Events Calendar

Network Interference Management via Interference Alignment for Wireless Communications and Distributed Storage Systems

Speaker: Viveck R. Cadambe, University of California, Irvine

Talk Title: Network Interference Management via Interference Alignment for Wireless Communications and Distributed Storage Systems

Abstract: Our current times are witnessing a veritable explosion in the number of mobile devices with network connectivity. This explosion in the number of mobile devices which will guzzle data is resulting in bandwidth is becoming an increasingly scarce resource. The surge in the demand for data calls for new techniques to understand and improve the capacity (data rates) of wireless networks. In this talk, I will describe and explore a new technique to manage interference, which is the primary bottleneck of rates of communication in wireless communication networks.

A widely held belief in wireless network design, and also a formal conjecture, is that for a wireless network with K interfering users competing for the same spectrum (also known as the wireless interference network), it is optimal from a network capacity (degrees of freedom) perspective to divide the spectrum among the users like cutting a cake. This cake cutting view of spectrum access also known as orthogonalization enables each user in the interference network to get a fraction of 1/K of the spectrum free of interference. The cake cutting view of spectrum access lies at the heart of the design of most current wireless communication systems. In this talk, we will show that this cake cutting view of spectrum access is flawed and show that each of the K users of an interference network can essentially get 'half the cake', i.e., each user can simultaneously get half the spectrum free of interference. To show this, the strategy of "interference alignment", which is a far more effective interference management strategy as compared to orthogonalization, will be presented and described in detail. The talk will explore the impact of interference alignment on fundamental design issues of wireless communication systems and briefly describe challenges for the design of future generation wireless systems.

The talk will also explore a second application of interference alignment - erasure coding for distributed storage systems. With the advent of cloud computing and storage, the amount of data stored in distributed data storage systems (such as data centers) is scaling at an unprecedented rate. This scaling of stored data has motivated the use of erasure coding as a technique to build redundancy in distributed storage systems, to replace the conventional redundancy design strategy of replication. While erasure coding is attractive because it provides higher redundancy for a given amount (cost) of storage as compared to the conventional strategy of replication, practical implementation of coding for large distributed storage systems faces one principal bottleneck - the efficiency of repair when a storage device (node) fails in the distributed storage system. In the second part of this talk, by connecting the repair problem to interference alignment, I will (briefly) describe codes which improved repair efficiency and thus potentially relieve an important obstacle in the use of erasure coding for distributed storage systems.

Biography: Viveck R. Cadambe received his B.Tech and M.Tech. degrees in Electrical Engineering from the Indian Institute of Technology Madras, Chennai, India in 2006. He is currently working toward my Ph.D. degree at the University of California, Irvine. His research interests include multiuser information theory and wireless networks. In the summer of 2010, he was an intern in the Communication and Collaboration Systems Group at Microsoft Research, Redmond. Mr. Cadambe is a recipient of the 2009 IEEE Information Theory Society Paper Award and the UCI Electrical Engineering and Computer Science Department Best Paper Award for 2008-09. He also received the University of California, Irvine CPCC graduate fellowship for the year 2007-08.

Host: Giuseppe Caire, caire@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos