Multicarrier Techniques for 4th Generation Mobile Systems

Abstract

This thesis investigates the effectiveness of Orthogonal Frequency Division Multiplexing (OFDM) and Multicarrier Code Division Multiple Access (MC-CDMA) as a Multicarrier transmission technique for wireless radio applications. The main aim is to access the suitability of OFDM and MC-CDMA for fourth generation mobile network. Since the existing mobile generations suffer from multipath propagation and fading problems especially frequency selective fading. There are several techniques used to overcome these problems such as equalization, diversity, and coding. In the fourth generation, OFDM and MC-CDMA is an attractive Multicarrier transmission method for channels with nonflat frequency response. In addition, OFDM offers several advantages like high spectral efficiency, inherent resistance to narrowband interference and robustness in multipath environment; it will be more convenient for the fourth generation mobile systems. In this thesis, the performance of the OFDM system is investigated by measuring the effect of multipath delay spread, noise, and peak power clipping in terms of Bit Error Rate (BER). The investigation will done using a MATLAB program. Several modulation techniques for OFDM were investigated in this thesis including BPSK, QPSK, and 16PSK. System performance gains may be possible by dynamically choosing the modulation technique based on the type of data being transmitted. OFDM promises to be a suitable transmission technique for high capacity wireless communications and is increasingly becomes important in the future wireless networks.