Method and/or System for Determining Time of Arrival of Data Packets

• US 20140254402A1
• Filed: 03/08/2013
• Published: 09/11/2014
• Est. Priority Date: 03/08/2013
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Aldana, Carlos Horacio
• Application Number:
  US13/791,834
• Publication Number:
  US 20140254402A1
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Disclosed are systems, methods and devices for application of estimating a apposition of a mobile device based, at least in part, on measuring differences of times of arrival of data packets transmitted to the mobile device from transmitters. In specific implementations, time-staggered quasi-matched filter correlators may applying a known waveform or data sequence to a payload of a received data packet to detect a correlation peak or correlation maximum corresponding to a time of arrival of the received data packet.

Claims

1. A method comprising, at a mobile device:

wirelessly receiving one or more packets from a transmitter transmitted according to an IEEE std. 802.11 waveform, a payload of at least one of said received packets comprising a known waveform or data sequence; and

applying said known waveform or data sequence at time-staggered quasi-matched filter correlators to said payload to detect a correlation peak; and

estimating a time of arrival of said at least one of said received packets based, at least in part, on said correlation peak and a time reference.

2. The method of claim 1, and further comprising:

receiving at least one of said packets transmitted according to the IEEE std. 802.11 waveform from each of three or more transmitters positioned at known locations;

measuring differences in times of arrival of said packets received from each of said three or more transmitters; and

estimating a location of said mobile device based, at least in part, on the measured differences.

3. The method of claim 1, and further comprising:

transmitting one or more request messages to the transmitter requesting the at least one of said received packets having the payload comprising the known waveform or data sequence; and

configuring a baseband processor to apply said time-staggered quasi-matched filter correlators.

4. The method of claim 1, wherein said known waveform or data sequence comprises a repeated field in the at least one said received packets.

5. The method of claim 1, wherein the known waveform or data sequence comprises a pseudonoise code.

6. The method of claim 1, wherein the time-staggered quasi-matched filter correlators are configured to convolve a quantized version of the known waveform or data sequence with at least a portion of the payload.

7. The method of claim 6, wherein the quantized version of the known waveform or data sequence is less than an entirety of the known waveform or data sequence.

8. The method of claim 6, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of discrete values.

9. The method of claim 6, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of two discrete values.

10. The method of claim 6, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of four discrete values.

11. A mobile device comprising:

a receiver to receive one or more signals from a wireless network;

a plurality of time-staggered quasi-matched filter correlators configurable to convolve at least a portion of one or more packets received at said receiver and transmitted according to an IEEE std. 802.11 waveform, a payload of at least one of said received packets comprising a known waveform or data sequence; and

one or more processors to;

determine a correlation peak output signal among said time-staggered quasi-matched filter correlators; and

estimate a time of arrival of said at least one of said received packets based, at least in part, on said correlation peak output signal and a time reference.

12. The mobile device of claim 11, wherein said one or more processors are further to:

measure differences in times of arrival of packets received at said receiver and transmitted according to the IEEE std. 802.11 waveform from each of three or more transmitters positioned at known locations; and

estimate a location of said mobile device based, at least in part, on the measured differences.

13. The mobile device of claim 11, wherein said one or more processors are further to:

initiate transmission of one or more request messages to a transmitter requesting the at least one of said received packets having the payload comprising the known waveform or data sequence.

14. The mobile device of claim 11, wherein said known waveform or data sequence comprises a repeated field in the at least one of said received packets.

15. The mobile device of claim 11, wherein the known waveform or data sequence comprises a pseudonoise code.

16. The mobile device of claim 11, wherein the time-staggered quasi-matched filter correlators are configured to convolve a quantized version of the known waveform or data sequence with at least a portion of the payload.

17. The mobile device of claim 16, wherein the quantized version of the known waveform or data sequence is less than an entirety of the known waveform or data sequence.

18. The mobile device of claim 16, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of discrete values.

19. The mobile device of claim 16, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of two discrete values.

20. The mobile device of claim 16, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of four discrete values.

21. An article comprising:

a non-transitory storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to;

obtain a payload portion of at least one packet wirelessly received from a transmitter transmitted according to an IEEE std. 802.11 waveform, the payload portion comprising a known waveform or data sequence;

apply said known waveform or data sequence at time-staggered quasi-matched filter correlators to said payload portion to detect a correlation peak; and

estimate a time of arrival of said at least one packet based, at least in part, on said correlation peak and a time reference.

22. The article of claim 21, wherein said instructions are further executable by said special purpose computing apparatus to:

initiate transmission of one or more request messages to the transmitter requesting the at least one said received packets having a payload comprising the known waveform or data sequence.

23. The article of claim 21, wherein said known waveform or data sequence comprises a repeated field in the at least one of said received packets.

24. The article of claim 21, wherein the known waveform or data sequence comprises a pseudonoise code.

25. The article of claim 21, wherein the time-staggered quasi-matched filter correlators are configured to convolve a quantized version of the known waveform or data sequence with at least a portion of the payload portion.

26. The article of claim 25, wherein the quantized version of the known waveform or data sequence is less than an entirety of the known waveform or data sequence.

27. The article of claim 25, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of discrete values.

28. The article of claim 25, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of two discrete values.

29. The article of claim 25, wherein said quantized version of the known waveform or data sequence comprises a mapping of the known waveform or data sequence to a finite set of four discrete values.

30. An apparatus comprising:

means for wirelessly receiving one or more packets from a transmitter transmitted according to an IEEE 802.11 waveform, a payload of at least one of said received packets comprising a known waveform or data sequence; and

means for applying said known waveform or data sequence at time-staggered quasi-matched filter correlators to said payload to detect a correlation peak; and

means for estimating a time of arrival of said at least one of said at least one of said received packets based, at least in part, on said correlation peak and a time reference.