Method and Apparatus for Compensating Signal Timing Measurements for Differences in Signal Frequencies

• US 20120182874A1
• Filed: 08/02/2011
• Published: 07/19/2012
• Est. Priority Date: 01/17/2011
• Status: Active Grant

• Current Assignee: Optis Cellular Technology LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Siomina, Iana, Kazmi, Muhammad
• Granted Patent: US 9,462,563 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 56/004 compensating for timing error of reception due to propagation delay
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods (100) and apparatuses (12, 24, 38) taught herein advantageously facilitate use of timing measurements in wireless communication networks (10) where radio signal timing measurements involve signals at different carrier frequencies. The methods and apparatuses in particular compensate such timing measurements for expected discrepancies in the measurements that arise from frequency-dependent differences in the propagation behavior of the radio signals being measured. In a non-limiting example, measurements at two or more frequencies may be compensated for the frequency distance between those frequencies, or with respect to a reference frequency. In such cases, timing measurements determined for one or more other radio signals are compensated as a function of the frequency distance between the reference frequency and the frequencies of such other radio signals.

Claims

1-31. -31. (canceled)

32. A method of compensating timing measurements made in a wireless communication network having multiple carriers operating at different carrier frequencies, said method implemented in a node configured for operation in the wireless communication network and comprising:

obtaining a timing measurement performed over first and second radio signals at first and second carrier frequencies, respectively;

determining whether timing compensation is needed for the timing measurement based at least in part on the frequency distance between the first and second carrier frequencies;

when timing compensation is needed, compensating the timing measurement using a compensation value that compensates the timing measurement for frequency-dependent propagation differences between the first and second carrier frequencies; and

providing the compensated timing measurement for use in processing dependent on said timing measurement.

33. The method of claim 32, wherein said processing comprises measurement processing for position estimation of the node or another positioning target.

34. The method of claim 32, wherein the first and second carrier frequencies belong to different frequency bands.

35. The method of claim 32, wherein a reference carrier frequency is pre-determined or decided prior to the compensation and the compensation is applied with respect to the reference carrier frequency.

36. The method of claim 32, wherein the compensation value depends on the Radio Access Technology (RAT) or technologies used for measurements on the first carrier frequency and the second carrier frequency.

37. The method of claim 32, wherein determining whether timing compensation is needed for the timing measurement comprises at least one of:

identifying the pair of radio carriers corresponding to the first and second carriers frequencies and determining whether timing compensation is indicated for the identified pair;

or comparing the frequency distance to one or more defined frequency distance thresholds or ranges that determine whether timing compensation is needed.

38. The method of claim 32, further comprising determining the compensation value as a function of the frequency distance either by computing the compensation value according to an expression that depends at least on the frequency distance, or selecting, based on at least the frequency distance, a precomputed compensation value from among a plurality of precomputed compensation values.

39. The method of claim 32, wherein determining whether timing compensation is needed for the timing measurement comprises deciding whether timing compensation is needed based on the frequency distance and further based on one or more parameters indicative of the propagation environment in which the timing measurement was made.

40. The method of claim 39, wherein the one or more parameters include at least one of:

a velocity estimate associated with a node that made the timing measurement; and

a radio environment value indicating or bearing on the time dispersiveness of the propagation environment in which the timing measurement was made.

41. The method of claim 32, wherein the node is a user equipment and wherein the method includes determining the timing measurement at the user equipment as one of:

a received signal timing difference between the first and second radio signals;

a receive-transmit signal timing difference involving the first and second radio signals;

a round-trip-time measurement determined from the first and second radio signals;

a one way propagation delay determined from the first and second radio signals or a timing advance determined from the first and second radio signals.

42. The method of claim 41, further comprising receiving at the user equipment signaling indicating the compensation value to use for compensating the timing measurement.

43. The method of claim 42, wherein the signaling comprises radio resource control signaling from a base station or from a network controller in the wireless communication network, or comprises positioning protocol signaling from a positioning node in the wireless communication network.

44. The method of claim 32, wherein the node comprises one of a base station, a location measurement unit, a network controller or a positioning node, and wherein the method further includes receiving the timing measurement from another node in the wireless communication network.

45. The method of claim 44, further comprising receiving the compensation value from the same other node or yet another node, for compensation of the timing measurement.

46. The method of claim 32, wherein determining whether timing compensation is needed includes determining an accuracy requirement for the timing measurement, such that timing compensation is or is not applied for a given frequency distance in dependence on the accuracy requirement applicable to the timing measurement or applicable to a calculation dependent on the timing measurement.

47. The method of claim 32, further comprising determining the particular compensation value to use for compensating the timing measurement based on at least one of a parameter indicating the type of propagation environment in which the timing measurement was determined, and an accuracy requirement associated with the timing measurement.

48. A node configured for operation in a wireless communication network having multiple carriers operating at different carrier frequencies, said node comprising:

a communication interface configured for communicating with one or more other nodes within the wireless communication network; and

one or more processing circuits configured to;

obtain a timing measurement performed over first and second radio signals at first and second carrier frequencies, respectively;

determine whether timing compensation is needed for the timing measurement based at least in part on the frequency distance between the first and second carrier frequencies;

when timing compensation is needed, compensate the timing measurement using a compensation value that compensates the timing measurement for frequency-dependent propagation differences between the first and second carrier frequencies; and

provide the compensated timing measurement for use in processing dependent on said timing measurement.

49. The node of claim 48, wherein a reference carrier frequency is pre-determined or decided prior to the compensation and wherein the node is configured to apply the compensation with respect to the reference carrier frequency.

50. The node of claim 48, wherein the one or more processing circuits are configured to determine whether timing compensation is needed for the timing measurement based on at least one of:

identifying a pair of radio carriers corresponding to the first and second radio carriers and determining whether timing compensation is indicated for the identified pair; and

comparing the frequency distance to one or more defined frequency distance thresholds or ranges that determine whether timing compensation is needed.

51. The node of claim 48, wherein the one or more processing circuits are configured to determine the compensation value as a function of the frequency distance either by computing the compensation value according to an expression that depends on the frequency distance, or selecting, based on the frequency distance, a precomputed compensation value from among a plurality of precomputed compensation values.

52. The node of claim 48, wherein the one or more processing circuits are configured to determine whether timing compensation is needed for the timing measurement based on the frequency distance and further based on one or more parameters indicative of the propagation environment in which the timing measurement was made.

53. The node of claim 52, wherein the one or more parameters include at least one of:

a velocity estimate associated with a node that made the timing measurement; and

a radio environment value indicating or bearing on the time dispersiveness of the propagation environment in which the timing measurement was made.

54. The node of claim 48, wherein the node is a user equipment and wherein the one or more processing circuits of the user equipment are configured to determine the timing measurement as at least one of:

a received signal timing difference between the first and second radio signals;

a receive/transmit signal timing difference involving the first and second radio signals;

a round-trip-time measurement determined from the first and second radio signals;

a one way propagation delay determined from the first and second radio carriers or timing advance determined from the first and second radio signals.

55. The node of claim 54, wherein the communication interface comprises a wireless communication interface and wherein the user equipment is configured to receive, via the communication interface, signaling indicating the compensation value to use for compensating the timing measurement, and further wherein the one or more processing circuits of the user equipment are configured to use the signaled compensation value for compensating the timing measurement.

56. The node of claim 55, wherein the signaling comprises radio resource control signaling from a base station in the wireless communication network, or comprises positioning protocol signaling from a positioning node in the wireless communication network, and wherein the user equipment is configured to implement at least one of a radio resource control protocol for processing radio resource control protocol signaling and a positioning protocol for processing positioning protocol signaling.

57. The node of claim 48, wherein the node comprises a base station or a positioning node, and wherein the node is configured to receive the timing measurement from another node in the wireless communication network, via the communication interface of the node.

58. The node of claim 57, wherein the node is configured to receive the compensation value from the same other node or yet another node, for compensation of the timing measurement.

59. The node of claim 48, wherein the one or more processing circuits are configured to determine whether timing compensation is needed further based on an accuracy requirement for the timing measurement, such that timing compensation is or is not applied for a given frequency distance in dependence on the accuracy requirement applicable to the timing measurement or applicable to a calculation dependent on the timing measurement.

60. The node of claim 48, wherein the one or more processing circuits are configured to determine the particular compensation value to use for compensating the timing measurement based on at least one of a parameter indicating the type of propagation environment in which the timing measurement was determined, and an accuracy requirement associated with the timing measurement.

61. The node of claim 48, wherein the one or more processing circuits comprises a timing measurement compensation circuit that is configured to apply the compensation value to the timing measurement, thereby obtaining the compensated timing measurement.

62. The node of claim 48, wherein the one or more processing circuits are configured to provide the compensated timing measurement for use in processing dependent on said timing measurement based on one of:

providing the compensated timing measurement to a local processing circuit within the node, for use by the local processing circuit in carrying said processing dependent on the compensated timing measurement;

or providing the compensated timing measurement for transmission from a communication interface of the node, for sending the compensated timing measurement to another node that performs said processing dependent on the compensated timing measurement.