Power control apparatus and method for a W-CDMA communication system employing a high-speed downlink packet access scheme

An apparatus for controlling uplink transmission power in a handover region by a UE (User Equipment) in communication with a Node B using an FCS (Fast Cell Selection) scheme, comprising:

• a power measure and best cell identification part for measuring transmission power of a received common pilot channel (CPICH) signal, and creating best cell maintain/change information by determining whether to maintain a current best cell or change the current best cell to a next best cell;
• a demultiplexer for demultiplexing shared control channel (SHCCH) signals received from a plurality of Node Bs in an active set and outputting TPC (Transmission Power Control) commands;
• a TPC command memory for storing the TPC commands output from the demultiplexer, received from the plurality of the Node Bs;
• and
• a UE transmission power controller for determining a transmission power offset based on TPC commands stored for a specific duration, which is defined by a number of time slots counted backwards, upon receipt of best cell change information indicating that the best cell must be changed from the current best cell to the next best cell, and then compensating initial transmission power for the next best cell based on the determined power control offset.