Communications Receivers Employing Wavelet-Domain Zero-Forcing Equalization of Multipath Fading Channels

Abstract

In this paper communications receivers that implement Zero-Forcing (ZF) equalization using the Discrete Wavelet Transform (DWT) are examined. In such receivers, noisy faded received signals are first decomposed using the DWT into detail and approximation coefficients. Instead of the received signals being directly equalized in the discrete time-domain the DWT coefficients of the signals are equalized using ZF equalization. In this work the performance of such receivers under various transmission channel conditions is evaluated. Both slow- and fast- fading multipath channels are considered. In addition, the effect of using different wavelets on receiver performance is also examined. Overall system performance is evaluated using Monte Carlo simulations employing 16-QAM modulation. For all cases considered, the transmitted signals have also been corrupted by additive White Gaussian Noise (WGN). It is found that performance of receivers using wavelet-domain ZF equalization is similar to the performance of receivers using discrete time-domain ZF equalization.