| 摘要 |
PURPOSE:To accurately adjust phase synchronism, an f<1/2> equalizer, and a BT equalizer by transmitting a 0-cross signal, a signal of a low frequency component, and a random signal of a wide frequency range spectrum in order to a terminal equipment coupled with a subscriber line with BTs. CONSTITUTION:From the phase synchronous training TRG signal generator 7 of a transmitting terminal 16 coupled with a telephone subscriber line 3 with free circuit branches BT4-1-BT4-3, a signal having a 0-cross at the best discrimination point is sent to a receiving terminal 17 through a switch SW14. The best discrimination timing is determined by receiving said signal by the phase synchronizing circuit 11 of the receiving terminal 17 to operate an SW15, and an equalized digital output is supplied from a discriminator 13 to the terminal 6. Then, a signal TRG having a low frequency component is sent from an f<1/2> equalizer TRG signal generator 8. At a reception side, the signal is received to adjust an f<1/2> equalizer 10. From a BT equalizer TRG signal generator 9, a pseudo-random signal having a wide frequency spectrum range is sent to adjust the BT equalier 12 of the reception side. After TRG, the SW14 connects the subscriber line 3 to a terminal 5 to carry out ordinary communication. |
