Abstract-Over the past few years, a lot of interest has focused on Orthogonal Frequency Division Multiple Access (OFDMA) and Multiple Input Multiple Output (MIMO) systems thanks to the tremendous gain on system capacity they offer. Transmit beamforming is a low complexity technique that helps in achieving the full diversity afforded by the multiple antenna environment. MIMO-OFDMA systems using opportunistic beamforming are a promising solution to satisfy the growing demand in terms of data rate and Quality of Service (QoS).An important practical issue in MIMO-OFDMA systems is the feedback load. As a large number of carriers (e.g. 2048 for WiMax) is usually used in such systems, feeding back full Channel State Information at the transmitter (CSIT) for each carrier is prohibitive. In this paper, the problem of feedback reduction in MIMO-OFDMA opportunistic beamforming is addressed. We present different partial CSIT schemes that reduce significantly the feedback overload at little expense of system throughput.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.