Position determination using ATSC-M/H signals

• US 8,677,440 B2
• Filed: 01/25/2010
• Issued: 03/18/2014
• Est. Priority Date: 02/02/2001
• Status: Expired due to Fees

• Current Assignee: TruePosition Incorporated
• Original Assignee: TruePosition Incorporated
• Inventors: Opshaug, Guttorm, Lee, Andy, Rubin, Dimitri, Spilker, James J. Jr., Rabinowitz, Matthew
• Primary Examiner(s): CHEN, CAI Y
• Application Number:
  US12/693,283
• Publication Number:
  US 20110025561A1
• Time in Patent Office: 1,513 Days
• Field of Search: None
• US Class Current: 725/126
• CPC Class Codes: A63F 2300/205 for detecting the geographical location of the game platform
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/0205 Details
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: H04H 20/57 for mobile receivers
• CPC Class Codes: H04H 60/51 of receiving stations
• CPC Class Codes: H04N 21/25841 involving the geographical location of the client retrieval from the Internet by querying based on geographical locations G06F16/9537; arrangements for identifying locations of receiving stations in broadcast systems H04H60/51; location of the user terminal in data switching networks H04L67/52; services making use of the location of users or terminals in wireless networks H04W4/02; locating users or terminals in wireless networks H04W64/00
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/2668 Creating a channel for a dedicated end-user group, e.g. insertion of targeted commercials based on end-user profiles information retrieval from the Internet by querying with filtering and personalisation G06F16/9535; arrangements for replacing or switching information during the broadcast H04H20/10; push services over packet-switching network H04L12/1859; adaptation of message content in packet-switching networks H04L51/063
• CPC Class Codes: H04N 21/41407 embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop constructional details of equipment or arrangements specially adapted for portable computer application G06F1/1626; arrangements specially adapted for mobile receivers in broadcast systems H04H20/57
• CPC Class Codes: H04N 21/41422 located in transportation means, e.g. personal vehicle arrangements specially adapted for transportation systems in broadcast systems H04H20/62
• CPC Class Codes: H04N 21/42202 environmental sensors, e.g. for detecting temperature, luminosity, pressure, earthquakes
• CPC Class Codes: H04N 21/615 Signal processing at physical level signal processing in analog two-way television systems H04N7/173
• CPC Class Codes: H04N 21/8126 involving additional data, e.g. news, sports, stocks, weather forecasts

Abstract

Apparatus to determine the position of a user terminal, the apparatus having corresponding methods and computer-readable media, comprise: a receiver to receive at the user terminal an American Television Standards Committee Mobile/Handheld (ATSC-M/H) broadcast signal from a ATSC-M/H transmitter; and a pseudorange module to determine a pseudorange between the receiver and the ATSC-M/H transmitter based on the ATSC-M/H) broadcast signal; wherein the position module determines the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter.

Claims

1. An apparatus to determine the position of a user terminal, comprising:

a receiver configured to receive at the user terminal an American Television Standards Committee Mobile/Handheld (ATSC-M/H) broadcast signal from a ATSC-M/H transmitter;

a pseudorange module configured to determine a pseudorange between the receiver and the ATSC-M/H transmitter based on the ATSC-M/H broadcast signal; and

a position module configured to determine the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter;

wherein the position module is configured to determine a clock offset between a local time reference in the user terminal and a master time reference, and to determine the position of the user terminal based on the pseudorange, the location of the ATSC-M/H transmitter, and the clock offset;

wherein the pseudorange module comprises at least one of;

(1) a correlator configured to correlate a stored portion of the ATSC-M/H broadcast signal with a signal generated by the user terminal; and

(2) a correlator configured to correlate the ATSC-M/H broadcast signal with a signal generated by the user terminal as the ATSC-M/H broadcast signal is received;

wherein the user terminal includes a clock that is not stabilized or corrected using a signal from a cellular base station or ATSC-M/H transmitter, such that the clock offset, T, is a function of time, T(t); and

wherein the apparatus is configured to project pseudorange measurements to a common instant of time, t0, using the following steps;

measuring, at a first time, t1, a first pseudorange, pr1(t1), with respect to a first transmitter, wherein the first pseudorange is representable as pr1(t1)=r1+T(t1), where r1 represents a distance between the first transmitter and the receiver at time t1 and T(t1) represents the clock offset at time t1;

measuring, at a second time, t2, a second pseudorange, pr2(t2), with respect to a second transmitter, wherein the second pseudorange is representable as pr2(t2)=r2+T(t2), where r2 represents a distance between the second transmitter and the receiver at time t2 and T(t2) represents the clock offset at time t2;

measuring, at a third time, t1+Δ

, a second instance of the first pseudorange, pr1(t1+Δ

), wherein Δ

represents a small time increment and the second instance of the first pseudorange is representable as pr1(t1+Δ

)=r1+T(t1)+[∂

T/∂

t]Δ

;

measuring, at a fourth time, t2+Δ

, a second instance of the second pseudorange, pr2(t2+Δ

), wherein the second instance of the second pseudorange is representable as pr2(t2+Δ

)=r2+T(t2)+[∂

T/∂

t]Δ

;

computing a first projection of the first pseudorange to the common instant of time, t0, wherein the first projection of the first pseudorange is representable as;

pr1(t0)=pr1(t1)+[pr1(t1+Δ

)−

pr1(t1)](t0−

t1)/Δ

; and

computing a second projection of the second pseudorange to the common instant of time, t0, wherein the second projection of the second pseudorange is representable as;

pr2(t0)=pr2(t2)+[pr2(t2+Δ

)−

pr2(t2)](t0−

t2)/Δ

.

2. The apparatus of claim 1, wherein the pseudorange module comprises:

a memory to store a portion of the ATSC-M/H broadcast signal; and

a correlator to correlate the stored portion with a signal generated by the user terminal.

3. The apparatus of claim 1, wherein the pseudorange module comprises:

a correlator to correlate the ATSC-M/H broadcast signal with a signal generated by the user terminal as the ATSC-M/H broadcast signal is received.

11. The apparatus of claim 1, wherein the position of the user terminal is determined by a position module of a location server remote from the user terminal.

12. The apparatus of claim 11, wherein the location server is configured to inform the user terminal of the best ATSC-M/H channels to monitor.

13. The apparatus of claim 12, wherein the user terminal is further configured to exchange messages with the location server via a base station and to select ATSC-M/H channels to monitor based on an identity of the base station and a stored table correlating base stations and ATSC-M/H channels.

14. The apparatus of claim 11, wherein the user terminal is further configured to accept a location input from a user that gives a general indication of the area, and to use this information to select ATSC-M/H channels for processing.

15. The apparatus of claim 11, wherein the user terminal is further configured to scan available ATSC-M/H channels, assemble a location fingerprint based on power levels of the available ATSC-M/H channels, compare the location fingerprint to a stored table, and select ATSC-M/H channels for processing based on the comparison.

16. The apparatus of claim 11, wherein the user terminal is further configured to determine a pseudorange between the user terminal and the ATSC-M/H transmitter, wherein the pseudorange represents a time difference or equivalent distance between a time of transmission from a transmitter of a component of the ATSC-M/H broadcast signal and a time of reception at the user terminal of the component, as well as a clock offset at the user terminal.

17. The apparatus of claim 16, wherein the user terminal is further configured to transmit the pseudorange to the location server;

and wherein the location server is configured to receive information describing a phase center of each ATSC-M/H transmitter.

18. The apparatus of claim 17, wherein the location server is further configured to receive weather information describing air temperature, atmospheric pressure, and humidity in a vicinity of the user terminal.

19. The apparatus of claim 18, wherein the location server is further configured to determine tropospheric propagation velocity from the weather information.

20. The apparatus of claim 13, wherein the location server is further configured to receive from the base station information identifying a general geographic location of the user terminal, wherein the information includes an identity of a cell or cell sector, said information being useful for ambiguity resolution.

21. The apparatus of claim 19, wherein the location server is further configured to adjust the value of a pseudorange according to a tropospheric propagation velocity and time offset for a corresponding ATSC-M/H transmitter.

22. The apparatus of claim 11, wherein the transmission times for individual ATSC-M/H transmitters include fixed offsets, and the offsets are stored and passed to the user terminal as needed.

23. The apparatus of claim 11, wherein the user terminal is configured to make measurements of ATSC-M/H signals sufficient to compute pseudorange, and to transmit these measurements to the location server for computation of pseudoranges.

24. The apparatus of claim 11, wherein the apparatus is further configured to determine position based on information concerning a time offset between a local clock of each ATSC-M/H transmitter and a reference clock, and information describing a phase center of each ATSC-M/H transmitter.

25. The apparatus of claim 24, wherein the apparatus is further configured to receive tropospheric propagation velocity computed by the location server.

26. The apparatus of claim 25, wherein the apparatus is further configured to receive weather information describing air temperature, atmospheric pressure, and humidity in a vicinity of the user terminal and to determine tropospheric propagation velocity from the weather information.

27. The apparatus of claim 11, wherein the user terminal is further configured to receive ATSC-M/H signals from a plurality of ATSC-M/H transmitters and to determine a pseudorange between the user terminal and each ATSC-M/H transmitter, and then to determine the user terminal'"'"'s position based on the pseudoranges and phase centers of the transmitters.

4. A method for determining the position of a user terminal, comprising:

receiving at the user terminal an American Television Standards Committee Mobile/Handheld (ATSC-M/H) broadcast signal from a ATSC-M/H transmitter; and

determining a pseudorange between the receiver and the ATSC-M/H transmitter based on the ATSC-M/H) broadcast signal; and

determining the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter;

wherein the ATSC-M/H broadcast signal includes a training sequence;

wherein the pseudorange is determined based on the training sequence;

wherein an offset between a local time reference in the user terminal and a master time reference is determined, and the position of the user terminal is determined based on the pseudorange, the location of the ATSC-M/H transmitter, and the offset;

wherein measurements at the user terminal are projected to a common instant in time; and

wherein the user terminal includes a clock that is not stabilized or corrected using a signal from a cellular base station or ATSC-M/H transmitter, such that the clock offset, T, is a function of time, T(t); and

wherein the method further includes projecting pseudorange measurements to a common instant of time, t0, using the following steps;

measuring, at a first time, t1, a first pseudorange, pr1(t1), with respect to a first transmitter, wherein the first pseudorange is representable as pr1(t1)=r1+T(t1), where r1 represents a distance between the first transmitter and the receiver at time t1 and T(t1) represents the clock offset at time t1;

measuring, at a second time, t2, a second pseudorange, pr2(t2), with respect to a second transmitter, wherein the second pseudorange is representable as pr2(t2)=r2+T(t2), where r2 represents a distance between the second transmitter and the receiver at time t2 and T(t2) represents the clock offset at time t2;

measuring, at a third time, t1+Δ

, a second instance of the first pseudorange, pr1(t1+A), wherein Δ

represents a small time increment and the second instance of the first pseudorange is representable as pr1(t1+Δ

)=r1+T(t1)+[∂

T/∂

t]Δ

;

measuring, at a fourth time, t2+Δ

, a second instance of the second pseudorange, pr2(t2+Δ

), wherein the second instance of the second pseudorange is representable as pr2(t2+Δ

)=r2+T(t2)+[∂

T/∂

t]Δ

;

computing a first projection of the first pseudorange to the common instant of time, t0, wherein the first projection of the first pseudorange is representable as;

pr1(t0)=pr1(t1)+[pr1(t1+Δ

)−

pr1(t1)](t0−

t1)/Δ

; and

computing a second projection of the second pseudorange to the common instant of time, t0, wherein the second projection of the second pseudorange is representable as;

pr2(t0)=pr2(t2)+[pr2(t2+Δ

)−

pr2(t2)](t0−

t2)/Δ

.

5. The method of claim 4, further comprising:

storing a portion of the ATSC-M/H broadcast signal; and

correlating the stored portion with a signal generated by the user terminal.

6. The method of claim 4, further comprising:

correlating the ATSC-M/H broadcast signal with a signal generated by the user terminal as the ATSC-M/H broadcast signal is received.

7. A non transitory computer-readable media embodying instructions executable by a computer to perform a method for determining the position of a user terminal, the method comprising:

determining a pseudorange between a receiver and an American Television Standards Committee Mobile/Handheld (ATSC-M/H) transmitter based on a ATSC-M/H broadcast signal received at the user terminal from the ATSC-M/H transmitter; and

determining the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter;

wherein an offset between a local time reference in the user terminal and a master time reference is determined, and the position of the user terminal is determined based on the pseudorange, the location of the ATSC-M/H transmitter, and the offset;

wherein measurements at the user terminal are projected to a common instant in time; and

wherein the user terminal includes a clock that is not stabilized or corrected using a signal from a cellular base station or ATSC-M/H transmitter, such that the clock offset, T, is a function of time, T(t); and

wherein the method further includes projecting pseudorange measurements to a common instant of time, t0, using the following steps;

measuring, at a first time, t1, a first pseudorange, pr1(t1), with respect to a first transmitter, wherein the first pseudorange is representable as pr1(t1)=r1+T(t1), where r1 represents a distance between the first transmitter and the receiver at time t1 and T(t1) represents the clock offset at time t1;

measuring, at a second time, t2, a second pseudorange, pr2(t2), with respect to a second transmitter, wherein the second pseudorange is representable as pr2(t2)=r2+T(t2), where r2 represents a distance between the second transmitter and the receiver at time t2 and T(t2) represents the clock offset at time t2;

measuring, at a third time, t1+Δ

, a second instance of the first pseudorange, pr1(t1+Δ

), wherein Δ

represents a small time increment and the second instance of the first pseudorange is representable as pr1(t1+Δ

)=r1+T(t1)+[∂

T/∂

t]Δ

;

measuring, at a fourth time, t2+Δ

, a second instance of the second pseudorange, pr2(t2+Δ

), wherein the second instance of the second pseudorange is representable as pr2(t2+Δ

)=r2+T(t2)+[∂

T/∂

t]Δ

;

computing a first projection of the first pseudorange to the common instant of time, t0, wherein the first projection of the first pseudorange is representable as;

pr1(t0)=pr1(t1)+[pr1(t1+Δ

)−

pr1(t1)](t0−

t1)/Δ

; and

computing a second projection of the second pseudorange to the common instant of time, t0, wherein the second projection of the second pseudorange is representable as;

pr2(t0)=pr2(t2)+[pr2(t2+Δ

)−

pr2(t2)](t0−

t2)/Δ

.

8. The non transitory computer-readable media of claim 7:

wherein determining the 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 pseudorange, the location of the ATSC-M/H transmitter, and the offset.

9. The non transitory computer-readable media of claim 7, wherein the method further comprises:

storing a portion of the ATSC-M/H broadcast signal; and

correlating the stored portion with a signal generated by the user terminal.

10. The non transitory computer-readable media of claim 7, wherein the method further comprises:

correlating the ATSC-M/H broadcast signal with a signal generated by the user terminal as the ATSC-M/H broadcast signal is received.

28. A system, comprising:

a user terminal including a receiver configured to receive an American Television Standards Committee Mobile/Handheld (ATSC-M/H) broadcast signal from a ATSC-M/H transmitter;

a location server remote from the user terminal;

a pseudorange module configured to determine a pseudorange between the receiver and the ATSC-M/H transmitter based on the ATSC-M/H broadcast signal, wherein the ATSC-M/H broadcast signal includes a training sequence and the pseudorange module is configured to determine the pseudorange based on the training sequence; and

a position module configured to determine the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter, wherein, to determine the position of the user terminal, the position module determines an offset between a local time reference in the user terminal and a master time reference, and determines the position of the user terminal based on the pseudorange, the location of the ATSC-M/H transmitter, and the offset;

wherein the user terminal is configured to make measurements of ATSC-M/H signals sufficient to compute pseudorange, and to transmit these measurements to the location server for computation of pseudoranges;

wherein measurements at the user terminal are projected to a common instant in time;

wherein the pseudorange module comprises a correlator configured either (a) to correlate a stored signal portion with a signal generated by the user terminal, or (b) to correlate the ATSC-M/H broadcast signal with a signal generated by the user terminal as the ATSC-M/H broadcast signal is received;

wherein the user terminal includes a clock that is not stabilized or corrected using a signal from a cellular base station or ATSC-M/H transmitter, such that the clock offset, T, is a function of time, T(t); and

wherein the system is configured to project pseudorange measurements to a common instant of time, t0, using the following steps;

measuring, at a first time, t1, a first pseudorange, pr1(t1), with respect to a first transmitter, wherein the first pseudorange is representable as pr1(t1)=r1+T(t1), where r1 represents a distance between the first transmitter and the receiver at time t1 and T(t1) represents the clock offset at time t1;

measuring, at a second time, t2, a second pseudorange, pr2(t2), with respect to a second transmitter, wherein the second pseudorange is representable as pr2(t2)=r2+T(t2), where r2 represents a distance between the second transmitter and the receiver at time t2 and T(t2) represents the clock offset at time t2;

measuring, at a third time, t1+Δ

, a second instance of the first pseudorange, pr1(t1+Δ

), wherein Δ

represents a small time increment and the second instance of the first pseudorange is representable as pr1(t1+Δ

)=r1+T(t1)+[∂

T/∂

t]Δ

;

measuring, at a fourth time, t2+Δ

, a second instance of the second pseudorange, pr2(t2+Δ

), wherein the second instance of the second pseudorange is representable as pr2(t2+Δ

)=r2+T(t2)+[∂

T/∂

t]Δ

;

computing a first projection of the first pseudorange to the common instant of time, t0, wherein the first projection of the first pseudorange is representable as;

pr1(t0)=pr1(t1)+[pr1(t1+Δ

)−

pr1(t1)](t0−

t1)/Δ

; and

computing a second projection of the second pseudorange to the common instant of time, t0, wherein the second projection of the second pseudorange is representable as;

pr2(t0)=pr2(t2)+[pr2(t2+Δ

)−

pr2(t2)](t0−

t2)/Δ

.

29. The system of claim 28, wherein the position module is part of the location server.

30. The system of claim 28, wherein the location server is configured to inform the user terminal of the best ATSC-M/H channels to monitor.

31. The system of claim 28, wherein the user terminal is further configured to exchange messages with the location server via a base station and to select ATSC-M/H channels to monitor based on an identity of base station and a stored table correlating base stations and ATSC-M/H channels.

32. The system of claim 28, wherein the user terminal is further configured to accept a location input from a user that gives a general indication of the area, and to use this information to select ATSC-M/H channels for processing.

33. The system of claim 28, wherein the user terminal is further configured to scan available ATSC-M/H channels, assemble a location fingerprint based on power levels of the available ATSC-M/H channels, compare the location fingerprint to a stored table, and select ATSC-M/H channels for processing based on the comparison.

34. The system of claim 28, wherein the user terminal is further configured to determine a pseudorange between the user terminal and the ATSC-M/H transmitter, wherein the pseudorange represents a time difference or equivalent distance between a time of transmission from a transmitter of a component of the ATSC-M/H broadcast signal and a time of reception at the user terminal of the component, as well as a clock offset at the user terminal.

35. The system of claim 34, wherein the user terminal is further configured to transmit the pseudorange to the location server;

and wherein the location server is configured to receive information describing a phase center of each ATSC-M/H transmitter.

36. The system of claim 28, wherein the location server is further configured to receive weather information describing air temperature, atmospheric pressure, and humidity in a vicinity of the user terminal.

37. The system of claim 36, wherein the location server is further configured to determine tropospheric propagation velocity from the weather information.

38. The system of claim 28, wherein the location server is further configured to receive from a base station information identifying a general geographic location of the user terminal, wherein the information includes an identity of a cell or cell sector, said information being useful for ambiguity resolution.

39. The system of claim 37, wherein the location server is further configured to adjust the value of a pseudorange according to a tropospheric propagation velocity and time offset for a corresponding ATSC-M/H transmitter.

40. The system of claim 28, wherein the transmission times for individual ATSC-M/H transmitters include fixed offsets, and the offsets are stored and passed to the user terminal as needed.

41. The system of claim 28, wherein the system is configured to determine position based on information concerning a time offset between a local clock of each ATSC-M/H transmitter and a reference clock, and information describing a phase center of each ATSC-M/H transmitter.