LOCATION DETERMINATION IN WIRELESS COMMUNICATION SYSTEMS

• US 20110110338A1
• Filed: 07/27/2010
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Chervyakov, Andrey, Shilov, Mikhail A., Maslennikov, Roman O., Maltsev, Alexander, Khoryaev, Alexey, Choi, Yang-Seok, Etemad, Kamran
• Granted Patent: US 8,477,690 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: G01S 5/0215 Interference
• 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: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Briefly, in accordance with one or more embodiments, a mobile station receives a location beacon transmitted from multiple base stations based on a transmission plan for a predefined downlink location based services zone in the superframes of a signal frame structure. The transmission plan includes spreading transmissions of the location beacon that are unique to respective base stations. The mobile station identifies the base stations based on the respective location beacons and the transmission plan. The mobile station identifies a present location based on the location beacons and the identities of the base stations that from which the location beacons were received.

Claims

1. A method, comprising:

configuring a transmission plan for a downlink location based services (D-LBS) zone based at least in part on resources available for transmission of location beacons, wherein the transmission plan assigns different base stations for transmission on different resources of the D-LBS zone to perform measurements of signal location parameters from multiple base stations or relay stations, or combinations thereof, of a network;

transmitting configuration parameters for the D-LBS zone from said configuring; and

transmitting one or more location beacon signals on an assigned resource of the D-LBS zone in accordance with the D-LBS zone transmission plan.

2. A method as claimed in claim 1, further comprising transmitting information about one or more neighboring base stations coordinates.

3. A method as claimed in claim 1, said transmitting one or more location beacon signals comprising transmitting in a subframe resource, frame resource, or superframe resource, or combinations thereof, in accordance with the transmission plan for coordinated transmission of location beacon signals.

4. A method as claimed in claim 1, wherein a mobile station receiving the one or more location beacon signals has knowledge of the transmission plan.

5. A method as claimed in claim 1, wherein said transmitting one or more location beacon signals includes designating a reference signal unique to a transmitting base station or relay station, or combinations thereof, appropriate for measurement of signal location parameters.

6. A method as claimed in claim 1, wherein the one or more location beacon signals comprise preamble signals, common pilot signals, precoded pilot signals, cell-specific reference signals, multiple-input and multiple-output (MIMO)-midable signals, or positioning reference signals, or combinations thereof.

7. A method as claimed in claim 1, wherein the configuration parameters comprise signal parameters capable of being measured and used for mobile positioning including time of arrival of the location beacon signals, time difference of arrival of the location beacon signals, received signal powers, received strength indicators, spatial angular information, or channel state information, or combinations thereof.

8. A method as claimed in claim 1, further comprising coordinating said transmitting one or more location beacon signals with the transmission of location beacon signals from other base stations or relay stations, or another source of a reference signal, or combinations thereof, of the network.

9. A method as claimed in claim 1, wherein the D-LBS zone comprises a set of orthogonal or quasi orthogonal frame resources including orthogonal carrier sets, subcarrier sets, time intervals, code division multiple access (CDMA) code sequences, or spatial beam forming, or combinations thereof, used for coordinated transmission of location beacon signals.

10. A method as claimed in claim 1, further comprising spreading said transmitting of the one or more location beacon signals that are unique to a transmitter to facilitate identification of the transmitter and to mitigate interference from other transmitters to result in more accurate measurements of signal location parameters.

11. A method as claimed in claim 1, said transmitting one or more location beacon signals comprising transmitting an existing reference signal or a new reference signal, or combinations thereof, for measurement of signal location parameters transmitted in accordance with the transmission plan.

12. A method as claimed in claim 1, wherein the location beacons signals comprise secondary advanced preamble (SA-Preamble) sequences or any other kind of existing reference signal that are transmitted in accordance with the D-LBS zone transmission plan. The retransmission of existing (already defined in the standard) reference signals in D-LBS zone is useful since allows to use the same hardware or software processing modules that responsible for measurements of signal location parameters and significantly simplifies implementation efforts.

13. A method as claimed in claim 1, said transmitting one or more location beacon signals on an assigned resource of the D-LBS zone being performed in lieu of existing synchronization signals or downlink control channels, or in the event a specific frame resource is assigned to the D-LBS zone, or combinations thereof.

14. A method as claimed in claim 1, wherein said transmitting one or more location beacon signals occurs periodically, or within a predefined window in response to a triggering event, or combinations thereof.

15. A method as claimed in claim 1, said transmitting one or more location beacon signals comprising using beam forming to carry spatial angular information via spatial precoding of the location beacon to facilitate determination of angle of departure of the location beam transmission.

16. A method as claimed in claim 1, wherein the transmission plan comprises:

partitioning a set of location beacons into a number of groups based on a number of resources available in the downlink location based services zone; and

assigning location a beacon that belongs to particular station for transmission on a particular resource of the D-LBS zone using a cell identification number of that station; and

executing said transmitting one or more location beacons the corresponding resource if the cell identification of the station matches a the station in the transmission plan.

17. A method as claimed in claim 1, wherein the transmission plan comprises a pseudorandom transmission plan.

18. A method as claimed in claim 1, wherein the transmission plan comprises a pseudorandom transmission plan, the pseudorandom transmission plan comprising:

setting a pseudorandom number generator to an initial value that depends on a cell identification if a superframe or a frame count is zeroed;

for subsequently allocated D-LBS zones, calculating a recursion using the pseudorandom number generator and an initial cell identification value of the station; and

executing said transmitting one or more location beacons based at least in part on the calculated recursion value.

23. A method as claimed in claim 12, further comprising using spatial angular information of the location beacon to facilitate determination of angle of departure of the location beam transmission of the base stations.

19. A method, comprising:

receiving a location beacon transmitted from multiple base stations based at least in part on a transmission plan for a downlink location based services zone (D-LBS) in a signal subframe, frame or superframe structure, or combinations thereof, wherein the transmission plan includes spreading transmissions of the location beacon that are unique to respective base stations;

identifying the base stations based at least in part on the respective location beacons and the transmission plan;

measuring signal location parameters of the identified base stations; and

identifying a present location based at least in part on the location beacons and the identities of the base stations from which the location beacons were received.

20. A method as claimed in claim 19, wherein the location beacons are received using a physical structure of a secondary advanced preamble, an alternative reference signal, or a predefined reference signal, or combinations thereof.

21. A method as claimed in claim 19, wherein said receiving a location beacon or measuring of signal location parameters, or combinations thereof, occur periodically.

22. A method as claimed in claim 19, wherein said receiving a location beacon or said measuring of signal location parameters, or combinations thereof, occur within a predefined window in response to a triggering event.

24. A method as claimed in claim 19, wherein the transmission plan comprises a predefined transmission plan.

25. A method as claimed in claim 19, wherein the transmission plan comprises a predefined transmission plan, the predefined transmission plan comprising:

partitioning a set of location beacons into a number of groups based at least in part on a number of resources available in the downlink location based services zone (D-LBS); and

reproducing the transmission plan at the receiver side to identify on which resources candidate base stations of the D-LBS zone transmit location beacons and to perform measurement of signal location parameters for the set of advertised neighboring base station;

executing said identifying the base stations based at least in part on matching a cell identification of a base station of a corresponding D-LBS zone resource on which a location beacon was received and performing measurements of signal location parameters.

26. A method as claimed in claim 19, wherein the transmission plan comprises a pseudorandom transmission plan.

27. A method as claimed in claim 19, wherein the transmission plan comprises a pseudorandom transmission plan, the pseudorandom transmission plan comprising:

setting a pseudorandom number generator to an initial value that may depend on a cell identification;

reinitializing generator pseudorandom number generator in the event a superframe count or a frame count, or combinations thereof, is zeroed;

for subsequent allocation of D-LBS zone, calculating a generator recursion and reproducing the transmission plan to identify resources that belong to advertised neighboring stations; and

executing said identifying the base stations based at least in part on matching a cell identification of a base station to a resource in a D-LBS zone based at least in part on the calculated recursion value for a received location beacon and measuring of signal location parameters for identified base stations on particular D-LBS zone resource.

28. An article of manufacture comprising a storage medium having instructions stored thereon that, if executed, result in:

configuring a transmission plan for a downlink location based services (D-LBS) zone based at least in part on resources available for transmission of location beacons, wherein the transmission plan assigns different base stations for transmission on different resources of the D-LBS zone to perform measurements of signal location parameters from multiple base stations or relay stations, or combinations thereof, of a network;

transmitting configuration parameters for the D-LBS zone from said configuring; and

transmitting one or more location beacon signals on an assigned resource of the D-LBS zone in accordance with the D-LBS zone transmission plan.

29. An article of manufacture as claimed in claim 28, wherein the instructions, if executed, further result in transmitting information about one or more neighboring base stations coordinates.

30. An information handling system, comprising:

a processor and a memory coupled to the processor, wherein instructions in the memory configure the processor to;

receive a location beacon transmitted from multiple base stations based at least in part on a transmission plan for a downlink location based services zone (D-LBS) in a signal subframe, frame or superframe structure, or combinations thereof, wherein the transmission plan includes spreading transmissions of the location beacon that are unique to respective base stations;

identify the base stations based at least in part on the respective location beacons and the transmission plan;

measure signal location parameters of the identified base stations; and

identify a present location based at least in part on the location beacons and the identities of the base stations from which the location beacons were received.