| 摘要 |
PURPOSE:To send a data signal and a speech signal at the same time by utilizing a single analog line by converting an analog pass band signal into a base band signal, and superposing the signal on data signal points of transmitting data at a level where it can be regarded as a noise, thereby transmitting the signal. CONSTITUTION:A transmission part 30 is provided with data transmitting means 38 and 42 which convert the transmitting data into data signal points in a two-dimensional coordinate space and transmit modulated signals generated by modulating the data signal points and analog multiplexing means 50 and 40 which convert analog pass band signals into analog base band signals and then transmit the signals by superposing the signals on the data signal points. A reception part 32 is equipped with data regenerating means 60, 62, and 64 which receive the transmitted signals from an analog line 46 and regenerate the original transmitting data and analog regenerating means 72 and 76 which separate the analog base band signals from the received signals and then reconvert them into the original analog pass band signals. Consequently, there is no mutual interference and data and a speech can be multiplexed simultaneously. |
