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:
Mar. 30, 2004
Filed:
Jan. 10, 2003
Jarmo Mäkinen, Espoo, FI;
Nokia Telecommunications Oy, Espoo, FI;
Abstract
Method measures imperfections in the digital quadrature demodulator from the amplitude of the output signal of the demodulator quadrature mixer, i.e. from the amplitude of a vector formed by the I and Q channels, are taken, at a rate based on a symbol clock of the demodulator, numerous momentary samples; a direction angle of the demodulator output signal vector corresponding to the samples is divided, on the basis of the voltages of the I and Q channels, into different direction angle sectors; and direction angle sectors or from a nominal value are calculated the magnitudes of the distortions in the demodulator operation. The method advantageously also includes a step wherein the measurement results of the imperfections in the demodulator operation are used for adjusting the operation of the demodulator by generating feedback loops, which correct all the imperfections simultaneously in an iterative manner.