Modulation system for modulating data onto a carrier signal with offsets to compensate for doppler effect and allow a frequency synthesizing system to make steps equal to channel bandwidth
US7167528B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2002 |
| Grant date | Jan 23, 2007 |
| Priority date | — |
| Expiry date | Apr 5, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C3/403
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator. This signal has a frequency including an offset that allows the frequency synthesizing system and intermediate frequency modulator to make frequency steps equal to the channel bandwidth. The offset can also include a small offset that compensates for the Doppler effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.