On the Application of Nested Lattice Coding in Wireless Networks

Friday, March 22, 2013

Lattice coding has emerged as a fundamental theoretical tool in the Information Theory of Gaussian networks. Lattice codes under lattice decoding achieve the capacity of the Gaussian channel, achieve the diversity-multiplexing tradeoff of quasi-static MIMO point to point channels, have been used to construct ``practical'' Costa Coding and Wyner-Ziv coding schemes and, more recently, have been widely applied to relay networks (compute and forward scheme) and interference channels (signal-level interference alignment).In this talk, we review a number of recent applications of nested lattice coding. In particular, we consider simple multi-access and broadcast relay networks modeling the uplink and the downlink of Distributed Antenna Systems (DAS) with a capacity constrained digital backhaul and centralized decoding (for the uplink) and precoding (for the downlink). We introduce ``Reverse Compute and Forward'' as a new downlink precoding scheme for DAS that explicitly takes into account the limited backhaul capacity. Then, we consider a class of network-coded two-user cognitive interference channel where one sender has the two messages and the other sender has a rank-deficient linear combination of the two messages, and show that lattice coding can achieve 2 degrees of freedom and in general a significant improvement of the generalized degrees of freedom, while it is known that the standard cognitive case does not improve the degrees of freedom. We consider also applications to a 2x2x2 MIMO network and to a diamond relay network. In the first case, lattice coding yields the best known degrees of freedom and a sizable finite SNR performance, while in the second case we show how to achieve full duplex relaying with half duplex relays.


Giuseppe Caire was born in Torino, Italy, in 1965. He received the B.Sc. degree in electrical engineering from Politecnico diTorino, Italy, in 1990, the M.Sc. degree in electrical engineering from Princeton University, Princeton, NJ, in 1992 and the Ph.D. degree from Politecnico di Torino, in 1994. He has been Assistant Professor in Telecommunications at the Politecnico di Torino, Associate Professor at the University of Parma, Italy, Professor with the Department of Mobile Communications at the Eurecom Institute, Sophia-Antipolis, France, and he is now Professor with the Electrical Engineering Department of the ViterbiSchool of Engineering, University of Southern California, Los Angeles. He received the Jack Neubauer Best System Paper Award from the IEEE Vehicular Technology Society in 2003, and the IEEE Communications Society and Information Theory Society Joint Paper Award in 2004 and in 2011. Dr. Caire served as an Associate Editor for the IEEE TRANSACTIONS ON COMMUNICATIONS in 1998–2001 and as an Associate Editor for the IEEE TRANSACTIONS ON INFORMATION THEORY in 2001–2003 and was President of the IEEE Information Theory Society in 2011.