Downlink performance of adaptive antennas with null broadening

We compare different null broadening schemes and their ability to decrease the radiated interference for the co-channel users in a space division multiple access system with adaptive antennas. By link level simulations of the GSM 1800 system in urban and suburban environments we show that a gain of up to 8 dB in SNIR is feasible with null broadening. Therefore adequate null broadening seems to be a must in the downlink beamforming process.