Methods and apparatus for reducing modulation signal bandwidth in polar modulation transmitters
US8077770B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2008 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Oct 3, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/367
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for reducing the bandwidth of modulation signals in a phase path of a polar modulation transmitter. An exemplary method includes generating a phase difference modulation signal for a phase path of a polar modulation transmitter, and filtering the phase difference modulation signal using a linear-phase filter. Filtering the phase difference modulation signal may be performed by first detecting samples in the phase difference modulation signal that have phase difference values in excess of a phase difference threshold and then filtering samples in the vicinity of the threshold-violating samples to remove the threshold-violating events. Alternatively, all samples may be filtered, i.e., without regard as to whether any given sample exceeds a phase difference threshold, to remove large phase difference changes in the phase difference modulation signal, or a combination of linear-phase and nonlinear filters may be used to remove the large phase difference changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.