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Patent Searching and Data


Title:
METHOD AND APPARATUS FOR STEP TWO OF W-CDMA SEARCHING
Document Type and Number:
WIPO Patent Application WO2003026147
Kind Code:
A3
Abstract:
Techniques for searching in asynchronous systems are disclosed. In one aspect, a plurality of codes, such as SSCs, are correlated with a received signal at a plurality of offsets to produce a code/slot energy corresponding to each code/slot boundary pair. Unique subsets of the code/slot energies are summed to produce code sequence energies, the maximum of which indicates a located code sequence and slot boundary. In another aspect, the correlation is performed by sub-correlating the received signal with a common sequence, and performing a Fast Hadamard Transform FHT on the results. In yet another aspect, one sub-correlator can be used to search a plurality of peaks simultaneously. Various other aspects of the invention are also presented. These aspects collectively have the benefit of circuit area and search-time efficiency which translate into reduced costs, increased standby time, increased acquisition speed, higher quality signal transmission, increased data throughput, decreased power, and improved overall system capacity.

Inventors:
RAO SUBRAMANYA P
VENKATESAN SIVARAMA
GHO GWANG-HYUN
AGRAWAL AVNEESH
TERASAWA DAISUKE
Application Number:
US0230001W
Publication Date:
June 19, 2003
Filing Date:
September 19, 2002
Export Citation:
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Assignee:
QUALCOMM INCORPORATED
International Classes:
H04B1/7073; H04B1/7077; H04B1/7083; H04B1/7093; H04Q7/38; H04B1/7075; H04B1/709; (IPC1-7): H04B1/707; H04B7/26
Domestic Patent References:
WO2001001596A1
Foreign References:
US5930366A
EP1056217A2
Other References:
WANG Y -P E ET AL: "Cell search in W-CDMA", IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, AUG. 2000, IEEE, USA, vol. 18, no. 8, pages 1470 - 1482, XP002224578, ISSN: 0733-8716
NYSTROM J ET AL: "Comparison of cell search methods for asynchronous wideband CDMA cellular system", INTERNATIONAL CONFERENCE ON UNIVERSAL PERSONAL COMMUNICATIONS, IEEE, NEW YORK, NY, US, vol. 2, 5 October 1998 (1998-10-05), pages 783 - 787, XP002148255
HIGUCHI K ET AL: "Experiments on fast cell search algorithm for intercell asynchronous W-CDMA mobile radio", ELECTRONICS LETTERS, IEE STEVENAGE, GB, vol. 35, no. 13, 24 June 1999 (1999-06-24), pages 1046 - 1047, XP006012347, ISSN: 0013-5194
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