Communication satellite system having an increased power output density per unit of bandwidth
US5208829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1991 |
| Grant date | May 4, 1993 |
| Priority date | — |
| Expiry date | Mar 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A satellite communication system for providing maximum power output in a spread spectrum signal transmission is disclosed. Spectral shaping is provided at a satellite transmitter to shape a spread spectrum so that over a bandwidth of interest, the spectrum has a maximally flat characteristic. By maximizing the spectrum amplitude flatness, the required power density for a bandwidth limitation imposed to prevent interference with other communication facilities is maintained. In each earth station receiving the transmission from the satellite, a filtering is provided of the demodulated baseband satellite signal such that the spectrum is restored to its original shape. The filters on the receive side may be analog, having the same amplitude function as the transmit spectrum shaping filter, but having an inverse phase response. This insures a matched filter condition at transmitter and receiver, maximizing signal transfer. A programmable demodulator is provided to select a demodulation mode. The programmable demodulator may receive microcode from a microprocessor configuring the PLA into a despreader, demodulator for spread spectrum applications or as a straight BPSK demodulator where t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.