Advantages of hybrid OFDM systems in 3G and beyond

A new generation of broadband wireless access system will be required to provide voice, video, data and Internet services to meet a wide range of customers' demands. This system can support very high data rate services while combating multipath and fading channels. OFDM systems have outstanding features to fulfill these demands. In this survey paper, we will introduce the merits of OFDMA, capacity advantages of OFDM-CDMA over DS-CDMA. We will also demonstrate the more comprehensive hybrid system of OFDM/CDMA/SFH with better performance over plain OFDM systems. In addition, we will investigate how improvements can be achieved by taking advantage of diversity gain through space-time frequency block code.