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. 26, 2007
Filed:
Dec. 18, 2001
Kalle Asikainen, Pirkkala, FI;
Tomi-pekka Takalo, Pirkkala, FI;
Kalle Asikainen, Pirkkala, FI;
Tomi-Pekka Takalo, Pirkkala, FI;
Nokia Corporation, Espoo, FI;
Abstract
The invention relates to a direct conversion receiver and a method in a direct conversion receiver for processing received radio signals that are modulated and centered at a carrier frequency, the modulation extending a sideband above and below the carrier frequency. The method comprises the steps of mixing a local oscillator frequency signal with said received radio signals for generating baseband frequency signals; filtering out generated disturbing direct current (DC) components of said baseband signals centered at the zero frequency; setting said local oscillator frequency signal equal to or about the carrier frequency plus an offset frequency, said offset frequency being equal to the difference between the carrier frequency and a null frequency, said null frequency centered at a notch of said sideband; and centering said notch at the zero frequency of said baseband signals through mixing. The invention relates particularly to suppression of DC offsets generated in the receivers.