الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis is concerned with Channel Modeling for UMTS System in order to enhance and improve its performance in data transfer. The main objective of this thesis is to search for methods of channel models proper for simulation to be used in UMT systems when investigating the effect of different parameters that affect its performance and in the same time reduces the simulation time. The thesis starts with a summary on the history of mobile communications starting from first generation and ending with 3G. This thesis focuses on UMTS where a good study is presented on UMTS concerning its frequency spectrum, ystem Architecture, Handover, Transport, Logical and physical channels. Also duplex techniques, Modulation techniques. Multiple access and power control in UMTS is also presented. As this thesis is mainJy concerned with Channel models so a good study is presented starting from physical phenomena that affects any mobile communications channel model and ending at presenting many mobile communications models whether statistical or deterministic. A deep study is done on Independent Rayleigh Faders Model used in simulation trying to improve its performance from many points of view such as accuracy, simulation time and complexity. A brief study is done on Gans Fading Model and finally a small comparison between Rayleigh Independent Faders Model and Gans Fading Model is presented. An approximated model to that of Independent Rayleigh Faders Model which is called Triangular Model is also studied and a new proposed model which is called Approximated Piecewise Linear Model is also presented. And at the end a comparison is held This thesis is concerned with Channel Modeling for UMTS System in order to enhance and improve its performance in data transfer. The main objective of this thesis is to search for methods of channel models proper for simulation to be used in UMT systems when investigating the effect of different parameters that affect its performance and in the same time reduces the simulation time. The thesis starts with a summary on the history of mobile communications starting from first generation and ending with 3G. This thesis focuses on UMTS where a good study is presented on UMTS concerning its frequency spectrum, ystem Architecture, Handover, Transport, Logical and physical channels. Also duplex techniques, Modulation techniques. Multiple access and power control in UMTS is also presented. As this thesis is mainJy concerned with Channel models so a good study is presented starting from physical phenomena that affects any mobile communications channel model and ending at presenting many mobile communications models whether statistical or deterministic. A deep study is done on Independent Rayleigh Faders Model used in simulation trying to improve its performance from many points of view such as accuracy, simulation time and complexity. A brief study is done on Gans Fading Model and finally a small comparison between Rayleigh Independent Faders Model and Gans Fading Model is presented. An approximated model to that of Independent Rayleigh Faders Model which is called Triangular Model is also studied and a new proposed model which is called Approximated Piecewise Linear Model is also presented. And at the end a comparison is held |