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:
Apr. 19, 2011
Filed:
Sep. 11, 2006
Yuri Okunev, Middle Island, NY (US);
Yuri Okunev, Middle Island, NY (US);
Symbol Technologies, Inc., Holtsville, NY (US);
Abstract
The present invention provides methods and apparatuses for demodulation and decoding of backscattered 16-QAM RFID tag signals, represented by their in-phase and quadrature components at the output of the demodulator in the receiver portion of a reader interrogator. In a communication channel with fast changing parameters, a reader receiver adaptively and coherently corrects the in-phase and quadrature-phase components of a signal received from a tag by tracking the phase and amplitude of the signal based on a decision-feedback. A reference signal is used to correct the signal components, where the coordinates of the reference signal is updated by a tracking and an averaging algorithm. A simple implementation of the receiver in a digital signal processing environment is enabled.