BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:How Rate-Limited Feedback Increases Capacity for Memoryless Broadc ast Channels DTSTART:20140203T141500 DTEND:20140203T160000 DTSTAMP:20260408T005640Z UID:d76950c3af6a497c48feb20f19390c3407b28684b5ca6c007daa23f5 CATEGORIES:Conferences - Seminars DESCRIPTION:Prof. Michèle Wigger\, Telecom Paris\nBio: Michèle Wigger re ceived the M.Sc. degree and the Ph.D. degree both in electrical engineerin g from ETH Zurich in 2003 and 2008\, respectively.  After her PhD\, she s pent 7 months as a postdoctoral researcher at the Information Theory and A pplications (ITA) center\, University of California\, San Diego. Since Dec ember 2009\, she has been an assistant professor at Telecom Paris-Tech (fo rmer ENST)\, Paris\, France.\nWe present new coding schemes for the two-re ceiver discrete memoryless broadcast channel (BC) with rate-limited feedba ck from one or two receivers. With an appropriate modification\, our schem es also apply to the setup with noisy feedback when the receivers can code over the feedback links. Our first scheme strictly improves over the nofe edback capacity region for the class of strictly essentially less-noisy BC s\, even when there is only feedback from the weaker receiver and no matte r how small (but positive) the feedback rate. Examples of essentially stri ctly less-noisy BCs are the binary symmetric BC or the binary erasure BC w ith unequal  cross-over probabilities or unequal erasure probabilities to the two receivers. Our scheme also improves over the nofeedback capacity region of the binary symmetric/binary erasure BC and also for parameter ra nges where the BC is not essentially less-noisy but more capable. So far\, feedback was known to increase capacity only for a few very specific memo ryless BCs with feedback.\nThe second scheme that we present has the follo wing property. When the feedback-rates are sufficiently large\, then it ca n recover all previously known  capacity and degrees of freedom results f or memoryless BCs with feedback\, i.e.\, the results by Dueck\, Wang\,  G eorgiadis and Tassiulas\, Shayevitz and Wigger\, and  Maddah-Ali and Tse. In particular\, as the feedback-rates tend to infinity our scheme converg es to a special case of the Shayevitz-Wigger scheme which is known to incl ude the other schemes as special cases.\nWe further show a duality relatio nship between the set of rates achieved with linear-feedback schemes over multi-antenna memoryless Gaussian MACs and BCs. In this part we assume tha t the feedback is perfect\, i.e.\, of infinite rate. When either transmitt ers or receiver are single-antenna\, the  capacity region of the Gaussian MAC with feedback is known and is achieved by a linear-feedback scheme. F or these special cases our result thus allows us to determine the set of r ates that can be achieved over the Gaussian BC with linear-feedback scheme s\, and to identify the optimal linear-feedback schemes.\nJoint work with Selma Belhadj Amor\, Yossef Steinberg\, and Youlong Wu. LOCATION:BC 410 https://plan.epfl.ch/?room==BC%20410 STATUS:CONFIRMED END:VEVENT END:VCALENDAR