Disputas: Behrouz Maham

Behrouz Maham

ved Institutt for informatikk vil forsvare sin avhandling for graden ph.d. (philosophiae doctor)

"Transmission Strategies and Performance Analysis of Resource-Constrained Wireless Relay Networks"

Tid og sted for prøveforelesning

27. apr. 2010 10:15 (Lille auditorium, Informatikkbygningen, Gaustadalléen 23) - Interference Alignment in Wireless Systems

 

Bedømmelseskomité

  • Professor Hamid Aghvami, Centre for Telecommunication Research, King’s College London

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

  • Professor Sverre Holm, Department of Informatics, University of Oslo

Leder av disputas

Dag Langmyhr

Veileder

  • Are Hjørungnes
  • Pål Orten
  • John Cioffi

For mer informasjon

Demand for mobile and personal communications is growing at a rapid pace, both in terms of the number of potential users and introduction of new high-speed services. Meeting this demand is challenging since wireless communications are subject to a complex and channels, a scarce usable radio spectrum, and limitations on the power and size of hand-held terminals. Cooperative diversity schemes have been introduced in an effort to overcome this limitation. Cooperative techniques allow a collection of radios to relay signals amongst each other, effectively creating a virtual antenna array, which combat multipath fading in wireless channels.
In this thesis, we consider the design of practical distributed space-time codes and power efficient fading mitigation techniques for wireless relay networks. We show that using the proposed techniques the system performance is significantly improved under the respective resource constraints such as the energy, bit-error rate, or outage probability. Furthermore, the performance analysis of the wireless relay networks under different protocols and fading channels are investigated. The simplicity of the analytical results provides valuable insights into the performance of cooperative networks and suggests means of optimizing them. We next apply our proposed cooperative schemes to some practical wireless networks. For instance, we propose several cooperative schemes which consider the residual battery energy, as well as the statistical channel state information, for the purpose of lifetime maximization in multi-branch, multihop wireless networks. We also propose new energy-efficient cooperative routing protocols in multihop wireless networks. In contrast to previous works, our proposed cooperating routings depend only on the statistics of the channels, and are implemented by both the centralized and distributed approaches.
This dissertation has been submitted to the Faculty of Mathematics and Natural Sciences at the University of Oslo in partial fulfillment of the requirements for the degree of Philosophiae Doctor (PhD). The studies were carried out over a period of three years, from June 2007 to May 2010. I spent the first and the third year of my PhD studies at UNIK- University Graduate Center, Kjeller, Norway, while the second year my workplace has been the Star Laboratory at Stanford University, USA.

Kontaktperson

For mer informasjon, kontakt Lena Korsnes.

Published Feb. 18, 2011 1:05 PM - Last modified Mar. 25, 2014 10:51 AM