Communication apparatus and estimation method

A communication apparatus comprising:

• a synchronizer configured to perform synchronization processing according to a Doppler shift on a reception signal;
• and
• an equalizer configured to perform equalization processing on a reception signal on which the synchronization processing has been performed, wherein
• the synchronizer includes
• a correlator configured to output a correlation between a reception signal and a known preamble sequence and a correlation between the reception signal and a known postamble sequence,
• a slide correlator configured to output a sliding correlation based on a correlation between a preamble sequence extracted from head of the reception signal and a known preamble sequence and a correlation between a postamble sequence extracted from end of the reception signal and a known postamble sequence output by the correlator, and
• a Doppler estimator configured to estimate a Doppler shift based on the sliding correlation of the slide correlator,
• wherein a delay amount output from the correlator to the slide correlator is calculated based on a waveform compression amount corresponding to a maximum assumed Doppler frequency.