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:
Dec. 10, 2019
Filed:
Apr. 30, 2018
Nokia Solutions and Networks Oy, Espoo, FI;
Nokia Solutions and Networks OY, Espoo, FI;
Abstract
A coherent optical receiver in which the channel equalizer and the clock-recovery circuit are connected in a nested-loop configuration, wherein the channel estimate generated by the equalizer is used to adjust the phase of the clock signal generated by the clock-recovery circuit. The channel equalizer can be implemented using a bank of time-domain or frequency-domain FIR filters. In an example embodiment, the clock-recovery circuit is configured to track the phase rotation corresponding to the equalized signals in a frequency-dependent manner; track the phase rotation in the channel equalizer either in a frequency-dependent manner or based on the mean signal delay therein; and adjust the phase of the clock signal based on an effective difference between these two phase rotations. The clock-recovery circuit enhances the clock tone by applying a Fourier transform to the squared absolute values of the equalized signals outputted by the channel equalizer.