Chirp信号多径时延估计算法研究

Research on multipath delay estimation algorithm for Chirp signal

针对分数阶傅里叶变换(FRFT)对Chirp信号进行多径时延估计时的不足,改进了一种按照多径分量能量大小依次消除的FRFT多径时延估计算法。该算法以迭代方式进行,按多径分量的能量大小依次返回多径分量的估计值;在每次迭代中,包含子迭代以准确判定当前分量的多径参数和起止时间,然后利用当前多径参数生成探测信号时域副本,将其从残余信号中减去,达到多径信号的分离。以根据功率时延分布特点拟定的信道模型作为传输环境,对该算法进行了仿真验证。仿真表明,相比于其他三种时延估计算法,改进算法能够更准确地对多径时延进行估计。

In order to solve the problem of the fractional Fourier transform( FRFT) in estimating the multipath delay for Chirp signal,this paper proposed an improved FRFT multipath delay estimation algorithm based on the energy of each multipath component. The algorithm sequentially returned the estimated values of multipath components by iteration according to the energy magnitude of multipath components. In each iteration,there were a sub-iteration to accurately estimate the parameter and location of the current component,and then generated a time domain copy of the sounding signal,which was subtracted from the residual signal to reach separation of the multipath signal. This paper made some experiments which used channel model based on the characteristics of power delay distribution. The results show that the improved algorithm can estimate the multipath delay more accurately than the other three delay estimation approaches.