Indian Journal of Science and Technology

Abstract

OFDM comes out as a key technology in contemporary wireless communication systems. OFDM offers a diverse kind of advantages like fading immunity, eminent data rate transmission, and efficient bandwidth capabilities. In order to have a reliable errorfree communication, various channel coding schemes viz. Convolution Codes (CC), Bose-Chaudhuri-Hocquenghem (BCH) and Reed-Solomon (RS)encoding and decoding schemes are being used at the transmitter and receiver side. These channel encoding schemes makes possible the error detection and correction possible at the receiver end. In present work, an OFDM system based on the diverse level of M-PSK digital modulation scheme is demonstrated integrating dissimilar channel encoding techniques over the Rician fading channel. Bit Error Rate (BER) assessment as a function of SNR is being presented for the simulated testbed. The simulation results present a substantial enhancement in BER performance of the simulated system using BCH over CC and RS. Also, as we keep on increasing the level of modulation scheme to get higher efficiency the BER performance keeps on degrading due to diminishing Euclidean distance between the constellation points. This degradation in BER performance is compensated by increasing the SNR values to get the desired BER performance. For all the diverse level of M-PSK modulation the RS encoding offers an advantage of 2-3 dB over convolution encoding to achieve a desired BER performance, but BCH enhances this performance further by providing an improvement of 2-3 dB over RS encoding schemes for all diverse level of M-PSK over Rician channel.
Keywords: BCH, BER, CC, FEC, M-PSK, OFDM, RS