Performance Analysis of Adaptive Modulation and Coding Over AWGN Channel in an OFDM System

Abstract

Orthogonal frequency division multiplexing (OFDM) as a special multi-carrier transmission technology has good resistance to narrow-band interference and frequency selective fading ability. Compared with traditional modulation techniques, adaptive modulation can enhance bandwidth efficiency and system capacity. Therefore, applying adaptive modulation in OFDM systems can take full advantage of spectrum resources, and it is suitable for the high-speed and reliable mobile communication systems in the future. The purpose of this paper is to investigate the effect of adaptive modulation and coding in OFDM system to improve bit error rate performance over AWGN fading channel. In this paper OFDM system performance in terms of bit error rate (BER) is investigated using fixed and adaptive modulation technique using convolutional coding and BCH coding over AWGN channel. From the comparative result analysis of adaptive modulation using convolutional coding and BCH coding over AWGN channel, it can be concluded that Bit Error Rate (BER) is improved by using Adaptive modulation with Convolution coding in comparison with adaptive modulation with BCH coding over AWGN channel.