ECE Seminar Speaker: Prof. Ram Zamir, The Modulo Output is a Sufficient Statistic (for a Strong Interference)

2:00 pm on Thursday, June 26, 2014
4:00 pm on Thursday, June 26, 2014
Room 339, Photonics Center
Room 339 ECE Seminar Speaker: Prof. Ram Zamir Department of Electrical Engineering - Systems at Tel Aviv University Abstract: Lattice decoding of a lattice-shaped codebook is a simple alternative for ML decoding, and it is equivalent to ML decoding after modulo-lattice reduction of the channel output. For good (high-dimensional) lattices, this modulo operation is information lossless in the presence of AWGN. At a finite shaping dimension, however, the lattice decoder is inferior to direct ML decoding from the channel output. The “modulo loss” is particularly large at low SNR, and it gets up to 4dB for scalar shaping. We consider the effect of a known interference (i.e., a dirty-paper channel) on the gap between the two decoders. We show that in the limit of a strong interference, the modulo output becomes a sufficient statistic for decoding the input. Thus, in the strong-interference regime, ML decoding suffers the same “modulo loss” as lattice decoding. Speaker Bio: Ram Zamir was born in Ramat-Gan, Israel in 1961. He received the B.Sc., M.Sc. (summa cum laude) and D.Sc. (with distinction) degrees from Tel-Aviv University, Israel, in 1983, 1991, and 1994, respectively, all in electrical engineering. In the years 1994 - 1996 he spent a post-doctoral period at Cornell University, Ithaca, NY, and at the University of California, Santa Barbara. In 2002 he spent a Sabbatical year at MIT, and in 2008 and 2009 short Sabbaticals at ETH and MIT. Since 1996 he has been with the department of Elect. Eng. - Systems at Tel Aviv University. Prof. Zamir has been consulting in the areas of radar and communications (DSL and WiFi); since 2005 he is the Chief Scientist of Celeno Communications. He has been teaching information theory, data compression, random processes, communications systems and communications circuits at Tel Aviv University. He served as an Associate Editor for Source Coding in the IEEE transactions on Information Theory (2001-2003), and headed the Information Theory Chapter of the Israeli IEEE society (2000-2005). His research interests include information theory (in particular: lattice codes for multi-terminal problems), source coding, communications and statistical signal processing. His book "Lattice coding for signals and networks" is going to be published in the summer of 2014.