The emerging cognitive radio network (CRN) paradigm has a great potential to solve what seems to be a spectrum crisis, by allowing the unlicensed or secondary users (SUs) to opportunistically and dynamically utilize the white spaces within the licensed bands, without causing harmful interference to the licensed or primary users (PUs). This research investigates two essential components of CRNs: spectrum sensing and spectrum access and sharing. More specifically, the PIs study: 1) novel integrated signal processing and communication designs for data fusion in cooperative spectrum sensing, and 2) novel cooperative spectrum sharing and communication schemes that benefit both PUs and SUs.
In contrast to the existing data fusion rules that assume error-free communication channels with capacity constraints, this research involves novel integrated designs that consider the deteriorating effects of communication channels between the radios and the fusion point and therefore are robust against channel errors and provide higher detection reliability. The robustness can further be improved by employing distributed space-time coding and harvesting diversity gain. Novel cooperative communication schemes are developed based on modern coding and enable SUs to relay PUs? rateless coded data packets in a fashion that is completely seamless to PUs. The schemes have mutual benefits for both PUs and SUs and differ from the existing ones in which SUs are silent during PUs? transmission. Broader impacts include (1) bonding the research groups from OSU and the UR and enhancing research and education through this partnership, (2) making a significant impact on the theory and practice of CRNs, (3) increasing the participation of under-represented students in PIs? research groups and promoting engineering among high school students, and (4) integrating research and education through development of new courses.
