| 摘要 |
PURPOSE:To reduce the capacity of a buffer circuit and to reduce the size of hardware greatly, by equipping the buffer circuit for temporarily storing a signal of a channel to be return-test, and inserting its storage contents into a corresponding time slot on a reception-side highway. CONSTITUTION:A transmitter 6 sends out a transmitted digital signal to a signal inserting circuit 5, which inserts the transmitted signal into a digital highway for unidirectional transmission. A receiver 7, on the other hand, obtains a received signal from a digital highway for transmission in the opposite direction to said digital highway. Then, a signal sampling circuit 2 extracts a signal of a specific channel in the signal inserted into the digital highway by the circuit 5. This extracted signal is stored in a temporary buffer circuit 11 and a returning circuit 4 transmits the output signal of the circuit 11 in the opposite direction. Consequently, the signal sent out of the transmitter 6 is received by the receiver 7. |
