Excess Delay Estimation Using Total Received Power

• US 20080094277A1
• Filed: 12/08/2004
• Published: 04/24/2008
• Est. Priority Date: 12/08/2003
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V., Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rick, Roland Reinhard
• Granted Patent: US 8,725,161 B2
• Time in Patent Office: Days
• US Class Current: 342/357.29
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

To determine the position of a mobile device located within a coverage area of a base station, the time of arrival (TOA) of the CDMA signal received by the mobile device from the base station is reduced in proportion to the received power of the CDMA signal. The mobile device uses the reduced TOA of the CDMA signals together with the received GPS signals to detect its position. Alternatively, the mobile device transmits the TOA and power measurements of the received CDMA signals to a position determination entity (PDE). The PDE biases the TOA to estimate the position of the mobile device and transmits assistance data to the mobile device, thereby enabling the mobile device to receive GPS signals. The received GPS signals alone, or in combination with the biased TOA are then used to recompute the position of the mobile device.

Claims

1. A method for detecting a location of a mobile device in a wireless communication network, comprising:

receiving a signal from a base station in the wireless communication network;

measuring a time of arrival and a power of the received signal;

defining a time delay according to the measured power;

reducing the time of arrival by the defined time delay; and

detecting the location of the mobile device according to the reduced time of arrival.

2. The method of claim 1 wherein the time delay can be described by:

E=A exp(−

BP_dBm)

where E represents the time delay, P_dBm represents the received power in dB, and A, B are constants.

3. The method claim 1 wherein the time delay is defined using data gathered at the field.

4. The method of claim 1 further comprising transmitting the detected position to another entity via the base station.

5. The method of claim 1 further comprising:

receiving data regarding location and position of at least one GPS satellite;

receiving a signal from the at least one GPS satellite; and

detecting the location of the mobile device in accordance with the reduced time of arrival and a time of arrival of the signal received from the at least one GPS satellite.

6. The method of claim 1 further comprising:

receiving data regarding locations and positions of a plurality of GPS satellites;

receiving a signal from each of the plurality of the GPS satellites; and

detecting the location of the mobile device in accordance with time of arrival of each of the signals received from the plurality of the GPS satellites.

7. A mobile device configured to receive a signal from a base station disposed in a wireless communication network, comprising:

a module to measure a time of arrival and a power of the received signal;

a module to define a time delay in accordance with the measured power;

a module to reduce the time of arrival signal by the defined time delay; and

a module to detect the location of the mobile device in accordance with the reduced time of arrival.

8. The mobile device of claim 7 wherein the time delay can be described by:

E=A exp(−

BP_dBm)

where E represents the time delay, P_dBm represents the received power in dB, and A, B are constants.

9. The mobile device of claim 7 wherein the time delay is defined using data gathered at the field.

10. The mobile device of claim 7 further comprising a module adapted to transmit the detected position to another entity via the base station.

11. A wireless communication network comprising:

a plurality of base stations; and

a mobile device configured to receive a signal from at least one of the plurality of base stations, and comprising;

a module to measure a time of arrival and a power of the received signal;

a module to define a time delay in accordance with the measured power;

a module to reduce the time of arrival by the defined time delay; and

a module to detect the location of the mobile device according to the reduced time of arrival.

12. The wireless communication network of claim 11 wherein the time delay can be described by:

E=A exp(−

BP_dBm)

where E represents the time delay, P_dBm represents the received power in dB, and A, B are constants.

13. The wireless communication network of claim 11 wherein the time delay is defined using data gathered at the field.

14. The wireless communication network of claim 11 wherein the mobile device further comprises a module adapted to transmit the detected position to another entity via the base station.

15. The wireless communication network of claim 11 further comprising a position determination entity in communication with the mobile device via the at least one of the plurality of base stations, and including a module to transmit data regarding location and position of at least one GPS satellite to the mobile device, and a module to detect the location of the mobile device in accordance with the reduced time of arrival and a time of arrival of a signal transmitted by the at least one GPS satellite and received by the mobile device.

16. The wireless communication network of claim 11 further comprising a position determination entity in communication with the mobile device via the at least one of the plurality of base stations, and including a module to transmit data regarding locations and positions of a plurality of GPS satellites, and a module to detect the location of the mobile device in accordance with time of arrivals of signals transmitted by the plurality of GPS satellite and received by the mobile device.

17. The wireless communication network of claim 11 wherein said mobile device further comprises:

a module to receive data regarding location and position of at least one GPS satellite from a position determination entity; and

a module to detect the location of the mobile device in accordance with the reduced time of arrival and a time of arrival of a signal received from the at least one GPS satellite.

18. The wireless communication network of claim 11 wherein said mobile device further comprises:

a module to receive data regarding locations and positions of a plurality of GPS satellites; and

a module to detect the location of the mobile device in accordance with time of arrivals of signals received from the plurality of GPS satellite.

19. A mobile device to receive a signal from a base station in a wireless communication network, comprising:

means for measuring a time of arrival and a power of the received signal;

means for defining a time delay according to the measured power;

means for reducing the time of arrival by the defined time delay; and

means for detecting the location of the mobile device according to the reduced time of arrival.

20. The mobile device of claim 19 wherein the time delay can be described by:

E=A exp(−

BP_dBm)

where E represents the time delay, P_dBm represents the received power in dB, and A, B are constants.

21. The mobile device of claim 19 wherein the time delay is defined using data gathered at the field.

22. The mobile device of claim 19 further comprising means for transmitting the detected position to another entity via the base station.

23. A wireless communication network comprising:

a plurality of base stations; and

a mobile device configured to receive a signal from at least one of the plurality of base stations, including;

means for measuring a time of arrival and a power of the received signal;

means for defining a time delay according to the measured power;

means for reducing the time of arrival by the defined time delay; and

means for detecting the location of the mobile device according to the reduced time of arrival.

24. The wireless communication network of claim 23 wherein the time delay can be described by:

E=A exp(−

BP_dBm)

where E represents the time delay, Pd_dBm represents the received power in dB, and A, B are constants.

25. The wireless communication network of claim 23 wherein the time delay is defined using data gathered at the field.

26. The wireless communication network of claim 23 wherein the mobile device further comprises means for transmitting the detected position to another entity via the base station.

27. The wireless communication network of claim 23 further comprising a position determination entity in communication with the mobile device via the at least one of the plurality of base stations, and including means for transmitting data regarding location and position of at least one GPS satellite to the mobile device, and means for detecting the location of the mobile device in accordance with the reduced time of arrival and a time of arrival of a signal transmitted by the at least one GPS satellite and received by the mobile device.

28. The wireless communication network of claim 23 further comprising a position determination entity in communication with the mobile device via the at least one of the plurality of base stations, and including means for transmitting data regarding locations and positions of a plurality of GPS satellites, and means for detecting the location of the mobile device in accordance with time of arrivals of signals transmitted by the plurality of GPS satellite and received by the mobile device.

29. The wireless communication network of claim 23 wherein said mobile device further comprises:

means for receiving data regarding location and position of at least one GPS satellite from a position determination entity; and

means for detecting the location of the mobile device in accordance with the reduced time of arrival and a time of arrival of a signal received from the at least one GPS satellite.

30. The wireless communication network of claim 23 wherein said mobile device further comprises:

means for receiving data regarding locations and positions of a plurality of GPS satellites; and

means for detecting the location of the mobile device in accordance with time of arrivals of signals received from the plurality of GPS satellite.