| 摘要 |
<p>PURPOSE:To transmit a signal with sufficiently low correlation even if an input is interrupted by switching a scramble signal into a pseudo non-correlation signal having a long period when the absence of an input signal is detected. CONSTITUTION:A digital input signal is fed to a multiplex conversion circuit 13 via a line 100 and the signal is fed to a scrambler 15 while being inserted with a frame synchronizing signal. When a signal detection circuit 12 detects an input signal, the scrambler 15 acts as a synchronizing scrambler. On the other hand, if the input signal is lost and the signal detection circuit 12 detects it, the mode is switched that the scrambler 15 acts as an asynchronous scrambler from the start of the next frame, an output of the scrambler 15 is transmitted on radio, the frame synchronism is established at a reception side 2 and the result is fed to a de-scrambler 26. On the other hand, when input missing information is detected by a parity comparator circuit 24, an alarm output is inhibited.</p> |
