At the beginning of wireless networks (e.g. GSM, AMPS) were mainly base station antennas Omni or directional. Using these Fixed antenna scheme, power radiated from antenna covers a larger area than just the user.
For example, omni antenna power was 360 degrees of radiation. This power was not only in the direction of radiation, but in ways that would be considered as an increase in interference to other users. If the site has been redesigned with omni directional antenna to the threesectors sector is limited, the district covers, thus reducing noise. If further increased the number of sectors, directional antenna became more targeted leads in the ability to have a smaller template reuse.
With LTE all sectors operate on the same channel and reuse the template is always one site. Objective for LTE smart antenna base station must send a bundle of energy to the Subscriber with increased power during less interference to other users.
Smart antennas for LTE is adaptive antenna, which is an array of multiple antenna elements, where weighted and combined to maximise the received signals signal to noise plus interference power ratio.
It basically Steers the main beam in the direction of the desired signal and reduces his pacemaker in all other directions. Ray is a method used to create directional antenna array by adding constructively the phases of the signals in the direction of the desired subscriber, and Subscriber template zeroing units are undesirable (i.e. interference).
Smart antenna adapts to the environment. That is, for adaptive array beam template changes the user and interference move.
Using smart antennas has benefits outreach, capacity building, Improving efficiency of spectrum, but they also have drawbacks (e.g., cost, size, and complexity).