METHOD FOR POSITIONING MOBILE DEVICES AND APPARATUS FOR POSITIONING MOBILE DEVICES

• US 20110019567A1
• Filed: 01/29/2008
• Published: 01/27/2011
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Ma, Yuanyuan, Jiao, Wenhua, Liu, Ruoju, Jiang, Pin
• Granted Patent: US 8,588,087 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination
• CPC Class Codes: G01S 5/08 Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The present invention relates to a mobile communication field. The present invention provides a method and an apparatus for WiMAX positioning by downlink preamble fast detection DPFD. The method comprises steps of: Mobile user station MSS detects downlink preambles from BSs, all of which are synchronized by in TDD mode mobile WiMAX; the TDoA of different BSs'"'"' preamble is get through preamble-based synchronization detection; and the exact location is calculated through classical TDoA algorithms. The embodiment of the present invention describes a novel concept for measuring the position of the mobile user equipment by the uplink ranging assistant downlink preamble detection. With the mobile WiMAX is accepted as a 3G standard by ITU and widely populated, the position based on WiMAX will be a market-potential service.

Claims

1. A method for WiMAX positioning by downlink preamble fast detection DPFD, comprising steps of:

Mobile user station MSS detecting downlink preambles from BSs, all of which are synchronized by in TDD mode mobile WiMAX;

Getting the TDoA of different BSs'"'"' preamble through preamble-based synchronization detection; and

Calculating the exact location through classical TDoA algorithms.

2. The method as claimed in claim 1, wherein if there are less than three preambles detected, an Uplink Ranging Assistant detection (URAD) approach is performed to provide assistant data to perform ranging.

4. The method as claimed in claim 2, wherein the MSS do ranging with the serving/anchor BS to get additional delay measurements for TDoA calculation in the URAD method.

5. The method as claimed in claim 4, wherein in the case that there are two possible roots for one round trip delay RTD, the cell ID or sector ID information is used to choose one accurate root for the cell/sector.

6. The method as claimed in claim 4, wherein in the case that there are two possible roots for one round trip delay RTD, if the two roots are at the same cell/sector, the middle point of the two roots is chosen as the estimated position.

7. The method as claimed in claim 1, wherein after the downlink synchronization and uplink transmission parameters are acquired, the MSS transmits randomly selected Ranging code in a randomly selected Ranging Slot from available Ranging Region.

8. The method as claimed in claim 1, wherein after the BS receives the Ranging Code, it will send RNG-RSP with Time Corrections and the delay measurement will be gotten simultaneously.

9. The method as claimed in claim 1, wherein the single/round trip delay can be obtained by BS when either initial ranging or periodical ranging happens, and the BS stores such a delay, i.e. latest updated value, in its memory and send it to the location computation server along with the one time offset when two preambles detected in MSS.

12. The method as claimed in claim 1, wherein the moving-window based preamble detection is used for TDoA detection.

13. The method as claimed in claim 12, wherein said TDoA detection comprises steps of:

Moving one sample chip;

FFT converting; and

Correlating with the neighbor BS preamble by the local candidate preamble series.

14. The method as claimed in claim 1, wherein

if many NLoS preambles and two LoS ones are detected, the Wylie identification method is used to identify which signal is NLoS;

and

the two LoS signals as well as uplink ranging information are used to calculate location through said URAD-TDoA approach.

15. The method as claimed in claim 1, wherein If only one LoS preamble is detected or only one LoS is reconstructed from NLoS signals, uplink ranging assistant cell/sector ID approach is used.

16. The method as claimed in claim 1, wherein

for the cases that only one LOS preamble is detected, the ranging information is used to obtain a circle whose diameter is the RTD;

and

the cell ID and sector ID are used to assist positioning.

17. The method as claimed in claim 16, wherein the middle of the arc in the sector is used as the estimated positioning.

3. (canceled)

10. (canceled)

11. (canceled)

18. (canceled)

19. (canceled)

20. An apparatus for WiMAX positioning, comprising of:

a PHY layer module, for performing time difference detection in MSS;

a MAC layer module, for performing certain signaling and providing conditions for the channel measurement according to positioning request from application layer; and

an application layer module, for performing positioning or optional velocity computation based on measurements.

21-25. -25. (canceled)