Investigation of different types of array structures for smart antennas

As the growing demand for mobile communications constantly increases, the need for better coverage, improved capacity, and higher transmission quality rises. Smart antenna used in code division multiple access (CDMA) systems can effectively maximum capacity and improve reliability and coverage by directing beam patterns towards the desired signals and null-patterns towards the interferers. Although numerous studies for smart antennas have already been conducted, including mostly uniform linear arrays (ULA), not as much effort has been devoted to other configurations. In this paper, the performance of smart antennas with uniform linear arrays (ULA), uniform circular arrays (UCA) and uniform rectangular arrays (URA) is examined and compared. With the use of three different types of array antennas, the two main issues related to smart antennas - estimation of the direction of arrival from incoming signals and adaptive beamforming - are both analyzed.