Automatic frequency correction
US8483322B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 2008 |
| Grant date | Jul 9, 2013 |
| Priority date | — |
| Expiry date | Aug 31, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0091
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A receiver front end receives a local frequency reference signal and a Frequency Shift Keying modulated signal comprising a synchronisation sequence, and downconverts the Frequency Shift Keying modulated signal to provide baseband in-phase and quadrature signals. A pulse generator receives the in-phase and quadrature signals, generates an in-phase pulse signal ILEAD comprising pulses aligned with edges of the baseband in-phase and quadrature signals when the baseband in-phase signal leads the baseband quadrature signal, and generates a quadrature pulse signal QLEAD comprising pulses aligned with edges of the baseband quadrature and in-phase signals when the baseband quadrature signal leads the baseband in-phase signal. A frequency corrector receives the in-phase and quadrature pulse signals during receipt of the synchronisation sequence, compares the pulse signals to a target, and generates a control signal for controlling the local signal generator in dependence upon the result of the comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.