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Presenter: Himika Rahman
Supervisor: Dr. Pan Agathoklis; Co-Supervisor: Dr. Dale Shpak

Date: Fri, August 28, 2015
Time: 11:00:00 - 00:00:00
Place: ECS 467

ABSTRACT

ABSTRACT:

In recent times, an immense increase in traffic has been experienced by wireless communication systems, due to a significant growth as the number of users as well as to the development of new high bit rate applications. It is expected that soon this trend will be confirmed. This challenging scenario involves not only the well-established market of cellular systems, but also the field of emerging wireless technologies, such as WiMAX (Worldwide Interoperability for Microwave Access) for wireless metropolitan area networks, and Wi-Fi (Wireless Fidelity) for wireless local-area networks, mobile ad-hoc networks and wireless mesh networks. To satisfy the increasing demand of network capacity, the exploitation of the spatial domain of the communication channel using multiple antenna systems can be a crucial improvement for enhancing the spectral efficiency of the wireless systems. In propagation environments characterized by small angular spreads, the combination of antenna arrays and beamforming algorithms provide the possibility to suppress the undesired sources and to receive the signals incoming from the desired ones. Downlink beamforming is a promising technique for direct-sequence code-division multiple-access (DS-CDMA) systems with multimedia services to reduce effectively strong interferences induced by high data rate users. A weighted method for downlink transmission beamformer design is presented in cellular mobile communications systems using an antenna array at the base station. The technique is based on estimation of the beam pattern at the base transceiver station using the new weighted algorithm when signals from the base transceiver station to different mobile stations have different power with different resistance to co-channel interference. Therefore, the power of co-channel interference of downlink signal has lower resistance in the direction of the mobile station to co-channel interference can be significantly reduced.