Reconfigurable adaptive RAKE receiver for wideband CDMA systems

Abstract

Conventional RAKE receiver is near-far limited in code-division multiple-access (CDMA) systems. Linear minimum mean squared error (LMMSE) criterion can be used to obtain near-far resistant single-user receivers. Depending on the optimization criterion different adaptive receivers are obtained. A novel adaptive LMMSE-RAKE receiver based on two different LMMSE criteria is presented. The receiver combines the conventional RAKE receiver and single-user LMMSE receivers. Depending on a quality indicator the receiver switches itself to different modes depending on the radio channel conditions. According to the simulation results the novel receiver concept remarkably improves the performance of the conventional RAKE receivers under various channel conditions and data rates.