Alignment of signal copies from an asynchronous sensor network

Patent metadata

Field	Value
Publication number	US-9426007-B1
Application number	US-201313947435-A
Country	US
Kind code	B1
Filing date	Jul 22, 2013
Priority date	Jul 22, 2013
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

Various embodiments associated with resampling signal copies for asynchronous sensors are described. A plurality of asynchronous sensors that sample signals at different frequencies can be distributed in an area. These sensors can sense a signal of interest for an entity. The sensors can send copies of the signal of interest that they have sensed to a system of the entity for processing. However, since the sensors are asynchronous the copies are sampled at different sampling time periods or sampling frequencies. A specific copy of the signal of interest can be selected from among the copies as a reference to estimate relative sampling frequency offset and the remaining copies can be resampled such that their resampled sampling time period or sampling frequency align with the reference signal. With the copies aligned, combination of the copies occurs and further processing can take place.

First claim

What is claimed is:

1. A method, comprising:
identifying a first signal copy as a reference signal, where the first signal copy is a copy of a signal of interest and where the first signal copy is a digital signal sampled at a first sampling time period;
resampling a second signal copy of the signal of interest in accordance with the first sampling time period to produce a resampled second signal copy, where the second signal copy is a digital signal sampled at a second sampling time period and where the first sampling time period and the second sampling time period are different;
fusing the first signal copy with the resampled second signal copy into a fused copy of the signal of interest;
matching the fused copy of the signal of interest with a known signal;
recognizing a modulation scheme associated with the known signal; and
appointing the modulation scheme associated with the known signal as a modulation scheme for the signal of interest;
demodulating the fused copy of the signal of interest through use of the modulation scheme for the signal of interest; and
causing the signal of interest to be outputted after demodulation.

2. The method of claim 1 , where the first signal copy is a copy of the signal of interest from a first sensor, where the second signal copy is a copy of the signal of interest from a second sensor, where the first sensor and the second sensor are different sensors, where the first sensor is part of a first network, where the second sensor is part of a second network, and where the first network and second network are different networks.

3. The method of claim 2 , where the first sensor and the second sensor are asynchronous with one another.

4. The method of claim 1 , the method comprising:
sending a signal copy request to a first sensor;
sending the signal copy request to a second sensor;
receiving the first signal copy from the first sensor in response to the signal copy request, where the first signal copy is identified as the first reference signal after reception; and
receiving the second signal copy from the second sensor in response to the signal copy request, where the second signal copy is resampled after reception.

5. The method of claim 4 , where the first sensor and the second sensor are asynchronous with one another.

6. The method of claim 4 , where the first sensor is part of a first network, where the second sensor is part of a second network, and where the first network and second network are different networks.

7. The method of claim 4 , where the first signal copy when received is a first time-stamped data packet and where the second signal copy when received is a second time-stamped data packet.

8. The method of claim 1 , where matching the signal of interest with a known signal comprises matching the fused copy of the signal of interest with the known signal.

9. The method of claim 1 , where matching the signal of interest with a known signal occurs before the first signal copy is fused with the resampled second signal copy into the fused copy of the signal of interest.

10. The method of claim 1 , where the first signal copy is a copy of the signal of interest from a first sensor, where the second signal copy is a copy of the signal of interest from a second sensor, where the first sensor and the second sensor are different sensors, where the first sensor is part of a first electronic device with a primary purpose other than functioning as a sensor of the first signal copy, and where the second sensor is part of a second electronic device with a primary purpose other than functioning as a sensor of the second signal copy.

11. The method of claim 1 , where the method is at least in part performed by a processor and where a network of the signal of interest in unknown to the processor.

12. A non-transitory computer-readable medium configured to store computer-executable instructions that when executed by a processor cause the processor to perform a method, the method comprising:
receiving a first signal copy of a signal of interest from a first sensor, where the first signal copy is a digital signal sampled at a first sampling time period;
receiving a second signal copy of the signal of interest from a second sensor, where the second signal copy is a digital signal sampled at a second sampling time period, where the first sampling time period is different from the second sampling time period, where the first sensor and second sensor are different sensors, and where the first sensor and second sensor are asynchronous;
identifying the first sampling time period;
estimating and resampling the second signal copy in accordance with the first sampling time period to produce a resampled second signal copy, where the resampled second signal copy and the first signal copy have the same sampling time period;
fusing the first signal copy and the resampled second signal copy into a fused signal copy of the signal of interest;
matching the fused copy of the signal of interest with a known signal;
identifying a modulation scheme associated with the known signal;
demodulating the fused copy of the signal of interest through use of the modulation scheme; and
outputting the signal of interest after demodulation.

13. The non-transitory computer-readable medium of claim 12 , where the signal of interest is unknown to the non-transitory computer-readable medium, where a frequency of the signal of interest is unknown, where the first sensor is non-cooperative with the second sensor, where the second sensor is non-cooperative with the first sensor, where the first sensor and the second sensor are dumb sensors, where the first sensor does not make a local decision regarding synchronization of the first signal copy, and where the second sensor does not make a local decision regarding synchronization of the second signal copy.

14. The non-transitory computer-readable medium of claim 12 , where the first sensor is part of a first electronic device with a primary purpose other than functioning as a sensor of the first signal copy and where the second sensor is part of a second electronic device with a primary purpose other than functioning as a sensor of the second signal copy.

15. A system, comprising:
an identification component configured to identify a first signal copy as a reference signal, where the first signal copy is a copy of a signal of interest, where the first signal copy is a digital signal sampled at a first sampling time period, and where a network of the signal of interest is unknown to the system;
a resample component configured to resample a second signal copy of the signal of interest in accordance with the first sampling time period to produce a resampled second signal copy, where the second signal copy is a digital signal sampled at a second sampling time period and where the first sampling time period and the second sampling time period are different;
a fusion component configured to fuse the first signal copy with the resampled second signal copy into a fused copy of the signal of interest; and
a demodulation component configured to perform a demodulation on the fused copy of the signal of interest.

16. The system of claim 15 , comprising:
a match component configured to match the signal of interest with a known signal; and
a recognition component configured to recognize a modulation scheme associated with the known signal, where the demodulation component is configured to perform the demodulation through use of the demodulation scheme associated with the known signal.

17. The system of claim 15 , comprising

Assignees

• Us Army

Inventors

• Su Wei

Classifications

• H04Q9/00

  Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom · CPC title

• H04B1/7115

  Constructive combining of multi-path signals, i.e. RAKE receivers · CPC title

• H04Q2209/845

  where the measuring is synchronized between sensing devices · CPC title

• H04L27/0012 Primary

  arrangements for identifying the type of modulation · CPC title

• H04B3/23

  using a replica of transmitted signal in the time domain, e.g. echo cancellers · CPC title