Smart Antenna Technology, Applied Research, In The Third Generation Mobile Communication Systems

The number of the subscribers has been increasing rapidly, and the research of new wireless services has been made in recent years. How to use the limited frequency resource effectively and to improve system capacity has been the pivotal matter of the third generation wireless communications (international mobile telecommunications 2000). As an effective method, smart antennas technology is paid much more attention. It examines the application of smart antennas technology in the 3rd mobile communication based on TD-SCDMA system in this thesis.The thesis introduces the 3G mobile communication system in the first, expounds the TD-SCDMA technology and smart antennas system. Secondly, the author deeply analyze the application of the 3G mobile communication system; when the base stations use different antenna systems, gives the simulating results of the number of subscribers of each cell and BER (bit error rate) at different path loss. It examines the shaped-beam technology of smart antennas in this thesis at last, gives a design for eight-unit switched-beam circular array and the Matlab simulation.An eight-unit circular array realizing multi-beam is given by modified traditional Bulter network. The traditional Bulter multi-beam network is modified to add eight extra phase splitters, and it can be used eight-unit circular array. The frame of the circular array is simple, the array is realized easily, and it has no characteristic of complicated calculation of weight, the pattern of the array can cover the whole horizontal surface. It can be used for estimation of DOA, the directional resolution can be improved to 45 degree.