| 摘要 |
<p>METHOD OF AND APPARATUS FOR REGENERATING A SIGNAL FREQUENCY IN A DIGITAL SIGNAL TRANSMISSION SYSTEM In a digital signal transmission system, digital signals at a first frequency are synchronized to a second, slightly higher, frequency for transmission in frames and superframes, positive stuffing being effected one frame at a time at a slow rate. At the receiver, the received signals, but not stuffed frames, are written into a memory and the signals are read from the memory at the first frequency. The first frequency at the receiver is generated using an oscillator whose frequency is controlled in dependence upon a comparison of the relative phases of writing into and reading from the memory. The digital signals at the first frequency are derived from an incoming bit stream having a frequency which is higher than the first and second frequencies, by omitting synchronizing bits from the incoming bit stream.</p> |
