Cognitive mobile devices that sense and exploit available spectral resources have the potential for very broad societal impact, from business and government to the education and non-profit sectors.The proposed research leverages the interdisciplinary nature of the team and the industry-academic partnership towards realizing the cognitive radio vision to enhance access to the radio spectrum. The industrial partnership will specifically provide the essential system and application context to facilitate faster translation of the research into practice. Three graduate students will be trained in this highly cross-disciplinary area. The PIs will further develop Research Experience for Undergraduates (REU) projects as part of the program to expand undergraduate participation.
As wireless systems continue to proliferate and the demand for instantaneous, over-the-air access to large volumes of content continues to grow, radio spectrum (especially in the 500MHz-6GHz range) is an increasingly scarce resource. Most of the useful spectrum has been licensed. A few license-free bands are crowded to capacity, while many licensed bands are underutilized. Cognitive radios propose to scan and opportunistically share spectrum. They have the potential for expanding the available spectrum through opportunistic use, if conflict can be sensed and avoided by continuously monitoring higher priority traffic. This requires agile, low-power solutions for spectrum scanning and bandwidth aggregation receivers. This project studies these challenges in the context of a multi-tiered shared-spectrum access communication system. It focuses on tier-3 cognitive radio terminals that scan and dynamically use radio spectrum that is underutilized by higher tier users. It proposes novel bandpass compressed spectrum scanner architectures and recovery algorithms, that promise to substantially reduce power consumption and scan time compared to existing solutions. To enable interference-robust, reconfigurable receiver architectures with noncontiguous bandwidth aggregation, reconfigurable arrays of bulk acoustic wave devices fabricated on top of CMOS will be investigated. The industrial partnership is key to provide system and application knowledge, as well as system integration expertise to test and evaluate the innovations. The cross-disciplinary research questions are important for broadband RF systems in general, and the proposed solutions will have impact beyond multi-tiered cognitive radio systems.
