| 摘要 |
PURPOSE:To attain efficient data transmission/reception without decreasing transmission speed and complicating equipment constitution by combining a PB signal in response to a character code signal to generate a multi-frequency mixing signal and sending data. CONSTITUTION:An 8-bit code signal representing a transmission character CE is sent to an oscillator 14 from an encoder 12 at the sender side and the oscillator 14 generates a multi-frequency mixing signal corresponding to the code signal and sends it to a telephone line 18. Then a mixed signal is fed to a reception filter 22 of a receiver 20 via an exchange 16. The frequency component included in the input mixing signal is detected by the filter 22 and the presence/ absence is binarized and the 8-bit signal of each binarized frequency is given to a decoder 24. Then the received character CD is decoded. Thus, one character is sent by using one mixing signal. |
