WCDMA initial cell search

In this paper the performance of the WCDMA initial cell search for multiple carrier frequencies is analyzed. The performance is quantified by the probability of acquisition and the mean and variance of the search time. Analytical expressions derived by signal flow graph techniques are combined with simulation results in order to determine the initial cell search performance numerically. A three-step cell search algorithm is used in WCDMA to acquire the scrambling code and phase. An implementation example based on parallel search technique and maximum-likelihood detection is presented. For this example, the mean search time is below 3 sec. when the mobile station has to search through a list of 12 frequencies where only one is a WCDMA carrier for an E_c/N₀ of -21 dB and in case of AWGN and one-path Rayleigh fading channels