On the Design of RAKE Receivers with Non-uniform Tap Spacing

摘要

In this paper the effect of non-uniform tap spacing on the performance of a RAKE receiver is studied. A new RAKE receiver implementation, named MPMC (maximum power minimum correlation) RAKE, is suggested. Taps positions optimization is done according to the MPMC criterion. This implies the simultaneous maximization of the sum of squares of total average signal power received in each branch and minimization of the sum of squares of autocorrelation between each pair of branches. The proposed receiver performs better than the conventional MRC and the optimum ML RAKE with constant tap spacing especially at higher E_b/N_o. Optimum taps settings depend only on the channel characteristics. The case of channel estimation errors is also studied. Results are satisfactory.