Method and device for generating a location signal

• US 8,169,369 B2
• Filed: 12/15/2008
• Issued: 05/01/2012
• Est. Priority Date: 12/15/2008
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Gonzalez, Armando J., Ruelke, Charles R., Swope, Charles B.
• Primary Examiner(s): Issing, Gregory C
• Application Number:
  US12/335,156
• Publication Number:
  US 20100150209A1
• Time in Patent Office: 1,233 Days
• Field of Search: 342/385, 342/386, 342/458, 342/465
• US Class Current: 342/386
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence

Abstract

A frequency generation unit (FGU) in a communication device includes a voltage controlled oscillator (VCO), an adjustable filter having a capacitive element for wideband operation, a current source with variable gain, and chirp generation control circuitry (CGC) that is used to generate location signals. The FGU receives, from a reference device, at least one location signal control parameter that defines linear frequency slope characteristics for a location signal. The CGC configures, based on the at least one location signal control parameter, the gain and a polarity of the current source to generate a first current during a first time period for charging the capacitive element to generate a control signal that is coupled to the VCO to generate a first part of the location signal having the defined linear frequency slope characteristics, wherein the first part of the location signal is transmitted using a transceiver of the communication device.

Claims

1. A method for generating a location signal, the method comprising:

receiving, from a reference device, at least one location signal control parameter that defines linear frequency slope characteristics for a location signal;

configuring a frequency generation unit (FGU) to generate a first current having a first magnitude and a first polarity that are based on the at least one location signal control parameter; and

for at least one iteration;

during a first time period that is set based on the at least one location signal control parameter, charging a capacitive element in the FGU with the first current to generate a first control signal;

coupling the first control signal to a voltage controlled oscillator (VCO) to generate a first part of the location signal having the defined linear frequency slope characteristics; and

transmitting the first part of the location signal;

wherein configuring the FGU comprising operating the FGU as an open loop while generating the location signal; and

wherein the at least one location signal control parameter is received over a narrowband channel and the location signal is transmitted over a wideband channel.

2. The method of claim 1 further comprising;

configuring the FGU to generate a second current having a second magnitude that is based on the at least one location signal control parameter, wherein the second current has an opposite polarity from the first polarity; and

for at least one iteration;

during a second time period that is set based on the at least one location signal control parameter, charging the capacitive element with the second current to generate a second control signal;

coupling the second control signal to the VCO to generate a second part of the location signal having the defined linear frequency slope characteristics; and

transmitting the second part of the location signal directly following transmission of the first part of the location signal.

3. The method of claim 1, wherein the first part of the location signal is generated over a range of frequencies of at least 5 megahertz beginning with a first frequency and ending with a second frequency, and the second part of the location signal is generated over at least part of the range of frequencies beginning with the second frequency and ending with a final frequency;

the method further comprising;

communicating a data parameter using at least one of the first frequency, the second frequency, or the final frequency.

4. The method of claim 3, wherein the first frequency is the same as the final frequency.

5. The method of claim 2, wherein the second part of the location signal comprises a plurality of different linear frequency slopes generated in sequence.

6. The method of claim 5 further comprising communicating a data parameter in the location signal using the plurality of linear frequency slopes.

7. The method of claim 1, wherein the first part of the location signal comprises a plurality of different linear frequency slopes generated in sequence.

8. The method of claim 7 further comprising communicating a data parameter in the location signal using the plurality of linear frequency slopes.

9. The method of claim 1 further comprising:

iteratively adjusting internal processing of a device that generates the location signal until a calibrated time delay is determined for the device, wherein the calibrated time delay comprises a steady state internal processing delay for the device; and

when the calibrated time delay is determined, associating the calibrated time delay to an internal processing state, which is stored as a calibrated state.

10. The method of claim 9, wherein the calibrated state is further determined by:

iteratively,

receiving an intermediate time delay value in response to the location signal transmission; and

adjusting the internal processing based on the intermediate time delay value, until the calibrated time delay is determined.

11. The method of claim 1, further comprising communicating a data parameter in the location signal using the defined linear frequency slope characteristics.

12. The method of claim 1, wherein configuring the FGU comprises changing a loop filter in the FGU from narrowband operation to wideband operation.

13. A method for generating a location signal, the method comprising:

receiving, from a reference device, at least one location signal control parameter that defines linear frequency slope characteristics for a calibrated location signal;

setting, to a calibrated state, internal processing of a device that generates the calibrated location signal, wherein the calibrated state generates a calibrated time delay within the device, wherein the calibrated time delay comprises a steady state internal processing delay for the device;

configuring a frequency generation unit (FGU) of the device to generate a first current having a first magnitude and a first polarity that are based on the at least one location signal control parameter; and

for at least one iteration;

during a first time period set based on the at least one location signal control parameter, charging a capacitive element in the FGU with the first current to generate a first control signal;

coupling the first control signal to a voltage controlled oscillator (VCO) to generate a first part of the calibrated location signal having the defined linear frequency slope characteristics;

transmitting the first part of the calibrated location signal;

configuring the FGU to generate a second current having a second magnitude that is based on the at least one location signal control parameter, wherein the second current has an opposite polarity from the first polarity; and

for at least one iteration;

during a second time period set based on the at least one location signal control parameter, charging the capacitive element with the second current to generate a second control signal;

coupling the second control signal to the VCO to generate a second part of the calibrated location signal having the defined linear frequency slope characteristics;

transmitting the second part of the calibrated location signal directly following transmission of the first part of the calibrated location signal;

wherein configuring the FGU comprising operating the FGU as an open loop while generating the location signal; and

wherein the at least one location signal control parameter is received over a narrowband channel and the location signal is transmitted over a wideband channel.

14. A device for generating a chirp signal, the device comprising:

a transceiver for receiving, from a reference device, at least one chirp signal control parameter that defines linear frequency slope characteristics for a chirp signal;

a frequency generation unit (FGU) coupled to the transceiver and comprising;

a current source having variable gain,

an adjustable filter with a capacitive element for wideband operation;

a voltage controlled oscillator (VCO); and

chirp generation control circuitry that configures, based on the at least one chirp control parameter, the gain and a polarity of the current source to generate a first current during a first time period for charging the capacitive element to generate a control signal that is coupled to the VCO to generate a first part of the chirp signal having the defined linear frequency slope characteristics, wherein the first part of the chirp signal is transmitted using the transceiver;

wherein configuring the FGU comprising operating the FGU as an open loop while generating the chirp signal; and

wherein the at least one chirp signal control parameter is received over a narrowband channel and the chirp signal is transmitted over a wideband channel.