Performance analysis and comparison of different RAKE receivers for UWB channel

In diversity rich environments, such as in Ultra-Wideband (UWB) applications, a priori determination of the number of strong diversity branches is difficult, because of the considerably large number of diversity paths, which are characterized by a variety of power delay profiles (PDPs). Rake implementations have been proposed in this paper, in order to reduce the number of the estimated and combined paths. To this aim, we introduce two adaptive Rake receivers, which combine a subset of the resolvable paths. These schemes achieve better adaptation to channel conditions compared to other known receivers, without further increasing the complexity. We evaluate the performance of an ultra-wide band (UWB) system using reduced-complexity Rake receivers, which are based on either partial combining (called PRake) or selective combining (called SRake). The first is suboptimum and combines the first arriving multipath components, while the second combines the strongest multipath components.