To allocate a terminal apparatus to a time slot to which a plurality of subcarriers are assigned, a base station apparatus first acquires the strength of signals between the base station apparatus and the terminal apparatus. Then the base station apparatus specifies a group, containing the acquired strength, among a plurality of groups. The plurality of groups are predefined in a manner such that the ranges of values of the acquired strengths differs respectively. Time slots to be allocated are predefined respectively for the plurality of groups. A time slot corresponding to the specified group is selected, and a subcarrier to be assigned to the terminal apparatus is selected from among a plurality of subcarriers contained in the selected time slot.