| 摘要 |
PURPOSE:To prevent deterioration in the resolution without attenuating a high frequency signal different from a conventional device by adopting the method selecting a filter whose amplitude frequency characteristic is unchanged for eliminating ringing. CONSTITUTION:A reception reference waveform signal yj is extracted from a reception signal by a gate circuit 30. The obtained signal yj is stored in a memory 31. On the other hand, a reference waveform signal xj is stored in a memory 32 in advance. An impulse response coefficient hj is obtained from the obtained signals yj, xj at a polynomial divider 33 by using equation. The obtained coefficient hj is processed to be a symmetrical coefficient as (hj+hL-j)/2 at a symmetry processing computing element 34. Moreover, a front ringing portion of the impulse response of the symmetrical coefficient filter is expanded to point-symmetry with respect to the center of the response to obtain a point- symmetry coefficient by using a point symmetry processing computing element 35. The obtained symmetry coefficient and point-symmetry coefficient are given to a symmetry coefficient filter 21 and a point-symmetry coefficient filter 22 to build up a ringing elimination device with the same coefficient as a transfer function of the transmission line at a receiver side. |
