Demapper for rotated QAM constellations
US8811539B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2012 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Feb 2, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/38
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method includes receiving a symbol modulated with multiple bits according to a signal constellation including multiple constellation points. A soft metric is computed for a given bit in the symbol: A first constellation point closest to the received symbol according to a distance measure is found. A row or column of the constellation points, which is closest to the first constellation point according to the distance measure, and over which a value of the given bit is constant and is opposite to the value of the given bit in the first constellation point, is identified. At least the identified row or column is searched for a second constellation point that is closest to the received symbol according to the distance measure. The soft metric is calculated based on the first and second constellation points. The value of the given bit is reconstructed based on the soft metric.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.