基于PMF-FFT的高动态多进制扩频信号的捕获算法

摘要

针对微弱高动态多进制扩频信号的捕获问题展开研究,提出了将PMF-FFT和功率谱累积平均相结合的捕获算法.该算法通过部分相关,得到反映多普勒频偏的带有噪声的正弦信号,然后对其作FFT变换,将功率谱累积平均,从而达到检测微弱信号的目的.给出了基于该算法的多进制扩频信号模型、捕获方案及性能分析,并在此基础上分析了部分相关器长度、FFT点数及累积次数对捕获性能的影响.在理论分析的前提下,通过计算机仿真验证了该方法的可行性.%Aimed at dealing with the acquisition of high dynamic M-ary spread spectrum, this paper presented the method of using PMF-FFT and cumulative power spectral. Through partial correlation, it could get a sinusoidal signal, which reflected the Doppler shift. By an average of the cumulative power spectrum, it could achieve the purpose of weak signal. It gave the M-ary spread spectrum signal model, the capture scheme and performance analysis. Based on this, analyzed the impact of partial correlatiors' length, FFT points and the cumulative power spectrum to the capture performance. In the end, the computer simulation proves that this method has favorable capture performance.