基于 FFT 的时频并行捕获算法研究

摘要

The acquisition of PN codes plays an important part in the Spread Spectrum Communication Systems .In order to accelerate the procedure of acquisition , we study parallel acquisition algorithm , which concurrently per-forms frequency domain searching with FFT and time domain searching with multi channels .And the theoretical de-duction result validates the correctness .Further analysis on precision, speed, complexity and low-pass effect re-veals the superiority.Finally we demonstrate the feasibility from the aspect of simulation .From the theoretical anal-ysis and simulation verification, we can conclude that the proposed parallel acquisition algorithm can accelerate the acquisition without the sacrifice of precision .%　　在扩频通信系统中，PN 码的捕获是系统正常工作的前提。为了进一步实现快速捕获，研究了基于 FFT 的时频并行捕获算法，利用 FFT 实现频域并行捕获、利用多通道实现码域并行捕获。理论推导验证了该算法的正确性，分析了该算法捕获精度、捕获速度、实现复杂度以及低通滤波效应。仿真结果进一步验证了该算法捕获的正确性。基于 FFT 的时频并行捕获算法在不降低精度的前提下，可以有效提高捕获速度。