Miniaturization of base station antennas by using adaptive antenna technique for indoor high-speed wireless communication systems

Suppressing multiple reflected waves in an indoor propagation environment is now in great demand because multiple reflected waves significantly degrade the transmission quality of wide-band wireless communication systems. This paper clarifies that adaptive arrays with M+1 elements can completely suppress the multipath waves whose delay times are up to M times greater than the inverse of the signal transmission speed (1/baud) regardless of the number of incoming waves in an indoor environment. Furthermore, it is also shown that the adaptive antenna technique can miniaturize an ordinary base station antenna obtaining a specified average bit-error-rate (BER) performance.