New cell search algorithm for inter-cell asynchronous mode DS-CDMA mobile radio system

Inter-cell asynchronous DS-CDMA systems were proposed for third-generation mobile systems, and many research studies on this system are in progress. An inter-cell asynchronous mode DS-CDMA system using a two-pilot structure was proposed by Hong, Lee, Yang, Ahn and (see IEEE ICUPC'96, vol.2, p.365-8, 1996) for flexible cell deployment. In the system, a cell site transmits two pilots, a cluster and a cell pilot, and the cell search is performed by two steps to decrease the cell search time. In this paper, a practical cell structure and cell search algorithm based on the two-pilot scheme of Hong et al. are described, and the performance of the cell search algorithm is evaluated by computer simulations. The results shows that over than 90% of the cell search can be completed within about 600 ms when 512 cell pilot codes of 40960 chip length is used.