| 摘要 |
PURPOSE:To demodulate a base band signal with excellent S/N by means of a simple circuit by superimposing a subcarrier on one of base band signals, sending the result, and extracting the subcarrier from a demodulated signal with a band pass filter. CONSTITUTION:A transmission means superimposes the subcarrier on one of binary base band signals, sends the result, and a homodyne detection output outputted from detection circuits 14, 15 is given respectively to band pass filters 61, 62 at a receiving means and the extracted subcarrier is subjected to the envelope detection by detection circuits 65, 66 respectively and demodulated. Moreover, an envelope detection output detected from a detection circuit 29 is given to a band pass filter 70 and the extracted subcarrier is subjected to envelope detection by a detection circuit 72 further and demodulated. Thus, the base band signal is demodulated with excellent S/N and the simple circuit. |
