Current cellular communications systems have adopted digital technology. However, the major services they provide are limited to basic services, such as voice, and relatively low-bit-rate data. We are now in the 21st century, where the demands for a variety of wideband services such as high-speed Internet access and video/high-quality image transmission, will continue to increase. The third-generation mobile communication system based on wideband CDMA has been designed to support wideband services at data rates with the same quality as fixed networks. This book describes diversity schemes in which signal processing at the receiver is combined, where it is possible to design systems in which the reliability/throughput far exceeds systems in use today. It will study the performance of non-coherent OFDM modulations over generalized mobile radio fading channels with correlated branches, based on balance incomplete block design. It will focus on post-detection combining systems and study the effect of diversity, fading severity and sensitivity of channel correlation for the various signaling systems.