ADAPTIVE ANTENNAS FOR FUTURE MOBILE RADIO

In future mobile radio, high-speed transmission and efficient spectrum utilization will be important. However, multipath propagation with la rge delay difference and cochannel interference are obstacles to the a dvanced mobile communication system. An adaptive antenna can suppress multipath signals and cochannel interference signals. This paper revie ws basic performance of multipath fading reduction and cochannel inter ference suppression using the adaptive antenna. After a brief explanat ion of adaptive antenna concepts, we show simulation and experimental results of the fading reduction. It is pointed out that the adaptive a ntenna cancels multipath signals with large delay difference strongly. This feature is very important for high-speed TDMA systems. Moreover, it is shown from simulation results that the adaptive antenna improve s the spectrum efficiency by suppressing the cochannel interference si gnals.