| 摘要 |
PURPOSE:To enhance the stability of an aqualizer, by carrying out a learning process when a turn-on sequence is detected and then carrying out automatic equalization when no turn-on sequence is detected respectively in a state under which a carrier wave detecting circuit is detecting an arrival of the carrier wave. CONSTITUTION:A switch 5 works by the detection signal delivered from a turn-on sequence detecting circuit 10, and thus the result of decision of a learning utilizing circuit is supplied to a subtractor 6. The subtractor 6 calculates an error between the result and the output of equalization and supplies the result of calculation to a correlator 7 in the form of an error signal. The correlator 7 obtains correlation between the error signal and the received signal stored in a memory 1 and then sends a correction signal to a coefficient device 8 to give correction to the coefficient of an equalizer. Thus the gain of the unit 8 is set large in the turn-on sequence to ensure a high-speed completion of leaning. Then the switch 5 is released when the turn-on sequence is through and a transmission of data is started, and thus automatic equalization is carried out based on the result of decision given from a deciding circuit 3. |
