Position location using transmitters with timing offset and phase adjustment

• US 20070069953A1
• Filed: 01/05/2006
• Published: 03/29/2007
• Est. Priority Date: 09/27/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ling, Fuyun, Walker, Gordon, Mukkavilli, Krishna
• Granted Patent: US 8,981,996 B2
• Time in Patent Office: Days
• US Class Current: 342/463
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0226 Transmitters
• 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

Abstract

Systems and methods are provided for determining position location information in a wireless network. In one embodiment, timing offset information is communicated between multiple transmitters and one or more receivers. Such information enables accurate position or location determinations to be made that account for timing differences throughout the network. In another embodiment, transmitter phase adjustments are made that advance or delay transmissions from the transmitters to account for potential timing differences at receivers. In yet another embodiment, combinations of timing offset communications and/or transmitter phase adjustments can be employed in the wireless network to facilitate position location determinations.

Claims

1. A method to determine position information in a wireless network, comprising:

determining time offset information between a common clock and at least one other clock;

adjusting a phase of at least one transmitter based in part on the time offset information; and

determining a position for the receiver based in part on the time offset information or the adjusted phase of the transmitter.

2. The method of claim 1, the common clock is based on a global positioning system signal.

3. The method of claim of claim 1, further comprising communicating the time offset information to at least one receiver.

4. The method of claim 3, further comprising transmitting the timing offset information in a Forward Link Only (FLO) network;

and advancing or delaying transmitter timing in a Forward Link Only network to regulate an effective channel delay spread as perceived by the receiver.

5. The method of claim 4, the FLO network is deployed for Single Frequency Network (SFN) mode of operation where transmitters are synchronized to a common clock or performing a linear convolution of c channel with a transmitted signal.

6. The method of claim 1, further comprising generating at least two timing offsets.

7. The method of claim 6, further comprising controlling a delay spread by delaying or advancing a signal with respect to a synchronization pulse from a common clock.

8. The method of claim 6, further comprising setting a fixed timing offset between at least two transmitters.

9. The method of claim 6, further comprising sending a positive or negative parameter to indicate an advancing or a delaying of a transmission with respect to a common clock or delaying transmissions from transmitters to satisfy cyclic prefix requirements.

10. The method of claim 9, further comprising employing a long cyclic prefix to enable an estimation of delay from transmitters that are farther away.

11. The method of claim 1, further comprising determining a relative distance of a receiver from three or more known locations via triangulation methods.

12. A method for determining position information in a wireless network system, comprising:

determining at least one timing offset between a receiver and a transmitter in view of a common clock source in a wireless network system;

transmitting the time offset to the receiver or modifying a signal at the transmitter in view of the common clock source; and

calculating a position at the receiver base on the time offset or the modified signal.

13. The method of claim 12, further comprising broadcasting the timing offset using overhead symbols;

in a local area Overhead Information Symbol field, or a wide area Overhead Information Symbol field.

14. The method of claim 12, further comprising embedding the timing offset in a positioning pilot channel (PPC).

15. The method of claim 13, further comprising broadcasting an almanac of transmitters having the timing offset or relaying one or more pseudo ranges to the almanac of transmitters.

16. A wireless positioning system, comprising:

means for determining a timing offset between a common clock and at least one other clock in a wireless network;

means for transmitting the timing offset in the wireless network; and

means for altering a transmitter signal phase or a transmitter signal frequency base in part on the timing offset.

17. The system of claim 16, further comprising means for determining a location for a device based at least in part on the timing offset, the transmitter signal phase, or the transmitter signal frequency.

18. A machine readable medium having machine executable instructions stored thereon, comprising:

determining timing differences between a common clock with respect to a subset of transmitter clocks;

communicating the timing differences to at least one receiver; and

adjusting the transmitter clocks based in part on the timing differences.

19. The machine readable medium of claim 18, further comprising determining a location for the receiver based on the adjusted transmitter clocks or the determined timing differences.

20. The machine readable medium of claim 18, further comprising employing triangulation techniques with the subset of transmitter clocks to determine the location.

21. The machine readable medium of claim 18, further comprising a component to perform calculations to determine timing differences between transmitters, receivers, or a global positioning clock source.

22. The machine readable medium of claim 21, further comprising a component to determine how much to advance or delay transmitter broadcasts in order to account for timing differences.

23. The machine readable medium of claim 18, further comprising providing one or more test devices to monitor for potential system changes, where feedback is received from the test devices to facilitate determining offsets or transmitter signal adjustments.

24. The machine readable medium of claim 18, further comprising a component to transmit constant time offsets and utilize an adjustable signal source to advance or delay timing when environmental or electrical conditions change.

25. The machine readable medium of claim 24, further comprising changing time offsets or signal timing based upon closed-loop mechanisms.

26. A machine readable medium having a data structure stored thereon, comprising:

determining timing offsets between a common clock with respect to a subset of transmitter clocks;

storing the timing offsets in at least one data field; and

determining a transmitter signal phase or frequency adjustment for at least one device based in part on the timing offsets in the data field.

27. The machine readable medium of claim 26, further comprising a layer component having at least one of a physical layer, a stream layer, a medium access layer, and an upper layer, the physical layer further comprising at least one of a frame field, a pilot field, an overhead information field, a wide area field, and a local area field.

28. The machine readable medium of claim 27, further comprising a component to determine a position for at least one wireless device.

29. A wireless communications apparatus, comprising:

a memory that includes a component to determine a time base from time offset parameters received over a wireless network; and

a processor that determines a position for at least one receiver base on the time offset parameters or from signal or phase adjustments received from at least one transmitter.

30. The apparatus of claim 29, further comprising one or more components to decode a Forward Link Only data stream, time offset parameters, or adjusted transmitter signals.

31. An apparatus for operating base station resources in a wireless positioning network, comprising:

means for determining timing offsets for a set of transmitters;

means for communicating the timing offsets to at least one receiver; and

means for adjust a signal phase or a signal frequency for the set of transmitters in view of the timing offsets.

32. The apparatus of claim 31, further comprising means for coordinating with the receiver to determine a position for the receiver based on the timing offsets or the adjusted signal phase and signal frequency.