1. An adaptive array communication system comprising a transmitter which modulates coded information data by a predetermined modulation method, and a receiver which performs known viterbi decoding to a received signal from the transmitter to select a most likely path, wherein the receiver includes, for each state of the viterbi decoding, an adaptive control unit which performs weight control on the basis of a known adaptive algorithm, multiplies received signals from a plurality of antennas by complex weights which are different from each other for the respective states to perform weighting processes depending on the received signals, and, thereafter, combines the weighted signals to perform such control that a desired wave component is maximized and an interference wave component is minimized; a decoding unit which adds a branch metric calculated by a difference between a signal obtained after the weighting combining and a reference signal (replicate signal) serving as an ideal received signal and a path metric to calculate a metric corresponding to a transition to a desired state; and an error vector calculation unit which calculates an error vector for calculating complex weights which are different from each other for the respective states on the basis of the signal obtained after the weighting combining and the reference signal, and wherein the directivities of the plurality of antennas are adaptively controlled to perform a process of removing an interference wave except for a desired wave and a process of combining a plurality of desired waves.