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Jad Nasreddine is currently working as a Postdoctoral researcher at the Department of Wireless Networks at RWTH Aachen University, Germany. Between 2005 and 2008 he was working as post-doctoral researcher at ENST-Bretagne, France and UPC, Spain respectively. He received his Ph.D degree in March 2008 from the university of Rennes I and his engeneering diploma in computer science and telecommunications in 2001 from the Lebanese university, faculty of engineering. During his Ph.D, he was working as research assistant at the ENST-Bretagne. He has participated in national and industrial projects in France, Spain and Germany. He has also participated in several FP6 and FP7 European projects as well as the IEEE P1900.4 working group. He is an IEEE member and he has served as track chair, TPC and reviewer for several conferences and journals.

ASM (Advanced Spectrum Management)
CN (Cognitive Network)
CR (Cognitive Radio)
DCA (Dynamic Channel Allocation)
DFM (Dynamic Frequency Allocation)
DSA (Dynamic Spectrum Allocation)
FSM (Flexible Spectrum Allocation)
PC (Power control)
RRM (Radio Resource Management)
Shadowing models
TDD (Time Division Duplex)

His research interests include cognitive and composite networks, spectrum and radio resource management, opportunistic access and cooperative networks.

 
     
 

In systems using CDMA technique, users share the same bandwidth. Therefore, these systems are interference limited and the most important procedure to increase system capacity and ameliorate QoS level is interference management. In systems using pure CDMA technique, power control is a widely used procedure for decreasing interference and upholding required QoS levels. In addition to power control, the combination of TDMA and TDD techniques with CDMA provides a new degree of flexibility in interference management using slot allocation techniques. However, exploiting this flexibility induces new challenges to mitigate such as the presence of pernicious mobile-to-mobile interference.

In this thesis, we exploit the flexibility of TDMA-CDMA/TDD systems and the characteristics of the CDMA technique. We propose power control algorithms combined with slot allocation techniques in order to provide required QoS levels for users. First, we develop a simple generic optimum power control algorithm and we propose different schemes using this algorithm. The developed model can be applied to uplink, downlink and crossed slots to evaluate system performance and can be used to design efficient distributed algorithms.

SLot Allocation
Power control

Moreover, we propose simple modifications to the standardized closed-loop power control of the UMTS. The proposed modifications lead to a significant increase in system performance without increasing system complexity and signaling traffic. We also propose heuristic and meta-heuristic methods combining the optimum power control and slot allocation techniques to find the upper bound of system performance in TDMA-CDMA/TDD systems. These methods can be adapted to real systems using radio interface measurements. Finally, we investigate flexible slot allocation techniques to avoid high interference that can appear in systems supporting heterogeneous services and asymmetric traffic between uplink and downlink (i.e. mobile-to-mobile interference).

 

 
   
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