| 摘要 |
PURPOSE:To prevent the reduction in a data transmission efficiency by varying the amplitude of a data point at a transmission section synchronously with a synchronizing signal of time division multiplex, detecting its amplitude change at the reception section and reproducing the synchronizing signal. CONSTITUTION:A transmission section 1 is provided with a switch 12 selecting an output signal of a multiplier 11 only at pulse leading period of a synchronizing signal (b) for time division multiplex and selecting a modulation signal (a) in other case, a reception section 2 demodulates and equalizes an output signal of the transmission section through a demodulator 21 and a equalizer 22, obtains square of the amplitude and inputs the result to an amplitude comparator 23. Then the transmission section 1 varies the amplitude of a 2-dimension signal having a symbol value designated in advance at the appearance period of a synchronizing pulse representing the synchronizing timing of a time division multiplex signal so as to discriminate the amplitude in the non-appearance period of the synchronizing pulse and sends the result to a modulator 15. Then the reception section 2 discriminates the level of the amplitude of the 2-dimension signal obtained through the demodulation to reproduce the synchronizing pulse. Thus, the deterioration in the data transmission efficiency is prevented. |
