Demodulator
US6442218B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1999 |
| Grant date | Aug 27, 2002 |
| Priority date | — |
| Expiry date | Aug 19, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03114
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a demodulator which receives a signal transmitted via phase modulation or multivalue QAM modulation, and decides transmitted data based on the received signal. The present invention enhances a transmission-line estimate by using tentatively decided data symbols as pilot symbols and in estimating a transmission line without a decrease in accuracy of transmission-line estimate even when an error rate of the tentatively decided data symbols is increased. The demodulator includes a pilot-based transmission-line estimation unit for estimating transmission-line characteristics by using pilot symbols. A tentative-data-decision unit for tentatively deciding data symbols based on the pilot-based transmission-line estimate. A data-based transmission-line estimation unit for estimating the transmission-line characteristics by using the tentatively decided data. Weight-coefficient-multiplication units for multiplying pilot-based and data-based transmission-line estimates by respective weights having a ratio therebetween varying in accordance with reliability of the tentatively ascertained data. A pilot&data-based transmission-line estimation unit for obtaining …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.