Abstract

In a CDMA cellular system, the process of the mobile station searching for a cell and achieving code and time synchronization to its downlink scrambling code is referred to as cell search. In WCDMA, the cell search is divided into five acquisition stages: slot synchronization, frame synchronization and scrambling code group identification, scrambling code identification, frequency acquisition, and cell identification. A pipelined process of the first three stages minimizes the average code and acquisition time. This report presents algorithms and results for serial search and pipeline search. The acquisition times in different cases are compared. We present six policies. A simulation testbed is used to compare the performance of the six algorithms. It is shown from the simulation results that system performance is greatly improved by using modified cell search. Our WCDMA algorithms is shown to outperform the other algorithms in all of the test situations considered (e.g., AWGN channel, four types of fading channels). In addition, our algorithm requires less time to get code acquisition than the other algorithms.