| 摘要 |
PURPOSE:To eliminate the need for the synchronizing processing between the sending side and the receiving circuit by using an M-series code so as to apply spread spectrum modulation to a differential code, sending the result and demodulating a retarded reception modulation signal and a received modulation signal with multiplication. CONSTITUTION:A differential code CS to a transmission signal PS is obtained at each period of the M series code M at the sending side, the code CS and the code M are multiplied to supply a modulation signal MS subject to spread spectrum modulation to a power line 17. The receiving side obtains the correlation between the received modulation signal RMS sent via the power line and the retarded receiving modulation signal DRMS being the result of delay of the said received modulation signal over one period of the M series code used at the modulation to apply the demodulation of the received signal. In demodulating the received signal, since the generation of the M series code synchronously with the M series code included in the received modulation signal is not used, exact communication is attained by applying synchronization between the sending and receiving ends. |
