Christopher A Patrick

US Patent:

6861980, Mar 1, 2005

Filed:

May 26, 2004

Appl. No.:

10/854981

Inventors:

Douglas N. Rowitch - Del Mar CA, US
Christopher Patrick - San Diego CA, US

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04B007/185

US Classification:

34235706, 701213

Abstract:

An assisted wireless position determination system includes a plurality of base stations and a plurality of wireless devices, such as mobile telephones and personal digital assistants, adapted to communicate with the base stations. The wireless position determination system also includes a position determination system for determining the geographic position of the wireless devices. The position determination system includes a position determination entity (PDE) that is connected to the base stations and serves as a processing server for computing the position of the wireless devices. The system and method reduces or eliminates redundant and superfluous data. In addition, the system and method ensure that the wireless device is not loaded with additional capacity, and that the wireless device is provided with precise location information. The embodiments of the system and method of the invention are compliant with the TIA/EIA IS-801 standard or other standards.

US Patent:

6873910, Mar 29, 2005

Filed:

Oct 22, 2002

Appl. No.:

10/278694

Inventors:

Douglas N. Rowitch - Del Mar CA, US
Christopher Patrick - San Diego CA, US

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

G01S005/04
G01C021/36

US Classification:

701213, 34235712

Abstract:

A method of and system for searching for position determination signals using a plurality of progressively more sensitive search modes comprising a first level mode, a second mode, and at least one higher level mode. If any of the search window parameters exceed prescribed limits, a first level search is performed, and the search window parameters are refined responsive to the ensuing search results so they are within the prescribed limits. Then, the second level search is performed, and measurements derived from the ensuing search results. If the measurements satisfy selected measurement sufficiency criteria, additional searching within the position fix attempt is avoided. If the measurements do not satisfy the selected measurement sufficiency criteria, a higher level, more sensitive search is performed.

US Patent:

6903684, Jun 7, 2005

Filed:

Mar 31, 2003

Appl. No.:

10/404711

Inventors:

Emilija Simic - La Jolla CA, US
Christopher Patrick - San Diego CA, US
Douglas Rowitch - Del Mar CA, US

Assignee:

Qualcomm Incorporated - San Diego CA

International Classification:

H04B007/185

US Classification:

34235715, 3423571

Abstract:

Position determination accuracy of a wireless communication device may be negatively affected by a large unaccounted GPS doppler bias, which in turn may affect GPS doppler estimations and GPS doppler measurements conducted by the wireless communication device. The quality of GPS doppler measurements is very important for position location, because poor quality GPS doppler measurements may prevent the wireless communication device from acquiring satellites in the most sensitive modes with narrow frequency ranges, which results in reduced GPS pseudorange measurement yield. Large unaccounted GPS doppler bias also adversely affects position accuracy because of the adverse effect on the GPS code phase measurements time propagation to common time prior to their use in position location calculation. The same is true in the case of unaccounted CDMA code doppler, through the adverse effect on the AFLT code phase measurements time propagation to common time prior to their use in a position location engine. This effect is the biggest concern in the case of large search windows.

US Patent:

6961367, Nov 1, 2005

Filed:

Mar 17, 2003

Appl. No.:

10/392442

Inventors:

Emilija Simic - La Jolla CA, US
Christopher Patrick - San Diego CA, US

Assignee:

QUALCOMM, Incorporated - San Diego CA

International Classification:

H04B007/185

US Classification:

375214, 375271, 375302, 375340, 455 121, 455 23, 4555501, 4554561, 370316

Abstract:

A forward link repeater frequency watermarking (FLRFWM) system and method that enable accurate position location of mobile stations in areas where repeaters are present by watermarking repeated signals with repeater information. A repeater watermarks a forward link signal with a (unique or non-unique) fast frequency modulation waveform watermark every time a signal passes through the repeater. A mobile station detects and/or identifies the fast frequency watermark on the forward link signal to determine repeater information that aids the network position determination entity or mobile station position location system in determining position location using AFLT and/or A-GPS systems. A forward link fast frequency watermarking system described herein achieves minimal impact on FL, AFLT, and GPS performance, good detection, identification and false alarm probabilities, short time-to-detect/identify, and good detection/identification sensitivity.

US Patent:

7016688, Mar 21, 2006

Filed:

May 9, 2003

Appl. No.:

10/435237

Inventors:

Emilija Simic - La Jolla CA, US
Christopher Patrick - San Diego CA, US
Douglas Rowitch - Del Mar CA, US
Luca Blessent - San Marcos CA, US
Roland Rick - San Diego CA, US

Assignee:

Qualcomm, Incorporated - San Diego CA

International Classification:

H04Q 7/20

US Classification:

4554561, 4554042, 4554565, 455 111, 342387

Abstract:

A forward link repeater delay watermarking (FLRDWM) system and method that enable accurate position location of mobile stations in areas where repeaters are present by watermarking repeated signals with repeater information. A repeater watermarks a forward link signal with a (unique or non-unique) time delay modulation waveform watermark every time a signal passes through the repeater. A mobile station detects and/or identifies the time delay watermark on the forward link signal to determine repeater information that aids the network position determination entity or mobile station position location system in determining position location using AFLT and/or A-GPS systems. A forward link time delay watermarking system can be implemented to achieve low impact on FL and AFLT performance, favorable detection and identification probabilities, and short time-to-detect/identify.

US Patent:

7764726, Jul 27, 2010

Filed:

Nov 30, 2005

Appl. No.:

11/291173

Inventors:

Emilija Simic - La Jolla CA, US
Douglas Rowitch - Del Mar CA, US
Christopher Patrick - San Diego CA, US

Assignee:

QUALOMM Incorporated - San Diego CA

International Classification:

H04B 1/00

US Classification:

375150

Abstract:

A method according to an embodiment obtains a list of peaks for each of a number of frequency hypotheses. Each peak has an energy result and corresponds to a code phase hypothesis. Embodiments include methods and apparatus that may be used in identifying a location of a signal (such as a GPS signal) in a two-dimensional search space. Location information may be further applied to operations such as signal acquisition, signal tracking, position location of a receiver, and timing operations such as the synchronization of one or more other processes.

US Patent:

8139685, Mar 20, 2012

Filed:

May 8, 2006

Appl. No.:

11/430613

Inventors:

Emilija Simic - La Jolla CA, US
Christopher Patrick - San Diego CA, US
Raghu Challa - San Diego CA, US
Douglas Neal Rowitch - Del Mar CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04L 27/00

US Classification:

375324, 375322, 375316, 375346, 375339, 455318, 455139, 455319

Abstract:

A receiver according to one embodiment includes a frequency control unit configured to receive a stream of samples including a plurality of received instances of a transmitted signal. The frequency control unit is configured to output a first correction signal (e. g. indicating a rotation) that is based on more than one of the received instances and a second correction signal (e. g. to control an oscillator) that is also based on more than one of the received instances. In some embodiments, a controlled oscillator is used to receive and/or transmit another signal, such as a signal received from a GPS space vehicle. In other embodiments, the received instances are from a GPS signal. In further embodiments, a fixed-frequency oscillator is used, and the second correction signal is used to receive and/or transmit another signal, such as a GPS signal.

US Patent:

8213487, Jul 3, 2012

Filed:

Jul 26, 2010

Appl. No.:

12/843605

Inventors:

Emilija Simic - La Jolla CA, US
Douglas Neal Rowitch - Del Mar CA, US
Christopher Patrick - San Diego CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

H04B 1/00

US Classification:

375150

Abstract:

A method according to an embodiment obtains a list of peaks for each of a number of frequency hypotheses. Each peak has an energy result and corresponds to a code phase hypothesis. Embodiments include methods and apparatus that may be used in identifying a location of a signal (such as a GPS signal) in a two-dimensional search space. Location information may be further applied to operations such as signal acquisition, signal tracking, position location of a receiver, and timing operations such as the synchronization of one or more other processes.