A first reception circuit (SR1) separates a signal from a desired terminal among signals from an adaptive array antenna (#1 to #4), based on a reception weight vector calculated in a reception weight vector calculator (20.1). A remodulation circuit (32.1) generates a first replica signal from a signal of a demodulated desired wave. A replica generating circuit (40.1) multiplies signals from a plurality of antennas by a weight vector for an interfering wave from a second reception circuit (SR2), and generates a second replica signal corresponding to a signal from an interfering wave terminal. A reception response vector calculator (24.1) derives an impulse response of a propagation path of the signal from the desired terminal, based on the first and second replica signals.