Cooperative MAC for Rate Adaptive Randomized Distributed Space-Time Coding

In a distributed wireless network, it is possible to employ several relays and mimic a multiple antenna transmission system. In this paper, the authors propose a MAC layer solution that allows multiple relays to send information to the receiver at unison, using a randomized distributed space time code. The randomized space-time coding can recruit relays on the fly, thus significantly reducing signaling overhead. The cross-layer design between physical layer and MAC layer involves relay discovery and rate adaptation, and results in improvements in throughput and delay performance. The design is dynamic and can be adapted to changing network conditions.