Monitor Units for Television Signals

• US 20070182633A1
• Filed: 10/24/2006
• Published: 08/09/2007
• Est. Priority Date: 02/02/2001
• Status: Active Grant

• Current Assignee: TruePosition Incorporated
• Original Assignee: Rosum Corporation (Liberty Broadband Corp.)
• Inventors: Lee, Andy, Rabinowitz, Matthew, Do, Ju-Yong, Spilker, James, Omura, Jim
• Granted Patent: US 7,471,244 B2
• Time in Patent Office: Days
• US Class Current: 342/464
• 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 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements

Abstract

Apparatus having corresponding methods comprises a reference clock; a receiver to receive a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and a clock offset unit to determine a clock offset between the reference clock and the transmitter clock based on the wireless television signal.

Claims

1. An apparatus comprising:

a reference clock;

a receiver to receive a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and

a clock offset unit to determine a clock offset between the reference clock and the transmitter clock based on the wireless television signal.

2. The apparatus of claim 1, wherein the wireless television signal comprises at least one of:

an American Television Standards Committee (ATSC) digital television (DTV) signal;

a Digital Video Broadcasting (DVB) signal;

an Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal; and

a National Television System Committee (NTSC) analog television signal.

3. The apparatus of claim 1:

wherein a location of a user terminal is determined based on the clock offset, a pseudorange determined between the user terminal and the television transmitter based on the wireless television signal, and a location of the television transmitter.

4. The apparatus of claim 3, further comprising:

a processor to determine the location of the user terminal.

5. The apparatus of claim 1, further comprising:

a satellite receiver to receive a satellite positioning signal;

a processor to determine the location of the receiver based on the satellite positioning signal; and

a time transfer unit to adjust the reference clock based on the satellite positioning signal.

6. The apparatus of claim 5:

wherein the satellite positioning signal comprises a global positioning system (GPS) signal.

7. An apparatus comprising:

means for generating a reference clock signal;

means for receiving a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and

means for determining a clock offset between the reference clock signal and the transmitter clock based on the wireless television signal.

8. The apparatus of claim 7, wherein the wireless television signal comprises at least one of:

an American Television Standards Committee (ATSC) digital television (DTV) signal;

a Digital Video Broadcasting (DVB) signal;

an Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal; and

a National Television System Committee (NTSC) analog television signal.

9. The apparatus of claim 7:

wherein a location of a user terminal is determined based on the clock offset, a pseudorange determined between the user terminal and the television transmitter based on the wireless television signal, and a location of the television transmitter.

10. The apparatus of claim 9, further comprising:

means for determining the location of the user terminal.

11. The apparatus of claim 7, further comprising:

means for receiving a satellite positioning signal;

means for determining the location of the receiver based on the satellite positioning signal; and

means for adjusting the reference clock signal based on the satellite positioning signal.

12. The apparatus of claim 11:

wherein the satellite positioning signal comprises a global positioning system (GPS) signal.

13. A method comprising:

generating a reference clock signal;

receiving a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and

determining a clock offset between the reference clock signal and the transmitter clock based on the wireless television signal.

14. The method of claim 13, wherein the wireless television signal comprises at least one of:

an American Television Standards Committee (ATSC) digital television (DTV) signal;

a Digital Video Broadcasting (DVB) signal;

an Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal; and

a National Television System Committee (NTSC) analog television signal.

15. The method of claim 13:

wherein a location of a user terminal is determined based on the clock offset, a pseudorange determined between the user terminal and the television transmitter based on the wireless television signal, and a location of the television transmitter.

16. The method of claim 15, further comprising:

determining the location of the user terminal.

17. The method of claim 13, further comprising:

receiving a satellite positioning signal;

determining the location of the receiver based on the satellite positioning signal; and

adjusting the reference clock signal based on the satellite positioning signal.

18. The method of claim 17:

wherein the satellite positioning signal comprises a global positioning system (GPS) signal.