PIs: Sundeep Rangan, Elza Erkip
Collaboration with Mark Rodwell, Jim Buckwalter, UCSB

A key challenge for communication in the mmWave and THz bands is power consumption. Systems in these frequencies require large numbers of antenna elements running at very high sampling rates, often with relatively inefficient radio frequency (RF) devices. Mobile and portable devices, as well as small cell access points, have highly constrained power budgets. To address these challenges, this project investigates energy consumption from a system’s perspective in an integrated manner across circuits, signal processing and network protocols. Our results include studies of low power fully digital arrays with low resolution ADCs as well as a systematic and general methodology for understanding and optimizing trade-offs of power consumption and end-to-end performance of a large class of potential receivers. In collaboration with researchers at UCSB, the framework has been applied to the design of a fully digital 140 GHz in 90 nm SiGe BiCMOS, where we have optimized key RF components including the low noise amplifier (LNA), mixer, local oscillator (LO) and analog-digital converter (ADC) to achieve power savings of up to 80%. MAC-layer protocols, particularly with low-power idle modes, have also demonstrated to offer dramatic savings in cases of intermittent traffic.

Selected Publications:

• Skrimponis, P., Hosseinzadeh, N., Khalili, A., Erkip, E., Rodwell, M. J., Buckwalter, J. F., & Rangan, S. (2020). Towards energy efficient mobile wireless receivers above 100 GHz. IEEE Access, 9, 20704-20716.
• Shah, S. H. A., Aditya, S., & Rangan, S. (2021). Power-efficient beam tracking during connected mode DRX in mmWave and sub-THz systems. IEEE Journal on Selected Areas in Communications, 39(6), 1711-1724.
• Dutta, S., Barati, C. N., Ramirez, D., Dhananjay, A., Buckwalter, J. F., & Rangan, S. (2019). A case for digital beamforming at mmWave. IEEE Transactions on Wireless Communications, 19(2), 756-770.
• Orhan, Oner, Elza Erkip, and Sundeep Rangan. “Low power analog-to-digital conversion in millimeter wave systems: Impact of resolution and bandwidth on performance.” 2015 Information Theory and Applications Workshop (ITA). IEEE, 2015.

Figure 1.  Fully digital RX at 140 GHz used for analysis of power reduction methods.