Multimedia two-way communication terminal

• US 6,801,768 B2
• Filed: 11/09/2001
• Issued: 10/05/2004
• Est. Priority Date: 05/10/1999
• Status: Expired due to Fees

• Current Assignee: Centre National D'Etudes Spatiales
• Original Assignee: Centre National D'Etudes Spatiales
• Inventors: Sirmain, Christian, Gleyzes, Yves-Paul
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): CHOW, CHARLES CHIANG
• Application Number:
  US09/986,610
• Publication Number:
  US 20020028654A1
• Time in Patent Office: 1,061 Days
• Field of Search: 455/25, 455/12.1, 455/19, 455/3.02, 455/13.1, 455/562, 455/427, 455/428, 455/129, 455/121, 455/194.1, 455/550, 455/1, 455/430, 455/13.2, 455/13.3, 342/359, 342/352, 342/422, 342/374, 342/56, 342/74, 342/75-77, 342/357, 343/757, 343/781, 343/839, 343/840, 343/779, 343/870, 343/765, 370/320, 370/321
• US Class Current: 455/430
• CPC Class Codes: H04B 7/18571 for satellites; for fixed or mobile stations
• CPC Class Codes: H04B 7/18597 Arrangements for system physical machines management, i.e. for construction, operations control, administration, maintenance

Abstract

A bidirectional multimedia communication terminal with two orientable antennas for sending/receiving radio signals conveying multimedia data, electronic signal processors for processing signals received/sent via the antennas, a pointing system for pointing each antenna at a predetermined satellite from a constellation of non-geostationary satellites forming part of a multimedia telecommunication system, and a switching system for selectively switching the transmission of multimedia data between the terminal and the satellites of the constellation from the satellite at which one of the antennas is pointed to the satellite at which the other antenna is pointed. The pointing system includes an antenna orientation unit associated with each antenna and a control unit for controlling the orientation units on the basis of data on the position of the terminal in a frame of reference tied to the Earth and on ephemerides of visible satellites of the constellation.

Claims

1. A bidirectional multimedia communication terminal comprising two orientable antennas for sending/receiving radio signals conveying multimedia data, an electronic signal processor for processing signals received or to be sent via said antennas, a pointing system associated with each antenna for pointing the respective antenna at a predetermined satellite from a constellation of non-geostationary satellites forming part of a multimedia telecommunication system, and a switching system for selectively switching the transmission of multimedia data between the terminal and the satellites of said constellation from a satellite at which one of said antennas is pointed to another satellite at which the other antenna is pointed, so as to guarantee continuous transmission of a data stream between said terminal and said constellation, said pointing system including an antenna orientation unit associated with each antenna and a control unit for controlling said orientation units on the basis of data on the position of said terminal in a frame of reference tied to the Earth and on ephemerides of visible satellites of said constellation supplied by a mission center of said constellation, said terminal further including a terminal positioning system for delivering said data on the position of said terminal.

2. The terminal claimed in claim 1 wherein a GPS constellation supplies terminal position and time data to said control unit.

3. The terminal claimed in claim 1 wherein said frame of reference tied to the Earth is defined by a geostationary satellite.

4. The terminal claimed in claim 1 including connection and interface means with a personal or business computer and with a video camera and/or a modem.

5. The terminal claimed in claim 1 wherein said electronic signal processor includes, for receiving signals sent by a satellite of said constellation, a cascade of frequency step-down devices, a plurality of frequency amplifiers each associated with one of said frequency step-down devices, and a receiver/demodulator for demodulating and communicating signals transmitted in this way.

6. The terminal claimed in claim 5 including means for compensating the Doppler effect on the signals sent or received.

7. The terminal claimed in claim 1 wherein said electronic signal processor includes, for sending signals to a satellite of said constellation, a cascade of frequency step-up devices, a plurality of frequency amplifiers each associated with one of said frequency step-up devices, and a modulator for modulating and communicating signals to be sent.

8. The terminal claimed in claim 1 wherein said antennas are protected by a common radome and the system consisting of said radome, said antennas, said orientation units and part of said electronic signal processor means constitutes an autonomous and mobile system.

9. The terminal claimed in claim 1 wherein said electronic signal processor includes means of adaptation to specific frequency bands.

10. The terminal claimed in claim 1 wherein said terminal positioning system is built into said terminal and includes an antenna for receiving GPS signals sent by satellites of a GPS constellation, an electronic circuit card for processing said GPS signals, and an interface for communication with said control unit.

11. A bidirectional multimedia communication terminal comprising:

two orientable antennas for sending/receiving radio signals conveying multimedia data;

an electronic signal processor for processing signals received or to be sent via said antennas;

an antenna orientation unit associated with each antenna for pointing the respective antenna at a predetermined satellite from a constellation of non-geostationary satellites forming part of a multimedia telecommunication system;

a control unit for controlling said orientation units on the basis of data on the position of said terminal in a frame of reference tied to the Earth and on ephemerides of visible satellites of said constellation of non-geostationary satellites;

means for receiving said ephemerides from a mission center and for transmitting them to said control unit;

a switching system for selectively switching the transmission of multimedia data between the terminal and the satellites of said constellation from a satellite at which one of said antennas is pointed to another satellite at which the other antenna is pointed, so as to guarantee continuous transmission of a data stream between said terminal and said constellation; and

a terminal positioning system for delivering said data on the position of said terminal, said positioning system being built into said terminal and including an antenna for receiving GPS signals sent by satellites of a GPS constellation, an electronic circuit card for processing said GPS signals, and an interface for communication with said control unit.

12. The terminal claimed in claim 11 wherein said frame of reference tied to the Earth is defined by a geostationary satellite.

13. The terminal claimed in claim 11 including connection and interface means with a personal or business computer and with a video camera and/or a modem.

14. The terminal claimed in claim 11 wherein said electronic signal processor includes, for receiving signals sent by a satellite of said constellation, a cascade of frequency step-down devices, a plurality of frequency amplifiers each associated with one of said frequency step-down devices, and a receiver/demodulator for demodulating and communicating signals transmitted in this way.

15. The terminal claimed in claim 13 including means for compensating the Doppler effect on the signals sent or received.

16. The terminal claimed in claim 11 wherein said electronic signal processor includes, for sending signals to a satellite of said constellation, a cascade of frequency step-up devices, a plurality of frequency amplifiers each associated with one of said frequency step-up devices, and a modulator for modulating and communicating signals to be sent.

17. The terminal claimed in claim 11 wherein said antennas are protected by a common radome.

18. The terminal claimed in claim 11, wherein said electronic signal processor includes means of adaptation to specific frequency bands.