Digital time alignment in a polar modulator
US7042958B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2003 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Jun 4, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C5/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods of and apparatus for digitally controlling, with sub-sample resolution, the relative timing of the magnitude and phase paths in a polar modulator. The timing resolution is limited by the dynamic range of the system as opposed to the sample rate. The methods and apparatus of the invention use a digital filter to approximate a sub-sample time delay. Various techniques for approximating a sub-sample time delay using digital signal processing may be used to achieve the approximation. Ideally, the filter will have an all-pass magnitude response and a linear phase response. In practice, the magnitude may be low-pass and the phase may not be perfectly linear. Such deviation from the ideal response will introduce some distortion. However, this distortion may be acceptably small depending on the particular signal being processed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.