Research On Technology About Smart Antenna

In the middle 1970s, the naissance of mobile technology meet to people's requestion of convenience and fast communication. Mobile system has developed quickly, and come through the first generation mobile system represent by FDMA; the second generation mobile system represent by TDMA and CDMA; the third generation mobile system represent by WCDMA and CDMA2000. Smart antenna and array signal transaction is one of the third generation mobile system important technology. It can restrains multi-address interference by space field information, so it can improve the system capacity and quality. This article researches on the technology about smart antenna by this elements.The smart antenna key technology are beam-forming and null, which are primarily researched in this article .This paper introduces background and significance, work principle and theoretic foundation of smart antenna. By studying about the past arithmetic, we analyse the merit and defect among them. Then we research on LMS arithmetic about its step size. Then we ameliorate relation formula based on the foregone variable step size arithmetic. It improve the system's convergence. After that we research on smart antenna null question and advance the antilogy of angle extend based on phase interference arithmetic, it extend system null and ameliorate system capability.