A wireless communication apparatus includes an antenna receiving a radio
signal, a variable gain amplifier amplifying the received signal using a
variable gain, an analog-to-digital converter converting the amplified
signal into a digital signal, a gain setting unit periodically updating
the gain of the variable gain amplifier in accordance with an output from
the analog-to-digital converter, and an operating mode selection unit
selecting one of a plurality of operating modes characterized by
different gain updating periods in accordance with the output from the
analog-to-digital converter, the selected operating mode being set in the
gain setting unit. With this construction, the precision in conversion by
the analog-to-digital converter is maintained at a proper level when an
environment for signal reception varies.