To provide technology for determining a DL CQI level at a base station without notifying DL CQI information by a mobile station and individually setting transmission parameters of response signals to random access for each mobile station.

According to this invention, a mobile station using a signature meeting a detection criterion is detected and delay time at a propagation path is measured with respect to a reception random access signal from the detected mobile station. Then, a table in which relation between the delay time and the DL CQL level is preliminarily defined is prepared, the DL CQI level is determined using the measured delay time and the table and the transmission parameters of the random access response which are the response signals to the random access are individually set for each mobile station based on the determined DL CQI level.