GMSK modulator formed of PLL to which continuous phase modulated signal is applied
US5825257A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1997 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Jun 17, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2039
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A Gaussian Minimum Shift Keying modulator that provides direct modulation of a carrier signal, produced by a single microwave high power voltage controlled oscillator. A continuous phase frequency shift keyed modulated signal with a modulation index of 0.5 is produced at the desired output frequency using a full 360 degree linear continuous phase modulator, controlled by a linear baseband signal that is the integral of the binary baseband information signal. This modulated signal is used as the reference signal for a phase locked high power voltage controlled oscillator. The phase locked loop provides frequency tracking and Gaussian spectral shaping to the modulated output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.