| This dissertation discusses the key problems of the synchronization of WCDMA access network. It contains the following three aspects: Using UE in soft handoff, the synchronization of Node Bs are fulfilled through the air interface; The realization of Iub interface synchronization between RNC and Node Bs; Through simulation to get the best cell search performance under certain circumstance.In WCDMA system under TDD mode, there are two kinds of synchronization methods between Node Bs. One method is using GPS system, the other is through air interface. Usually, the synchronization method of Node Bs through air interface is sending signal between Node Bs directly. In this paper, a new method using UE in soft handoff, which is communicating with several Node Bs, to measure the time difference of Node Bs. After getting the time differences, the Node Bs get its synchronized time through recursion operation.The synchronization of Iub between RNC and Node Bs has great meaning in improving interface performance and upgrading communication quality. The main problem is the calculation of the corresponding CFN(connection frame number) of each TBS(transport block series), which is sending from RNC to Node Bs, and the configuration of accepting window of Node Bs. In this paper, combing the correlation content, the calculation of CFN and the configuration of accepting window is analyzed. The calculation method is validated through simulation.The cell search of WCDMA can be divided into slot synchronization, frame synchronization and scrambling code identification. The performance of the three steps under different conditions is analyzed through simulation. For WCDMA system, the power allocation of SCH and CPICH has important affect on system capacity and other system performances. Therefore, through simulation, the cell search performance is analyzed when the power allocation of SCH and CPICH is different. The simulation and analyzing result have some reference value in system design. |
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