Data transmission method and apparatus using networked receivers having spatial diversity

• US 7,876,849 B2
• Filed: 05/25/2006
• Issued: 01/25/2011
• Est. Priority Date: 05/25/2006
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Gardner, Steven H.
• Primary Examiner(s): Liu; Shuwang
• Assistant Examiner(s): Timory; Kabir A
• Application Number:
  US11/441,697
• Publication Number:
  US 20070274410A1
• Time in Patent Office: 1,706 Days
• Field of Search: 375/267, 375/260, 375/347, 375/349, 375/220
• US Class Current: 375/267
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04L 1/06 using space diversity

Abstract

A data transmission method and apparatus are disclosed using receivers having spatial diversity, with the receivers communicating with a common client via network communication. Improved systems and methods for data transmission according to the disclosed method and apparatus include at least: a transmission source for transmitting a data signal; a first receiver for receiving the data signal; a second receiver for receiving the data signal, wherein the second receiver is spaced apart from the first receiver thereby providing spatial diversity; and a communication network for facilitating communication between a client and at least the first receiver and the second receiver, as needed, wherein the client is capable of analyzing individual data signals received by the first and second receivers and forming a composite signal of a higher quality than the quality of the individual data signals.

Claims

1. A system for transmission of data, the system comprising:

an aerial based transmission source configured at least to transmit a data signal, the data signal comprising at least one data signal portion corresponding to digital data packets, at least some of the data packets including a source sequence of data components of compressed video data;

a first receiver configured at least to receive the data signal and to communicate a first relayed sequence of data components corresponding to the source sequence of data components via a communication network;

a second receiver configured at least to receive the data signal and to communicate a second relayed sequence of data components corresponding to the source sequence of data components via the communication network, wherein the second receiver is positioned a physical distance apart from the first receiver thereby providing spatial diversity; and

at least one client device, the client device configured to, at least;

receive the first relayed sequence of data components via the communication network,

receive the second relayed sequence of data components via the communication network,

choose between data components of the first and second relayed sequences having corresponding sequence identifiers at least in part by comparing quality indicators for at least some of the data components of the first and second relayed sequences,

discard the data components not chosen,

form a composite data packet stream at least in part by combining the chosen data components in sequence order, wherein the chosen data components comprise those respective data components of the first and second relayed sequences having highest comparative quality indicators, and

decompress the composite data packet stream of compressed video data.

2. The system of claim 1, further comprising a plurality of client devices, wherein the first receiver and the second receiver are further configured to communicate the respective sequences of data components via multicast to the plurality of client devices.

3. The system of claim 1, further comprising a third receiver configured at least to receive the transmitted data signal and to communicate a third relayed sequence of data components corresponding to the source sequence of data components via the communication network, wherein the third receiver is located at a first distance from the first receiver, at a second distance from the second receiver, and the first distance and the second distance are unequal.

4. The system of claim 1, wherein the at least some of the data packets include a sequence number associated with the source sequence of data components of compressed video data.

5. The system of claim 1, wherein the second receiver is positioned at least one-hundred kilometers apart from the first receiver.

6. The system of claim 1, wherein the communication network communicates utilizing Internet Protocol (IP) communication protocols.

7. The system of claim 1, wherein the quality indicator is determined using at least one error-detecting code or signal-to-noise ratio estimates.

8. The system of claim 1, wherein the composite data packet stream comprises error-free sequential data components obtained from the first and second receivers.

9. The system of claim 1, wherein the first receiver and the client device are integrated into one physical component.

10. The system of claim 1, wherein the aerial based transmission source is configured at least to transmit the data signal from an altitude greater than two thousand meters.

12. The method of claim 1, further communicating the data components and associated quality indicators from the first and second receivers to a plurality of clients via multicasting through the communication network.

11. A method of transmitting data, the method comprising:

transmitting a data signal from an aerial based transmission source to at least two receivers, wherein a first receiver of the at least two receivers is spaced apart from a second receiver of the at least two receivers thereby providing spatial diversity, and wherein the data signal includes at least one data signal portion corresponding to digital data packets including a plurality of sequential data components of compressed video data;

associating a quality indicator with each received sequential data component;

communicating the received data components and associated quality indicators from the first and second receivers to a client through a communication network;

comparing the quality indicators associated with each received sequential data component at the client;

for each element of a sequence associated with the sequential data components, discarding received sequential data components other than a received sequential data component having a highest quality indicator;

forming a composite data packet stream from the retained sequential data components; and

decompressing the composite data packet stream of compressed video data.

13. The method of claim 11, wherein the decompressing is performed by the first and second receivers prior to the first and second receivers communicating decompressed data components and associated quality indicators to the client.

14. The method of claim 11, wherein communicating the data components and the associated quality indicators from the first and second receivers to the client comprises using Internet Protocol (IP) communication protocols.

15. The method of claim 11, wherein associating the quality indicator with each sequential data component comprises using an error-detecting code.

16. The method of claim 11, further comprising receiving the sequential data components out of order at the client from the first and second receivers, wherein forming the composite signal comprises re-ordering the sequential data components having the highest quality indicators prior to the decompressing.

17. A computer-implemented method for receiving video transmitted by an aerial based transmission source to a plurality of spatially diverse receivers comprising:

receiving a first sequence of digitized video frames corresponding to the transmitted video;

receiving a second sequence of digitized video frames corresponding to the transmitted video;

identifying a first digitized video frame in the first sequence corresponding to a second digitized video frame in the second sequence, the correspondence being at least with respect to sequence order;

identifying a first quality indicator for the first digitized video frame;

identifying a second quality indicator for the second digitized video frame;

determining that the first digitized video frame is of a higher quality than the second digitized video frame at least in part by comparing the first quality indicator to the second quality indicator;

selecting the first digitized video frame for inclusion in a composite digitized video data stream;

discarding the second digitized video frame; and

storing the composite digitized video data stream in a computer-readable storage medium for display.

18. The method of claim 17, further comprising:

receiving a third sequence of digitized video frames corresponding to the transmitted video;

identifying a third digitized video frame in the third sequence corresponding to the first and second digitized video frames;

identifying a third quality indicator for the third digitized video frame; and

determining that the first digitized video frame is of a higher quality than the second and third digitized video frames at least in part by comparing the first quality indicator to the second and third quality indicators.

19. The method of claim 17, wherein:

the first sequence of digitized video frames comprises compressed video frames;

the method further comprises;

selecting further digitized video frames for inclusion in the composite digitized video data stream so that the composite digitized video data stream is decompressible; and

decompressing the composite digitized video data stream.