초록 ▼

A method and computer program product for determining the position of a user terminal includes receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Ins

A method and computer program product for determining the position of a user terminal includes receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting-Terrestrial (DVB-T) signal; determining a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals based on a known component in the DTV signals; and determining a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters.

대표청구항 ▼

What is claimed is: 1. A method for determining the position of a user terminal, comprising: receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Inst

What is claimed is: 1. A method for determining the position of a user terminal, comprising: receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; determining a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals; and determining a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 2. The method of claim 1, wherein determining a position of the user terminal comprises: adjusting the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 3. The method of claim 1, wherein the known component is a scattered pilot carrier. 4. The method of claim 1, wherein determining a position of the user terminal comprises: determining an offset between a local time reference in the user terminal and a master time reference; and determining the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 5. The method of claim 4, further comprising: determining a subsequent position of the user terminal using the offset. 6. The method of claim 1, wherein determining a pseudo-range comprises: storing a portion of each of the DTV signals; and subsequently correlating each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 7. The method of claim 1, wherein determining a pseudo-range comprises: correlating each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 8. The method of claim 1, wherein determining a position of the user terminal comprises: determining a general geographic area within which the user terminal is located; and determining the position of the user terminal based on the pseudo-ranges and the general geographic area. 9. The method of claim 8, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 10. The method of claim 1, wherein determining a position of the user terminal comprises: determining a tropospheric propagation velocity in a vicinity of the user terminal; adjusting the value of each pseudo-range based on the tropospheric propagation velocity; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 11. The method of claim 1, wherein determining a position of the user terminal comprises: adjusting each pseudo-range based on a terrain elevation in a vicinity of the user terminal; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 12. The method of claim 1, further comprising: selecting the DTV signals based on an identity of an additional transmitter communicably linked to the user terminal and a stored table correlating the additional transmitter and the received DTV broadcast signals. 13. The method of claim 1, further comprising: accepting a location input from a user; and selecting the DTV signals based on the location input. 14. The method of claim 1, further comprising: scanning available DTV signals to assemble a fingerprint of the location; and selecting the DTV broadcast signals used to determine the pseudo-ranges based on the fingerprint and a stored table that matches known fingerprints with known locations. 15. The method of claim 1, further comprising: using receiver autonomous integrity monitoring (RAIM) to check the integrity of each pseudo-range based on redundant pseudo-ranges from the DTV transmitters. 16. A method for determining the position of a user terminal, comprising: receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; determining a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals; and transmitting the pseudo-ranges to a location server configured to determine a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 17. The method of claim 16, wherein determining a pseudo-range comprises: determining a time of transmission from one of the DTV transmitters of a known component of the DTV broadcast signal; determining a time of reception at the user terminal of the known component; and determining the difference between the time of transmission and the time of reception. 18. The method of claim 16, wherein the known component is a scattered pilot carrier. 19. The method of claim 16, wherein determining a pseudo-range comprises: storing a portion of each of the DTV signals; and subsequently correlating each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 20. The method of claim 16, wherein determining a pseudo-range comprises: correlating each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 21. A method for determining the position of a user terminal, comprising: receiving a plurality of pseudo-ranges from a user terminal, each pseudo-range determined between the user terminal and one of a plurality of DTV transmitters based on DTV signals broadcast by the DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal, and wherein the pseudo-ranges are determined based on a known component in the DVB-T signals; and determining a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 22. The method of claim 21, wherein determining a position of the user terminal comprises: adjusting the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 23. The method of claim 21, wherein the known component is a scattered pilot carrier. 24. The method of claim 21, wherein determining a position of the user terminal comprises: determining an offset between a local time reference in the user terminal and a master time reference; and determining the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 25. The method of claim 24, further comprising: determining a subsequent position of the user terminal using the offset. 26. The method of claim 21, wherein determining a position of the user terminal comprises: determining a general geographic area within which the user terminal is located; and determining the position of the user terminal based on the pseudo-ranges and the general geographic area. 27. The method of claim 26, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 28. The method of claim 21, wherein determining a position of the user terminal comprises: determining a tropospheric propagation velocity in a vicinity of the user terminal; adjusting the value of each pseudo-range based on the tropospheric propagation velocity; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 29. The method of claim 21, wherein determining a position of the user terminal comprises: adjusting each pseudo-range based on the terrain elevation in the vicinity of the user terminal; and determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 30. An apparatus for determining the position of a user terminal, comprising: means for receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; means for determining a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals; and means for determining a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 31. The apparatus of claim 30, wherein means for determining a position of the user terminal comprises: means for adjusting the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 32. The apparatus of claim 31, wherein the known component is a scattered pilot carrier. 33. The apparatus of claim 30, wherein means for determining a position of the user terminal comprises: means for determining an offset between a local time reference in the user terminal and a master time reference; and means for determining the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 34. The apparatus of claim 33, further comprising: means for determining a subsequent position of the user terminal using the offset. 35. The apparatus of claim 30, wherein means for determining a pseudo-range comprises: means for storing a portion of each of the DTV signals; and means for subsequently correlating each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 36. The apparatus of claim 30, wherein means for determining a pseudo-range comprises: means for correlating each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 37. The apparatus of claim 30, wherein means for determining a position of the user terminal comprises: means for determining a general geographic area within which the user terminal is located; and means for determining the position of the user terminal based on the pseudo-ranges and the general geographic area. 38. The apparatus of claim 37, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 39. The apparatus of claim 30, wherein means for determining a position of the user terminal comprises: means for determining a tropospheric propagation velocity in the vicinity of the user terminal; means for adjusting the value of each pseudo-range based on the tropospheric propagation velocity; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 40. The apparatus of claim 30, wherein means for determining a position of the user terminal comprises: means for adjusting each pseudo-range based on a terrain elevation in a vicinity of the user terminal; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 41. The apparatus of claim 30, further comprising: means for selecting the DTV signals based on an identity of an additional transmitter communicably linked to the user terminal and a stored table correlating the additional transmitter and the received DTV broadcast signals. 42. The apparatus of claim 30, further comprising: means for accepting a location input from a user; and means for selecting the DTV signals based on the location input. 43. The apparatus of claim 30, further comprising: means for scanning available DTV signals to assemble a fingerprint of the location; and means for selecting the DTV broadcast signals used to determine the pseudo-ranges based on the fingerprint and a stored table that matches known fingerprints with known locations. 44. The apparatus of claim 30, further comprising: means for using receiver autonomous integrity monitoring (RAIM) to check the integrity of each pseudo-range based on redundant pseudo-ranges from the DTV transmitters. 45. An apparatus for determining the position of a user terminal, comprising: means for receiving at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; means for determining a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals; and means for transmitting the pseudo-ranges to a location server configured to determine a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 46. The apparatus of claim 45, wherein means for determining a pseudo-range comprises: means for determining a time of transmission from one of the DTV transmitters of a component of the DTV broadcast signal; means for determining a time of reception at the user terminal of the component; and means for determining the difference between the time of transmission and the time of reception. 47. The apparatus of claim 45, wherein the component is a scattered pilot carrier. 48. The apparatus of claim 45, wherein means for determining a pseudo-range comprises: means for storing a portion of each of the DTV signals; and means for subsequently correlating each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 49. The apparatus of claim 45, wherein means for determining a pseudo-range comprises: means for correlating each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 50. An apparatus for determining the position of a user terminal, comprising: means for receiving a plurality of pseudo-ranges from a user terminal, each pseudo-range determined between the user terminal and one of a plurality of DTV transmitters based on DTV signals broadcast by the DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal, and wherein the pseudo-ranges are determined based on a known component in the DTV signals; and means for determining a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 51. The apparatus of claim 50, wherein means for determining a position of the user terminal comprises: means for adjusting the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 52. The apparatus of claim 50, wherein the known component is a scattered pilot carrier. 53. The apparatus of claim 50, wherein means for determining a position of the user terminal comprises: means for determining an offset between a local time reference in the user terminal and a master time reference; and means for determining the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 54. The apparatus of claim 53, further comprising: means for determining a subsequent position of the user terminal using the offset. 55. The apparatus of claim 50, wherein means for determining a position of the user terminal comprises: means for determining a general geographic area within which the user terminal is located; and means for determining the position of the user terminal based on the pseudo-ranges and the general geographic area. 56. The apparatus of claim 55, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 57. The apparatus of claim 50, wherein means for determining a position of the user terminal comprises: means for determining a tropospheric propagation velocity in a vicinity of the user terminal; means for adjusting the value of each pseudo-range based on the tropospheric propagation velocity; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 58. The apparatus of claim 50, wherein means for determining a position of the user terminal comprises: means for adjusting each pseudo-range based on the terrain elevation in the vicinity of the user terminal; and means for determining the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 59. A computer program product, tangibly stored on a computer-readable medium, for determining the position of a user terminal, comprising instructions operable to cause a programmable processor to: receive at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; determine a pseudo-range between the user terminal and each DTV transmitter based on the DTV broadcast signals; and determine a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 60. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: adjust the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 61. The computer program product of claim 59, wherein the known component is a scattered pilot carrier. 62. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: determine an offset between a local time reference in the user terminal and a master time reference; and determine the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 63. The computer program product of claim 62, further comprising instructions operable to cause a programmable processor to: determine a subsequent position of the user terminal using the offset. 64. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a pseudo-range comprise instructions operable to cause a programmable processor to: store a portion of each of the DTV signals; and subsequently correlate each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 65. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a pseudo-range comprise instructions operable to cause a programmable processor to: correlate each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 66. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: determine a general geographic area within which the user terminal is located; and determine the position of the user terminal based on the pseudo-ranges and the general geographic area. 67. The computer program product of claim 66, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 68. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to determine a tropospheric propagation velocity in a vicinity of the user terminal; adjust the value of each pseudo-range based on the tropospheric propagation velocity; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 69. The computer program product of claim 59, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: adjust each pseudo-range based on the terrain elevation in the vicinity of the user terminal; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 70. The computer program product of claim 59, further comprising instructions operable to cause a programmable processor to: select the DTV signals based on an identity of an additional transmitter communicably linked to the user terminal and a stored table correlating the additional transmitter and the received DTV broadcast signals. 71. The computer program product of claim 59, further comprising instructions operable to cause a programmable processor to: accept a location input from a user; and select the DTV signals based on the location input. 72. The computer program product of claim 59, further comprising instructions operable to cause a programmable processor to: scan available DTV signals to assemble a fingerprint of the location; and select the DTV broadcast signals used to determine the pseudo-ranges based on the fingerprint and a stored table that matches known fingerprints with known locations. 73. The computer program product of claim 59, further comprising instructions operable to cause a programmable processor to: use receiver autonomous integrity monitoring (RAIM) to check the integrity of each pseudo-range based on redundant pseudo-ranges from the DTV transmitters. 74. A computer program product, tangibly stored on a computer-readable medium, for determining the position of a user terminal, comprising instructions operable to cause a programmable processor to: receive at the user terminal a plurality of digital television (DTV) broadcast signals from a plurality of DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal; determine a pseudo-range between the user terminal and each DTV transmitter based on a known component in the DTV broadcast signals; and transmit the pseudo-ranges to a location server configured to determine a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 75. The computer program product of claim 74, wherein instructions operable to cause a programmable processor to determine a pseudo-range comprise instructions operable to cause a programmable processor to: determine a time of transmission from one of the DTV transmitters of a component of the DTV broadcast signal; determine a time of reception at the user terminal of the component; and determining the difference between the time of transmission and the time of reception. 76. The computer program product of claim 74, wherein the component is a scattered pilot carrier. 77. The computer program product of claim 74, wherein instructions operable to cause a programmable processor to determine a pseudo-range comprise instructions operable to cause a programmable processor to: store a portion of each of the DTV signals; and subsequently correlate each of the stored portions and a signal generated by the user terminal to produce the pseudo-ranges. 78. The computer program product of claim 74, wherein instructions operable to cause a programmable processor to determine a pseudo-range comprise instructions operable to cause a programmable processor to: correlate each of the DTV signals with a signal generated by the user terminal as the DTV signals are received to produce the pseudo-ranges. 79. A computer program product, tangibly stored on a computer-readable medium, for determining the position of a user terminal, comprising instructions operable to cause a programmable processor to: receive a plurality of pseudo-ranges from a user terminal, each pseudo-range determined between the user terminal and one of a plurality of DTV transmitters based on DTV signals broadcast by the DTV transmitters, wherein each of the DTV signals is a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting--Terrestrial (DVB-T) signal, and wherein the pseudo-ranges are determined based on the DTV signals; and determine a position of the user terminal based on the pseudo-ranges and a location of each of the DTV transmitters. 80. The computer program product of claim 79, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: adjust the pseudo-ranges based on a difference between a transmitter clock at one of the DTV transmitters and a known time reference; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 81. The computer program product of claim 79, wherein the known component is a scattered pilot carrier. 82. The computer program product of claim 79, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: determine an offset between a local time reference in the user terminal and a master time reference; and determine the position of the user terminal based on the pseudo-ranges, the location of each of the DTV transmitters, and the offset. 83. The computer program product of claim 82, further comprising instructions operable to cause a programmable processor to: determine a subsequent position of the user terminal using the offset. 84. The computer program product of claim 79, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: determine a general geographic area within which the user terminal is located; and determine the position of the user terminal based on the pseudo-ranges and the general geographic area. 85. The computer program product of claim 84, wherein the general geographic area is a footprint of an additional transmitter communicably linked to the user terminal. 86. The computer program product of claim 79, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: determine a tropospheric propagation velocity in the vicinity of the user terminal; adjust the value of each pseudo-range based on the tropospheric propagation velocity; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters. 87. The computer program product of claim 79, wherein instructions operable to cause a programmable processor to determine a position of the user terminal comprise instructions operable to cause a programmable processor to: adjust each pseudo-range based on the terrain elevation in the vicinity of the user terminal; and determine the position of the user terminal based on the adjusted pseudo-ranges and the location of each of the DTV transmitters.