Position location with low tolerance oscillator

• US 6,208,292 B1
• Filed: 09/09/1998
• Issued: 03/27/2001
• Est. Priority Date: 09/09/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sih, Gilbert C., Zou, Qiuzhen
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/150,093
• Time in Patent Office: 930 Days
• Field of Search: 342/357.02, 342/357.12, 342/357.15, 342/357.1, 342/357.06, 455/456
• US Class Current: 342/357.31
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/246 involving long acquisition integration times, extended snapshots of signals or methods specifically directed towards weak signal acquisition
• CPC Class Codes: G01S 2205/008 using a mobile telephone network

Abstract

The present invention is a novel and improved method and apparatus for performing position location in wireless communications system. One embodiment of the invention comprises a method of performing position location in a wireless subscriber unit having a local oscillator, including the steps of receiving a position location request, acquiring a timing signal when a sufficient period of time has elapsed since the local oscillator has been corrected and correcting said local oscillator using a correction signal based on said timing signal, substantially freezing the correction signal, performing a position location procedure using the local oscillator with the correction signal applied, and ending said position location procedure.

Claims

1. A method of performing position location in a wireless subscriber unit having a local oscillator, comprising the steps of:

receiving a position location request;

acquiring a timing signal a period of time after the local oscillator had been corrected and correcting said local oscillator using a correction signal based on said timing signal;

substantially freezing the correction signal;

performing a position location procedure using the local oscillator with the correction signal applied; and

ending said position location procedure.

2. The method as set forth in claim 1 wherein said timing signal is a pilot signal of a wireless communication system.

3. The method as set forth in claim 2 wherein said pilot signal is a CDMA pilot signal.

4. The method as set forth in claim 2 wherein said pilot signal is a GSM pilot signal.

5. The method as set forth in claim 2 wherein said pilot signal is a TDMA pilot signal.

6. The method of claim 1 further comprising the step of entering a communications mode after performing position location procedure.