The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 1989
Filed:
Jun. 30, 1988
Ephraim Arnon, Ottawa, CA;
Sami Aly, Kanata, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
Apparatus for suppressing intersymbol interference and improving the signal-to-noise ratio in a digital line amplifier includes a filter with a fixed transfer function that couples equalized digital signals to a first differential input of a difference amplifier and substantially filters out high frequency random noise present in the signals to achieve signal-to-noise enhancement with consequent degradation of the signals by intersymbol interference. Subsequently, an output from the amplifier is sampled by a quantizer that produces a bit stream output of portions of the enhanced signals, excluding the intersymbol interference. Signals from the bit stream are then coupled to a fixed coefficient decision feedback equalizer having the same transfer function as the filter and are output therefrom as feedback signals to a second differential input of the amplifier such that the signals at both differential inputs are substantially equal in terms of intersymbol interference, thereby suppressing such interference in the amplifier output.