Space-time optimal combination for DS-SS. The 2D RAKE receiver

An algorithm that implements a 2D RAKE receiver for a cellular CDMA system that cancels strong multi-user access interference (MAI) and optimally combines multipath is presented in this paper. The algorithm asymptotically provides the optimum combination of space-time samples to maximize the SINR for the signal with the desired code (SDC) by optimally combining its multipath and canceling strong multi-user access interference (MUAI). This algorithm asymptotically provides the exact time of arrivals of the multipaths within a bit period, and subsequently the optimum space-time weights for combining the fingers across both space and time. The instrumental property exploited in this technique is the fact that although the respective spectra of the SDC and MUAI components at the output of the matched filter are statistically equal, the respective spectra of their squared values differ.