Doppler insensitive non-terrestrial digital cellular communications network
US6377802B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Dec 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The Doppler insensitive non-terrestrial digital cellular communications network ensures that, independent of the aircraft direction and apparent velocity of the mobile subscriber station, at least one and very likely two cells/antennas, carry the call even though other cells/antennas in the non-terrestrial digital cellular communications network encounter an apparent velocity of the mobile subscriber station which disables system operation. Since the architecture of the non-terrestrial digital cellular communications network and the non-terrestrial communication application have a common element, namely altitude, it is also possible to minimize the Doppler/capacity problem by segmenting the non-terrestrial space into layers, or PN code words. This topology makes use of spatial diversity in the elevation plane, or “Z direction” to ensure that at least one and very likely two layers, can carry the call. Each layer in the cell is formed by an antenna beam, having different system configurations to preset the level of soft hand-off. Spatial diversity within the cell site can also be implemented in the “X & Y directions”, or azimuthally. This is accomplished by i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.