A novel distributed antenna selection scheme for fixed-gain amplify-and-forward relaying systems

This paper proposes a novel distributed transmit antenna selection (AS) concept for dual-hop fixed-gain amplify-and-forward (AF) relaying systems, where a multiantenna source transmits information to a single-antenna destination by using a single-antenna half-duplex relay. By invoking a local channel information exploitation/decision mechanism along with decision feedback between terminals, a distributed AS (DAS) scheme is formulated. Compared with the optimal/suboptimal AS, DAS can maintain a low and constant delay/feedback overhead, irrespective of the number of transmit antennas. Moreover, asymptotic outage analysis reveals that DAS can still achieve full diversity order. In addition, it is numerically shown that when the relay is deployed in an outage-optimal manner, DAS can attain very close outage performance to that of the optimal AS.