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.

Date of Patent:
Feb. 26, 2019

Filed:

Jan. 24, 2018
Applicant:

National Instruments Corporation, Austin, TX (US);

Inventors:

Michael Löhning, Dresden, DE;

Eckhard Ohlmer, Dresden, DE;

Assignee:
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04L 1/00 (2006.01); H04L 7/00 (2006.01); H04L 27/227 (2006.01); H04L 25/03 (2006.01);
U.S. Cl.
CPC ...
H04L 27/2278 (2013.01); H04L 1/00 (2013.01); H04L 7/00 (2013.01); H04L 7/0012 (2013.01); H04L 7/0029 (2013.01); H04L 7/0087 (2013.01); H04L 7/0091 (2013.01); H04L 25/03057 (2013.01);
Abstract

A post-equalization phase tracking unit, for each signal block of a received series: computes beginning absolute phase rotation using equalized preceding pilot symbols; subdivides the block into a time sequence of groups of equalized symbols; initializes accumulated phase associated with the first-in-time group with the absolute phase rotation. For each group, the unit: computes a de-rotated version of each symbol using the previous group's accumulated phase used to blindly estimate a residual group phase; assigns the group's accumulated phase with a sum of the group's residual phase and the previous group's accumulated phase; estimates phase drift within the group by using at least the group's accumulated phase to compute a phase compensation signal. A pre-equalization phase tracking unit computes a phase of autocorrelation between identical-as-transmitted initial/terminal sequence portions; estimates a start phase using the autocorrelation phase and the previous signal block start phase; interpolates start phases to estimate phase drift.


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