| 摘要 |
PURPOSE:To offer a digital transmitter where a clock frequency of a transmitter/receiver is matched stably with high accuracy and with a simple constitution. CONSTITUTION:A staff information generator 13 uses relative information DELTAS representing the relative relation between a sampling clock frequency fs and a transmission line clock frequency fl, discriminates if a sampling clock phis and a transmission line clock phil have a phase difference close to one time slot, and obtains staff information S. This staff information is coded and multiplexed at a multiplexer 4 for the input signal and transmitted to a transmission line 6 via a modulator 5. Next at the reception section, the relative information DELTAS converted from the staff signal S at a code converter 26 and relative information DELTAR picked up at an output of a comparator 29 are subtracted at a subtractor 33 and the phase error DELTA is picked up for the output. The amplitude of the phase error DELTA is limited at a limiter 34, jitter is suppressed at a digital filter and converted into a control voltage V of a voltage controlled oscillator 27 with a D/A converter 36. |
