| 摘要 |
PURPOSE:To realize the data demodulation system in which the data in NRZI coded can normally be received even if the period or duty ratio are more or less changed. CONSTITUTION:After wave shape of the reception signal RXDATA, the pulse G6 including the positive going edge and negative going edge is obtained with differentiating operation. When the time distance TE of the pulse G6 is TE>TCXalpha to the average value TC of the repetitive time distance of the reception data(where: alpha is the coefficient corresponding to the degree of permission to the variation in frequency and duty ratio, and 0.8 to 0.85 experimentally), the pulse is regarded as correct pulse. Thus, the signal is demodulated into RZ signal by driving the set and reset flip flop with the N and P pulse thus selected. |
