慢衰落多径信道下DS-CDMA信号传输时延的估计

Estimation of propagation delay of DS-CDMA signals in slow fading multipath channels

使用最大似然 (ML)估计 ,采用CLEAN和RELAX算法的估计思想 ,把多维优化问题转化为多个一维优化问题 ,实现了慢衰落多径传输环境下DS CDMA信号的时延和幅度的最大似然估计 .仿真结果表明 :该算法可有效估计多径信号的幅度和传输时延 ,对远近效应稳健 ,其性能接近Cramer Rao界 (CRB) ,较传统的滑动相关器估计方法有明显提高 .

A new efficient propagation delay estimator is proposed, which is an extension of the Maximum Likelihood estimator based on the algorithm of CLEAN and RELAX, and decomposes a multidimensional optimization problem into multiple one-dimension optimizations. The estimator is shown to be robust against the near-far problem and it is also compared with several other code-timing estimators via numerical examples. The estimator can offer noticeable performance improvement over the conventional sliding correlator.