Method and apparatus for performing soft demapping in rotated quadrature amplitude modulation (QAM) based communication system
US9203681B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 2014 |
| Grant date | Dec 1, 2015 |
| Priority date | — |
| Expiry date | Oct 20, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/067
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of performing a soft demapping, includes obtaining a signal from a symbol representing bits that is transmitted from a transmitter, and calculating a gradient of a reference line in a constellation for a bit based on a rotation angle and a channel state of the constellation. The method further includes selecting a candidate for each of lines that corresponds to a logic value of the bit from constellation points included in the constellation based on the signal and the gradient of the reference line, and calculating a log-likelihood ratio (LLR) of the bit based on the signal and the selected candidate for each of the lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.