An adaptive nonlinear rake receiver in UWB wireless communications

In ultra wideband (UWB) systems, one of main the problems is that the UWB system must coexist with other narrowband wireless systems that may cause interference to each other. On other hand, a large bandwidth also results in multipath channels and the Rake receiver has been an appropriate choice to combat multipath fading. However, the performance of Rake receiver degrades when the narrowband interference (NBI) is present. Although we can adopt optimized Rake receiver to suppress the NBI such as the minimum mean square error (MMSE) Rake receiver the computational complexity is prohibitive in practical implementation. In this paper, based on nonlinear techniques we present a new adaptive Rake receiver which can effectively suppress the NBI with a low complexity. Simulation results show that the proposed receiver outperforms the linear predictor and nonlinear predictor, and it achieves almost the same performance as that of a MMSE Rake receiver but with a much lower complexity.