Protocol Coding and Secondary Wireless Channels: Some Capacity Results and Applications

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Friday, February 4, Giedt Hall 1002, 12:00pm-1:00pm

Petar Popovski
Associate Professor, Department of Electronic Systems, Aalborg University

Host: Professor Anna Scaglione


While there are continuous e orts to introduce new communication systems and standards, it is legitimate to ask the question: how can one send additional bits by minimally changing the systems that are already operating? This is of a significant practical interest, since it has a potential to generate additional value of the systems through, for example, introduction of new devices and only a software update of the access points or base stations, without incurring additional cost for infrastructure hardware installation. The place to look for such an opportunity is the communication protocol and we use the term protocol coding to refer to strategies for send ing information by using the degrees of freedom available when one needs to decide the actions taken by a particular communication protocol. Several instances of protocol coding have appeared before, notably the concepts in \Bits through Queues" by Anantharam and Verd u. In this paper we consider protocol coding that gives a rise to secondary communication channels, de ned by combinatorial ordering of the user resources (packets, channels) in a primary (legacy) communication system. We introduce communication models that enable us to compute the capacity of such secondary channels under suitable restrictions imposed by the primary systems. We rst show the relation to the capacity of channels with causal channel state information at the transmitter (CSIT), originally considered by Shannon. By using the speci c communication setup, we develop an alternative framework for achieving the capacity and we discuss coding strategies that need to be used over the secondary channels. We also discuss some practical features of the secondary channels and their applications that add value to the existing wireless systems.


Petar Popovski received the Dipl.-Ing. in electrical engineering and M. Sc. in communication engineering from the Faculty of Electrical Engineering, Sts. Cyril and Methodius University, Skopje, Macedonia, in 1997 and 2000, respectively and a Ph. D. degree from Aalborg University, Denmark, in 2004. He worked as Assistant Professor at Aalborg University from 2004 to 2009. From 2008 to 2009 he held part-time position as a wireless architect at Oticon A/S. Since 2009 he is an Associate Professor at Aalborg University. He has received several best paper awards: from the Technical Committee of Software Radio in (IEICE) in 2008, at IEEE Globecom 2008 and 2009, and best recent result in communication theory at the IEEE Communication Theory Workshop 2010. Prof. Popovski serves on the editorial board of IEEE Transactions on Wireless Communications, IEEE Communications Letters, Ad Hoc and Sensor Wireless Networks journal, and International Journal of Communications, Network and System Sciences (IJCNS). He has been a Guest Editor for special issues in EURASIP Journal on Applied Signal Processing, EURASIP Journal on Wireless Communications and Networking and the Journal of Communication Networks. In January 2009 he received the Young Elite Researcher award from the Danish Ministry of Science and Technology. His research interests are in the broad area of wire less communication and networking, such as cooperative communications, cognitive radio, low{power wireless networking, and information{theoretic aspects of wireless systems.