Systems and methods for location positioning within radio access systems

• US 8,326,324 B2
• Filed: 01/08/2008
• Issued: 12/04/2012
• Est. Priority Date: 01/08/2008
• Status: Expired due to Fees

• Current Assignee: Wi-LAN Inc.
• Original Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Inventors: Yee, Jung, Wu, Shiquan
• Primary Examiner(s): BALAOING, ARIEL A
• Application Number:
  US12/007,198
• Publication Number:
  US 20090176507A1
• Time in Patent Office: 1,792 Days
• Field of Search: 455/456.2, 455/456.6, 455/414.2, 455/521, 342/450, 701/213, 701/214
• US Class Current: 455/456.2
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method for calculating the geographical position of a user equipment (UE) unit includes collecting position parameters conveying the relative position of the UE unit from two or more base stations using technologies mandated for the modern wireless networks. Particularly, know (predetermined) signals embedded in the downlink and uplink subframes, such as preambles, pilots, ranging codes are used for determining the coordinates of the UE unit. In addition, the methods and systems proposed here take advantage of the multiple antennas systems mandated at both the UE and BTS.

Claims

1. A method of operating a user equipment (UE) unit for determining the location of the UE, the UE operating within the coverage area of two or more base transceiver stations (BTS) that each transmit a respective specified periodic bit sequence over a radio access network, comprising:

at said UE unit,

obtaining geographical coordinates of a serving BTS and at least a first and a second BTS;

monitoring incoming traffic received from the serving BTS and the first and the second BTSs for detecting respective specified periodic bit sequences from the serving BTS and the first and second BTSs, wherein the first and second BTSs are selected based on the strength of said specified periodic bit sequences at said UE;

determining from said specified periodic bit sequences received from the serving BTS and the first and second BTSs a first set of position parameters using a first technique that convey the relative position of said UE unit to two or more of said BTSs;

determining from said specified periodic bit sequences received from the serving BTS and the first and second BTSs a second set of position parameters using a second technique that convey the relative angular position of said UE unit with respect to two or more of said BTSs; and

processing said first set of position parameters and said second set of position parameters for establishing the geographical coordinates of said UE unit.

2. A method as claimed in claim 1, wherein determining the first set of position parameters comprises:

establishing a first time of arrival (TOA1), a second time of arrival (TOA2) and third time of arrival (TOA3) of said specified periodic bit sequence from the serving BTS, and the first and second BTSs, respectively;

determining a first position parameter as a first time difference (T12) between the first and the second time of arrival; and

determining a second position parameter as a second time difference (T13) between the first and the third time of arrival.

3. A method as claimed in claim 1, wherein determining the second set of position parameters comprises:

determining a first position parameter as a first angle of arrival (AOA1) of said specified periodic bit sequence from a first BTS on a first antenna of said UE unit; and

determining a second position parameter as a second angle of arrival (AOA1) of said specified periodic bit sequence from a second BTS on a second antenna of said UE unit.

4. A method as claimed in claim 3, further comprising:

obtaining at said UE unit geographical coordinates of said BTSs; and

establishing the geographical coordinates of said UE unit based on said first and second angles of arrival and the geographical coordinates of said BTSs.

5. A method as claimed in claim 3, wherein said one of the first and second BTSs is selected based on the strength of their periodic bit sequence at said second antenna.

6. A method as claimed in claim 1, wherein said radio access network is a one of a WiMax, a 3GPP LTE and a UMB network.

7. A method as claimed in claim 1, wherein said specified periodic bit sequence used for said first technique is a preamble transmitted in the downlink subframes by each said BTS and said specified periodic bit sequence used for the second technique is a pilot tone transmitted in the downlink subframes by each said BTS.

8. A method as claimed in claim 1, wherein said specified periodic bit sequence is a pilot tone transmitted in the downlink subframes by each said BTS.

9. A method as claimed in claim 1, further comprising:

appending said geographical coordinates to an emergency call generated on said UE unit; and

routing said call from said UE unit to a public safety answering point.

10. A location identification module for a user equipment (UE) unit equipped with a first and a second antenna, comprising:

a monitoring unit for monitoring the incoming traffic received from a serving base transceiver station (BTS) and a first and a second BTS and identifying a respective specified periodic bit sequence received from each of the BTSs wherein the first and second BTSs are selected based on the strength of said periodic bit sequence at said UE;

a position parameters calculation arrangement for

determining from said specified periodic bit sequences received from the serving BTS and the first and second BTSs, a first set of position parameters using a first technique that convey the relative position of said UE unit to the BTSs and determining from said specified periodic bit sequences received from the serving BTS and the first and second BTSs a second set of position parameters using a second technique that convey the relative angular position of said UE unit to two or more of said BTS;

a memory for storing the geographical coordinates of said BTSs; and

a coordinate estimator for processing said first and second sets of position parameters and establishing the geographical coordinates of said UE unit.

11. A location identification module as claimed in claim 10, wherein said position parameters calculation arrangement includes:

means for establishing a first, second and third time of arrival (TOA1, TOA2, TOA3) of said specified periodic bit sequence from the serving BTS, and the first and the second BTS; and

means for determining the first set of position parameters including a first position parameter as a first time difference (T12) between the first and the second time of arrival and a second position parameter as a second time difference (T13) between the first and the third time of arrival.

12. A location identification module as claimed in claim 11, wherein said coordinate estimator comprises:

means for establishing the coordinates of said UE unit based on said first and second time differences and the geographical coordinates of said BTSs.

13. A location identification module as claimed in claim 10, wherein said position parameters calculation arrangement is configured to determine the second set of position parameters including a first angle of arrival of said specified periodic bit sequence received from the serving BTS at said first antenna and a second angle of arrival of said specified periodic bit sequence received from one of the first and second BTSs at said second antenna.

14. A location identification module as claimed in claim 10, further comprising a location call processor for appending said geographical coordinates to an emergency call generated on said UE unit and routing said call from said UE unit to a public safety answering point.

15. A location identification module as claimed in claim 14, further comprising a GPS unit for providing additional detailed location information to said location call processor for insertion into said call.