US Patent 7155162 Radio base station and program recorded medium

A frequency estimation unit (57) and a timing estimation unit (58) respectively detect a frequency offset and a timing offset from a signal received from a mobile station via a control channel. A weight calculation unit (53) corrects reception signals received via a communication channel, using the detected frequency offset and timing offset when new wireless connection to the mobile station is performed by forming an antenna directivity. A signal intended for the mobile station is separated from the corrected reception signals with high accuracy.