WIRELESS COMMUNICATION APPARATUS

摘要

During a handover, a mobile station receives, from a handover-source base station, information of a handover-destination base station and related information of a sequence used for a random access signal to be transmitted to the handover-destination base station. The mobile station also receives a synchronization channel signal transmitted from the handover-destination base station. The mobile station then transmits the random access signal to the handover-destination base station at a frequency corresponding to the synchronization channel at a timing after a predetermined time offset from a timing of receiving the synchronization channel. When the random access signal is transmitted during the handover, the places of the time timing/frequency used for the transmission are exclusively used for the random access signal to be transmitted by the mobile station or are exclusively used for a plurality of handover terminals at the same time. Therefore, the interferences among the random access signals from the plurality of mobile stations can be suppressed to zero or a low level. The chance of the successful reception of the random access signals at the handover-destination base station can be raised and the chance of the retransmittal of the random access signals can be reduced. As a result, the time required to perform the handover can be shortened.