The use of Rateless Codes in Cooperative Wireless Routing...
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Speaker:  Dr. Tolga Girici, TOBB University, Ankara

Title:  "The use of Rateless Codes in Cooperative Wireless Routing and Multiple Access"

Date/Time:  Nov 2 Wednesday at 14.40

Location:  FENS L058

Abstract:
Rateless codes have a self-adjusting code rate and potentially limitless rateless-coded packets can be generated until the receiver is able to collect a sufficient number of coded packets. With this property, rateless codes provide great benefits in multicast applications and in wireless transmissions where transmitter has imperfect channel information.  In multihop transmission, a node can accumulate and make use of all received packets that were transmitted in previous hops.  This way, energy and delay can be significantly improved. In case of ideal rateless codes, this is called “mutual information accumulation” in the literature.

In this presentation, first some introductory information is given on rateless codes, their decoding mechanisms and potential applications. Then, some current applications and performance results on cooperative multihop routing with rateless codes is explained. Here the optimization variables are node transmission powers, number of transmitted  rateless-coded packets and the routing path. Possible objectives are success probability, delay and energy efficiency. Later,  a study on optimal resource allocation in an OFDMA based relayed  multicast  with mutual information accumulation will be explained. Here the aim is to optimize the subchannel transmit powers and relay selection in order to transmit to a multicast group with  minimum energy.


Biography:
  Tolga Girici obtained his B.S. degree from METU Electrical –Electronics Engineering in 2000 and  his Ph.D. degree in Electrical Engineering from University of Maryland , College Park, MD USA. During his Ph.D. he held part-time positions at Intelligent Automation Inc. and Fujitsu Laboratories, MD. Since 2007 he is an assistant professor at TOBB University of Economics and Technology, Department of Electrical and Electronics Engineering. He is the primary investigator in two TUBİTAK funded projects. His research interests are resource allocation in cooperative relayed wireless multiple access, OFDMA based resource allocation, cooperative routing in wireless ad-hoc Networks, performance analysis of wireless systems and satellite communications.