Current radio receiver designs are pushing the boundaries of Analog-to-Digital conversion and digital signal processing technology in terms of speed and energy efficiency. These technology limitations present a major bottleneck in transferring promising wideband and energy-efficient receiver design paradigms from theory to practice. This project investigates whether these bottlenecks can be circumvented by designing digital communication system receivers that are sampled at sub-Nyquist rates. By sampling below the Nyquist rate, current technology can be used for very wideband communication systems and energy consumption can be significantly reduced below that required for Nyquist-rate sampling. The proposed research brings together the areas of Shannon theory and sampling theory by exploring the fundamental capacity limits of single-user and multi-user subsampled channels as well as the optimal sampling mechanisms that achieve these limits. In addition, the project will extend the ideas of sub-sampled communication to determine the rate-distortion trade-off of sub-sampled sources along with joint source-channel coding when both the source and channel are undersampled. The proposed activity will develop a broader understanding of communication system design subject to hardware constraints by exploring an important and unanswered question at the intersection of two important fields within electrical engineering: signal processing and information theory. The results of the proposed work can enable low-complexity high-performance radio designs for 60 GHz wideband communications and for cognitive radios. Furthermore, these results impact other engineering systems such as radar, optical systems, medical imaging and more, since the mathematical machinery and hardware insights developed in the proposed research can provide important insights into related areas in which reduced rate sampling and processing is needed.
The broader impacts resulting from the proposed activity will include significant enhancement of the communications capabilities beyond the current state of the art in wideband, cognitive, and energy-efficient radio design. Wideband radios are of key importance to meet the significant demand for multimedia wireless communications, especially video. Cognitive radios have the ability to more efficiently utilize the limited available radio spectrum. In addition, there is a great need to design communication systems that consume minimal energy, especially sensor networks, which have application to enable smart buildings, enhance homeland security, and improve the reliability and robustness of our power grid.
