Position location using ghost canceling reference television signals
View Patent ↗A method, apparatus, and computer-readable media for determining the position of a user terminal comprises receiving, at the user terminal, a broadcast analog television signal comprising a chirp-type signal; and generating a pseudorange based on the chirp-type signal; and wherein the location of the user terminal is determined based on the pseudorange and a location of a transmitter of the broadcast analog television signal.
1. An apparatus for determining the position of a user terminal, comprising:
a receiver to receive, at the user terminal, a broadcast analog television signal comprising a chirp-type signal; and
a pseudorange unit to generate a pseudorange based on the chirp-type signal; and wherein
the location of the user terminal is determined based on the pseudorange and a location of a transmitter of the broadcast analog television signal.
2. The apparatus of claim 1 , wherein the chirp-type signal is a vertical interval test signal, a ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.
3. The apparatus of claim 1 , further comprising:
a processor to determine the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.
4. The apparatus of claim 1 , wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.
5. A The apparatus of claim 1 , wherein the pseudorange unit:
determines a further pseudorange based on a further broadcast analog television signal; and
projects the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.
6. The apparatus of claim 1 , further comprising:
a time-gated delay-lock loop to track the chirp-type signal.
7. An apparatus for determining the position of a user terminal, comprising:
means for receiving, at the user terminal, a broadcast analog television signal comprising a chirp-type signal; and
means for generating a pseudorange based on the chirp-type signal; and wherein
the location of the user terminal is determined based on the pseudorange and a location of a transmitter of the broadcast analog television signal.
8. The apparatus of claim 7 , wherein the chirp-type signal is a vertical interval test signal, a ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.
9. The apparatus of claim 7 , further comprising:
means for determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.
10. The apparatus of claim 7 , wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.
11. The apparatus of claim 7 , wherein the means for generating:
determines a further pseudorange based on a further broadcast analog television signal; and
projects the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.
12. The apparatus of claim 7 , further comprising:
means for tracking the chirp-type signal using a time-gated delay-lock loop.
13. A method for determining the position of a user terminal, comprising:
receiving, at the user terminal, a broadcast analog television signal comprising a chirp-type signal; and
generating a pseudorange based on the chirp-type signal; and wherein
the location of the user terminal is determined based on the pseudorange and a location of a transmitter of the broadcast analog television signal.
14. The method of claim 13 , wherein the chirp-type signal is a vertical interval test signal, a ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.
15. The method of claim 13 , further comprising:
determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.
16. The method of claim 13 , wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.
17. The method of claim 13 , further comprising:
determining a further pseudorange based on a further broadcast analog television signal; and
projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.
18. The method of claim 13 , further comprising:
tracking the chirp-type signal using a time-gated delay-lock loop.
19. Computer-readable media embodying instructions executable by a computer to perform a method for determining the position of a user terminal, the method comprising:
receiving, at the user terminal, a broadcast analog television signal comprising a chirp-type signal; and
generating a pseudorange based on the chirp-type signal; and wherein
the location of the user terminal is determined based on the pseudorange and a location of a transmitter of the broadcast analog television signal.
20. The media of claim 19 , wherein the chirp-type signal is a vertical interval test signal, a ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.
21. The media of claim 19 , wherein the method further comprises:
determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.
22. The media of claim 19 , wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.
23. The media of claim 19 , wherein the method further comprises:
determining a further pseudorange based on a further broadcast analog television signal; and
projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.
24. The media of claim 19 , wherein the method further comprises:
tracking the chirp-type signal using a time-gated delay-lock loop.