Adaptive communications focal plane array

• US 9,917,652 B1
• Filed: 06/06/2017
• Issued: 03/13/2018
• Est. Priority Date: 06/06/2017
• Status: Active Grant

• Current Assignee: Aron Surefire, LLC
• Original Assignee: SureFire LLC (Surefire Holdings LLC)
• Inventors: Bortz, John C., Shatz, Narkis
• Primary Examiner(s): Vanderpuye, Ken N
• Assistant Examiner(s): Alagheband, Abbas H
• Application Number:
  US15/615,819
• Time in Patent Office: 280 Days
• Field of Search: 398 26
• CPC Class Codes: G01C 21/36 Input/output arrangements for on-board computers
• CPC Class Codes: G02F 1/31 Digital deflection, i.e. optical switchingG02F1/33 takes precedence
• CPC Class Codes: G06K 19/06 characterised by the kind of the digital marking, e.g. shape, nature, code
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G11B 7/00 Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor G11B11/00, G11B13/00 take precedence
• CPC Class Codes: H04B 1/60 Supervising unattended repeaters
• CPC Class Codes: H04B 10/07953 Monitoring or measuring OSNR, BER or Q
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H04B 10/112 Line-of-sight transmission over an extended range
• CPC Class Codes: H04B 10/1129 Arrangements for outdoor wireless networking of information
• CPC Class Codes: H04B 10/1141 One-way transmission
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04B 10/69 Electrical arrangements in the receiver
• CPC Class Codes: H04B 10/691 Arrangements for optimizing the photodetector in the receiver
• CPC Class Codes: H04B 10/80 Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/022 For interconnection of WDM optical networks

Abstract

Adaptive communications focal plane arrays that may be implemented in, e.g., a specially-configured camera that can be utilized to receive and/or process information in the form of optical beams are presented. A specialized focal plane array (FPA) having a plurality of optical detectors is utilized, where one or more optical detectors are suppressed such that data is not allowed to be output from the one or more suppressed optical detectors, and only a significantly smaller number or subset of optical detectors receiving optical beams are allowed to output data. In this way, the rate at which data is to be output by an adaptive communications FPA (ACFPA) can be significantly reduced.

Claims

1. An adaptive communications focal plane array comprising:

a plurality of optical detectors, a subset of which receive one or more optical beams transmitted by one or more optical transmitter assemblies;

a plurality of signal discrimination circuits, each of which is operatively connected to a corresponding one of the plurality of optical detectors and performs the following;

detects the presence of an optical beam that is currently being received by its corresponding optical detector;

computes an estimated signal-to-noise ratio associated with the optical beam it has detected; and

sets a value of the estimated signal-to-noise ratio to a set value when it has not detected the presence of the optical beam;

a plurality of switching circuits, each of which is operatively connected to a corresponding one of the plurality of optical detectors and a corresponding one of the plurality of signal discrimination circuits, wherein each of the plurality of switching circuits;

controls a flow of information being received from the optical beam;

outputs a location relative to other detectors of the plurality of optical detectors indicative of the corresponding optical detector receiving the optical beam; and

outputs the estimated signal-to-noise ratio provided by its corresponding signal discrimination circuit; and

an analog output detector operatively connected to each of the plurality of switching circuits, the analog output detector informing each of the plurality of switching circuits whether or not information being received by an optical detector from the optical beam is currently being output by any one of the plurality of switching circuits.

2. The adaptive communications focal plane array of claim 1, wherein the plurality of optical detectors are configured in a two-dimensional array.

3. The adaptive communications focal plane array of claim 1, wherein each of the plurality of signal discrimination circuits distinguishes between a single optical beam being received by a corresponding optical detector and two or more optical beams simultaneously being received by the corresponding optical detector.

4. The adaptive communications focal plane array of claim 1, wherein each of the plurality of signal discrimination circuits outputs an indicator representative of an invalid condition upon a determination that two or more optical beams are simultaneously being received by the corresponding optical detector.

5. The adaptive communications focal plane array of claim 1, wherein each of the plurality of switching circuits receives a command initializing an optical beacon receiver mode, and wherein the optical beam comprises an optical beacon.

6. The adaptive communications focal plane array of claim 5, wherein the command causes each of the plurality of switching circuits to be disabled, or to remain disabled if one or more of the plurality of switching circuits is already disabled, and wherein a disabled switching circuit is in a state in which it suppresses an output of an electrical signal being produced by its corresponding optical detector, thereby preventing the electrical signal from contributing to a flow of information being output by the adaptive communications focal plane array.

7. The adaptive communications focal plane array of claim 6, wherein each of the plurality of switching circuits operatively remains disabled unless one of the plurality of switching circuits operatively connected to the corresponding optical detector receiving the optical beam receives, from its corresponding signal discrimination circuit, the estimated signal-to-noise ratio, and the estimated signal-to-noise ratio is greater than or equal to a minimum signal-to-noise ratio threshold, and the analog output detector informs the one of the plurality of switching circuits that all others of the plurality of switching circuits are currently disabled.

8. The adaptive communications focal plane array of claim 7, wherein the one of the plurality of switching circuits remains enabled unless it receives from its corresponding signal-discrimination circuit, a value of the estimated signal-to-noise ratio that is less than the minimum signal-to-noise ratio threshold, such that upon receiving the value of the estimated signal-to-noise ratio that is less than the minimum signal-to-noise ratio threshold, the one of the plurality of switching circuits is disabled.

9. The adaptive communications focal plane array of claim 7, wherein one or more of the plurality of switching circuits whose corresponding optical detectors are neighboring that optical detector to which the one of the plurality of switching circuits that has already been enabled is operatively connected, are enabled, enhancing the signal strength of the optical beacon.

10. The adaptive communications focal plane array of claim 9, wherein the one or more of the optical detectors corresponding to the plurality of switching circuits are determined to be neighboring based upon a focal area centered on the optical detector corresponding to the one of the plurality of switching circuits that has already been enabled.

11. The adaptive communications focal plane array of claim 10, wherein the focal area comprises one of a blur circle or blur ellipse, one or more parameters of which depends upon a size of a point-spread function of an imaging lens associated with the adaptive communications focal plane array.

12. The adaptive communications focal plane array of claim 9, wherein the enabling of the one or more neighboring plurality of switching circuits is initiated by receipt of a signal-to-noise ratio request and a determination that an estimated signal-to-noise ratio output from a corresponding one of the plurality of signal discrimination circuits is greater than or equal to the minimum signal-to-noise ratio threshold.

13. The adaptive communications focal plane array of claim 10, wherein the adaptive communications focal plane array performs a re-centering procedure to re-center the focal area based upon recent signal-to-noise ratio estimates.

14. The adaptive communications focal plane array of claim 1, wherein the adaptive communications focal plane array is operatively implemented within an optical receiver assembly, the optical receiver assembly monitoring and processing the optical beacon portion of the optical beam until optical beacon information embedded in the optical beacon is extracted.

15. The adaptive communications focal plane array of claim 14, wherein the optical receiver assembly outputs the optical beacon information to an augmented reality device, the augmented reality device presenting one or more aspects of the optical beacon information in an augmented reality presentation displayed to a user of the augmented reality device.

16. The adaptive communications focal plane array of claim 14, wherein all of the plurality of switching circuits except one or more of the plurality of switching circuits operatively connected to the one or more of the plurality of optical detectors receiving the optical beam are suppressed by being maintained in a disabled state until the optical beacon information has been extracted from the optical beam.

17. The adaptive communications focal plane array of claim 16, wherein another one or more of the plurality of switching circuits operatively connected to another one or more of the plurality of optical detectors receiving another optical beam are enabled while outputs from all of the remaining plurality of switching circuits are suppressed by the remaining plurality of switching circuits being maintained in the disabled state until optical beacon information embedded in the other optical beam has been extracted.

18. The adaptive communications focal plane array of claim 1, wherein the optical beam comprises an optical beacon and an optical signal.

19. The adaptive communications focal plane array of claim 18, wherein one or more of the plurality of optical detectors, one or more of the plurality of signal discrimination circuits, and one or more of the plurality of switching circuits process the optical beam to extract optical signal information embedded in the optical beam upon selection of an augmented reality representation of the optical beacon, and wherein a re-centering procedure is carried out periodically to re-center a focal area from which the optical signal is being extracted based upon recent signal-to-noise ratio estimates.

20. The adaptive communications focal plane array of claim 19, wherein ones of the plurality of switching circuits having corresponding ones of the plurality of optical detectors that are not receiving the optical beam are operationally suppressed during the extraction of the optical signal information.

21. The adaptive communications focal plane array of claim 1, wherein analog signals representative of the optical beams output from one or more of the plurality of switching circuits are combined.

22. The adaptive communications focal plane array of claim 21, further comprising a digital-signal converter adapted to convert the combined analog signals representative of the optical beam into digital signals representative of the optical beam.

23. The adaptive communications focal plane array of claim 22, wherein the digital signal converter transmits the digital signals to an optical receiver assembly.

24. A method of extracting optical beacon information embedded in an optical beam comprising:

initializing each of a plurality of switched detector assemblies of an adaptive communications focal plane array, such that all the switching circuits are initially turned off;

for each of the plurality of switched detector assemblies, determining existence of the following two conditions;

a signal-to-noise ratio of an optical beam being received by the optical detector of the switched detector assembly equals or exceeds a minimum signal-to-noise ratio value; and

no optical beams are detected as being output from any of the plurality of switched detector assemblies;

turning on each of the plurality of switched detector assemblies for which the two conditions are met; and

maintaining each of the plurality of switched detector assemblies in an on mode unless one or more of the following occurs;

the signal-to-noise ratio of the received optical beam falls below the minimum signal-to-noise ratio value or a command is received instructing one or more of the plurality of switched detector assemblies to turn off.

25. The method of claim 24, wherein all the switched detector assemblies not receiving the optical beam are kept turned off until the information embedded in the optical beacon of the beam being received is extracted.

26. The method of claim 24, wherein the optical beam comprises both an optical signal and an optical beacon, the optical beacon comprising optical beacon information identifying an entity from which the optical beacon is transmitted, and the optical signal comprising additional information associated with the entity from which the optical beacon is transmitted.