A base station apparatus is disclosed, which can efficiently process a reception signal from a user with a simpler constitution. The base station includes: a packet data user control unit that controls packet data for a user and transmits the packet data and notifies a user ID of a user who transmits data in an arbitrary frame (packet transmission period) and a number of this frame; and a layer control unit that manages the frame number and the user ID and controls de-spread and demodulation. The layer control unit creates finger/user allocation information indicating to which user a finger is allocated and outputs the finger/user allocation information to a demodulation unit. The demodulation unit performs demodulation processing using this information such that generated phase compensation data is connected with an identical user and an identical path.