This proposal will be awarded using funds made available by the American Recovery and Reinvestment Act of 2009 (Public Law 111-5), and meets the requirements established in Section 2 of the White House Memorandum entitled, Ensuring Responsible Spending of Recovery Act Funds, dated March 20, 2009. I also affirm, as the cognizant Program Officer, that the proposal does not support projects described in Section 1604 of Division A of the Recovery Act. "See Section I.B. above for additional information on implementation of ARRA Section 1604
Intellectual Merit This instrumentation supports research and development of adaptive digital beam forming antennas and related digital signal processing techniques to enable reliable high-speed wireless communications in ad hoc and mesh networks. This project explores the use of smart, adaptive antennas in conjunction with a high bandwidth radio system to yield improved range and also to suppress potential interference from unwanted signals. The goal is to develop a compact, low cost, light weight, smart, adaptive antenna system using digital signal processing techniques that can readily inter-work with new chip-scale radio technologies. This technology has commercial and government application in remote sensor networks, fixed and mobile ad hoc networks, intelligent transportation networks, and high-speed internet access and backbone networks. The facilities will serve as a center of excellence for the test, measurement and characterization of analog and digital communication equipment and systems, providing unique research and training opportunities in the Rocky Mountain west.
Broader Impacts The instrumentation provides design and system-level training to graduate students, postdoctoral students, research staff and undergraduates in the use of state-of-the-art RF and digital test equipment and methodology. This instrumentation further enables interdisciplinary work combining RF design, embedded systems, digital signal processing and telecommunications. This instrumentation grant leverages REU and other programs designed to encourage graduate education for Native American students, providing additional educational opportunities. The instrumentation is foundational to continued curriculum development for RF design, telecommunications and embedded systems courses at both the undergraduate and graduate levels.
Adaptive smart antennas have high potential for future developments in wireless communications. Many modern wireless systems already use multiple antennas (e.g., multi input multi output, or MIMO). Emerging radio standards have interfaces for adaptive antennas for both capacity improvements, interference mitigation and range extension. Finally, the current interest in cognitive radios, where the environment is factored into the radio’s operation, provides increased motivation for adaptive antennas as well. Digital beamformering antennas have a wide range of uses in modern radio systems. Our initial motivation was to address tactical network requirements, where nodes are numerous, possibly in motion, and constrained in size, weight and power. The beamformer is an ideal solution for this situation as it can mounted on a central node and multiple simultaneous beams directed to moving nodes. The nulling capability can be used as well, to reducing interference and vulnerability of the system to hostile jamming signals. A second application area for digital beam forming antennas is in commercial wireless networks, where a base station of access point serves multiple fixed or mobile users. The formation of beams can extend the range of the system, mitigating the need to add extra access points to provide connectivity to remote users. This is particularly important in sparse networks, as the costs of infrastructure can be significant and make the economics unfavourable when the number of users is small. In dense networks, digital beam forming antennas can be utilized to increase capacity. Spatial reuse is already common in today’s cellular networks, through the use of fixed direction sector antennas. The digital beam former can be employed to direct energy dynamically making the radio system more efficient and allowing for even more spatial frequency reuse. Our lab is currently working in several related areas. In cooperation with our colleagues in Computer Science, we are looking at methods of incorporating digital beam forming in multi-hop, or relay networks, to avoid primary and secondary interference effects and at the same time maximize throughput and achieve uniform quality of service for all users. This is a very complicated multi-variable optimization problem, with beamforming and link assignment as one of the parameters. Also related is our work on cognitive radios and the se of TV white space spectrum. As the FCC has recently ruled that secondary users can transmit on unused TV channels under certain circumstances, this opens up significant opportunities in rural areas, where there is little TV broadcasting. We have been exploring the feasibility of leveraging digital beamforming methods to improve the performance of TV white space radio systems for high speed internet access and other telecommunications services. We have also made the facilities that we have developed under the NSF MRI grant available to local companies. Our anechoic chamber has been used for antenna and RF testing, and our other test equipment has been used for instrument development and calibration measurements. Digital and RF test equipment is quite expensive, and often out of the reach of small companies and startups. We are glad that we can work collaboratively with local engineers to further their innovations. Our work has been highly collaborative. Within electrical engineering, the development of digital beamforming antennas has involved analog circuit designers, RF antenna experts, as well as embedded systems and digital signal processing methods. We have also worked closely with computer scientists expert in algorithm development and optimization techniques. For the six summers, we have involved over fifty undergraduate students from colleges around the United States through NSF-funded Research Experience for Undergraduates program. During the school year, we have had many undergraduates engaged in aspects of this work as part of their senior design capstone project requirements. Of course graduate students have been involved as well, and the research has led to ten MS degrees and one PhD degree already.
