Experiments on Fast Cell Search Algorithm Using Scrambling Code Masking for Inter-Cell Asynchronous W-CDMA System

Fumiyuki ADACHI

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E83-A    No.11    pp.2102-2109
Publication Date: 2000/11/25
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Spread Spectrum Techniques and Applications)
cell search,  inter-cell asynchronous system,  DS-CDMA,  mobile radio,  

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This paper presents the fast cell search time performance based on laboratory and field experiments of a 2-step cell search algorithm that uses scrambling code masking for inter-cell asynchronous wideband DS-CDMA (W-CDMA) mobile radio. The scrambling code is masked at different time positions during each scrambling period on the forward-link common control channel (CCH) to detect the scrambling code timing at the mobile receiver. Experiments were conducted using the CCH-to-dedicated traffic channel (DTCH) power ratio, R of 3 dB, 10 DTCHs, and 16 scrambling codes in a single-cell and two-cell models. The field experimental results show that the cell search time of about 600 msec was achieved in vehicular environments at the detection probability of 90% and the average received Eb/N0 (N0 is the background noise without interference) of 13-15 dB for DTCH, even in the worst case scenario when the received signal power ratios of the CCH from two cell sites were 0 dB. The cell search time that was achieved with the 3-step cell search algorithm previously proposed by the authors is estimated from the experimental results; the cell search can be accomplished within about 720 msec at a probability of 96% for 512 scrambling codes and 16 scrambling code groups.