Performance of cellular CDMA systems using SBF and TBF array antennas

Abstract

We investigate the performance of cellular CDMA systems through adopting two types of array antennas, switched beam forming (SBF) and tracking beam forming (TBF) in the base station. Also, in order to enhance the system performance, we optimize a beam shape using side-lobeto-main-beam-energy ratio (SMER) defined by the energy ratio of side lobe region and main beam region. As a result, it is observed that the TBF method gives about 30% capacity improvement over the SBF method under 1% outage probability requirement. In addition, an optimized beam shape using SMER provides maximally 8% and 14% more capacity increment comparing conventional non-optimized beam shapes under 1% outage probability requirement when we use 5 and 7 beams per sector with SBF method, respectively.