Mobile device indoor navigation

Patent metadata

Field	Value
Publication number	US-11604247-B2
Application number	US-201916377700-A
Country	US
Kind code	B2
Filing date	Apr 8, 2019
Priority date	Dec 6, 2013
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

Mobile device positioning employs various forms of audio signal structures and detection methodologies. In one method, detection of an audio signal from a first source enables construction of a signal to facilitate detection of an audio signal from another source. Signals detected from these sources enable positioning of the mobile device receiving those signals. Another method forms audio signals transmitted from audio sources so that they have parts that add constructively and parts that differentiate the sources to enable positioning. Another audio signal based positioning method adaptively switches among positioning methods so that positioning remains operative as a mobile device moves toward and away from the sources. Another method tracks positioning history, evaluates it for errors and performs error mitigation to improve accuracy. Various other positioning technologies are detailed as well.

First claim

We claim:

1. A method of forming audio signals for determining device positioning, the method comprising:
providing a first signal to be transmitted from a first audio source;
providing a second signal to be transmitted form a second audio source;
wherein the first and second signals are configured to have a common code signal part that adds constructively in a receiver, and a different code signal part that discriminates the first and second audio sources;
transmitting signals from sources, the signals forming an interference pattern in which symbols formed by the interference pattern at locations between the sources correspond to a position; and
detecting a symbol from among the symbols from a signal formed from capturing a combination of the signals at the position corresponding the symbol.

2. The method of claim 1 wherein the signals comprise audio code signals, and in which the common and different code parts are encoded using frequency division multiplexing.

3. The method of claim 2 wherein the audio code signals are transmitted so as to be imperceptible by humans yet captured in a mobile device microphone, the symbol being detected from the combination of audio signals from the sources captured through the microphone.

4. A method of forming audio signals for determining device positioning, the method comprising:
providing a first signal to be transmitted from a first audio source;
providing a second signal to be transmitted form a second audio source;
wherein the first and second signals are configured to have a common code signal part that adds constructively in a receiver, and a different code signal part that discriminates the first and second audio sources;
from a signal received at a mobile device, detecting at least a first signal encoded in an audio signal from a first audio source;
using the first signal to identify a neighboring audio source;
reconstructing a second signal associated with the neighboring audio source;
using the reconstructed second signal to detect a second signal transmitted from the neighboring audio source; and
based on detecting of the first and second signals, determining position of the mobile device.

5. The method of claim 4 wherein the first and second signals are embedded in a host audio signal and the first and second audio sources correspond to a first speaker transmitting the host audio with the first signal embedded, and a second speaker transmitting the host signal with the second signal embedded.

6. The method of claim 4 wherein the first and second signals comprise payloads modulated on corresponding carrier signals.

7. The method of claim 6 wherein the payloads and corresponding carrier signals are both different for the first and second signals.

8. The method of claim 4 wherein a filter is adapted based on detecting the first signal, and further including:
filtering the signal received at the mobile device using the adapted filter to reduce the first signal relative to the second signal, and facilitate detecting of the second signal.

9. The method of claim 8 wherein the filter is adapted based on a reconstructed version of the first signal obtained by decoding a message from the received signal, and reconstructing the first signal from the decoded message.

10. The method of claim 4 wherein the first and second signals are encoded using frequency division multiplexing.

11. A non-transitory computer readable medium comprising instructions stored therein that, when executed by one or more processors, cause said one or more processors to perform the following acts:
providing a first signal to be transmitted from a first audio source;
providing a second signal to be transmitted form a second audio source;
wherein the first and second signals are configured to have a common code signal part that adds constructively in a receiver, and a different code signal part that discriminates the first and second audio sources;
transmitting signals from sources, the signals forming an interference pattern in which symbols formed by the interference pattern at locations between the sources correspond to a position; and
detecting a symbol from among the symbols from a signal formed from capturing a combination of the signals at the position corresponding the symbol.

12. The non-transitory computer readable medium of claim 11 , wherein the common and different code parts are encoded using frequency division multiplexing.

13. The non-transitory computer readable medium of claim 11 wherein the signals comprise audio code signals.

14. The non-transitory computer readable medium of claim 13 wherein the audio code signals are transmitted so as to be imperceptible by humans yet captured in a mobile device microphone, the symbol being detected from the combination of audio signals from the sources captured through the microphone.

15. A non-transitory computer readable medium comprising instructions stored therein that, when executed by one or more processors, cause said one or more processors to perform the following acts:
providing a first signal to be transmitted from a first audio source;
providing a second signal to be transmitted form a second audio source;
wherein the first and second signals are configured to have a common code signal part that adds constructively in a receiver, and a different code signal part that discriminates the first and second audio sources;
from a signal received at a mobile device, detecting at least a first signal encoded in an audio signal from a first audio source;
using the first signal to identify a neighboring audio source;
reconstructing a second signal associated with the neighboring audio source;
using the reconstructed second signal to detect a second signal transmitted from the neighboring audio source; and
based on detecting of the first and second signals, determining position of the mobile device.

16. The non-transitory computer readable medium of claim 15 wherein the first and second signals are embedded in a host audio signal and the first and second audio sources correspond to a first speaker transmitting the host audio with the first signal embedded, and a second speaker transmitting the host signal with the second signal embedded.

17. The non-transitory computer readable medium of claim 15 wherein the first and second signals comprise payloads modulated on corresponding carrier signals.

18. The non-transitory computer readable medium of claim 17 wherein the payloads and corresponding carrier signals are both different for the first and second signals.

19. The non-transitory computer readable medium of claim 15 wherein a filter is adapted based on detecting the first signal, and further including instructions that, when executed by said one or more processors, cause said one or more processors to perform the following acts:
filtering the signal received at the mobile device using the adapted filter to reduce the first signal relative to the second signal, and facilitate detecting of the second signal.

20. The non-transitory computer readable medium of claim 19 wherein the filter is adapted based on a reconstructed version of the first signal obtained by decoding a message from the received signal, and reconstructing the first signal from the decoded message.

21. The non-transitory computer readable medium of claim 15 wherein the first and second signals are encoded using frequency division multiplexing.

Assignees

• Digimarc Corp

Inventors

• Bradley Brett A
• Sharma Ravi K
• Thagadur Shivappa Shankar
• Lord John D

Classifications

• G01S5/18 Primary

  using ultrasonic, sonic or infrasonic waves · CPC title