Spectrally-efficient relay selection with limited feedback

This paper addresses the multiplexing loss that occurs in relay networks due to causality of relays and the halfduplex constraint. We devise relay selection methods to recover the multiplexing loss in decode-and-forward (DF) relay networks, while requiring very little feedback (merely bits/relay). Two network topologies are studied: First the case is considered where a direct link is available between the source and destination, in addition to the relayed links. For this configuration, an incremental transmission scheme is proposed, and comprehensively analyzed, which uses limited feedback to improve both diversity as well as multiplexing gain. Then, the case without a direct link is considered, for which efficient non-orthogonal DF protocols are produced and analyzed. An interesting feature of the latter methods is unequal error protection capability via a family of embedded diversity-multiplexing (DMT) curves, which can be very useful for practical applications. Even considering this...

• Type: Journal
• Year: 2008
• Where: JSAC
• Authors: Ramy Tannious, Aria Nosratinia
• Keywords: Direct Link, JSAC 2008, Multiplexing Loss, Relay