System, method, and apparatus for generating a timing signal

• US 6,788,663 B2
• Filed: 05/03/2002
• Issued: 09/07/2004
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rowitch, Douglas Neal
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Hoang, Thai D
• Application Number:
  US10/138,704
• Publication Number:
  US 20030207681A1
• Time in Patent Office: 858 Days
• Field of Search: 370/332, 370/342, 370/343, 370/350, 455/502, 455/456--45, 455/13.2, 455/12.1, 455/18
• US Class Current: 370/335
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]

Abstract

A method of wireless communications according to one embodiment of the invention includes obtaining a first time base (e.g. obtaining a code phase) from a signal received from a ground transmitter (e.g. a CDMA base station). A predetermined offset based on at least a propagation delay of the received signal is applied to the first time base to obtain a second time base. For example, the second time base may be aligned to a time base of a positioning satellite system (e.g. the NAVSTAR GPS). A timing signal is generated that has a code phase based on the second time base.

Claims

1. An apparatus for wireless communications, said apparatus comprising:

a receiver configured and arranged to receive a signal from a ground transmitter;

a decoder configured and arranged to decode a time information message from the received signal and arranged to output a strobe signal indicating a coincidence between code phases of a spreading code of the signal being decoded and a corresponding GPS C/A code;

a time base processor configured and arranged to apply a predetermined offset to a time base of the received sign to obtain a second time base; and

a timing signal generator configured and arranged to generate a timing signal,

wherein a code phase of the timing signal is based on the second time base.

2. The apparatus for wireless communications according to claim 1, said apparatus further comprising a searcher configured and arranged to obtain a code phase of the received signal.

3. The apparatus for wireless communications according to claim 1, wherein the second time base is aligned with a time base of a positioning satellite system.

4. The apparatus for wireless communications according to claim 3, wherein said timing signal generator is further configured and arranged to spread the timing signal with a spreading code of positioning satellite system.

5. The apparatus for wireless communications according to claim 1, wherein said time base processor is further configured and arranged to perform at least one among the acts of (A) synchronizing an oscillator according to the time base of the received signal and (B) adjusting a code generator according to the time base of the received signal.

6. The apparatus for wireless communications according to claim 1, wherein said time base processor is further configured and arranged to perform at least one among the acts of (A) synchronizing an oscillator according to the second time base and (B) adjusting a code generator according to the second time base.