Simple detector and method for QPSK symbols
US7123668B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 2002 |
| Grant date | Oct 17, 2006 |
| Priority date | — |
| Expiry date | Aug 10, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0054
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A simplified Viterbi detector for maximum likelihood detection of nine-bit QPSK symbols, employing a difference metric and two comparators, instead of using two state metrics and four comparators. The detector is used to process the outputs of synchronously sampled matched filters. A multiplexer is employed to select the difference metric from amongst the input sample, the fed back value of the difference metric itself, or the inverses of either, depending on decision signals output from the comparators, which in turn compare the difference metric with the input sample and it's inverse. The even path history then represents the most likely value of the detected symbol.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.