Radio method and apparatus for gathering and processing information coming from a plurality of stations
US4398286A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1980 |
| Grant date | Aug 9, 1983 |
| Priority date | — |
| Expiry date | Jul 7, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/1851
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a satellite which asynchronously receives radio frequency signals from a lurality of beacons scattered at the surface of the earth, each signal received has a pure carrier wave portion followed by a phase modulated message carrying portion. The frequencies of the signals are not known within a predetermined frequency band. The satellite has a plurality of essentially identical processing units which each receive on their input all the signals present at any given instant in the input frequency band. Each processing unit has a phase locked loop which may be progressively tuned to the frequency of one of these input signals in response to a frequency estimate of this signal to which the operating frequency of the phase locked loop is preset. This frequency estimate is updated until the phase lock occurs on this input signal, ready for demodulation of the message part to begin. The estimate frequencies are derived from an input band frequency spectrum analyzer. A command unit selectively allocates each new frequency estimate to a respective processing unit as a result of a comparison therof with the previously allocated frequency estimates to accelerate the tuning of the processing…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.