Bit log likelihood ratio evaluation
US7660368B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 2006 |
| Grant date | Feb 9, 2010 |
| Priority date | — |
| Expiry date | Oct 2, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2001/0098
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method are provided for generating bit log likelihood ratio (LLR) values for two-layered Quadrature Phase-Shift Keying (QPSK) turbo decoding in a wireless communications user terminal (UT). The method includes receiving a two-layered QPSK signal with an energy ratio that is unknown, but typically defined as either k12 or k22. The method selects a mismatched energy ratio (k2) between k12 and k22, and generating bit LLR values for two-layered QPSK turbo decoding, using the mismatched k2 energy ratio. For example, if the received two-layered QPSK signal is known to have an energy ratio of about 4 or about 6.25. Then, k2 is selected to be about 5.0625. Alternately stated, the mismatched k2 energy ratio in selected by determining the approximate midpoint between k12 and k22.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.