World Applied Sciences Journal 6 (6): 754-758, 2009 ISSN 1818-4952 © IDOSI Publications, 2009 Corresponding Author: Dr. Saleem F. Shaukat, Department of Electrical Engineering, COMSATS Institute of Information Technology, University Road, Post code 22060, Abbottabad, Pakistan 754 Sequential Studies of Beamforming Algorithms for Smart Antenna Systems S.F. Shaukat, Mukhtar ul Hassan, R. Farooq, H.U. Saeed and Z. Saleem 1 2 3 1 1 Department of Electrical Engineering, COMSATS, Abbottabad, Pakistan 1 Brunel University, Uxbridge, United Kingdom (UK) 2 Department of Chemistry, COMSATS, Abbottabad, Pakistan 3 Abstract: Smart antenna is the most efficient leading innovation for maximum capacity and improved quality and coverage. A systematic comparison of the performance of different Adaptive Algorithms for beamforming for Smart Antenna System has been extensively studied in this research work. Simulation results revealed that training sequence algorithms like Recursive Least Squares (RLS) and Least Mean Squares (LMS) are best for beamforming (to form main lobes) towards desired user but they have limitations towards interference rejection. While Constant Modulus Algorithm (CMA) has satisfactory response towards beamforming and it gives better outcome for interference rejection, but Bit Error Rate (BER) is maximum in case of single antenna element in CMA. It is verified that convergence rate of RLS is faster than LMS so RLS is proved the best choice. The effect of changing step size for LMS algorithm has also been studied. Key words: Smart Antenna System %Beamforming %Training sequence algorithms %Bit error rate INTRODUCTION the signals from other directions, signals not of interest Smart antenna for mobile communication has received capacity enhancements without the need for additional enormous interests worldwide in recent years. In the last power or spectrum. Many practical algorithms for MIMO decade wireless cellular communication has experienced have been proposed in recent years. The techniques of rapid growth in the demand for provision of new wireless placing nulls in the antenna patterns to suppress multimedia services such as Internet access, multimedia interference and maximizing their gain in the direction of data transfer and video conferencing. In order to meet desired signal have received considerable attention in the this demand and to overcome the limited capacity of past and are still of great interest using evolutionary conventional single input single output (SISO) systems, algorithms such as genetic algorithms (GA) [7-10]. the use of multiple element antennas (MEAs) has been A smart antenna has the potential to reduce noise, to under consideration [1,2]. A multiple input multiple increase signal to noise ratio and enhance system output (MIMO) system offers greater capacity than capacity. Several approaches have been studied to SISO counterparts. The multiple antennas can be used introduce smart antenna technology into GSM, IS-136 and to increase the communication reliability by diversity third generation systems. They have been considered or to increase the data rate by spatial multiplexing or a mostly for base stations so far. Recently, they have been combination of both. Smart antennas refer to a group of applied to mobile stations or handsets. Also, one of the antenna technologies that increase the system capacity third generation wireless personal communication by reducing the co-channel interference and increase the systems, 3GPP (third generation partnership project), quality by reducing the fading effects. Co-channel requires antenna diversity at base stations and optionally interference is the limiting factor to the communication at mobile stations but cost of fabrication increases with systems [3,4]. Array containing M identical elements can the number of array elements [11-14]. steer a directional beam to maximize the signal from Smart antennas involve processing of signal induced desired users, signals of interest (SOI), while nullifying on an array of antennas. They have application in the (SNOI) [5,6]. Multiple antennas have performance and