Adaptive communications focal plane array

Patent metadata

Field	Value
Publication number	US-9853740-B1
Application number	US-201715615826-A
Country	US
Kind code	B1
Filing date	Jun 6, 2017
Priority date	Jun 6, 2017
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

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.

First claim

What is claimed is:

1. A multi-channel 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 an 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, and each of the plurality of switching circuits comprising two or more analog output ports where each analog output port corresponds to a different channel of the multi-channel adaptive communications focal-plane array, wherein each of the plurality of switching circuits performs the following:
controls a flow of information being received in the form of an optical beam by either suppressing the flow completely or by outputting the flow to any one of the two or more analog output ports;
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 a first of the two or more analog output ports of 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 an optical beam is currently being output via the first of the two or more analog output ports of any one of the plurality of switching circuits.

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

3. The multi-channel 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 the corresponding optical detector and two or more optical beams simultaneously being received by the corresponding optical detector.

4. The multi-channel 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 multi-channel 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 multi-channel 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, such that a disabled switching circuit suppresses an output of an electrical signal being produced by its corresponding optical detector, preventing the electrical signal from contributing to the flow of information being output by any output channels of the multi-channel adaptive communications focal plane array.

7. The multi-channel adaptive communications focal plane array of claim 6 , wherein one of the plurality of switching circuits becomes enabled for output via its first analog output port when both of the following conditions are simultaneously met: one of the plurality of signal discrimination circuits corresponding to the one of the plurality of switching circuits sends the one of the plurality of switching circuits an estimated signal-to-noise ratio value that 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 the others of the plurality of switching circuits are all currently suppressing outputs from their respective first analog output ports.

8. The multi-channel adaptive communications focal plane array of claim 7 , wherein the one of the plurality of switching circuits remains enabled for output via its first analog output port 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 less than the minimum estimated signal-to-noise ratio, the one of the plurality of switching circuits is disabled.

9. The multi-channel adaptive communications focal plane array of claim 7 , wherein one or more of the plurality of switching circuits whose corresponding optical detectors are neighboring the optical detector to which the one of the plurality of switching circuits that has already been enabled is operatively connected are enabled for output via their respective first analog output ports enhancing the signal strength of the optical beacon.

10. The multi-channel 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 for output via its first analog output port.

11. The multi-channel 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 multi-channel adaptive communications focal plane array.

12. The multi-channel adaptive communications focal plane array of claim 9 , wherein the enabling of the one or more neighboring plurality of switching circuits for output via the first analog output port 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 multi-channel adaptive communications focal plane array of claim 12 , wherein the multi-channel adaptive communications focal plane array performs a re-centering procedure to re-center a focal area based upon recent signal-to-noise ratio estimates, the focal area being centered on the optical detector corresponding to the one of the plurality of switching circuits that has already been enabled for output via its first analog output port.

14. The multi-channel adaptive communications focal plane array of claim 1 , wherein the multi-channel 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 an optical beam until optical beacon information embedded in the optical beacon is extracted.

15. The multi-channel adap

Assignees

• Surefire Llc

Inventors

• Bortz John C
• Shatz Narkis

Classifications

• H04B1/60

  Supervising unattended repeaters · CPC title

• H04B10/07953

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04B10/116 Primary

  Visible light communication · CPC title

• H04B10/11

  Arrangements specific to free-space transmission, i.e. transmission through air or vacuum · CPC title

• G02F1/31

  Digital deflection, {i.e. optical switching}(G02F1/33 takes precedence) · CPC title