Fading Channel with Orthogonal Multi-carrier Code Division Multiple Access Signal

Abstract

The wireless industry is currently undergoing a major transition from second generation (2G) to third genera- tion (3G) wireless technologies, and the increasing demands for communication services require higher transmission rates that further stimulates the demand on wideband technologies depicted in the form of code division multiple access (CDMA) on one hand. Also, as the privacy is a prime issue in modern communications therefore the carriers orthogonality is a fun- damental concept for a sustainable development of the communications sector. This paper attempts to assess wireless communications channels and propose techniques to improve the performance of modern wireless communications. Hence from a strategic perspective, an analytical study into the performance of Group Orthogonal Multi Carrier Code Division Multiple Access (GO-MC-CDMA) in which subcarriers assigned to users which are orthogonal to other groups, the channel bandwidth is the main theme of this paper; from which the problems that may affect the communications link are high lighted and measures to counterbalance and alleviate multipath fading are proposed and investigated. Such measures are: Space diversity combining techniques and minimum - mean square error, and interference cancellation and detection are considered in this research. As a result of this research it can be stipulated that subcarriers grouping does reduce Mul- ti-User-Interference (MUI) between frequency groups thus enhance the performance of MC-CDMA system in the mission of meeting newly emerging wideband communications services, such as video conference and others.