An evaluation of adaptive antennas for a UMTS FDD network deployed in a suburban area of Norway

A system simulator for performance evaluation of adaptive antennas in UMTS FDD networks has been developed. The simulator is flexible, it uses realistic channel and system assumptions, and for a given scenario provides the maximum network capacity. The antenna types included in the simulator are switched lobe, phased array and adaptive array as well as conventional fixed sector antenna. Analyses of a UMTS network deployment in a suburban area of Oslo, Norway, reveal that adaptive antenna techniques potentially can more than double the radio capacity compared to conventional sector antennas. The majority of the gained capacity is obtained by using a relatively simple switched lobe antenna implementation, providing approximately 75% of the capacity compared to the adaptive arrays. The phased array alternative offered a slight improvement over switched lobe, with average throughputs per base station of 2.4 Mbit/s and 2.3 Mbit/s respectively. These results demonstrate that beam forming techniques can provide significant radio capacity gains for UMTS FDD.