To obtain a digital demodulator preventing the increase of a circuit scale by providing a selection part and a threshold value generation part.
An extraction part 1 extracts received data equivalent for the past, a fixed time ago, and for the future, a fixed time later, specified by a basic threshold value set in advance from data obtained by A/D-converting a received and wave-detected analog signal. The extaction part 1 extracts data obtained by A/D-converting received data equivalent for the past or the future and data equivalent for the present in addition. A specifying part 2 specifies present received data A by comparing the A/D-converted data A equivalent for present received data extracted by the extraction part 1 and prescribed plural number of threshold value set by selected by a selection part 3 and generated by a generation part 4 by means of each transition pattern of extracted data one symbol ago and later.
INOUE TAKESHI
SHIMIZU MASAHIKO
MATSUYAMA KOJI
