Blind Channel Equalization of Star QAM using Dual Dispersion MCMA Algorithm

Abstract

In wireless communication, the transmission of signal has to deal with the effects of channel on the signal. The channel due to its inherent characteristic introduces channel effects such as distortion and inter symbol interference which causes problems at the receiver making the information in the received signal distorted and unable to be recovered. In order to combat this, channel equalization techniques are used at the receiver. This thesis investigates the performance of blind channel equalization on Star QAM and introduces the Dual Dispersion MCMA Algorithm for Star QAM which is the enhanced version of Modified Constant Modulus Algorithm (MCMA) designed for Star QAM. The algorithm uses the concept from MCMA algorithm and introduces the multiple dispersion points for Star QAM because of its constellation to achieve improved performance and convergence rate. The performance is further improved by using decision directed mode. Simulation results validate the improved performance of Dual Dispersion MCMA algorithm over MCMA algorithm.