Closed loop transmitter IQ calibration
US8175549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 2008 |
| Grant date | May 8, 2012 |
| Priority date | — |
| Expiry date | Feb 6, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B17/10
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A novel and useful apparatus for and method of closed loop IQ calibration for use in a transmitter. The IQ calibration mechanism functions to provide calibration of IQ imbalance in the presence of real world RF impairments. An iterative process is used to update the gain and phase mismatch values whereby the metrics are calculated in a differential manner without the need for calculation absolute imbalance values. At each iteration, updating the gain and phase mismatch estimate requires only the direction of the correction to be determined. The direction of the correction is calculated using only the differences between output power measurements. The updated gain and phase mismatch estimates are used to update an IQ correction matrix. This process is repeated until a desired stopping criterion is reached. Gear shifting is used to ensure quick convergence of the algorithm while providing the ability to achieve any desired level of accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.