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:
Jun. 19, 2001
Filed:
Apr. 17, 2000
Khaled Maalej, Paris, FR;
Emmanuel Hamman, Paris, FR;
Amaury Demol, Paris, FR;
Yannick Levy, Paris, FR;
Atmel Corporation, San Jose, CA (US);
Abstract
A QAM demodulator having a carrier recovery circuit that includes a phase estimation circuit and an additive noise estimation circuit which produces an estimation of the residual phase noise and additive noise viewed by the QAM demodulator. The phase noise estimation is based on the least mean square error between the QAM symbol decided by a symbol decision circuit and the received QAM symbol. The additive noise estimation is based on the same error as in the phase noise estimation, except that it is based only on QAM symbols having the minimum amplitude on the I and Q coordinates. The additive noise estimation is not dependent on the phase of the signal, thus, is independent of the phase noise estimator.