BER PERFORMANCE OF CMA ADAPTIVE ARRAY FOR HIGH-SPEED GMSK MOBILE COMMUNICATION - A DESCRIPTION OF MEASUREMENTS IN CENTRAL TOKYO

This paper describes the performance of an adaptive array as a counter measure to multipath fading for a 256 kbps Gaussian-filtered minimum s hift keying (GMSK) mobile communication system operating in the 1.5 GH z band. An adaptive array having four antenna elements is implemented using the digital beam forming concept. The constant modulus algorithm (CMA) is employed for the adaptation process to ease the implementati on. Measurements in central Tokyo of the bit error rate (BER) performa nce and an array pattern arising in the multipath environment are pres ented. Analysis of the array pattern confirms that the array succeeds in directing nulls to the delayed signals. BER performance shows an im provement in E(b)/N-o compared with that of a single antenna system, o f 17.5 to 22 dB at a BER of 1.0 x 10(-2) in a frequency-selective fadi ng channel.