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4G Wireless and Beyond

Naga Bhushan


The performance of most urban cellular networks is limited by inter-cell interference. This is particularly true of a cellular network with heterogeneous infrastructure, wherein the same spectrum is shared by different types of base-stations such as macro-cells, pico-cells, femto-cells and relays. Performance of such dense/heterogeneous deployments may be greatly enhanced through the use of smart association techniques, coupled with adaptive interference management. Unlike traditional cellular systems where association is predominantly based on maximizing signal quality between the base-station and the user, a smart association scheme in a heterogeneous network should be based on several additional criteria such as access-load balancing, backhaul capacity consideration, path-loss minimization, or minimization of interference-cost to other links. Aggressive load-balancing (in particular) requires advanced interference management, which can may be realized through soft, adaptive resource partitioning, beam-coordination or joint signal processing among neighboring base-stations. We will begin the presentation with a brief overview of R&D programs at Qualcomm. Next, we will take stock of where the wireless industry stands with current emerging 4G technologies, and where we might be heading over a period of another 8-10 years . This will be followed by a closer look at resource-level interference management among disparate base-station classes sharing a common spectrum, and some performance analysis to validate our ideas.


Naga Bhushan obtained his B. Tech. degree in Electronics from I.I.T. Madras, Chennai, India in 1989, and his M.S an PhD degrees in Electrical Engineering from Cornell University, New York, USA in 1992 and 1994 respectively. He has been working as a Communication Systems Engineer at Qualcomm since 1994, where he is now a Vice President of Technology in the Corporate R&D group. He has been actively contributing to the evolution, development and commercialization of advanced cellular technologies such as EV-DO, UMB and LTE-Advanced over the past 15 years. He has authored several journal and conference papers, and has earned over 100 issued patents in the area of wireless communication systems.

Naga Bhushan Headshot
Naga Bhushan
EEB 105
21 Feb 2012, 10:30am until 11:30am