Positioning method and radio system

• US 7,376,428 B2
• Filed: 07/10/2003
• Issued: 05/20/2008
• Est. Priority Date: 01/12/2001
• Status: Expired due to Term

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Hottinen, Ari
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US10/616,292
• Publication Number:
  US 20040072579A1
• Time in Patent Office: 1,776 Days
• Field of Search: 4554561-4566, 455/404.1, 455/404.2, 455457-458, 455524-526, 455/550.1, 455/556.2, 455560-561, 455/562.1, 455101-103, 455/91, 455/130, 455/132, 455/143, 455/15, 455/575.7, 455/115.1, 455/13.3, 370/310.1, 370319-321, 370/328, 370/395.3, 343/907, 343/844, 343/824, 343/729, 342/423, 342/437, 342/445, 375/267, 375/295, 375/299, 375/347
• US Class Current: 455/456.1
• CPC Class Codes: G01S 3/40 adjusting orientation of a single directivity characteristic to produce maximum or minimum signal, e.g. rotatable loop antenna or equivalent goniometer system
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0667 of delayed versions of same signal using space-time coding H04L1/0618
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming

Abstract

The invention relates to a method for performing positioning in a radio system. At least two different antenna elements of an array antenna of a base station transmit mutually non-interfering identifier signals that are received by a terminal that generates a spatial signature of the received signals. Either the terminal or the network part of the radio system defines the location of a transmitter or receiver by means of the spatial signature of the signals.

Claims

1. A method for performing positioning in a radio system, the method comprising:

transmitting at least one identifier signal to at least two different channels, each identifier signal being suited for channel estimation;

receiving, in a receiver, said at least one identifier signal through at least two different channels;

estimating, based on the at least one received identifier signal from the at least two different channels, a spatial signature of the channels; and

defining, based on the spatial signature, information related to a position of the receiver or the transmitter, of the at least one identifier signal.

2. A method as claimed in claim 1, further comprising defining, as the information related to the location, at least one direction between the receiver and transmitter based on the spatial signature of the signals.

3. A method as claimed in claim 1, further comprising defining the information related to the location by comparing an estimated spatial signature with known spatial signatures and defining, as the location, a position whose known spatial signature is closest to the estimated spatial signature.

4. A method as claimed in claim 1, further comprising transmitting the identifier from at least two different antenna elements in order to transmit the identifier signals to the at least two different channels.

5. A method as claimed in claim 1, further comprising defining the information related to the location according to a map coordinate system when the location of at least the transmitter or receiver is specified in the map coordinate system.

6. A method as claimed in claim 1, further comprising forming the spatial signature by utilizing several channel estimate matrices generated at different time instants.

7. A method as claimed in claim 6, further comprising generating from different channel estimates at least one covariance matrix of at least one channel and forming the spatial signature based on at least one specific vector of the covariance matrix.

8. A method as claimed in claim 7, further comprising defining a first dominant delay path by utilizing specific values of the channel covariance matrix calculated for different delay paths or the channel singular values in such a manner that the dominant delay path is the path having the highest specific value energy.

9. A method as claimed in claim 7, further comprising defining a first delay path whose specific value energy exceeds a predefined threshold value.

10. A method as claimed in claim 6, further comprising generating a singular value decomposition for a channel estimate matrix, by means of which specific value vectors of the covariance matrix are defined for the definition of the information related to the location.

11. A method as claimed in claim 1, further comprising forming the spatial signature by utilizing several channel estimate matrices generated on different frequencies.

12. A method as claimed in claim 1, further comprising forming the spatial signature by utilizing several channel estimate matrices calculated from different reception antennas.

13. A method as claimed in claim 1, further comprising utilizing additionally in the positioning at least one of the following measurements:

defining the direction of arrival as a DOA measurement,

defining the angle of arrival as an AOA measurement,

for the purpose of comparing the direction of reception and transmission with each other.

14. A method as claimed in claim 1, further comprising utilizing additionally in the positioning at least one of the following measurements:

measuring the time of arrival as a TOA measurement,

measuring the time difference of arrival as a TDOA measurement,

for the purpose of defining the distance between the transmitter and receiver.

15. A method as claimed in claim 1, wherein in the receiving of said at least one identifier signals, the identifier signals are at least partly uncorrelated.

16. A method as claimed in claim 1, wherein in the receiving of said at least one identifier signals, the identifier signals are orthogonal.

17. A method as claimed in claim 1, further comprising using the elements or parameters of the channel estimate corresponding to the shortest delay in the spatial signature of the signals.

18. A method as claimed in claim 1, further comprising generating the identifier signals in such a manner that the signals are transmitted from the different antenna elements at different time instants.

19. A method as claimed in claim 1, further comprising generating the identifier signals by coding the signals to be substantially non-interfering to each other.

20. A method as claimed in claim 1, further comprising generating the identifier signals by transmitting the signals on different frequencies.

21. A method as claimed in claim 1, wherein in the receiving of said at least one identifier signals, a terminal serves as the receiver and performs its own positioning.

22. A method as claimed in claim 21, further comprising signalling necessary information on the antenna structure or antenna element location of a base station to the terminal.

23. A method as claimed in claim 1, further comprising signalling the spatial signatures or the parameters of the spatial signatures of the received signals to a base station and defining the location of the receiver in the network part of the radio system.

24. A method as claimed in claim 1, further comprising using one or more base stations in defining the location of the receiver.

25. A method as claimed in claim 1, further comprising calculating a received power based on the spatial signature of the signals and maximizing the received power in relation to a transmission direction for the purpose of defining the information related to the location between the transmitter and receiver.

26. A method as claimed in claim 1, further comprising estimating, by the terminal, the position of the transmitter, transmitting the identifier signal.

27. A method as claimed in claim 1, wherein the identifier signals are broadcast signals.

28. A method as claimed in claim 27, wherein the identifier signals are common pilot channel signals of a WCDMA radio system.

29. A method as claimed in claim 1, wherein the identifier signals are channel-specific training sequences.

30. A method as claimed in claim 1, wherein the identifier signals are transmitted on a dedicated channel.

31. A radio system configured to perform positioning the radio system comprising:

a transmitter;

a receiver;

at least one base station; and

wherein the transmitter comprises an antenna comprising at least two antenna elements;

the transmitter is configured to transmit at least one identifier signal to at least two different channels, each identifier signal being suited for channel estimation;

the receiver is configured to receive said at least one identifier signal;

the receiver is configured to estimate, on the basis of the at least one received identifier signal from the at least two different channels, a spatial signature of the channels; and

wherein in the radio system, positioning is configured to define, based on the spatial signature, information related to the location of a receiver or a transmitter, of the at least one identifier signal.

32. A radio system as claimed in claim 31, wherein the radio system is further configured to define, as the information related to the location, at least one direction between the receiver and transmitter based on the spatial signature of the signals.

33. A radio system as claimed in claim 31, wherein to transmit the identifier signals to at least two different channels, the transmitter is further configured to transmit the identifier signal from at least two different antenna elements.

34. A radio system as claimed in claim 31, wherein the radio system is further configured to compare an estimated spatial signature with known spatial signatures and to define, as the location, a position whose known spatial signature is closest to the estimated spatial signature.

35. A radio system as claimed in claim 31, wherein in the radio system the location of the transmitter or receiver is specified in a map coordinate system, the radio system is further configured to define the information related to the location according to the map coordinate system.

36. A radio system as claimed in claim 31, wherein in the radio system, the receiver is further configured to form the spatial signature by utilizing several channel estimate matrices generated at different time instants.

37. A radio system as claimed in claim 36, wherein in the radio system, the receiver is further configured to generate from different channel estimates at least one covariance matrix of at least one channel, and to form the spatial signature based on at least one specific vector of the covariance matrix.

38. A radio system as claimed in claim 36, wherein in the radio system, the receiver is further configured to generate a singular value decomposition for a channel estimate matrix, and wherein the receiver is further configured to define specific value vectors of the covariance matrix for the definition of the information related to the location.

39. A radio system as claimed in claim 31, wherein in the radio system the receiver is further configured to form the spatial signature by utilizing several channel estimate matrices generated on different frequencies.

40. A radio system as claimed in claim 39, wherein the radio system is further configured to define a first dominant delay path by utilizing the specific values of the channel covariance matrix calculated for different delay paths or the channel singular values, and the radio system is further configured to define as the dominant delay path the path having the highest specific value energy.

41. A radio system as claimed in claim 39, wherein the radio system is further configured to define a first delay path whose specific value energy exceeds a predefined threshold value.

42. A radio system as claimed in claim 31, wherein in the radio system the receiver is further configured to form the spatial signature by utilizing several channel estimate matrices calculated from different reception antennas.

43. A radio system as claimed in claim 31, wherein the radio system is further configured to utilize in the positioning at least one of the following measurements:

a DOA measurement of the direction of arrival,

an AOA measurement of the angle of arrival,

for the purpose of comparing the direction of reception and transmission with each other.

44. A radio system as claimed in claim 31, wherein the radio system is further configured to utilize in the positioning at least one of the following measurements:

a TOA measurement of the time of arrival,

a TDOA measurement of the time difference of arrival,

for the purpose of defining the distance between the transmitter and receiver.

45. A radio system as claimed in claim 31, wherein the identifier signals are at least partly uncorrelated.

46. A radio system as claimed in claim 31, wherein the identifier signals are orthogonal.

47. A radio system as claimed in claim 31, wherein the identifier signals are broadcast signals.

48. A radio system as claimed in claim 47, wherein the identifier signals are common pilot channel signals of a WCDMA radio system.

49. A radio system as claimed in claim 31, wherein the identifier signals are channel-specific training sequences.

50. A radio system as claimed in claim 31, wherein the identifier signals are transmitted on a dedicated channel.

51. A radio system as claimed in claim 31, wherein the radio system is further configured to use the elements corresponding to the shortest delay in the spatial signature of the signals.

52. A radio system as claimed in claim 31, wherein the base station is further configured to transmit the identifier signals from the different antenna elements at different time instants.

53. A radio system as claimed in claim 31, wherein the base station is further configured to code the identifier signals to be non-interfering to each other.

54. A radio system as claimed in claim 31, wherein the base station is further configured to transmit the identifier signals on different frequencies.

55. A radio system as claimed in claim 31, wherein the terminal is the receiver and adapted to perform its own positioning.

56. A radio system as claimed in claim 55, wherein necessary information on the antenna structure or antenna element location of the base station are signalled to the terminal.

57. A radio system as claimed in claim 31, wherein the terminal is further configured to signal the spatial signatures or the parameters of the spatial signatures of the received signals to the base station and to define the location of the terminal in the network part of the radio system.

58. A radio system as claimed in claim 31, wherein the radio system is further configured to use one or more base stations in defining the location of the terminal.

59. A radio system as claimed in claim 31, wherein the radio system is further configured to calculate the received power based on the spatial signature of the signals, and to maximize the received power in relation to the transmission direction for the purpose of defining the information related to the location.

60. A method for performing positioning in a radio system, the method comprising:

transmitting, from a transmitter, at least one identifier signal to at least two different directions, each identifier signal being suited for channel estimation related to the different directions;

receiving, in a receiver, said at least one identifier signal transmitted through the at least two different directions;

estimating, based on the at least one received identifier signal from the at least two different directions, a spatial signature of the channels; and

defining, based on the spatial signature, information related to the position of the receiver or the transmitter, of the at least one identifier signal.

61. A radio system comprising:

a transmitter;

a receiver; and

at least one base station;

wherein the transmitter comprises an antenna having at least two antenna elements;

the transmitter is configured to transmit at least one identifier signal to at least two different directions, each identifier signal being suited for channel estimation related to the different directions;

the receiver is configured to receive said at least one identifier signal transmitted to said at least two different directions;

the receiver is configured to estimate, based on the at least one received identifier signal from the at least two different directions, a spatial signature of the channels; and

wherein in the radio system, positioning is configured to define, based on the spatial signature, information related to the location of the receiver or the transmitter, of the at least one identifier signal.

62. A transmitter in a radio system, the transmitter comprising:

an antenna having at least two antenna elements; and

wherein the transmitter is configured to transmit at least one identifier signal to at least two different channels for a receiver to receive the at least on identifier signal, to estimate a spatial signature of the channels based on the at least one identifier signal received from the at least two different channels, and for positioning the receiver or the transmitter of the at least one identifier signal in the radio system based on the spatial signature.

63. A base station in a radio system, the base station comprising:

an antenna having at least two antenna elements; and

wherein the base station is configured to transmit at least one identifier signal to at least two different channels for a receiver to receive the at least on identifier signal, to estimate a spatial signature of the channels based on the at least one identifier signal received from said two different channels, and for positioning the receiver or the base station based on the spatial signature.

64. A receiver in a radio system, wherein the receiver is configured to:

receive at least one identifier signal transmitted from a transmitter having an antenna with at least two antenna elements to at least two different channels;

estimate, based on the at least one identifier signal received from the at least two different channels, a spatial signature of the channels for positioning the receiver or the transmitter of the at least one identifier signal.

65. User equipment in a radio system, wherein the user equipment is configured to:

receive at least one identifier signal transmitted from a transmitter having an antenna with at least two antenna elements to at least two different channels;

estimate, based on the at least one identifier signal received from the at least different channels, a spatial signature of the channels for positioning the user equipment or the transmitter.