公开(公告)号：EP1428325A2

公开(公告)日：2004-06-16

申请号：EP02759739.2

申请日：2002-09-19

申请人： QUALCOMM Incorporated

发明人： RAO, Subramanya, P. ,  VENKATESAN, Sivarama ,  GHO, Gwang-Hyun ,  AGRAWAL, Avneesh ,  TERASAWA, Daisuke

IPC分类号： H04B1/707 ,  H04B7/26

CPC分类号： H04B1/7077 ,  H04B1/70735 ,  H04B1/70752 ,  H04B1/7083 ,  H04B1/709 ,  H04B1/7093 ,  H04B2201/70701 ,  H04B2201/70707

摘要： 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.