Bulk despreading of multiple independent CDMA sources
US6091703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1997 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Oct 10, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communications system (100) is disclosed for processing at least one uplink channel contained in at least one uplink beam (112) transmitted to a satellite (106). The communications system (100) includes at least one user terminal (110) that extracts a system clock, a synchronization word, and timing correction information from a downlink beam transmitted by a satellite. The user terminal includes a timing controller (226) that aligns uplink channel transmissions by generating a system clock based on the downlink symbol clock, said synchronization word, and said timing correction information. The user terminal includes at least one spread-spectrum spreader (254) for encoding at least one uplink channel, and a transmitter connected to the spread-spectrum spreader (254) for transmitting said at least one uplink channel in an uplink beam (112). The system also includes a satellite (106) which generates the synchronization word, downlink symbol clock, and the timing correction information needed by the user terminal. The satellite also includes a wideband FFT processor (322) that extracts uplink channels from the uplink beam (112) in bulk, and a despreader (326) connected to the FFT p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.