Does Downlink Nulling Make Sense for Combined Packet/circuit Switched Wireless Systems?

Downlink beamforming is the limiting factor in the application of adaptive antennas in cellular mobile communication systems. Directing nulls of the antenna pattern to active mobiles in the downlink will be impractical in the case of packet data transmission. But in the evolution of 2 generation mobile communication systems packet switched data transmission (e.g. GPRS/EGPRS in GSM Phase 2+) and circuit switched speech communication will be used in parallel. We show by link level simulations that also in combined packet/circuit switched mobile communication systems „gentle“ downlink interferer nulling leads to performance and capacity improvements.