Cognitive radio has recently emerged as a promising technology to overcome the imbalance between the increase in spectrum access demand and the inefficiency in spectrum usage by allowing dynamic spectrum access. However, existing cognitive radio network research work is based on a number of conventional spectrum sensing and access mechanisms that suffer several drawbacks and are unable to exploit additional available spectrum opportunities. These conventional spectrum sensing mechanisms cannot differentiate primary user and secondary user signals effectively. They also cannot distinguish a primary user transmitter and receiver. In addition, conventional omnidirectional antenna-based spectrum access schemes cannot exploit the spatial spectrum availability to optimize the secondary user spectrum access capability. These drawbacks lead to spectrum resource waste and cannot be solved by physical-layer spectrum sensing and access techniques alone. Therefore, upper layer networking techniques are incorporated to solve these challenging problems. This research is potentially transformative as it will help generate innovative techniques to numerous applications of the cognitive radio technology, e.g., public safety networks, emergency networks, and health monitoring. It will also have significant impacts on research in emerging technologies with dynamic spectrum access, such as vehicular networks, mobile health, and opportunistic interconnections of heterogeneous wireless networks. The proposed designs can be applied to Internet-of-Things (IoT) with IoT devices efficiently accessing the wide spectrum. This project also integrates research findings into related graduate/undergraduate courses and diversity support.
This project will have a significant impact on enhancing radio spectrum access. It aims at systematically investigating a novel spectrum sensing and access framework to discover and access additional available spectrum hidden from conventional spectrum sensing and access techniques in cognitive radio networks. In particular, this project consists of three major research tasks to achieve the goals of enhancing radio spectrum access: 1) network layer spectrum sensing scheduling to differentiate primary user and secondary user signals; 2) data link layer spectrum sensing to distinguish between a primary user transmitter and receiver; and (3) directional antenna-based spectrum access to proactively utilize the spatial spectrum opportunities, exploit the temporal and spatial channel availability, and obtain the optimal directional antenna sector angle.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
