7 Smart Antennas in 4G

“Smart Antenna ” technology is one of the most vital developments in mobile communication.This paper deals with the principle and working of smart antennas and the elegance of their applications in various fields such a 4G-telephony system, best suitability of multi carrier modulations such as OFDMA etc., This paper mainly concentrates on use of smart antennas in mobile communications that enhances the capabilities of the mobile and cellular system such a faster bit rate, multi use interference, space division multiplexing (SDMA), increase in range, Multi path Mitigation, reduction of errors due to multi path fading and with one great advantage that is a very high security. The signal that is been transmitted by a smart antenna cannot tracked or received any other antenna thus ensuring a very high security of the data transmitted. This paper also deals the required algorithms that are need for the beam forming in the antenna patters. The application of smart antennas such as in WI-FI transmitter, Discrete Multi Tone modulation (DMT), OFDMA and TD-SCDMA is already in real world use is also incorporated in this paper