| 摘要 |
PURPOSE:To increase the transmission efficiency and to assure bit synchronization, by differential coding of inputted RZ signals and transmission of the signals with AM-PM-VSB modulation. CONSTITUTION:An RZ digital signal is inputted to a data input terminal 1 and differentiated at a differentiation circuit 2. An output of the differentiation circuit 2 is given to a flip-flop 3, which is inverted with a positive differentiation output only, and a signal differentially coding the input RZ digital signal appears at the output. The output of the flip-flop 3 is converted with a binary-ternary conversion circuit 5 so that consecutive pulses are opposite and transmitted through an amplitude modulation circuit 6 and a VSB filter 7. The ternary signal demodulated at the reception side through a demodulator 10 is converted into a binary signal with full-wave rectification at a ternary-binary conversion circuit 11. This signal passes through a differentiation circuit 13, a full wave rectification circuit 14 and one-shot multivibrator 15, and the original RZ digital signal can be reproduced. |
