A hybrid equalizer/Rake receiver for the Wideband CDMA Downlink in large delay spread channels

Abstract. Signals transmitted over a multi-path propagation channel exhibit Inter-Path Interference (IPI) and fading. The receiver has to employ measures to mitigate these effects or it will incur severe performance degradation. A classic approach in Code Division Multiple Access (CDMA) communications is the Rake receiver. Alternatively, a Linear Minimum Mean Square Error (LMMSE) equalizer can further improve performance. This paper compares performance and computational complexity of these two algorithms. A hybrid solution will be introduced in order to decrease computational complexity while retaining most of the interference suppression capabilities of the LMMSE equalizer.