Patent Number: 6,295,316

Title: Automatic equalization system

Abstract: An automatic equalization system includes an analog-to-digital converter for periodically sampling an analog signal representative of digital information in response to a sampling clock signal, and for converting every sample of the analog signal into a corresponding digital sample to convert the analog signal into a corresponding digital signal. A first device operates for detecting a phase error of the sampling clock signal in response to a correlation between samples of the digital signal generated by the analog-to-digital converter. A second device operates for controlling a frequency of the sampling clock signal in response to the phase error detected by the first device. A variable filter operates for subjecting the digital signal generated by the analog-to-digital converter to a variable filtering process to convert the digital signal generated by the analog-to-digital converter into a filtering-resultant signal. The filtering process corresponds to a waveform equalization process. A third device operates for detecting an amplitude error of the digital signal generated by the analog-to-digital converter in response to a correlation between samples of the filtering-resultant signal generated by the variable filter. A fourth device operates for controlling the filtering process implemented by the variable filter in response to the amplitude error detected by the third device. The analog-to-digital converter, the first device, and the second device compose a phase locked loop while the variable filter, the third device, and the fourth device compose an amplitude error correcting loop separate from the phase locked loop.

Inventors: Tonami; Junichiro (Yokohama, JP), Kiyofuji; Takashi (Yokohama, JP)

Assignee: Victor Company of Japan, Ltd.

International Classification: G11B 20/10 (20060101); H04L 25/497 (20060101); H03L 7/08 (20060101); H04L 25/03 (20060101); H03L 7/091 (20060101); G11B 20/22 (20060101); H03H 007/40 ()

Expiration Date: 09/25/2018