Study of strategies of selection of the transmission format for the uplink in systems WCDMA
Tutor / director / avaluadorSánchez González, Juan
Tipus de documentProjecte Final de Màster Oficial
Condicions d'accésAccés obert
The proposed PFC is in the framework of Radio Resources Management and Quality of Service (QoS) for CDMA based radio access networks (such as UMTS). One of the fundamental facts of these systems is to provide different types of multimedia services in order to guarantee certain quality requirements in the connections. The Radio Resources Management strategies (RRM) are in charge of controlling the different radio network parameters so guaranteeing the quality required to the connections and making a use efficient of the resources available. For the case of the uplink, it is very important to determine the format of transmission of the users, i.e., the rate of transmission that the user will have at every moment. The main objective of this PFC is to propose and to evaluate different strategies of user transmision format allocation in order to optimize the trade-off between the delay and the level of interferences that is added to the system. A simulator programed in C is available. This simulator models a real WCDMA system.With this simulator is possible to analyze the power condition, which is important for our study in this project. The study of this algorithm demonstrates how the user bit rate affects in the cell. By controlling the maximum power of each user, we can know if there are cell coverage problems. The analyses show the differences of having droppings or not with the new algorithm and the delay variation.
UMTS was born with the objective to improve on the limitations of the second generation mobile, being able to offer multimedia services. It was created to provide multimedia service that requires higher bit rates. UMTS appears because there were new burst‟s services. The physical layer of UMTS is based on the acces technique by WCDMA broadband code division. The WCDMA access networks provide an inherent flexibility in the third generation mobile multimedia services. The radio interface capacity optimization is done with algorithms of Radio Resources, which consider the levels of interference in the system. These algorithms are the congestion control, the admission control, the power control, the suitable transport format management and handover management. In order to be able to understand the Radio Resources Management in UMTS this project has been structured so that in the first chapter it is explained briefly what UMTS is, next, in the second chapter there is an introduction to the WCDMA access technique. In chapter 3 we were centered in the Radio Resources Management, having explained most precise. The next chapter shows the cell coverage study, and the new algorithm implemented in this project. In chapter 5, the system simulator used is explained. And before the conclusions, are the results chapter, explaining the difference of doing the new algorithm or not. Basically, this work consists on the study of the Radio Resources Management and the simulations results with the objective to evaluate the cell coverage study realized in chapter 3. In order to make this task, it had not to consider no type of environmental considerations, because this project is an theoretical work. A possible environmental study in this subject could be given, if the possible electromagnetic waves about the antennas of mobile telephony or the batteries of the terminals, the materials used in the manufacture, etc. will be.