Digital frequency measurement system and method with automatic frequency control
US7352831B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 2004 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Jun 27, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/144
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital frequency measurement system including first and second digital differentiators responsive to first and second digital quadrature signals representative of first and second quadrature modulated input signals that represent binary data having a center frequency equal to a predetermined IF frequency for generating first and second differentiated signals, first and second processing circuits responsive to the first and second digital quadrature signals representative of the modulated input signals and the first and second differentiated signals for multiplying the first differentiated signal by the second quadrature digital representation of the input signals and multiplying the second differentiated signal by the first quadrature digital representation of the input signals to provide first and second multiplied signals, a combining circuit responsive to the first and second multiplied signals for generating a density signal having a pulse density proportional to the frequency of the input signals, a digital filter responsive to the density signal for providing an output signal representing the average value of the pulse density, and an envelope detector circuit responsive t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.