Methods and Apparatuses for Improving Quality of Positioning

• US 20150071093A1
• Filed: 05/15/2014
• Published: 03/12/2015
• Est. Priority Date: 09/09/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ALDANA, Carlos Horacio
• Granted Patent: US 9,532,328 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/025 using location based information parameters
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods and apparatuses of improving quality of positioning are disclosed. According to aspects of the present disclosure, a transition from a short training field to a long training field in one or more communication messages between two wireless stations may be detected. A station may then determine a first arrival correction time based on the transition from the short training field and the long training field. With the first arrival correction time, more accurate timing of communications between the two wireless stations may be determined and used for improving quality of positioning applications.

Claims

1. A method of determining a range between two stations, comprising:

receiving a message at a first station, wherein the message comprises at least a short training field and a long training field received from a second station;

detecting a transition from the short training field to the long training field;

determining a first arrival correction time based at least in part on the transition from the short training field to the long training field; and

assisting the second station to determine a range of the second station in accordance with the first arrival correction time.

2. The method of claim 1, wherein the detecting the transition from the short training field to the long training field comprises:

monitoring a window of impulse responses of the message received;

generating a normalized energy level of the window of impulse responses with respect to time using the message received; and

identifying the transition from the short training field to the long training field based at least in part on the normalized energy level exceeds a predetermined threshold.

3. The method of claim 2, wherein the predetermined threshold represents a fraction of the normalized energy level of the window of impulse responses.

4. The method of claim 1, wherein the determining the first arrival correction time comprises:

determining a first arrival time using the transition from the short training field to the long training field; and

determining the first arrival correction time according to a difference between the first arrival time and an expected arrival time.

5. The method of claim 1, wherein the assisting the second station to determine the range of the second station in accordance with the first arrival correction time comprises:

transmitting a first message to the second station, wherein the first message is used to compute an adjusted time of reception of the first message from the first station using the first arrival correction time and to determine the range of the second station based at least in part on the adjusted time of reception of the first message.

6. The method of claim 5, wherein the assisting the second station to determine the range of the second station in accordance with the first arrival correction time further comprises:

transmitting a second message to the second station, wherein the second message includes an adjusted time stamp from the first station, and wherein the adjusted time stamp from the first station is used to determine the range of the second station.

7. The method of claim 6, wherein the adjusted time stamp from the first station comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time.

8. The method of claim 6, wherein the adjusted time stamp from the first station further comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time and a random noise.

9. A computer program product comprising a non-transitory medium storing instructions for execution by one or more computer systems, the instructions comprising:

instructions for receiving a message at a first station, wherein the message comprises at least a short training field and a long training field received from a second station;

instructions for detecting a transition from the short training field to the long training field;

instructions for determining a first arrival correction time based at least in part on the transition from the short training field to the long training field; and

instructions for assisting the second station to determine a range of the second station in accordance with the first arrival correction time.

10. The computer program product of claim 9, wherein the instructions for detecting the transition from the short training field to the long training field comprises:

instructions for monitoring a window of impulse responses of the message received;

instructions for generating a normalized energy level of the window of impulse responses with respect to time using the message received; and

instructions for identifying the transition from the short training field to the long training field based at least in part on the normalized energy level exceeds a predetermined threshold.

11. The computer program product of claim 10, wherein the predetermined threshold represents a fraction of the normalized energy level of the window of impulse responses.

12. The computer program product of claim 9, wherein the instructions for determining the first arrival correction time comprises:

instructions for determining a first arrival time using the transition from the short training field to the long training field; and

instructions for determining the first arrival correction time according to a difference between the first arrival time and an expected arrival time.

13. The computer program product of claim 9, wherein the instructions for assisting the second station to determine the range of the second station in accordance with the first arrival correction time comprises:

instructions for transmitting a first message to the second station, wherein the first message is used to compute an adjusted time of reception of the first message from the first station using the first arrival correction time and to determine the range of the second station based at least in part on the adjusted time of reception of the first message.

14. The computer program product of claim 13, wherein the instructions for assisting the second station to determine the range of the second station in accordance with the first arrival correction time further comprises:

instructions for transmitting a second message to the second station, wherein the second message includes an adjusted time stamp from the first station, and wherein the adjusted time stamp from the first station is used to determine the range of the second station.

15. The computer program product of claim 14, wherein the adjusted time stamp from the first station comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time.

16. The computer program product of claim 14, wherein the adjusted time stamp from the first station further comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time and a random noise.

17. A device, comprising:

a transceiver configured to receive a message at the device, wherein the message comprises at least a short training field and a long training field received from a second station;

one or more processors or digital signal processors or combination thereof configured to

detect a transition from the short training field to the long training field;

determine a first arrival correction time based at least in part on the transition from the short training field to the long training field; and

assist the second station to determine a range of the second station in accordance with the first arrival correction time.

18. The device of claim 17, wherein the one or more processors or digital signal processors or combination thereof configured to detect the transition from the short training field to the long training field are further configured to:

monitor a window of impulse responses of the message received;

generate a normalized energy level of the window of impulse responses with respect to time using the message received; and

identify the transition from the short training field to the long training field based at least in part on the normalized energy level exceeds a predetermined threshold.

19. The device of claim 17, wherein the one or more processors or digital signal processors or combination thereof configured to determine the first arrival correction time are further configured to:

determine a first arrival time using the transition from the short training field to the long training field; and

determine the first arrival correction time according to a difference between the first arrival time and an expected arrival time.

20. The device of claim 17, wherein the one or more processors or digital signal processors or combination thereof configured to assist the second station to determine the range of the second station in accordance with the first arrival correction time are further configured to:

transmit a first message to the second station, wherein the first message is used to compute an adjusted time of reception of the first message from the device using the first arrival correction time and to determine the range of the second station based at least in part on the adjusted time of reception of the first message.

21. The device of claim 20, wherein the one or more processors or digital signal processors or combination thereof configured to assist the second station to determine the range of the second station in accordance with the first arrival correction time further are further configured to:

transmit a second message to the second station, wherein the second message includes an adjusted time stamp from the device, and wherein the adjusted time stamp from the device is used to determine the range of the second station.

22. The device of claim 21, wherein the adjusted time stamp from the device comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time.

23. The device of claim 21, wherein the adjusted time stamp from the device further comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time and a random noise.

24. An apparatus, comprising:

means for receiving a message at the apparatus, wherein the message comprises at least a short training field and a long training field received from a second station;

means for detecting a transition from the short training field to the long training field;

means for determining a first arrival correction time based at least in part on the transition from the short training field to the long training field; and

means for assisting the second station to determine a range of the second station in accordance with the first arrival correction time.

25. The apparatus of claim 24, wherein the means for detecting the transition from the short training field to the long training field comprises:

means for monitoring a window of impulse responses of the message received;

means for generating a normalized energy level of the window of impulse responses with respect to time using the message received; and

means for identifying the transition from the short training field to the long training field based at least in part on the normalized energy level exceeds a predetermined threshold.

26. The apparatus of claim 24, wherein the means for determining the first arrival correction time comprises:

means for determining a first arrival time using the transition from the short training field to the long training field; and

means for determining the first arrival correction time according to a difference between the first arrival time and an expected arrival time.

27. The apparatus of claim 24, wherein the means for assisting the second station to determine the range of the second station in accordance with the first arrival correction time comprises:

means for transmitting a first message to the second station, wherein the first message is used to compute an adjusted time of reception of the first message from the apparatus using the first arrival correction time and to determine the range of the second station based at least in part on the adjusted time of reception of the first message.

28. The apparatus of claim 27, wherein the means for assisting the second station to determine the range of the second station in accordance with the first arrival correction time further comprises:

means for transmitting a second message to the second station, wherein the second message includes an adjusted time stamp from the apparatus, and wherein the adjusted time stamp from the apparatus is used to determine the range of the second station.

29. The apparatus of claim 28, wherein the adjusted time stamp from the apparatus comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time.

30. The apparatus of claim 28, wherein the adjusted time stamp from the apparatus further comprises:

a time of reception of acknowledgement from the second station plus the first arrival correction time and a random noise.