Method for reducing spectral regrowth in a spectrally efficient digital modulation scheme
US7970091B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 2007 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Jan 27, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/26265
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method that uses time-domain processing on a spectrally efficient digital modulation scheme to reduce the bandwidth expansion in envelope elimination and restoration (EER) amplifiers is disclosed. The method identifies and localizes sections of the signal responsible for the out of band emissions, or spectral regrowth, using a filter. The detected sections are flagged and extended to allow for introduction of a lower frequency transition in place of the extended section, thus reducing spectral regrowth from the output of an EER amplifier. The method is particularly useful for improving the quality of digital AM radio transmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.