Improving the performance of blind CDMA 2D-RAKE receivers with phase ambiguity in the bit decision variable

Previously, a blind equalization algorithm for a base station CDMA receiver exploiting antenna and path diversity, based on the principal eigenvector computation of a correlation matrix pair, has been presented. The phase ambiguity in the bit decision variable obtained with this algorithm leads, for PSK, to the use of differential detection. We present an algorithmic modification that consists in estimating and cancelling the phase ambiguity in the bit decision variable, so that a more efficient coherent detector can be used. The gain in the uplink capacity resulting from the use of this algorithmic modification is demonstrated via simulation.