Performance of three, six, nine and twelve sector sites in CDMA - based on measurements

We investigate the performance improvement achieved by increasing the number of sectors on a W-CDMA or cdma2000 site by increasing the number of sectors from today´s typical three to six, nine or twelve. The radio propagation environment determines if the narrow beams can be created and kept separated or if they blur together, which in turn determines the sector-to-sector isolation and the soft-handoff populations. The rate of change in signal strength of the beams also determines whether the handover mechanisms are sufficiently fast to allocate the correct beam. We analyze these issues based on simultaneous measurements of two antenna panels placed on the top of a building overlooking a typical European urban environment of mostly six to eight storeys-high buildings. Based on these measurements and simulations we find that a nine-sector site has more than double the capacity of a conventional three-sector site.