Constrained clipping for peak-to-average power ratio (crest factor) reduction in multicarrier transmission systems
US7944991B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2006 |
| Grant date | May 17, 2011 |
| Priority date | — |
| Expiry date | Jan 30, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2623
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Disclosed is a constrained clipping technique for reducing the peak-to-average power ratio (PAR) or crest factor of a multicarrier communications signal. This is a transmitter-side processing technique that does not impose any modification at the receiver. Constrained clipping achieves PAR reduction while simultaneously satisfying spectral mask and error vector magnitude (EVM) constraints that are specified by most modern communications standards. The constrained clipping technique includes two independent processing units, one to satisfy an in-band EVM constraint and the other to satisfy an out-of-band spectral constraint. Achievable PAR reduction results vary depending on a particular standard's requirements, but by using constrained clipping on a QPSK WiMax signal with 256 subcarriers, for example, a 4.5 dB PAR reduction at the 10−2 complementary cumulative distribution function (CCDF) level can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.