Feedback reduction-based resource allocation scheme using multiuser diversity over wireless networks

Abstract

Recently the demand for high data rate wireless data service has been increased enormously. To meet this growing demand, the efficient radio resource allocation scheme is the key requirement in the emerging and the future broadband wireless networks. However, a wireless communication channel suffers from many impairments such as the path loss in power as the radio signal propagates, the shadowing due to the presence of fixed obstacles in the radio path, and the fading which combines the effect of multiple propagation paths. Due to this problem, the overall system performance can be severely degraded. The diversity technique is the effective mean to compensate for the fading channel impairments. Among them, the technique based on the multiuser diversity has been attracted much attention due to its ability to provide a reliable high data rate services. There are two diversity techniques employed in the multiuser cooperative network: cooperative diversity (CD) and multiuser diversity (MUD). However, there are few researches considering both CD and MUD in cooperative relay networks where CD can improve the transmission reliability while MUD can increase the spectral efficiency. Moreover, the existing schemes based on the full channel state information (CSI) require the heavy feedback overhead between a base station (BS), relay stations (RSs), and mobile stations (MSs). In this dissertation, we focus on designing the radio resource allocation scheme with feedback reduction over multiuser diversity systems for two types of networks: single-hop network and relay-enhanced network. We consider a cellular network where data transmission are controlled and coordinate at the BS. In the single-hop network, in order to reduce feedback overload, a framework of contention-based feedback was established. However, since an MS is randomly chosen, it cannot maximize capacity. Moreover, if a collision occurs and thus, the BS cannot obtain any information to schedule an MS...