A robust channel equaliser with noise correlation subtraction for AF relay cooperative networks

Abstract

Analytical methods of signal recovery that are not limited to specific channel conditions are of great importance for an amplify and forward (AF) relay network, as the performance of diversity systems operating over such conditions are affected by various channel characteristics. Signal extraction from a correlated noise environment remains as another crucial issue that requires exploration. A block adaptive Wiener equaliser is proposed where the coefficients are set based on the correlation functions of the incoming signal. A further enhancement in signal recovery is obtained by using a modified correlation matrix by noise correlation subtraction method. One of the key features of these methods is that it does not require apriori knowledge of channel statistics at the receiver. The improvement in system performance owes to the enhanced correlation adaptation and matching between the actual channel and the filter coefficients derived at the receiver. The bit error rate (BER) performance of the proposed techniques are evaluated through computer simulation studies and are compared with that of a fixed interpolation method referred in the literature, to show the superiority of the proposed techniques.