Adaptive NonLinear Equalizer for SISO Wireless Channels.

Abstract

Channel equalization is an essential component of wireless receiver used in SISO (Single Input and Single Output) communication systems to mitigate the effect of inter symbol interference (ISI) and other channel impairments. Adaptive signal processing models with weight adjustment mechanisms can be utilized to design equalizer for wireless environments. In this paper nonlinear adaptive channel equalizer for SISO communication channels has been designed with the help of variable step size Least Mean Square/Fourth (VSSLMS/F) algorithm with a suitable control parameter. 4-QAM modulation is used to generate pass band input data sequence which is transmitted through the nonlinear channel. Output sequence is estimated by using equalized output with help of decision device. The performance of the proposed equalizer has been evaluated on basis of bit error rate (BER) with help of comparison results using MATLAB simulations in presence of additive channel noise.