A beamspace-time RAKE receiver for sectored CDMA systems

Abstract

A beamspace-time (BT) RAKE receiver is proposed for multiple access interference (MAI) suppression and multipath diversity reception in sectored wireless CDMA communications. The scheme involves two stages. First, a set of diversity beamformers is constructed and then combined for each finger which provides effective reception of in-sector signals and suppression of out-of-sector MAI. Second, an adaptive correlator is attached to each combined beam to combat in-sector MAI and collect signal multipaths in a coherent manner. The proposed BT RAKE receiver is blind in that no training signal is required. The only information required is the signature sequence, timing and a rough estimate of the angle of arrival (AOA) of the signal.