Performance of downlink nulling for combined packet/circuit switched systems

In the evolution of 2/sup nd/ generation mobile communication systems packet switched data transmission (e.g. GPRS/EGPRS in GSM Phase 2+) and circuit switched speech communication will be demanded in parallel. Directing nulls of the antenna pattern to active mobiles in the downlink beamforming process using antenna arrays at the base station may be useless in the case of packet data transmission. We show that even in combined packet/circuit switched mobile communication systems "gentle" downlink interferer nulling dependent on propagation conditions and traffic distribution leads to performance and capacity improvements.