Patent ID: 7957476

Claim:
A wireless communication apparatus for receiving a packet formed of a signal modulated by orthogonal frequency division multiplexing, comprising: a band-pass filter that extracts an orthogonal-frequency-division-multiplexing signal of a desired band; a low-noise amplifier having a gain controlled according to a received-signal intensity to amplify the orthogonal-frequency-division-multiplexing signal of the desired band; a frequency converter that down-converts the amplified orthogonal-frequency-division-multiplexing signal into a baseband signal; an analog-digital converter that converts the baseband signal into a digital signal; a first high-pass filter that removes a DC offset from the digital signal corresponding to a predetermined preamble portion of the packet; a frequency-offset estimator that estimates a frequency offset from sample signals constituting the digital signal from which the DC offset has been removed by the first high-pass filter; a frequency-offset corrector that removes the estimated frequency offset from the digital signal; and a demodulator that demodulates subcarrier signals arranged in a frequency domain from the digital signal compensated for the frequency offset.