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:
Oct. 20, 2015
Filed:
Feb. 20, 2009
Marco Secondini, Rome, IT;
Enrico Forestieri, Parma, IT;
Marco Secondini, Rome, IT;
Enrico Forestieri, Parma, IT;
TELEFONAKTIEBOLAGET L M ERICSSON (PUBL), Stockholm, SE;
Abstract
An equalizer () processes, in the electrical domain, a signal obtained from a path of an optical transmission system. The equalizer comprises N cascaded stages (where N≧1). At least one of the stages comprises a cascade of a linear equalization element () and a non-linear equalization element (). The equalizer () is able to compensate for both linear impairments, such as dispersion, and non-linear impairments. The cascaded linear and non-linear elements can simulate the effect of signal propagation through a fiber which has the opposite propagation parameters (e.g. attenuation, dispersion, non-linearity) to those of the propagation path experienced by a signal in the transmission system. The non-linear equalization element () can be a non-linear phase rotator which rotates phase of an input signal proportional to the squared modulus of the input signal amplitude. The linear equalization element () can comprise a digital filter, such as an Infinite Impulse Response (HR) filter or a Finite Impulse Response (FIR) filter.