A transmitting and receiving method for CDMA communications over indoor electrical power lines

Transmitting and receiving methods for CDMA communications through 2-wire or 3-wire power line cord over indoor power lines are proposed. The key idea for transmitting method is to use a fundamental model of a coupling transformer-less transmitting circuit including the influence of the distribution transformer and to find out the combinations of model parameters giving the acceptable distortion of the transmitted waveforms for CDMA communications. The receiving method is to use a filtering method that separates arbitrary waveforms of transmitted data signal from the superposition waveforms of the sinusoidal high power signal and transmitted data signal without distorting arbitrary waveforms of transmitting signal at all. These methods are experimentally confirmed to be effective