الفهرس 
INTRODUCTION TO SMART ANTENNASOnly 14 pages are availabe for public view
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Abstract
In recent years there has been an explosive growth in the number of wireless users, particularly in the area of mobile communication. In future, wireless mobile systems will be more sophisticated and more widespread. This growth has triggered an enormous demand not only for capacity but also better coverage and higher quality of service. Several new technologies have been explored and deployed in this regard to make effective use of the limited resources. Space Division Multiple Access (SDMA) has emerged as a key technology and holds a lot of promises for the future of mobile communication. SDMA exploits the spatial domain of the mobile radio channel to bring about an increase in network capacity in the existing wireless systems. Unlike wireless systems in the past, which used fixed antenna systems, SDMA based systems uses smart antennas or adaptive arrays that are dynamically able to adapt to the changing traffic requirements. Smart antennas, usually employed at the base station, radiate narrow beams to serve different users. As long as the users are spatially well separated, the same frequency can be reused even if the users are in the same cell. This additional intra-cell channel reuse based on spatial separation is the key in achieving an increase in the capacity ofthe system.
The main concern of this thesis is to investigate the direct data domain least squares (D3LS) approach to adaptive processing which operates on a single snapshot of data and therefore is quite suitable to operate in a highly dynamic environment. The main idea of adaptive processing is achieved by directing the main beam in the look direction while nul ling all undesired signal. The matrix pencil (MP) method and another fast direction of arrival (DOA) method based on D3LS are used in order to estiinate the DOA of all incoming signals. The D3LS approach is extended to deal with Space-Time Adaptive Processing (ST AP) where the goal is to enhance signals reception in nonstationary environment by applying two dimensional filtering in space and time. The receiving antenna used in our thesis consisting of real element of different configurations in order to account for mutual coupling between elements. Surely, the mutual coupling will affect on the estimation of the signal then a preprocessing technique is applied on the induced voltages in order to compensate for the strong mutual coupling between elements. The effect of missing elements on the performance of the approach will be investigated. An extension of the D3LS ST AP using real elements will be introduced for multiple target
detection in order to estimate more than one signal simultaneously. The deterministic approach will be presented to deal with signals of different operating frequencies impinging on the antenna array. Also, the STAP based on D3LS approach will be presented to handle signals operating in the wideband frequency range using an array of conventional elements and an array of patch antenna.