Peter S Loomis

US Patent:

20030223477, Dec 4, 2003

Filed:

May 17, 2001

Appl. No.:

09/860125

Inventors:

Peter Loomis - Sunnyvale CA, US
Yiming Yu - Cupertino CA, US

International Classification:

H04B001/707

US Classification:

375/147000

Abstract:

A GPS receiver and method using alternating “A” and “B” integration time segments. The polarities of certain GPS data bits are known beforehand and their expected reception times are known. The GPS signal in 10 millisecond “A” time segments and “B” time segments is depolarized according to the known polarities. The depolarized GPS signal during an “A” time period made up of all the “A” time segments is integrated for providing an “A” time period magnitude for each code phase. Likewise, the depolarized GPS signal during a “B” time period made up of all the “B” time segments is integrated for providing a “B” time period magnitude for each potential GPS code phase. The strongest of the time period magnitudes is compared to a correlation threshold for selecting a code phase for signal acquisition.

US Patent:

20060034353, Feb 16, 2006

Filed:

Oct 27, 2005

Appl. No.:

11/259836

Inventors:

Peter Loomis - Sunnyvale CA, US
Yiming Yu - Cupertino CA, US

International Classification:

H04B 1/707

US Classification:

375148000

Abstract:

A GPS receiver and method using alternating “A” and “B” integration time segments. The polarities of certain GPS data bits are known beforehand and their expected reception times are known. The GPS signal in 10 millisecond “A” time segments and “B” time segments is depolarized according to the known polarities. The depolarized GPS signal during an “A” time period made up of all the “A” time segments is integrated for providing an “A” time period magnitude for each code phase. Likewise, the depolarized GPS signal during a “B” time period made up of all the “B” time segments is integrated for providing a “B” time period magnitude for each potential GPS code phase. The strongest of the time period magnitudes is compared to a correlation threshold for selecting a code phase for signal acquisition.

US Patent:

20070040741, Feb 22, 2007

Filed:

Aug 8, 2005

Appl. No.:

11/199409

Inventors:

Peter Loomis - Sunnyvale CA, US

International Classification:

G01S 5/14

US Classification:

342357150

Abstract:

A mobile GPS location system. The location system includes a mobile radio transceiver for transmitting a radio positioning signal and receiving a responsive radio system signal having a radio positioning system (RPS)-based time and position derived from the radio positioning signal; a mobile global positioning system (GPS) receiver; and a code range selector using the RPS-based time and position for selecting a code search range. The mobile GPS receiver uses the code search range for focusing a code phase search to a narrow range for rapidly acquiring a GPS signal. The RPS-based time and position are derived from a plurality of radio signal times-of-arrival (TOA)s determined by a plurality of system units from the radio positioning signal.

US Patent:

20070252758, Nov 1, 2007

Filed:

Aug 8, 2005

Appl. No.:

11/199507

Inventors:

Peter Loomis - Sunnyvale CA, US

International Classification:

H04B 7/185
G01S 1/00

US Classification:

342357150, 342464000

Abstract:

A mobile location system. The GPS location system includes a radio positioning system (RPS) for determining times-of arrival at several locations for a radio positioning signal transmitted from a mobile unit and then using the times-of-arrival for determining an RPS-based position and time for the mobile unit. The mobile unit uses the RPS-based position and time for focusing a code phase search to a narrow range for rapidly acquiring a GPS signal.

US Patent:

58253289, Oct 20, 1998

Filed:

May 29, 1997

Appl. No.:

8/865480

Inventors:

John F. Schipper - Palo Alto CA
Peter Loomis - Sunnyvale CA

Assignee:

Trimble Navigation Limited - Sunnyvale CA

International Classification:

H04B 7185
G01S 502

US Classification:

342357

Abstract:

A method for determining J location fix coordinates, such as (x,y,z,b) for J=2-4, for a selected location, such as a mobile station location, with increased accuracy, for a satellite-based or ground-based location determination (LD) system such as GPS, GLONASS or LORAN. Pseudorange corrections for the pseudorange values measured at the reference station approximately at an observation time t' are used to correct the pseudorange values measured at the selected location. Location fix coordinates are computed from the pseudorange values at the selected location or at the reference station, using an exact, invertible transformation T(t') between the J location fix coordinates and J pseudorange values. Information including the location fix coordinates is transmitted from one station to another with a reduced or minimal number of information bytes and with small dynamic ranges. Locations fix coordinates, as corrected using the pseudorange corrections, for the selected location are computed at the selected location, at the reference station or at a supplemental data processor, using the transformation T(t') and/or its inverse.