Disclosed is a wireless communication apparatus having an array antenna
constituted by a plurality of antennas, radio receiving circuits, which
are provided for respective ones of the antennas, for amplifying
respective ones of antenna receive signals and applying a frequency
conversion to the baseband signals, and a demodulator for demodulating
receive data from the baseband signals. A narrow-band-signal extracting
unit extracts two narrow-band signals, which have the maximum frequency
spacing between them, from the baseband signals of each of the antennas,
an estimating unit estimates phase variation in each radio receiving
circuit using the two narrow-band signals of each antenna, and a
phase-variation correcting unit corrects for phase variation in each
radio receiving circuit. The estimating unit estimates the direction of
signal arrival using narrow-band signals of at least two antennas, a beam
former applies receive beam-forming processing to each corrected signal
based upon the direction of signal arrival, and a receive-signal
processor demodulates receive data from the receive signal that has
undergone beam-forming processing.