Sample timing control for demodulation of phase-modulated signals
US6665356B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1999 |
| Grant date | Dec 16, 2003 |
| Priority date | — |
| Expiry date | Jun 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0334
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A phase-modulated signal such as a quadrature phase-shift-keyed (QPSK) signal in a wireless communication system is demodulated using sample timing based at least in part on frequency information generated by frequency demodulating the phase-modulated signal. The phase-modulated signal is separated into first and second portions, the first portion is phase demodulated to generate demodulated symbols, and the second portion is frequency demodulated to generate, e.g., a measure of the instantaneous frequency of the phase-modulated signal. The instantaneous frequency measure is processed to identify one or more symbol transitions, and the identified transitions are used to establish the sample timing such that proper sampling of the symbols is ensured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.