On the effect of ideal and non ideal antenna sectorization on the uplink user capacity of a CDMA macrocell with a hotspot microcell

In this paper the effect of antenna sectorization on the uplink user capacity of a macrocell/microcell CDMA system is studied. A "hot spot" microcell is embedded within a large macrocell and operates over the same bandwidth as the large cell. The macrocell base station uses an omnidirectional antenna and the microcell base station uses an ideal and non ideal sectorized antenna to provide coverage to the hot spot. The optimum antenna position and beamwidth are determined. To evaluate the user capacity we use a computer simulation, and we take into account propagation loss, multiple access interference, power control and random location of users terminals. Our results show an increment of 15% in the capacity of the system by the use of antenna sectorization. The possibility of keeping the optimum value of capacity using smart antennas to account for traffic variability is also discussed.