Simulation and Analysis of QAM-OFDM System Based On Simulink

Abstract

Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation which a signal is split into several narrowband channels. OFDM uses a large number of closely-space orthogonal subcarriers to carry data. The data divided into several parallel data streams or channel, one for each subcarrier. Each subcarrier then has been modulated using conventional modulation scheme such as quadrature amplitude modulation (QAM) or phase shift keying (PSK). OFDM is a method that allows transmitting high data rates over extremely hostile channels at a comparable low complexity. One of the main reasons to use OFDM is to increase robustness against frequency selective fading or narrowband interference. The objective of this paper is to obtain the performance of the OFDM and get the measurements of bit error rate (BER) under different communication channels using a conventional modulation scheme (64-QAM). Orthogonal Frequency Division Multiplexing (OFDM) is modeled and simulated under different communication channels such as AWGN and Rayleigh fading. The functionality of the block diagram of OFDM will be obtained from the simulation using the MATLAB/SIMULINK software. The measurement of BER under the different channels conditions will be shown in graph format.