Performance evaluation of OFDM Channel For Fixed WiMAX System

Abstract

WiMAX operates on the same general principles as WiFi; it sends data from one computer to another via radio signals. A computer (either a desktop or a laptop) equipped with WiMAX card would receive data from the WiMAX transmitting station. WiMAX should be able to handle up to 70 Mbps. And will blanket a radius of 30 miles (50 km) with wireless access. The increased range is due to the frequencies used and the power of the transmitter. So these features make wimax system very suitable for work in Sudan, because Sudan has a very large area and the distribution of the population is rural rather than urban. This thesis is to evaluate and investigate the effects of few radio channel impairment factors such as AWGN, and multipath to the performance of OFDM channel. Also in this thesis the estimation of SNR was done under the effects of noise and multipath for the four recommended modulation techniques; BPSK, QPSK, 16-QAM, 64-QAM for different cyclic prefix lengths, and calculated BER. The evaluation was done in simulation developed using MATLAB 7.8.