| 摘要 |
PURPOSE:To reduce the training time and to derive a sufficient equalization state, by estimating the impulse response of a transmission line and setting the optimum initial value of an automatic equalizer without being affected with the sampling phase. CONSTITUTION:A timer 2 is started by an input test signal, a generator 3 is triggered, and a clock having the length L times a symbol rate 1/T or more is generated. On the other hand, a signal delayed 4 by a half of the base band signal and of an interval T is sample-held at 6, 7, and a symbol series generated at a generator 8 is multiplied 9, 10 respectively by the hold output, added at 11, 12 to the output of M-stage shift registers 13, 14 and inputted again to the registers 13, 14. The content of the registers 13, 14 is inputted to a latch 15 of the 2M- stage register at the same time when the timer 2 stops the generator 3, after being synthesized, it is multiplied by 1/L at 16, converted at 17 into a frequency region, and the stored corresponding value 19 is divided at 18, the result of division is converted at 20 and given as the tap gain initial value of an automatic equalizer 21. |
