Adaptive RAKE-blind source recovery algorithms for 3GPP UMTS/WCDMA downlink receivers

Wideband code division multiple access (WCDMA) is the dominant air interface for the Universal Mobile Telephone Services (UMTS) frequency domain duplex (FDD) mode and for future IMTS wireless networks. The transmitted CDMA signals from based station (BS) propagate through noisy multipath fading communication channels before arriving at the receiver of the mobile station (MS). In contrast to classical single-user detection (SUD) algorithms, which do not provide the requisite performance for modern high data rate applications, optimal multi-user detection (MUD) approaches require a lot of a-priori information not available to the user equipment (UE). We propose two adaptive approaches namely Rake-blind source recovery (RAKE-BSR) and RAKE-principal component analysis (RAKE-PCA) that fuse an info-theoretic stage into a standard RAKE receiver. This results in robust detection algorithms with performance exceeding the standard LMMSE detectors for WCDMA systems under conditions of congestion, imprecise channel estimation and unmodeled multiple access interference (MAI).