QAM de-mapping circuit
US6226333A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 3, 1998 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Aug 3, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/38
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
According to the invention, information from a differential decoder (1) receiving the MSB of the in-phase component and the MSB of the quadrature component is used to derotate the LSBs of the in-phase component and the LSBs of the quadrature component into the first quadrant with a rotator (2). Then only one quadrant is demapped by a single quadrant demapper (3). Thereby, the look-up table necessary for the demapping circuit is reduced considerably. The output signal of the QAM de-mapping circuit is build from the demapped LSBs of the in-phase and quadrature components output by the single quadrant demapper (3) and the outputs of the differential decoder (1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.