A spreader 112 of a base station apparatus 100 spreads transmission data at a low spreading factor at which a given signal quality can be little obtained after despreading at a mobile station apparatus 101, when an error detector 137 of the mobile station apparatus 101 detects an error in despread data of received data, a data retransmission request is performed to the base station apparatus 100 and despread data is held by a despreader/combiner 136. After that, the mobile station apparatus 101 repeats processing for combining the held data with the retransmitted data subjected to despreading until the time when an error-undetected state comes. This makes it possible to increase transmission efficiency, suppress transmission power extremely, and improve diversity performance to transmit data from a plurality of antennas.