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.

Dependencies are inferred from the claim text.