Patent ID: 7110438

Claim:
A cell search method for a CDMA system for a three-stage(a first stage, a second stage and a third stage) cell search procedure, comprising the steps of: matching incoming signals by a chip matched filter; over-sampling the incoming signals N times against a chip rate by a sampling device, thereby generating a plurality of N over-samples, wherein N is an integer; transmitting the N over-samples into a serial test unit by a down sampler; selecting a best sample among N over-samples in the first stage via the serial test unit controlled by a first stage detector; and transmitting the best sample of the N over-samples into a second stage detector and a third stage detector to accomplish a trial, the trial of the cell search method further comprising the steps of: achieving a slot synchronization in the first stage by a first stage detector; achieving a code group and frame synchronization in the second stage by a second stage detector; selecting a scrambling code in the third stage by the third stage detector; testing the scrambling code against a threshold η 0 by a comparator; determining the scrambling code by a first decision device after the comparator; wherein if the threshold is exceeded, then the selected scrambling code goes for a synchronization verification unit, otherwise the trial is considered to be failure, and a new trial will be restarted without penalty; and determining the scrambling code by a second decision device after the synchronization verification unit; wherein if the scrambling code passes the second decision device, then the trial is succeed, otherwise a new trial will be restarted with a penalty time T P (ms); and an initial sampling point at the chip matched filter is assumed uniformly distributed.