Optimizing the RAKE receiver for the CDMA downlink

The optimal filter solution for the code division multiple access (CDMA) downlink is derived. A practical suboptimal filter that recovers part of the loss introduced by the RAKE receiver is presented. A significant performance advantage is obtained when the proportion of total interference that comes from the same base station as the signal is large. There is a design tradeoff between the complexity of the practical filter and its performance. As the complexity increases, the performance approaches that of the optimal filter