A GA-FRBS Based Rate Enhancement Scheme for OFDM Based Hyperlans

Abstract

Adaptive communication is need and feature of every current communication system. In this technique the transmission parameters are adapted in such a way that overall system throughput may be enhanced while satisfying certain number of constraints. In short this is a constrained optimization problem. In this paper a similar constrained optimization problem is focused and solved by making certain parameters adaptive that are code rate, modulation scheme and transmit power in a multicarrier OFDM environment. For adapting the said parameters a Fuzzy Rule Base System (FRBS) is used in conjunction with Genetic Algorithm (GA). So FRBS and GA suggest the optimum code rate, modulation symbol and power with respect to the channel state information (CSI) given at any instance that can maximize the throughput while satisfying constraints like power and bit error rate (BER). Product codes and Quadrature Amplitude Modulation (QAM) are used as coding and modulation schemes respectively. Simulation results show the significance of proposed scheme.