On the capacity growth of opportunistic single-relay selection using quality-based feedback in fixed-gain amplify-and-forward relaying

In this letter, the capacity of simple opportunistic single-relay selection (OSRS) is addressed for a dual-hop cooperative network with a source, destination, and lots of possibly cooperative relays. We provide asymptotic lower and upper bounds on the capacity of OSRS. Quality-based channel state reporting (QBR) is used to avoid increases in the feedback load, especially when the number of relays is large. The numerical results show that QBR does not degrade the capacity while it successfully reduces feedback.