期刊名称：International Journal of Antennas and Propagation
印刷版ISSN：1687-5869
电子版ISSN：1687-5877
出版年度：2013
卷号：2013
页码：1-21
DOI：10.1155/2013/745018
出版社：Hindawi Publishing Corporation
摘要：One of the major challenges the mobile broadband community faces is the exponential increase in mobile data traffic, even more
so, for cell-edge users. Thus, in a multitier network, the demand for high-speed and interference-free transmission and reception
is inevitable. Beamforming (BF) is an advanced technology that offers a significantly improved solution to reduce the interference
levels and improve the system capacity. Accordingly, the establishment of relays in mobile data networks has emerged spectral
efficiency enhancements and cell capacity gains from an overall system perspective. This paper provides a comprehensive survey
focused on the performance of adopted beamforming technique on MIMO relay networks that is expected to overcome crucial
obstacles in terms of capacity and interference. The main objective is to point out the state-of-the-art research activity on BF
techniques in MIMO relay networks, under various network performance challenges. Thereby, it focuses on recently developed
procedures for interference modeling and mitigation, BF channel modeling, channel estimation and feedback, complexity and
power consumption, adaptive BF for multiuser relaying, degrees of freedom, diversity issues, and spectral efficiency, in cooperative
and opportunistic systems. Different network topologies have been considered and categorized, pertaining the challenges of BF
implementation in MIMO relay networks.
