Z.Uykan; "Design of Distributed Power Control...", July 11,2007, 15:00
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  • Z.Uykan; "Design of Distributed Power Control...", July 11,2007, 15:00

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Faculty of Engineering and Natural Sciences
FENS SEMINARS

Design of Distributed Power Control Algorithms in Cellular Radio Systems from a Control Engineering Point of View

Zekeriya Uykan
Nokia Siemens Networks, Helsinki, Finland

Effective transmit power control is essential for high capacity cellular radio systems.  There has been an excessive amount of work in literature on power control in both academia and industry studying different aspects in different kinds of wireless systems.
It’s well-known that distributiveness, convergence speed and robustness are important properties for a power control algorithm in order to be implemented in a real-world cellular radio system.  In this talk, we focus only on fully distributed power control algorithms (DPCA) and approach the design problem from a control engineering point of view.  This approach results in a framework suitable for developing and analysing new DPCAs.
Two DPCAs (in the same framework) are presented and analysed based on a nonlinear and a linear controller design problem: A sigmoid neural network basis nonlinear controller and a well known linear PI-controller based DPCAs. The advantage of using nonlinear controller is in fast convergence. Computer simulation results indicate that both the sigmoid and PI DPCA algorithms enhance the convergence speed of power control as compared with the Foschini and Miljanic Algorithm (FMA) as a reference case.
At the end of the talk, we present a DPCA designed by using well-known variable-structure systems theory in control engineering.  Some of well-known DPCAs (e.g. FMA, Fixed step, etc) are obtained as special cases of the proposed algorithm.  Simulation results show that the variable-structure power control is more robust against link gain matrix variations as compared to the FMA case.

Biography:
Zekeriya Uykan received the B.Sc. and M.Sc. degrees (both with honors) from Istanbul Technical University (ITU) in 1993 and 1996, respectively, and Licentiate  of Technology (with hon.) and Dr.Tech degrees from Helsinki University of Technology (HUT), Espoo, Finland, in 1998 and in 2001, respectively, all in electrical engineering.
He was a Research and Teaching Assistant at ITU from April 1994 to September 1996, and a Research Scientist at HUT, Finland, from September 1996 to February 2001. He was a visiting researcher at Sabanci University from May 2000 to July 2000, and a visiting scholar at Stanford University, Electrical Engineering, CA, from January 2002 to January 2003.  He was with Radio Communications Laboratory of Nokia Research Center, Helsinki, Finland from July 2000 to April 2007.  He has been with Nokia Siemens Networks in Helsinki Finland since April 2007.
His research interests are in the areas of wireless communications systems, neural networks and control engineering.  Currently, he continues his research on radio resource management algorithms in OFDMA based future generation radio systems.

July 11, 2007 Wednesday, 15:00, FENS G035