Effects of Tap Spacings to Discrete-Time RAKE Receivers in Exponentially Decaying Delay Profiles

In the literature the tap spacirngs for RAKE systems are typically analyzed for a channel with uniformly distributed multipath delay profile. However in realistic simulations, usually exponentially decaying delay profile is conrsidered. Furthermore, the analytical works do not take channel estimation errors into account. In this work we investigate the effect of tap spacing in exponentially decaying delay profile systems to the performance of several advanced discrete-time RAKE receivers under the effect of channel estimation errors. Our simulations indicate that 3T c /4 tap spacing is the best choice which gives good performance with less complexity compared to T c /2 spacing.