DC offset correction for very low intermediate frequency receiver
US7277688B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2004 |
| Grant date | Oct 2, 2007 |
| Priority date | — |
| Expiry date | Oct 27, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/008
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A wireless receiver includes a local oscillator, a mixer, a band pass filter, a DC offset determination module, a DC offset correction module, a subtraction module, and a down converter. The local oscillator produces a local oscillation that a mixer uses to down convert the RF information signal to produce a Very Low Intermediate Frequency (VLIF) information signal at a VLIF and having a DC offset. The band pass filter band pass filters the VLIF information signal. The DC offset determination module produces a DC offset indication for the VLIF information signal. The DC offset correction module generates a DC offset correction based upon the DC offset indication. The subtraction module subtracts the DC offset correction from the VLIF information signal to substantially remove a DC offset of the post-filtered VLIF information signal. The down converter down converts the VLIF information signal to a baseband information signal. In an alternate embodiment, the VLIF information signal is down converted to baseband prior to removal of the DC offset component, which then resides at −VLIF frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.