Doppler correction and path loss compensation for airborne cellular system
US6675013B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2000 |
| Grant date | Jan 6, 2004 |
| Priority date | — |
| Expiry date | Jan 12, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/18504
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention corrects for Doppler shift in both forward and reverse links in a cellular communications system including an airborne repeater. A reverse link pilot reference signal in a band similar to a communications signal band is received at a reverse link processor, and the Doppler shift in the reverse feeder link is corrected based on the reverse link pilot reference signal. The Doppler shift in the forward feeder link is also corrected based on the reverse link pilot reference signal prior to the forward feeder link being affected by the Doppler shift. The present invention also compensates for signal strength variations due to changing flight pattern positions of the repeater. Pre-compensation for forward feeder link path losses due to movement of the airplane is performed to cause communications signals transmitted to and from the cellular communications system repeater to have identical strength before the signals are transmitted to the system user cell phones within the area of coverage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.