Adaptive Incremental Relaying in Multi-Antenna Fixed Relay Networks

In infrastructure-based wireless networks, installing multiple antennas on fixed relay stations provides an effective and low-cost solution to increase network capacity and combat hostile fading channels. Previous work on multi-antenna relays either assumes that only one relay available in the network without benefiting from relay cooperation or all relays are used to assist the source transmission resulting extensive loss of spectral efficiency and high burden to the diversity combiner. For multi-relay cooperative networks, adaptive Incremental Relaying (IR) is considered in this paper as the cooperative strategy for multiple fixed relays performing uncoded Decode-and-Forward (DF). Unlike previous work on adaptive IR, relays employ multiple antennas to enhance the received signal quality.