Position determination using portable pseudo-television broadcast transmitters
View Patent ↗An apparatus, method, and computer-readable media comprise a receiver adapted to receive a plurality of broadcast signals; a signal processor adapted to determine a position based on the received plurality of broadcast signals; a signal generator adapted to generate a ranging signal comprising a known component of a television signal; and a transmitter adapted to broadcast a signal comprising the ranging signal and a position signal comprising a description of the position.
1. An apparatus comprising:
a receiver adapted to receive a plurality of broadcast signals;
a signal processor adapted to determine a position of the apparatus based on the received plurality of broadcast signals;
a signal generator adapted to generate a ranging signal comprising a known component of a television signal; and
a transmitter adapted to broadcast a signal comprising the ranging signal and a position signal comprising a description of the position of the apparatus.
2. The apparatus of claim 1 , wherein the known component of the television signal represents at least one of the group comprising:
a synchronization code, found in an American Television Standards Committee (ATSC) digital television signal, comprising at least one of the group comprising
a Field Synchronization Segment within an ATSC data frame, and
a Synchronization Segment within a Data Segment within an ATSC data frame;
a scattered pilot carrier found in a Japanese Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal;
a scattered pilot carrier found in a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting—Terrestrial (DVB-T) signal; and
a signal, found in an analog television signal, comprising at least one of the group comprising
a horizontal synchronization pulse,
a horizontal blanking pulse,
a horizontal blanking pulse and a horizontal synchronization pulse,
a chirp-type signal, and
a vertical interval test signal.
3. The apparatus of claim 1 , wherein the plurality of broadcast signals comprises at least one of:
a broadcast television signal; and
a satellite positioning system signal.
4. The apparatus of claim 3 , wherein the signal processor derives a time synchronization signal from the plurality of broadcast signals, further comprising:
a clock adapted to provide a clock signal in accordance with the synchronization signal; and
wherein the signal generator generates the known component of the television signal in accordance with the clock signal.
5. The apparatus of claim 4 , wherein the signal processor derives the time synchronization signal from a global positioning system (GPS) signal.
6. The apparatus of claim 1 , wherein the position signal comprises digital data, and wherein the ranging signal comprises a plurality of digital television (DTV) frames, each frame comprising a plurality of data segments, and wherein:
the signal processor is further adapted to encode the digital data as codewords; and
the transmitter is further adapted to replace data segments within the DTV frames with the codewords.
7. The apparatus of claim 1 , wherein the transmitter is further adapted to transmit the ranging signal over a plurality of television channels.
8. An apparatus comprising:
receiver means for receiving a plurality of broadcast signals;
signal processor means for determining a position of the apparatus based on the received plurality of broadcast signals;
signal generator means for generating a ranging signal comprising a known component of a television signal; and
transmitter means for broadcasting a signal comprising the ranging signal and a position signal comprising a description of the position of the apparatus.
9. The apparatus of claim 8 , wherein the known component of the television signal represents at least one of the group comprising:
a synchronization code, found in an American Television Standards Committee (ATSC) digital television signal, comprising at least one of the group comprising
a Field Synchronization Segment within an ATSC data frame, and
a Synchronization Segment within a Data Segment within an ATSC data frame;
a scattered pilot carrier found in a Japanese Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal;
a scattered pilot carrier found in a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting—Terrestrial (DVB-T) signal; and
a signal, found in an analog television signal, comprising at least one of the group comprising
a horizontal synchronization pulse,
a horizontal blanking pulse,
a horizontal blanking pulse and a horizontal synchronization pulse,
a chirp-type signal, and
a vertical interval test signal.
10. The apparatus of claim 8 , wherein the plurality of broadcast signals comprises at least one of:
a broadcast television signal; and
a satellite positioning system signal.
11. The apparatus of claim 10 , wherein the signal processor means derives a time synchronization signal from the plurality of broadcast signals, further comprising:
clock means for providing a clock signal in accordance with the synchronization signal; and
wherein the signal generator means generates the known component of the television signal in accordance with the clock signal.
12. The apparatus of claim 11 , wherein the signal processor means derives the time synchronization signal from a global positioning system (GPS) signal.
13. The apparatus of claim 8 , wherein the position signal comprises digital data, and wherein the ranging signal comprises a plurality of digital television (DTV) frames, each frame comprising a plurality of data segments, and wherein:
the signal processor means encodes the digital data as codewords; and
the transmitter means replaces data segments within the DTV frames with the codewords.
14. The apparatus of claim 8 , wherein the transmitter means transmits the ranging signal over a plurality of television channels.
15. A method comprising:
receiving a plurality of broadcast signals at an apparatus;
determining a position of the apparatus based on the received plurality of broadcast signals;
generating a ranging signal comprising a known component of a television signal; and
broadcasting a signal comprising the ranging signal and a position signal comprising a description of the position of the apparatus.
16. The method of claim 15 , wherein the known component of the television signal represents at least one of the group comprising:
a synchronization code, found in an American Television Standards Committee (ATSC) digital television signal, comprising at least one of the group comprising
a Field Synchronization Segment within an ATSC data frame, and
a Synchronization Segment within a Data Segment within an ATSC data frame;
a scattered pilot carrier found in a Japanese Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal;
a scattered pilot carrier found in a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting—Terrestrial (DVB-T) signal; and
a signal, found in an analog television signal, comprising at least one of the group comprising
a horizontal synchronization pulse,
a horizontal blanking pulse,
a horizontal blanking pulse and a horizontal synchronization pulse,
a chirp-type signal, and
a vertical interval test signal.
17. The method of claim 15 , wherein the plurality of broadcast signals comprises at least one of:
a broadcast television signal; and
a satellite positioning system signal.
18. The method of claim 17 , further comprising:
deriving a time synchronization signal from the plurality of broadcast signals;
providing a clock signal in accordance with the synchronization signal; and
generating the known component of the television signal in accordance with the clock signal.
19. The method of claim 18 , wherein deriving a time synchronization signal comprises:
deriving the time synchronization signal from a global positioning system (GPS) signal.
20. The method of claim 15 , wherein the position signal comprises digital data, and wherein the ranging signal comprises a plurality of digital television (DTV) frames, each frame comprising a plurality of data segments, further comprising:
encoding the digital data as codewords; and
replacing data segments within the DTV frames with the codewords.
21. The method of claim 15 , further comprising:
transmitting the ranging signal over a plurality of television channels.
22. Computer-readable media embodying instructions executable by a computer to perform a method comprising:
determining a position of an apparatus based on a plurality of broadcast signals received at the apparatus; and
causing the apparatus to broadcast a signal comprising
a ranging signal comprising a known component of a television signal, and
a position signal comprising a description of the position of the apparatus.
23. The media of claim 22 , wherein the known component of the television signal represents at least one of the group comprising:
a synchronization code, found in an American Television Standards Committee (ATSC) digital television signal, comprising at least one of the group comprising
a Field Synchronization Segment within an ATSC data frame, and
a Synchronization Segment within a Data Segment within an ATSC data frame;
a scattered pilot carrier found in a Japanese Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) signal;
a scattered pilot carrier found in a European Telecommunications Standards Institute (ETSI) Digital Video Broadcasting—Terrestrial (DVB-T) signal; and
a signal, found in an analog television signal, comprising at least one of the group comprising
a horizontal synchronization pulse,
a horizontal blanking pulse,
a horizontal blanking pulse and a horizontal synchronization pulse,
a chirp-type signal, and
a vertical interval test signal.
24. The media of claim 22 , wherein the plurality of broadcast signals comprises at least one of:
a broadcast television signal; and
a satellite positioning system signal.
25. The media of claim 24 , wherein the method further comprises:
deriving a time synchronization signal from the plurality of broadcast signals;
providing a clock signal in accordance with the synchronization signal; and
generating the known component of the television signal in accordance with the clock signal.
26. The media of claim 25 , wherein deriving a time synchronization signal comprises:
deriving the time synchronization signal from a global positioning system (GPS) signal.
27. The media of claim 22 , wherein the position signal comprises digital data, and wherein the ranging signal comprises a plurality of digital television (DTV) frames, each frame comprising a plurality of data segments, wherein the method further comprises:
encoding the digital data as codewords; and
replacing data segments within the DTV frames with the codewords.
28. The media of claim 22 , wherein the method further comprises:
transmitting the ranging signal over a plurality of television channels.