Position determination with NRSC-5 digital radio signals

• US 8,253,627 B1
• Filed: 02/15/2010
• Issued: 08/28/2012
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Skyhook Holding, Inc. (Liberty Broadband Corp.)
• Original Assignee: TruePosition Incorporated
• Inventors: Burgess, David
• Primary Examiner(s): Phan, Dao
• Application Number:
  US12/705,699
• Time in Patent Office: 925 Days
• Field of Search: 342/453, 342/458, 342463-465, 455/456.5, 455/456.6, 455/457
• US Class Current: 342/463
• CPC Class Codes: G01S 5/02216 Timing or synchronisation of the receivers
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements

Abstract

Apparatus to determine the position of a user terminal, the apparatus having corresponding methods and computer-readable media, comprises: a receiver to receive, at the user terminal, a wireless NRSC-5 digital radio signal; and a pseudorange module to determine a pseudorange between the receiver and a transmitter of the NRSC-5 digital radio signal based on the NRSC-5 digital radio signal; wherein the position module determines the position of the user terminal based on the pseudorange and a location of the transmitter.

Claims

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

a receiver configured to receive, at the user terminal, a wireless digital radio signal;

a pseudorange module configured to determine a pseudorange between the receiver and a transmitter of the digital radio signal based on the digital radio signal; and

a position module configured to determine the position of the user terminal based on the pseudorange and a location of the transmitter;

wherein the digital radio signal comprises a NRSC-5 signal, wherein said NRSC-5 signal is modulated using orthogonal frequency division multiplexing (OFDM) and is composed of a plurality of adjacent narrowband subcarriers, and further comprising;

a correlator configured to correlate the digital radio signal with a reference waveform;

wherein the pseudorange module is configured to determine the pseudorange based on an output of the correlator.

2. The apparatus of claim 1, further comprising:

a signal generator configured to generate the reference waveform.

3. The apparatus of claim 2:

wherein the receiver is configured to receive control data; and

wherein the signal generator is configured to generate the reference waveform based on the control data.

4. The apparatus of claim 1:

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 transmitter, and the offset.

5. The apparatus of claim 1, wherein the receiver, the pseudorange module, and the position module are installed in the user terminal.

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

receiving, at the user terminal, a wireless digital radio signal;

determining a pseudorange between the receiver and a transmitter of the digital radio signal based on the digital radio signal; and

determining the position of the user terminal based on the pseudorange and a location of the transmitter;

wherein the digital radio signal comprises a NRSC-5 signal, wherein said NRSC-5 signal is modulated using orthogonal frequency division multiplexing (OFDM) and is composed of a plurality of adjacent narrowband subcarriers, and further comprising;

correlating the digital radio signal with a reference waveform;

wherein the pseudorange is determined based on an output of the correlating.

7. The method of claim 6, further comprising:

generating the reference waveform.

8. The method of claim 7, further comprising:

receiving control data; and

generating the reference waveform based on the control data.

9. The method of claim 6, wherein determining the position of the user terminal further 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 transmitter, and the offset.

10. Non-transitory computer-readable storage media embodying instructions executable by a computer to perform a method comprising:

determining a pseudorange between a receiver of a wireless digital radio signal and a transmitter of the digital radio signal based on the digital radio signal; and

determining a position of a user terminal based on the pseudorange and a location of the transmitter;

wherein the digital radio signal comprises a NRSC-5 signal, wherein said NRSC-5 signal is modulated using orthogonal frequency division multiplexing (OFDM) and is composed of a plurality of adjacent narrowband subcarriers, and wherein the method further comprises;

correlating the digital radio signal with a reference waveform;

wherein the pseudorange is determined based on an output of the correlating.

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

generating the reference waveform.

12. The non-transitory computer-readable media of claim 11, wherein the method further comprises:

receiving control data; and

generating the reference waveform based on the control data.

13. The non-transitory computer-readable media of claim 10, 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 transmitter, and the offset.