Blind Channel Equalization in Impulsive Noise Environment

Abstract

The unsupervised/blind mitigation of intersymbol interference in an additive impulsive noise environment is a challenging task. In the present work, we exploit a theory of statistical invariance, known as Wijsman’s theorem, to develop a maximal-invariant test to discriminate equally likely pulsed signals against impulsive disturbance leading to an admissible cost function for blind equalization. The cost function is optimized to realize two adaptive equalizers capable of not only mitigating intersymbol interference but also robust to impulsive disturbance. We discuss the admissibility of the derived cost function mathematically and establish its effectiveness in removing the inter-symbol interference. We also discuss the stability of the derived algorithm using the arguments of energy-conservation principles. Numerical simulations, obtained on a baseband digital microwave radio system for amplitude-phase shift keying signalling in an additive (generalized Gaussian and symmetric-alpha stable) impulsive environment, confirm the admissibility of the proposed equalizers in terms of robustness and steady convergence.

Bio

Dr. Shafayat Abrar completed his BS, MS, and PhD in Electrical Engineering. His research interests are in signal processing and statistical methods in communications, control, estimation, and (more recently) robotics. He is the co-recipient of IEEE Heinrich Hertz Award for the Best Communications Letters in the year 2012. Since 2017, he has been serving as an Associate Professor at Habib University, Karachi.