Once a NodeB has been found and the necessary broadcast system information has been read from
the P-CCPCH, the UE would then need to continue to find multipaths that were spread with the same
modulation symbols. This is commonly called multipath searching.
Cell Search Procedure. One major difference between the CDMA2000 cellular system [6] and the
WCDMA system is cell site synchronization. In CDMA2000, each BS has a GPS receiver, in order to
maintain frame timing between them. In this case, the UE needs to find a single BS first and can then
find its neighbors simply by looking to the ???left??? and to the ???right??? of the present frame synchronization.
Now in the WCDMA system, the cell sites are asynchronous, meaning the frame timing among
the neighboring cells is not strictly time aligned. However, the standard allows for downlink timing
adjustments, so handoffs between NodeBs have timing uncertainties that are within a reasonable range.
In this case, the UTRAN relies on measurements made by various UE to update NodeB system timing.
As mentioned above on the downlink, 8192 scrambling codes are used, and if left to a brute force
method to determine the scrambling code used by the closest cell, the cell search time would be excessive.
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