讲演摘要

Rate adaptation, multiple antenna techniques, and scheduling enable contemporary 4G Long Term Evolution (LTE) and 5G New Radio (NR) cellular systems to achieve high downlink spectral efficiencies. Reduced feedback schemes play a crucial role in these systems by efficiently feeding back channel state information from the users to the base station (BS) without overwhelming the uplink feedback channels.

We develop a new, comprehensive framework based on a physical layer abstraction technique called Exponential effective SNR mapping (EESM) to analyze the combined effect of wideband rate adaptation, scheduling, and reduced feedback scheme on 4G/5G systems. What sets these wideband orthogonal frequency division multiplexing (OFDM) systems apart is that a packet is transmitted over multiple subchannels, which see different gains. Therefore, the choice of the user for a subchannel and the choice of the rate for a packet is based on the vector of signal-to-noise-ratios seen by these subchannels. We then propose new base station-side estimation techniques that exploit the structure of the limited feedback information available at the base station. These improve the cell throughput without requiring any additional feedback.

讲演者简介

Neelesh B. Mehta is a Professor in the Department of Electrical Communication Engineering at the Indian Institute of Science (IISc), Bangalore. His research focuses on wireless communications. He has worked on topics related to 3G/4G/5G cellular communication standards, energy harvesting and green wireless sensor networks, cognitive radio, cooperative communications, multi-antenna technologies, and multiple access protocols.

 He is a Fellow of the IEEE, the Indian National Academy of Engineering, and the National Academy of Sciences India. He is a recipient of the prestigious Shanti Swarup Bhatnagar Award in India.  He currently serves on the Steering Committee that oversees the IEEE Transactions on Wireless Communications and on the IEEE ComSoc Awards committee. He is currently an editor of the IEEE Transactions on Communications and has served as an editor for IEEE Wireless Communication Letters and Journal of Communications and Networks in the past. He served on the Executive Editorial Committee of the IEEE Transactions on Wireless Communications during 2014-17 and served as its Chair during 2017-18.  He served on the Board of Governors of the IEEE Communications Society from 2012-15