2012 Poster Sessions : Network MIMO Systems with Limited Backhaul Capacity

Student Name : Aakanksha Chowdhery
Advisor : John M. Cioffi
Research Areas: Information Systems
Base-station (BS) cooperation in wireless cellular networks offers a promising approach for interference mitigation. However, the implementation of practical network multi-input multi-output (MIMO) system also faces the challenge of high capacity cost for sharing the user data over the backhaul connections. This research work considers a downlink multi-cell orthogonal frequency-division multiple-access (OFDMA) network where the capacities of the backhaul links between the BSs are limited, and BSs are equipped with multiple-antennas. The BSs use zero-forcing precoding to spatially multiplex multiple users within each cell and to pre-subtract the interference of cooperating BSs that share user data with them. An iterative algorithm that maximizes the downlink network utility is proposed. The algorithm iteratively selects the cooperation links, schedules the users, and optimizes the precoding coefficients and the power spectra for each frequency tone. Numerical results suggest that the use of dynamic cooperation link selection is capable of providing better than linear trade-off between the downlink sum-rate gain and the backhaul capacity.

Aakanksha Chowdhery received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology, Delhi, in 2007 and the M.S. degree in electrical engineering in 2009 from Stanford University, Stanford, CA, where she is currently working toward the Ph.D. degree in electrical engineering under Prof. John M. Cioffi. Her research interests include communication theory, signal processing, and its applications to wireless and wire-line systems. During her graduate studies, she has been working on dynamic resource management algorithms for multicell wireless systems, digital subscriber lines and power-line communications. She is a recipient of Stanford’s Diversifying Academia, Recruiting Excellence (DARE) fellowship award in 2010.