Determining the position of a mobile device using the characteristics of received signals and a reference database

• US 9,173,187 B2
• Filed: 11/15/2012
• Issued: 10/27/2015
• Est. Priority Date: 03/31/2008
• Status: Expired due to Fees

• Current Assignee: Golba LLC
• Original Assignee: Golba LLC
• Inventors: Moshfeghi, Mehran
• Primary Examiner(s): Phan, Dao
• Application Number:
  US13/678,484
• Publication Number:
  US 20130143595A1
• Time in Patent Office: 1,076 Days
• Field of Search: 342/453, 342/457, 342463-465, 455/65, 455/456.1, 455/456.2
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Some embodiments use scanning devices to characterize radio signals received at a number of locations within a geographical area of interest. The signal characteristics along with the location information associated with the characteristics are stored in a centralized reference database. A mobile device characterizes signals it receives at a certain location and compares the characteristics with the signal characteristics stored in the reference database to obtain accurate location information of the certain location.

Claims

1. A method of determining a location of a mobile device, the method comprising:

from each of a plurality of antennas of a single transmitting device, receiving a signal in a first plurality of signals at the mobile device over a plurality of transmission channels, each transmission channel corresponding to an antenna in the plurality of the antennas of the single transmitting device, wherein each signal in the first plurality of signals is received from the transmitting device at the mobile device through a direct line of sight such that the first plurality of signals does not comprise a multipath signal;

generating a first multichannel profile from a superposition of the first plurality of signals, the first multichannel profile comprising a first plurality of peaks, each peak in the first plurality of peaks corresponding to a signal in the first plurality of signals received over a transmission channel in the plurality of transmission channels;

computing a first plurality of parameters associated with the peaks of the first multichannel profile;

retrieving, from a database, a second plurality of computed parameters associated with a second plurality of peaks of a second multichannel profile generated from a superposition of a second plurality of signals previously received from the plurality of antennas of said transmitting device at a set of scanning devices;

correlating the first plurality of parameters with the second plurality of parameters; and

determining the location of the mobile device based on the correlation.

2. The method of claim 1, wherein computing a first plurality of parameters associated with the peaks of the first multichannel profile comprises characterizing a profile of the first plurality of signals to determine a first plurality of peak time of arrivals associated with the profile of the signals received at the mobile device, wherein the second plurality of parameters comprises a second plurality of peak time of arrivals associated with profiles of said second plurality of signals previously received from the plurality of the antennas of the transmitting device by the set of scanning devices.

3. The method of claim 1, wherein computing a first plurality of parameters associated with the peaks of the first multichannel profile comprises characterizing a profile of the first plurality of signals to determine a first plurality of peak time of arrivals associated with the profile of the signals received at the mobile device, wherein the profile of each signal has only one peak time of arrival corresponding to one direct line of sight signal, wherein the second plurality of parameters comprise a second plurality of peak time of arrivals associated with profiles of said second plurality of signals previously received from the plurality of the antennas of the transmitting device by the set of scanning devices.

4. The method of claim 1, wherein the first and second pluralities of parameters comprise a plurality of parameters characterizing the plurality of transmission channels, wherein the first and second pluralities of parameters comprise multichannel profiles and channel fast Fourier transform (FFT) coefficients.

5. The method of claim 1, wherein the transmitting device transmits signals of different standards comprising at least two of Wireless Local Area Network (WLAN) 802.11, Bluetooth, WiMax, HD Radio, Ultra-wideband (UWB), GPS, cellular, and 60 GHz standards.

6. The method of claim 1 further comprising receiving signals from a plurality of transmitting devices, wherein the transmitting devices transmit signals of different standards comprising at least two of Wireless Local Area Network (WLAN) 802.11, Bluetooth, WiMax, HD Radio, Ultra-wideband (UWB), GPS, cellular, and 60 GHz standards.

7. The method of claim 1, wherein each of the plurality of antennas of said single transmitting device transmits with an associated preset time delay in relation to other antennas, wherein the mobile device receives signals from each particular antenna of said single transmitting device at a particular delay in relation to the signals received from the other antennas of said single transmitting device, each particular delay proportional to (i) a distance between the particular antenna and (ii) the preset time delay associated with the antenna.

8. The method of claim 1, wherein the plurality of antennas of the transmitting device transmit together without a preset time delay.

20. The method of claim 1, wherein each parameter in the second plurality of parameters is associated with a location where a corresponding signal from the second plurality of signals was received, wherein each location associated with a parameter in the second set of parameters is identified by a set of coordinate values, the method further comprising:

calculating a correlation coefficient corresponding to each particular location based on the first plurality of parameters and the second plurality of parameters that is associated with the particular location; and

determining the location of the mobile device by computing a set of coordinate values for the location of the mobile device, each coordinate value for the location of the mobile device computed as a weighted average of each correlation coefficient multiplied by a coordinate value in the set of coordinate values corresponding to the second set of parameters.

21. The method of claim 20, wherein calculating the correlation coefficient corresponding to each particular location comprises:

multiplying each parameter in the first plurality of parameters with each parameter in the second plurality of parameters that is associated with the particular location;

summing a result of each multiplication to determine a correlation coefficient corresponding to the particular location; and

normalizing each correlation coefficient.

22. The method of claim 1, wherein the transmission channels are direct line of sight propagation channels.

9. A non-transitory machine readable medium storing a program for determining a location of a mobile device, the program executable by at least one processor, the program comprising sets of instructions for:

receiving, from each of a plurality of antennas of a single transmitting device, a signal in a first plurality of signals at the mobile device over a plurality of transmission channels, each transmission channel corresponding to an antenna in the plurality of the antennas of the single transmitting device, wherein each signal in the first plurality of signals is received from the transmitting device at the mobile device through a direct line of sight such that the first plurality of signals does not comprise a multipath signal;

generating a first multichannel profile from a superposition of the first plurality of signals, the first multichannel profile comprising a first plurality of peaks, each peak in the first plurality of peaks corresponding to a signal received over a transmission channel in the plurality of transmission channels;

computing a first plurality of parameters associated with the peaks of the first multichannel profile;

retrieving, from a database, a second plurality of computed parameters associated with a second plurality of peaks of a second multichannel profile generated from a superposition of a second plurality of signals previously received from the plurality of antennas of said transmitting device at a set of scanning devices;

correlating the first plurality of parameters with the second plurality of parameters; and

determining the location of the mobile device based on the correlation.

10. The non-transitory machine readable medium of claim 9, wherein the set of instructions for computing a first plurality of parameters associated with the peaks of the first multichannel profile comprises a set of instructions for characterizing a profile of the first plurality of signals to determine a first plurality of peak time of arrivals associated with the profile of the signals received at the mobile device, wherein the second plurality of parameters comprises a second plurality of peak time of arrivals associated with profiles of said second plurality of signals previously received from the plurality of the antennas of the transmitting device by the set of scanning devices.

11. The non-transitory machine readable medium of claim 9, wherein the set of instructions for computing a first plurality of parameters associated with the peaks of the first multichannel profile comprises a set of instructions for characterizing a profile of the first plurality of signals to determine a first plurality of peak time of arrivals associated with the profile of the signals received at the mobile device, wherein the profile of each signal has only one peak time of arrival corresponding to one direct line of sight signal, wherein the second plurality of parameters comprises a second plurality of peak time of arrivals associated with profiles of said second plurality of signals previously received from the plurality of the antennas of the transmitting device by the set of scanning devices.

12. The non-transitory machine readable medium of claim 9, wherein the first and second pluralities of parameters comprise a plurality of parameters characterizing the plurality of transmission channels, wherein the first and second pluralities of parameters comprise multichannel profiles and channel fast Fourier transform (FFT) coefficients.

13. The non-transitory machine readable medium of claim 9, wherein the transmitting device transmits signals of different standards comprising at least two of Wireless Local Area Network (WLAN) 802.11, Bluetooth, WiMax, HD Radio, Ultra-wideband (UWB), GPS, cellular, and 60 GHz standards.

14. The non-transitory machine readable medium of claim 9, the program further comprising a set of instructions for receiving signals from a plurality of transmitting devices, wherein the transmitting devices transmit signals of different standards comprising at least two of Wireless Local Area Network (WLAN) 802.11, Bluetooth, WiMax, HD Radio, Ultra-wideband (UWB), GPS, cellular, and 60 GHz standards.

15. The non-transitory machine readable medium of claim 9, wherein each of the plurality of antennas of said single transmitting device transmits with an associated preset time delay in relation to other antennas, wherein the mobile device receives signals from each particular antenna of said single transmitting device at a particular delay in relation to the signals received from the other antennas of said single transmitting device, each particular delay proportional to (i) a distance between the particular antenna and (ii) the preset time delay associated with the antenna.

16. The non-transitory machine readable medium of claim 9, wherein the plurality of antennas of the transmitting device transmit together without a preset time delay.

17. The non-transitory machine readable medium of claim 9, wherein each parameter in the second plurality of parameters is associated with a location where a corresponding signal from the second plurality of signals was received, wherein each location associated with a parameter in the second set of parameters is identified by a set of coordinate values, the program further comprising sets of instructions for:

calculating a correlation coefficient corresponding to each particular location based on the first plurality of parameters and the second plurality of parameters that is associated with the particular location; and

determining the location of the mobile device by computing a set of coordinate values for the location of the mobile device, each coordinate value for the location of the mobile device computed as a weighted average of each correlation coefficient multiplied by a coordinate value in the set of coordinate values corresponding to the second set of parameters.

18. The non-transitory machine readable medium of claim 17, wherein the set of instructions for calculating the correlation coefficient corresponding to each particular location comprises sets of instructions for:

multiplying each parameter in the first plurality of parameters with each parameter in the second plurality of parameters that is associated with the particular location;

summing a result of each multiplication to determine a correlation coefficient corresponding to the particular location; and

normalizing each correlation coefficient.

19. The non-transitory machine readable medium of claim 9, wherein the transmission channels are direct line of sight propagation channels.