Fast cell search using I/Q multiplexed code under hierarchical cell structure

A novel I/Q multiplexed code assignment is proposed for asynchronous cell site operation under hierarchical cell structure, in which the I-channel code as a group code and the Q-channel code as a cell-specific code are assigned to a forward pilot channel. Simulation results show that cell search from macro to micro, or vice versa, can be accomplished in less than ∼50ms at 90% of the locations.