Method and apparatus for pulse communication

A communication apparatus comprising a pulse communication circuit consisting of a transmitter and receiver portions, said communication circuit being used to convert rectangular pulse communication to cosine pulse communication, wherein the pulse communication circuit is a cosine pulse code modulation circuit, and its transmitter circuit comprises:

• a coder/decoder (IC.sub.1) for outputting first and second rectangular pulse code modulation output signal PCMs, a positive and negative rectangular pulse separator to generate a first switching pulse signal from said first rectangular pulse code modulation output signal PCM, a positive and negative pulse duration expander for expanding a duration of said first switching signal, a fundamental frequency extractor for extracting a fundamental frequency from said second rectangular pulse code modulation output signal PCM, a phase adjustor for adjusting a phase of said second rectangular pulse code modulation output signal PCM, a positive and negative cosine pulse generator for generating positive and negative cosine pulses forming a second switching signal, a positive and negative electronic switch adapted to receive said first and second switching signals, and a positive and negative cosine pulse combining processing and outputting portion adapted to receive and combine a positive and negative cosine pulse from said electronic switch to form a cosine pulse code modulation signal CPCM.