Remote Sensing Using MIMO Systems

• US 20150138010A1
• Filed: 04/24/2012
• Published: 05/21/2015
• Est. Priority Date: 04/24/2012
• Status: Active Grant

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Bikhazi, Nicolas, Young, William F., Nguyen, Hung D.
• Granted Patent: US 9,019,148 B1
• Time in Patent Office: Days
• US Class Current: 342/28
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 13/62 Sense-of-movement determination G01S13/589 takes precedence
• CPC Class Codes: G01S 7/41 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming

Abstract

A technique for sensing a moving object within a physical environment using a MIMO communication link includes generating a channel matrix based upon channel state information of the MIMO communication link. The physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver. A spatial information variable is generated for the MIMO communication link based on the channel matrix. The spatial information variable includes spatial information about the moving object within the physical environment. A signature for the moving object is generated based on values of the spatial information variable accumulated over time. The moving object is identified based upon the signature.

Claims

1. A method of sensing a moving object within a physical environment, the method comprising:

generating a channel matrix based upon channel state information of a multiple-input and multiple-output (“

MIMO”

) communication link, wherein the physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver having multiple antennas;

generating a spatial information variable for the MIMO communication link based on the channel matrix, wherein the spatial information variable includes spatial information about the moving object within the physical environment, wherein generating the spatial information variable comprises factorizing the channel matrix to obtain singular values, wherein the spatial information variable comprises a channel capacity variable calculated based upon the singular values, and wherein the channel capacity variable is a measure of available channel throughput of the MIMO communication link between the transmitter and the receiver for a given transmit power level;

generating a signature for the moving object based on values of the spatial information variable accumulated over time; and

identifying the moving object within physical environment based upon the signature.

2. The method of claim 1, wherein the MIMO communication link includes multiple spatial communication channels between the transmitter and the receiver and wherein the spatial information variable is responsive to interactions between the moving object and one or more of the multiple spatial communication channels such that the moving object becomes part of the communication medium.

3. The method of claim 2, wherein the moving object interacts with one or more of the multiple spatial communication channels by one or more of creating a new spatial communication channel, attenuating an existing spatial communication channel, or enhancing the existing spatial communication channel.

5. The method claim 1, wherein the spatial information variable comprises one of the singular values, and wherein factorizing the channel matrix comprises performing a singular value decomposition on the channel matrix to obtain eigenvalues associated with eigenchannels of the MIMO communication link.

7. The method of claim 1, wherein identifying the moving object comprises statistically correlating the signature to a database of known signatures.

8. The method of claim 7, wherein the know signatures comprise one of a temporal series of eigenvalues or a temporal series of channel capacity values.

9. The method of claim 1, wherein identifying the moving object comprises:

thresholding one or both of a duration of the signature or an amplitude of the signature.

10. The method of claim 2, further comprising:

applying weighting values to components of the channel matrix to enhance a sensing contribution from a first one of the multiple spatial communication channels while reducing a sensing contribution from a second one of the multiple spatial communication channels.

11. The method of claim 1, wherein the MIMO communication link comprises a standards based wireless communication link.

12. The method of claim 11, wherein the transmitter comprises a first transceiver and the receiver comprises a second transceiver and wherein the MIMO communication link actively communicates data between the first and second transceivers while the channel matrix associated with the MIMO communication link is analyzed to sense the moving object.

13. The method of claim 1, wherein the spatial information about the moving object includes information related to one or more of a size of the object, a shape of the object, or a matter composition distribution of the object.

14. The method of claim 1, wherein the MIMO communication link comprises one of an optical MIMO communication link or an acoustical MIMO communication link.

4. (canceled)

6. (canceled)

15. At least one non-transitory machine-accessible storage medium that provides instructions that, when executed by a machine, will cause the machine to perform operations comprising:

generating a channel matrix based upon channel state information of a multiple-input and multiple-output (“

MIMO”

) communication link, wherein a physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver having multiple antennas;

generating a spatial information variable for the MIMO communication link based on the channel matrix, wherein the spatial information variable includes spatial information about the moving object within the physical environment, wherein generating the spatial information variable comprises factorizing the channel matrix to obtain singular values, wherein the spatial information variable comprises a channel capacity variable calculated based upon the singular values, and wherein the channel capacity variable is a measure of available channel throughput of the MIMO communication link between the transmitter and the receiver for a given transmit power level;

generating a signature for the moving object based on values of the spatial information variable accumulated over time; and

identifying the moving object within physical environment based upon the signature.

16. The machine-accessible storage medium of claim 15, wherein the MIMO communication link includes multiple spatial communication channels between the transmitter and the receiver and wherein the spatial information variable is responsive to interactions between the moving object and one or more of the multiple spatial communication channels such that the moving object becomes part of the communication medium.

17. The machine-accessible storage medium of claim 16, wherein the moving object interacts with one or more of the multiple spatial communication channels by one or more of creating a new spatial communication channel, attenuating an existing spatial communication channel, or enhancing the existing spatial communication channel.

20. The machine-accessible storage medium of claim 15, wherein identifying the moving object comprises statistically correlating the signature to a database of known signatures.

21. The machine-accessible storage medium of claim 15, wherein the MIMO communication link comprises a standards based wireless communication link.

22. The machine-accessible storage medium of claim 15, wherein the spatial information about the moving object includes information related to one or more of a size of the object, a shape of the object, or a matter composition distribution of the object.

18-19. -19. (canceled)

23. A multiple-input and multiple-output (“

MIMO”

) communication system capable of conveying data through a physical environment that operates as a communication medium while sensing a moving object within the physical environment, the MIMO communication system comprising;

a MIMO transmitter coupled to a first array of antennas;

a MIMO receiver coupled to a second array of antennas; and

a processing system communicatively coupled to one or both of the MIMO transmitter or receiver, the processing system including logic to perform operations comprising;

generating a channel matrix based upon channel state information of a MIMO communication link between the MIMO transmitter and receiver, wherein communication signals of the MIMO communication link propagate through the physical environment between the MIMO transmitter and receiver;

generating a spatial information variable for the MIMO communication link based on the channel matrix, wherein the spatial information variable includes spatial information about the moving object within the physical environment, wherein generating the spatial information variable comprises factorizing the channel matrix to obtain singular values, wherein the spatial information variable comprises a channel capacity variable calculated based upon the singular values, and wherein the channel capacity variable is a measure of available channel throughput of the MIMO communication link between the transmitter and the receiver for a given transmit power level;

generating a signature for the moving object based on values of the spatial information variable accumulated over time; and

identifying the moving object within physical environment based upon the signature.

24. The MIMO communication system of claim 23, wherein the MIMO communication link includes multiple spatial communication channels between the transmitter and the receiver and wherein the spatial information variable is responsive to interactions between the moving object and one or more of the multiple spatial communication channels such that the moving object becomes part of the communication medium.

27. The MIMO communication system of claim 23, wherein identifying the moving object comprises statistically correlating the signature to a database of known signatures.

28. The MIMO communication system of claim 23, wherein the spatial information about the moving object includes information related to one or more of a size of the object, a shape of the object, or a matter composition distribution of the object.

25-26. -26. (canceled)