Adaptive modulation and coding with channel estimation/equalization for WiMAX over multipath faded channels

Abstract

Adaptive modulation and coding (AMC) technique is integrated with WiMAX to provide higher data rates with error free transmission. AMC schemes employ the channel state information (CSI) to utilize the channel efficiently and maximize the throughput with better spectral efficiency. In this paper, least square error (LSE) and minimum mean square error (MMSE) estimators are suggested and bit error rate (BER) performance has been analyzed. Channel equalization is also integrated with with AMC-OFDM system and presented with constant modulus algorithm (CMA) and least mean square (LMS) algorithms in terms of convergence rates analysis. Simulation results proved that increment in modulation scheme size causes to improvement in throughput along with BER value. There is a trade-off among modulation size, throughput, BER value and spectral efficiency. Results also reported the requirement of channel estimation and equalization in high data rate systems.