An Opportunistic Virtual MISO (OVM) protocol for multi-hop wireless networks

By allowing neighboring nodes to effectively share their available resources, cooperative diversity-based protocols have shown improvements over the traditional routing and medium access control (MAC) protocols. In this work, we observe that while cooperative diversity-based protocols yield performance improvements in the presence of low-quality links, their performance improvements in the presence of high quality links is not significant. Although the neighboring resources are available regardless of link quality, cooperative protocols typically do not utilize the helper nodes when link quality is high (i.e., low error rate). Thus network resources remain under-utilized and performance is not maximized. In this work, we propose the Opportunistic Virtual MISO (OVM) protocol for multi-hop wireless networks. OVM combines virtual MISO (using spacetime block codes) and cooperative diversity-based multi-copy relaying, which together improves the utilization of the network resources in the presence of both low and high quality links. OVM provides an effective and simple design solution. Simulation results show that OVM is able to improve end-to-end network performance by up to eighty-six percent over previous works.