Seamless Sensor Network Communications

This proposal focuses on multi-node collaboration in communication systems involving channels using space-time coding (STC) such that groups of antenna transmitters and receivers collaborate across nodes to produce and enhance spatial diversity patterns. This approach, called collaborative STC, not only exploits the spatial and temporal diversities but also explores the potential of collective cooperation in networks of nodes and represents a major improvement over previous work in collaborative communications. Specifically, multiple nodes in clusters will be able to collaborate using distributed space-time coding achieving significantly higher bandwidth efficiencies by employing the collaborative transmission strategies disclosed in this proposal. While extremely powerful, the collaborative STC paradigm is largely unexplored, presenting a host of new challenges in the integration of data, models, communications, analysis, and control systems. From a coding perspective, the challenge is to design distributed space-time coding techniques maximizing the diversity benefits while minimizing the redundancy of information exchanged between nodes. From a system perspective, the challenge is to realize the performance gain resulting from collaborative STC in real-world wireless networks. The proposed research goal is to design and develop the first collaborative STC communications system using a software radio platform. Although this will be demonstrated for two transmitting collaborators and one receiver unit, many of the above implementation challenges will be overcome and addressed.