| 摘要 |
PURPOSE:To enable various measurements arbitrarily from an audio signal side, by folding the audio signal with a transmultiplexer via one channel of PCM multiplex signal. CONSTITUTION:An audio signal is coded at 13 by a monitoring circuit 12 to form a PCM signal, transmitted to an arbitrary one channel of a PCM multiplex signal with an interface 15 and supplied to a transmultiplexer 11. The circuit 11 converts the PCM multiplex signal into an audio signal, and the audio signal is converted to an FDM multiplex signal for output. In this case, the FDM multiplex signal is folded through the operation of a switch 16 and inputted to the circuit 11, outputted as the PCM multiplex signal after the conversion into audio signal, and a transmission channel is selected at the circuit 12 and decoded at 14 as the audio signal. |
