Channel estimation for a DS-CDMA mobile radio system with a coherent reception

A method to exploit channel estimation for a DS-CDMA mobile radio system with coherent reception in the Rake receiver is investigated by means of a software tool, named CDMASIM. Channel estimation is performed in the down link (base to mobile) by transmission of a pilot signal from the base station. Two different techniques for channel estimation are proposed and investigated in time and frequency selective channels. The first technique is based on correlation between the received signal and the pilot signal to perform channel identification, while the second is based on an adaptive stochastic gradient algorithm for channel equalization. The parameters that characterise the two techniques have been optimized in terms of BER and performance results are given in faded multipath environments with optimal parameters.<>