| 摘要 |
PURPOSE:To obtain a digital service channel circuit of simple constitution by quantizing linearly the service channel signals to be transmitted and then transmitting these quantized channel signals to a circular loop through stations forming said loop. CONSTITUTION:The service channel signal supplied through a terminal 7 is quantized linearly by a coder 23. The quantized service channel signal B is added linearly with a part of the digital signal X through a digital adder and sent to a circular loop in the form of (X+B). This signal (X+B) is delayed by a time tau with delay 1 of the loop 8 and fed back to own station to be applied to a digital subtractor 20. While the rest part of the signal B is delayed by tau equal to the delay amount of the loop 8 through alpha delay circuit 22 and applied to the subtractor 20. Then the signal B of own station is deleted from the signal fed back through the loop 8, and the linear addition is supplied to the signal B through a digital adder 21. Thus no deterioration is given to the existing signal. |
