An enhanced receiver for an impulsive UWB-based PLC system for low-bit rate applications

Abstract

This paper focuses on the convergence speed improvement and the computational complexity reduction during the training phase of a receiver based on reduced rank adaptive filter, which is applied to a power line communication system based on impulsive ultra wideband modulation. In this regard, the use of variable step-size, set-membership, and soft threshold into the training phase of a reduced rank adaptive filter is introduced. In order to evaluate the effectiveness of our proposal, performance analyses with measured in-home and outdoor power line channels distorted by additive noise, which are modeled as white Gaussian and impulsive Gaussian, are carried out. Based on the numerical results, we show that the convergence speed can be considerably improved with the proposed enhancement for training this adaptive filter. Regardless the types of adopted additive noises and power line channels, we show that the improved convergence speed results in low bit error rate if the number of training symbol is reduced, which is a severe constraint associated with the coherence time of power line channels. Moreover, we show that the use of epochs during the training phase is convenient to deal with short coherence time. Performance comparisons with other receivers show that the proposal is more effective to deal with the hardness of power line channels. Moreover, computational complexity comparison shows that the proposed improvement demands less computational complexity than its predecessors. Finally, we show that proposal yields a receiver that outperforms the receivers based on matched filter or a combination of matched filter with the median filter, when similar computational complexity applies.