Adaptive Channel Estimation Exploiting Pilot Diversity with SINR Estimation for WCDMA Downlink Receivers

This paper, addresses the issue of channel phaser estimation in WCDMA, in which both the Common Pilot Channel (CPICH), which is not power controlled, and the Dedicated Physical Control Channel (DPCCH), having pilot symbols with power control, are available. Depending on the user’s location, either the CPICH or DPCCH may have better SINR and hence, yield more reliable channel estimates. The proposed channel estimator estimates the channel gain by adaptively combining the estimates from common pilot channel and pilot symbols. We derive the optimum weights (SINR-based) for combining using Minimum Mean Square Error (MMSE) criterion. A subspace based SINR estimation method is also presented.