| 摘要 |
PURPOSE:To control the MODEM so that the state is transited from the divergence state, the divergence process and the quasi-steady-state into the steady- state at all times by changing a coefficient converging speed relating to equalizer coefficient revision calculation after refreshing so as to quicken the coefficient converging speed when a steady-state signal is inputted after an external disturbance. CONSTITUTION:The system is provided with an A/D converter 1, a QAM (orthogonal amplitude modulation) demodulator 2, a low pass filter (LPF) 3, an equalizer (EQ) 4, a timing estimate device, an arithmetic section 6 for evaluation and state measure, a control section (CPU) 7, a timing buffer 8, a phase estimate buffer 9, a phase estimate section 10, a phase rotating device 11, a discriminator (QUA) 12, a phase rotating device 13, an equalizer (EQ) buffer 14, and a decoder 15. In this case, the coefficient converging speed when a steady-state signal is inputted after an external disturbance is quickened by changing a coefficient converging speed relating to equalizer coefficient revision calculation after refreshing. Thus, the divergence of the MODEM operation is easily prevented and the convergence after production of an external disturbance is quickly realized. |
