Adaptive weighted energy detection receivers for NC-PPM-UWB communication systems

Energy detection receivers are attractive in non-coherent (NC-) ultra-wideband (UWB) communication systems with pulse position modulation (PPM) due to their simplicity of implementation. In order to mitigate the impact of noise on bit error rate (BER) performance, weighted energy detection (WED) receivers were proposed for NC-PPM-UWB systems. In this paper, adaptive WED receivers are further developed for system implementation without matrix manipulation and channel estimation. General adaptive algorithms, such as least mean square (LMS)-based and recursive least square (RLS) algorithms, are evaluated for WED receivers. Our analysis and simulation results show that in terms of the BER performance and convergence speed, the RLS outperforms the LMS-based algorithms. Compared to the RLS, normalized LMS (NLMS) and LMS-Newton methods can obtain comparable BER performance with the penalty in the convergence speed. At the same time, the NLMS possesses the benefit of computational complexity among all investigated adaptive algorithms. Therefore, comprehensive considerations are needed for the practical system implementation to achieve the trade-off among the BER performance, convergence behavior and the computational complexity.