| 摘要 |
PCT No. PCT/SE88/00100 Sec. 371 Date Nov. 14, 1988 Sec. 102(e) Date Nov. 14, 1988 PCT Filed Mar. 3, 1988 PCT Pub. No. WO88/07301 PCT Pub. Date Sep. 22, 1988.A method and apparatus for transmitting a synchronous data signal (D1) on a transmission medium (2) on which the transmission rate (Y bits/s) is greater than the data signal bit rate (X bits/s). The data signal is converted in a transmitter by over-sampling with a sampling frequency (Y Hz) which is equal to the transmission rate (Y bits/s) on the transmission medium (2), whereafter the data signal (D2) formed by the conversion is transmitted on the transmission medium (2). A clock signal (C2) is formed in a receiver, this signal being phase-locked to the transmitted data signal (D2') and has a frequency (X Hz) equal to the bit rate (X bits/s) of the original, synchronous data signal (D1), subsequent to which the transmitted data signal (D2') is re-sampled with the clock signal (C2) formed in the receiver. To avoid problems which can be caused by certain special bit combinations of the synchronous data signal (D1) or of certain special frequency conditions between it and the transmitted signal (D2'), the data signal (D 1) is converted in the transmitter such that an uneven distribution of the edges of the transmitted data signal (D2') in relation to their mean positions is avoided. |
