Open AccessDiversity‐multiplexing tradeoff of opportunistic relay system with multiple‐antenna destination
Author(s) -
Luo Sheng,
Li Qiang,
Hu Yongxu,
Teh Kah Chan
Publication year - 2014
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2014.0081
Subject(s) - relay , multiplexing , computer science , diversity (politics) , telecommunications , antenna (radio) , antenna diversity , computer network , political science , physics , power (physics) , quantum mechanics , law
In this study, the authors investigate the diversity‐multiplexing tradeoff (DMT) of a wireless system in which user equipments (UEs) are equipped with only one antenna while the destination has multiple antennas. Each UE is assisted by M half‐duplex cooperative users serving as relay nodes. They combine the opportunistic relaying scheme and the cooperative spatial multiplexing (C‐SM) scheme to produce an opportunistic C‐SM (OC‐SM) scheme. The fraction of time allocated to the source–relay link and the relay–destination link is treated as a design parameter to minimise the outage probability of the system. At high signal‐to‐noise ratio regime, the optimal time allocated factor is obtained in a closed‐form expression through DMT analysis. Based on the DMT result of the proposed OC‐SM scheme, an adaptive OC‐SM (AOC‐SM) approach in which the system can switch between different C‐SM models adaptively based on the rate transmitted is proposed. To reduce the complexity of the relay nodes, an AOC‐SM scheme with relay selection (SAOC‐SM) in which a constant number of relay nodes is selected from the set of relay nodes that have successfully decoded the source message is investigated. The DMT results of the SAOC‐SM scheme and the AOC‐SM scheme are obtained and compared.