm is used to decompose the process of DFT and the Winograd algorithm is applied to optimize the less sampling points DFT.Simulations are implemented with acquisitions of GPS L5 signal and the performance of the modified algorithm is compared with the conventional FFT algorithm.The results show that a significant improvement of the acquisition speed without losing any precision and sensitivity is achieved by using the proposed design.