A weight coefficient is feedback-controlled so as to maximize the ratio of desired signal power to interference power (SIR), whereby it is possible to improve reception quality and to increase the number of subscribers per cell and it is also possible to increase the speed of establishment of diffused code synchronization and the speed of convergence of the weight coefficient. A coherence adaptive diversity arrangement to which absolute synchronization detection is applicable is adopted. The weighht coefficient of each diversity branch is adaptively feedback-controlled, whereby it is possible to reduce the influence of interference power from other communicators, so that the number of subscribers per cell can be increased. Furthermore, a direction in which a highest reception SIR is obtainable is determined by rotating an antenna with directivity of predetermined angle being given to it. After that, by setting the initial value of the weight coefficient to the direction, the speed of convergence of the weight coefficient can be increased.