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:
Jan. 15, 2008
Filed:
Aug. 29, 2002
Nikolai Schlegel, San Diego, CA (US);
Christian Holenstein, San Diego, CA (US);
Daniel Filipovic, Solana Beach, CA (US);
Nitin Kasturi, Los Gatos, CA (US);
Nikolai Schlegel, San Diego, CA (US);
Christian Holenstein, San Diego, CA (US);
Daniel Filipovic, Solana Beach, CA (US);
Nitin Kasturi, Los Gatos, CA (US);
QUALCOMM, Incorporated, San Diego, CA (US);
Abstract
An apparatus for coarse compensation of a direct current (DC) offset in a direct to baseband receiver architecture utilizes a serial analog to digital converter (ADC), such as a Delta-Sigma converter, to convert the received signal to digital form. The output of the ADC is sampled for a predetermined number of samples and a counter coupled to the ADC is incremented each time the sample generated by the ADC is a logic one. The counter is not incremented if the sample from the ADC is a logic zero. After the predetermined number of samples is obtained, the counter value is indicative of the DC offset in the received signal. The counter value may be converted by a code converter to a correction value for easy operation of a digital to analog converter (DAC). If the number of samples from the ADC is a power of two, the code converted may be readily implemented by simply inverting the most significant bit (MSB) from the counter to thereby generate a twos complement version of the counter value. The correction value is coupled to the DAC to generate a compensation signal, which is provided to the received signal path in the form of a feedback signal to compensate for the DC offset.