Data boundary aware base station assisted position location

• US 6,323,805 B1
• Filed: 09/09/1998
• Issued: 11/27/2001
• Est. Priority Date: 09/09/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kang, Inyup, Sih, Gilbert C., Zou, Qiuzhen
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/150,410
• Time in Patent Office: 1,175 Days
• Field of Search: 375/149, 375/150, 342/357.06, 342/357.1, 342/357.12, 342/357.09, 701/213, 455/456
• US Class Current: 342/357.42
• 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 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station

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 for performing position location on a subscriber unit in a terrestrial wireless telephone system using a set of satellites each transmitting a signal, the terrestrial wireless telephone system having base stations, including the steps of transmitting an aiding message from the base station to the subscriber unit, said aiding message containing information regarding a data boundary for each signal from the set of satellites, applying correlation codes to each signal yielding corresponding correlation data and accumulating said correlation data over an first interval preceding a corresponding data boundary yielding a first accumulation result, and a second interval following said corresponding data boundary yielding a second accumulation result.

Claims

1. A method for increasing the sensitivity of a receiver, comprising the steps of:

receiving in the receiver a first signal having at least one data boundary from an external source;

receiving in the receiver, from a second source, an aiding message containing information regarding at least one of the data boundaries within the first signal;

applying correlation codes to the first signal to yield correlation data;

accumulating the correlation data yielded by applying the correlation codes over a first interval preceding a first one of the data boundaries for which information was received from the second source yielding a first accumulation result; and

accumulating the correlation data over a second interval following the first one of the data boundaries for which information was received from the second source yielding a second accumulation result, the timing of the first and second interval being based upon the knowledge of the timing of the at least one data boundary ascertained from the aiding message.

2. The method as set forth in claim 1, further comprising the steps of:

adding the first accumulation result and the second accumulation result yielding a first full accumulation result;

subtracting the first accumulation result from the second accumulation result yielding a second full accumulation result;

selecting the first full accumulation result when larger in magnitude then the second full accumulation result; and

selecting the second full accumulation result when larger in magnitude then the first full accumulation result.