United States Patent 7,911,993
Proctor, Jr. , et al. March 22, 2011
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Method and apparatus for allowing soft handoff of a CDMA reverse link utilizing an orthogonal channel structure
Abstract
Method and apparatus for base stations and subscriber units allows soft handoff of a CDMA reverse link utilizing an orthogonal channel structure. Subscriber units transmit an orthogonally coded signal over a reverse link to the base stations. A given base station provides timing control of the timing offset of the reverse link signal. Based on at least one criterion, an alignment controller determines that the given base station should hand off timing control to another base station, and a soft handoff process ensues. In response to a command or message for soft handoff of the subscriber unit from the given base station to another base station, the subscriber unit makes a coarse timing adjustment to the timing of the coded signal. The subscriber unit may make fine timing adjustments based on feedback from the base station controlling timing. Multiple base stations may provide power control feedback to the subscriber unit.
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Inventors: Proctor, Jr.; James A. (Melbourne Beach, FL), Alapuranen; Pertti O. (Indialantic, FL)
Assignee: IPR Licensing, Inc. (Wilmington, DE)
Appl. No.: 10/717,995
Filed: November 20, 2003
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
09898514 Jul., 2001 7006428
10717995 Nov., 2003
60219789 Jul., 2000
60427847 Nov., 2002
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Current U.S. Class: 370/324 ; 370/331; 370/350; 455/525
Current International Class: H04B 7/212 (20060101); H04B 7/00 (20060101); H04J 3/06 (20060101); H04W 4/00 (20090101)
Field of Search: 370/350,331,320,324,335 455/439,525
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