| Mobile cell communication system is one of the most concerned areas. The standard of 3rd generation mobile communication has been established. In TD-SCDMA of China, some new techniques such as Uplink Synchronization, Smart antenna and Joint Detection will be applied, which can solve the problems such as MAI (Multiple Access Interference) and Multipath Interference, and leads to the capacity improvement. In this thesis, Uplink synchronization and Smart antenna techniques will be discussed. The physical structure of TD-SCDMA is introduced firstly. Multipath channel model is discussed, and the algorithm for channel estimation by using midamble is presented. Two downlink beamforming proposals are presented: Subweight ED (Eigenvalue Decomposition) and "Switch DOA"algorithm. The first one is based on ED, and the other one is based on the parametric model. And two implement proposals for TD- SCDMA are presented, one is for Uplink synchronization system by using a correlator; the other is for channel estimation by using midamble. The simulation experiments are made under different conditions, the beamforming effect and angle tracking of "Switch DOA"are compared with Subweight ED approach, which show good performances and practical feasibility. Finally, the improvements of output SNR and SIR are discussed. The implement flowchart and basic principle of Uplink synchronization in TD- SCDMA are also presented. In the simulation experiments, the leads under different users and different channel environments are analyzed, the chart of the synchronization detecting probability versus the threshold, the noise measurement is close to the real noise power under the appropriate SNR. All the discussion and simulation prove the feasibility of Uplink Synchronization technique.
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