Erlang capacity of smart antenna CDMA system considering the sector operation

The contributions of this paper are two-fold: one is to investigate the reverse link capacity improvement of CDMA systems through adopting two types of smart antennas; fixed beam forming (FBF) and tracking beam forming (TBF) in the base station. The other is to study the Erlang capacity of CDMA systems according to two sector operation methods; the fixed-angle sectoring and the dynamic angle sectoring by simultaneously considering both the limitation of link capacity per sector and that of channel element in the base station. As a result, the FBF method with 2 beams and 4 beams per sector provides the 1.34 times and 2.09 times link capacity over one with one beam per sector; respectively when the system employs three sectors and the required outage probability is given as 5%. In addition, it is observed that the TBF method gives about 30% capacity improvement over the FBF method. Regarding the Erlang capacity, we can get about 20% capacity improvement through the dynamic angle sectoring over the fixed angle sectoring even under the statistically uniform traffic distribution among sectors.