Patent ID: 7236468
Filing Date: 2007-06-26
Classification: H04B

Abstract:
1. A method for performing a cell search by receiving from a Node B a primary synchronization channel signal transmitted with as many chips as a predetermined chip length at a beginning of each slot, a secondary synchronization channel signal overlapping with the primary synchronization channel signal, being transmitted while maintaining orthogonality with the primary synchronization channel, and a common pilot channel signal scrambled by a unique scrambling code, a one-frame length of the common pilot channel signal being equal to one period of the scrambling code, each frame being comprised of a predetermined number M of slots each having a predetermined chip length N, in a UE (User Equipment) for a W-CDMA (Wideband Code Division Multiple Access) mobile communication system, the method comprising the steps of: counting an index count value within a range of a one-frame length by a period shorter than or equal to the predetermined chip length, after being initialized at a predetermined time point; starting a first cell search step using the primary synchronization channel signal at a given time point, and storing the index count value at a time point where slot synchronization is acquired, as a slot timing index; starting a second cell search step using the secondary synchronization channel signal at a time point of the slot timing index, and storing the index count value at a time point where frame synchronization and a codeword group are acquired, as a frame timing index; and performing a third cell search step using the common pilot channel at a given time point, and detecting a scrambling code used by the Node B among scrambling codes constituting the codeword group.