Multiple access communication system
US5119225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1989 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Jan 18, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64G1/1085
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A multiple access communications system comprises a node spacecraft GEO and several user spacecraft LEO.sub.1 to LEO.sub.n. Each user spacecraft LEO.sub.1 to LEO.sub.n includes a transmit/receive terminal head 18.sub.1 to 18.sub.n, and the node spacecraft GEO includes n transmit/terminals 22 to 22.sub.n and a single beacon unit 24. The beacon beam may be operated to initiate acquisition phases which allow two-way communication to be established between the transmit/receive terminals 22.sub.1 to 22.sub.n on the node spacecraft and the transmit/receive terminals 18.sub.1 to 18.sub.n on the corresponding user terminals. The acquisition phases include a period during which the beacon scans an uncertainty cone associated with the node spacecraft. This scanning period is reduced for second and subseqeunt acquisitions by using the first and subsequently acquired communication links to provide a more accurate estimate of the angular attitude of the node spacecraft, thus reducing the extent of the uncertainty cone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.