Method and apparatus for combining transponders on multiple satellites into virtual channels

• US 6,549,582 B1
• Filed: 11/28/2000
• Issued: 04/15/2003
• Est. Priority Date: 02/04/1998
• Status: Expired due to Term

• Current Assignee: F Poszat Hu LLC (Intellectual Ventures LLC)
• Original Assignee: Virtual Satellite Corporation
• Inventors: Friedman, Robert F.
• Primary Examiner(s): BOCURE, TESFALDET
• Application Number:
  US09/723,877
• Time in Patent Office: 868 Days
• Field of Search: 455/13.1, 455/12.1, 455/61, 455/59, 455/101, 455/132, 455/137, 455/139, 375/260, 375/267, 375/211, 375/295, 375/347, 375/316, 375/299, 370/316, 370/480, 370/315
• US Class Current: 375/260
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays

Abstract

A satellite communications system provides an information channel between remotely located transmitters and receivers. A virtual satellite system provides the same service, but divides the signal either in power or in data content into subchannels such that any particular signal is conducted to the intended receiver via a plurality of traditional satellite channels. The receiving terminal accepts the plurality of signals simultaneously from a possible plurality of satellites, combining the subchannels comprising the virtual channel into the original signal content as if conducted via a single channel. The receiving antenna system receives satellite subchannel signals from a plurality of directions using multiple antennas or a single antenna with multi-direction capability. Prior to signal combining, the receiver necessarily time-synchronizes the plurality of subchannels by introducing time delay in some channels before combining the subsignals into the original composite. A timing signal present in the virtual satellite system assists the receiver in determining the amount of delay to apply to each incoming signal. The timing signal is either a separate carrier or an additional modulation on the existing information-bearing carrier.

Claims

1. A plurality of electrical subsignals for communication, wherein an electrical signal having a first bandwidth is divided into said plurality of electrical subsignals for transmission over a plurality of communication channels, wherein said plurality of electrical subsignals are embodied in a carrier wave, and each of said plurality of electrical subsignals has a bandwidth smaller than the first bandwidth, the plurality of electrical subsignals comprising some information unique to that subsignal so that said plurality of electrical subsignals may be identified and distinguished, wherein a common timing signal is added to said plurality of electrical subsignals within the bandwidth of each subsignal so that no additional bandwidth allocation is required to transmit the common timing signal and wherein said common timing signal is transmitted in a separate frequency allocation, so that a plurality of tuners receive the frequency-separated timing signal to measure relative propagation delay of the subsignals, the amount of delay in a plurality of delay means is set, and said plurality of tuners are redirected to receive the associated information-bearing subsignals;

whereby said plurality of electrical subsignals are received and combined for re-creating said electrical signal.

2. The plurality of electrical subsignals of claim 1 wherein frequencies of said plurality of electrical subsignals are translated to the frequency of a selected satellite transponder.

3. The plurality of electrical subsignals of claim 2 wherein said plurality of tuners translate the frequencies of said plurality of electrical subsignals to a fixed intermediate frequency.

4. The plurality of electrical subsignals of claim 3 wherein said plurality of electrical subsignals are demodulated for creating a plurality of bit streams corresponding to the information content of the associated subsignals.

5. The plurality of electrical subsignals of claim 4 wherein the information in each of said plurality of electrical subsignals are combined into a delayed reconstruction of the electrical signal.

6. A plurality of electrical subsignals for communication, wherein an electrical signal having a first bit rate is divided into said plurality of electrical subsignals for transmission over a plurality of communication channels, wherein said plurality of electrical subsignals are embodied in a carrier wave, and each of said plurality of electrical subsignals carries identical information at the same bit rate as the first bit rate, wherein the plurality of electrical subsignals comprises some information unique to that subsignal so that said plurality of electrical subsignals may be identified and distinguished, wherein a common timing signal is added to said plurality of electrical subsignals within the bandwidth of each subsignal so that no additional bandwidth allocation is required to transmit the common timing signal, and wherein said common timing signal subchannel is transmitted in a separate frequency allocation so that a plurality of tuners receive the frequency-separated timing signal to measure relative propagation delay of the subsignals, the amount of delay in a plurality of delay means is set, and said plurality of tuners are redirected to receive the associated information-bearing subchannels;

whereby said plurality of electrical subsignals are received and combined for re-creating said electrical signal.

7. The plurality of electrical subsignals of claim 6 wherein frequencies of said plurality of electrical subsignals are translated to the frequency of a selected satellite transponder.

8. The plurality of electrical subsignals of claim 7 wherein said plurality of tuners translate the frequencies of said plurality of electrical subsignals to a fixed intermediate frequency.

9. The plurality of electrical subsignals of claim 8 wherein said plurality of electrical subsignals are demodulated for creating a plurality of soft decisions in the form of digitized decision-confidence-values corresponding to the associated subsignals.

10. The plurality of electrical subsignals of claim 9 wherein the plurality of soft decisions are combined into a delayed reconstruction of the electrical signal.

11. A plurality of analog subsignals for communication, wherein an analog signal having a first power is divided into said plurality of analog subsignals for transmission over a plurality of communication channels, wherein said plurality of analog subsignals are embodied in a carrier wave, and each of said plurality of analog subsignals has a power smaller than the first power,

wherein a common timing signal is added to said plurality of analog subsignals within the bandwidth of each subsignal so that no additional bandwidth allocation is required to transmit the common timing signal, the common timing signal being transmitted in a separate frequency allocation so that a plurality of tuners receive the frequency-separated timing signal to measure relative propagation delay of the subsignals, the amount of delay in a plurality of delay means is set, and said plurality of tuners are redirected to receive the associated information-bearing subsignals;

and

whereby said plurality of analog subsignals are received and combined for reconstruction of said analog signal.

12. The plurality of analog subsignals of claim 11 wherein frequencies of said plurality of analog subsignals are translated to the frequency of a selected satellite transponder.

13. The plurality of analog subsignals of claim 12 wherein said plurality of tuners translate the frequencies of said plurality of analog subsignals to a fixed intermediate frequency.

14. The plurality of analog subsignals of claim 13 wherein said plurality of analog subsignals are combined and demodulated for creating a delayed reconstructed analog signal corresponding to the information content of the analog signal.