Systems for recovery communications via airborne platforms

• US 9,793,977 B2
• Filed: 04/11/2017
• Issued: 10/17/2017
• Est. Priority Date: 09/21/2012
• Status: Active Grant

• Current Assignee: Spatial Digital Systems Inc
• Original Assignee: Spatial Digital Systems Inc
• Inventors: Chang, Donald C. D.
• Primary Examiner(s): Huynh, Dung B
• Application Number:
  US15/485,193
• Publication Number:
  US 20170222712A1
• Time in Patent Office: 189 Days
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A communications system for providing recovery communication service to users in a coverage area affected by an emergency disruption of normal communication services. The system comprises a ground hub serving as a gateway to terrestrial networks including a dispatch center and configured to communicate with at least three mobile airborne platforms roving over the coverage area via respective feeder-links in a Ku or Ka band. A first mobile airborne platform communicates in a first frequency band with emergency workers that are working in the coverage area and associated with the dispatch center. A second mobile airborne platform communicates, in place of at least one disrupted base station in the coverage area, with user mobile phones in mobile phone frequency bands or user personal devices in WiFi bands located in the coverage area. A third mobile airborne platform generates real-time imaging of surfaces located in the coverage area.

Claims

1. A communications system for providing recovery communication service to users in a coverage area affected by an emergency disruption of normal communication services, the system comprising:

a ground hub serving as a gateway to terrestrial networks including a dispatch center, the ground hub being configured to communicate with at least three mobile airborne platforms roving over the coverage area via respective feeder-links in a Ku or Ka band;

a first mobile airborne platform of the at least three mobile airborne platforms, configured to communicate in a first frequency band with emergency workers that are working in the coverage area and associated with the dispatch center;

a second mobile airborne platform of the at least three mobile airborne platforms, configured to communicate, in place of at least one disrupted base station in the coverage area, with user mobile phones in mobile phone frequency bands or user personal devices in WiFi bands located in the coverage area; and

a third mobile airborne platform of the at least three mobile airborne platforms, configured to generate real-time imaging of surfaces located in the coverage area,

wherein the ground hub comprises;

a remote beam forming network to transform source signals into beam signals;

a wavefront multiplexer coupled to the remote beam forming network, the wavefront multiplexer performing a wavefront multiplexing transformation on input signals that include the beam signals and known diagnostic signals and generating wavefront multiplexed signals;

a bank of adaptive filters coupled to the wavefront multiplexer to equalize the wavefront multiplexed signals; and

an optimization unit coupled to the bank of adaptive filters to modify weightings of the adaptive filters based on differences between the known diagnostic signals and recovered diagnostic signals received from one of the at least three airborne platforms via a respective feeder-link.

2. The communications system of claim 1, wherein the ground hub comprises a remote beam forming network to provide remote beam forming for each of the at least three mobile airborne platforms.

3. The communications system of claim 1, wherein each of the at least three mobile airborne platforms comprises a retrodirective antenna system for transmitting and receiving in the Ku or Ka band.

4. The communications system of claim 1, wherein one of the at least three mobile airborne platforms comprises:

an antenna system to receive a signal from the ground hub via a respective feeder-link;

a receive frontend system coupled to the antenna system to condition the signal;

a frequency demultiplexing system coupled to the receive frontend system to frequency down convert and demultiplex the conditioned signal and generate baseband signals; and

a wavefront demultiplexer coupled to the frequency demultiplexing system to perform a wavefront demultiplexing transformation on the baseband signals and generate wavefront demultiplexed signals including recovered beam signals and recovered forward-link diagnostic signals.

5. The communications system of claim 1, wherein the ground hub further comprises:

a first antenna system for receiving a signal from one of the first and second mobile airborne platforms;

a receive frontend system coupled to the antenna system to condition the signal;

a frequency demultiplexing system coupled to the receive frontend system to frequency down convert and demultiplex the conditioned signal and generate baseband signals;

a bank of adaptive filters coupled to the frequency demultiplexing system to equalize the baseband signals;

a wavefront demultiplexer coupled to the bank of adaptive filters to perform a wavefront demultiplexing transformation on the baseband signals and generate wavefront demultiplexed signals including recovered element signals and recovered return-link diagnostic signals;

a receive digital beam forming network coupled to the wavefront demultiplexer to convert the recovered element signals to beam signals; and

a return-link optimization unit coupled to the wavefront demultiplexer and the bank of adaptive filters to modify weightings of the adaptive filters based on at least differences between the recovered diagnostic signals and known diagnostic signals.

6. The communications system of claim 5, wherein each of the first and second mobile airborne platforms comprises:

a second antenna system to capture signals radiated from the coverage area and generate captured signals;

low-noise amplifiers coupled to the second antenna system to amplify the captured signals;

frequency converter units coupled to the low-noise amplifiers to frequency-convert the amplified captured signals and generate element signals;

a wavefront multiplexer coupled to the frequency converter units, the wavefront multiplexer performing a wavefront multiplexing transformation on input signals that include the element signals, the known diagnostic signals, and recovered forward-link diagnostic signals that are previously obtained from a forward-link calibration, and generating wavefront multiplexed signals;

a frequency multiplexing system coupled to the wavefront multiplexer to transform the wavefront multiplexed signals into at least one frequency multiplexed signal;

a transmit frontend system coupled to the frequency multiplexing system to frequency up-convert and amplify the at least one frequency multiplexed signal and generate at least one amplified signal; and

a third antenna system coupled to the transmit frontend system to receive and radiate the at least one amplified signal.

7. The communications system of claim 1, wherein the third mobile airborne platform is configured to perform a radar function.

8. The communications system of claim 1, wherein the at least three mobile airborne platforms comprise a group of fourth mobile airborne platforms including the third mobile airborne platform to generate real-time imaging of the surfaces, the group of fourth mobile airborne platforms is configured to perform multi-static radar functions.

9. The communications system of claim 1, wherein the third mobile airborne platform comprises a bi-static radar receiver to capture radio-frequency radiations originated from a satellite via a direct path and via reflected paths from the surfaces located in the coverage area.

10. The communications system of claim 9, wherein the satellite is one of communications satellites and direct broadcasting satellites.

11. The communications system of claim 9, wherein the ground hub comprises a remote beam forming network to remotely form beams for the bi-static radar receiver.

12. The communications system of claim 1, wherein the third mobile airborne platform comprises at least one of optical sensors, infrared sensors, microwave sensors.

13. A communications system for providing recovery communication service to users in a coverage area affected by an emergency disruption of normal communication services, the system comprising:

a ground hub serving as a gateway to terrestrial networks including a dispatch center, the ground hub being configured to communicate with at least three mobile airborne platforms roving over the coverage area via respective feeder-links in a Ku or Ka band;

a first mobile airborne platform of the at least three mobile airborne platforms, configured to communicate in a first frequency band with emergency workers that are working in the coverage area and associated with the dispatch center;

a second mobile airborne platform of the at least three mobile airborne platforms, configured to communicate, in place of at least one disrupted base station in the coverage area, with user mobile phones in mobile phone frequency bands or user personal devices in WiFi bands located in the coverage area; and

a third mobile airborne platform of the at least three mobile airborne platforms, configured to generate real-time imaging of surfaces located in the coverage area, the third mobile airborne platform comprising a bi-static radar receiver to capture satellite signals originated from a satellite via a direct path and via reflected paths from the surfaces.

14. The communications system of claim 13, wherein the satellite is one of communications satellites and direct broadcasting satellites.

15. The communications system of claim 13, wherein the ground hub comprises a remote beam forming network to remotely form beams for the bi-static radar receiver.

16. The communications system of claim 13, wherein the third mobile airborne platform comprises at least one of optical sensors, infrared sensors, microwave sensors.

17. A communications system for providing real-time imaging of surfaces located in a coverage area affected by an emergency disruption of normal communication services, the system comprising:

a first mobile airborne platform configured to communicate in a first frequency band with emergency workers that are working in the coverage area and associated with a dispatch center;

a second mobile airborne platform configured to communicate, in place of at least one disrupted base station in the coverage area, with user mobile phones in mobile phone frequency bands or user personal devices in WiFi bands located in the coverage area;

a third mobile airborne platform configured to provide real-time imaging of the surfaces located in the coverage area, the third mobile airborne platform comprising a bi-static radar receiver to capture satellite signals originated from a satellite via a direct path and via reflected paths from the surfaces, the satellite being one of communications satellites and direct broadcasting satellites; and

a ground hub configured to communicate concurrently and independently with each of the first, second and third mobile airborne platforms via respective feeder-links in a Ku or Ka band.

18. The communications system of claim 17, wherein the ground hub comprises a remote beam forming network to remotely form beams for the bi-static radar receiver.

19. The communications system of claim 17, wherein the third mobile airborne platform comprises at least one of optical sensors, infrared sensors, microwave sensors.