Performance of cellular CDMA systems using SBF and TBF array antennas

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 the beam shape using sidelobe-to-main-beam-energy ratio (SMER) defined by the energy ratio of the sidelobe 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 probability requirement. In addition, an optimized beam shape using SMER provides maximally 8 comparing conventional non-optimized beam shapes under 1 probability requirement when we use 5 and 7 beams per sector with the SBF method, respectively.