A base station requests cooperative transmission of a base station forming a nearby cell that is near a mobile station. The base station further includes an acquirer that acquires a reception power for each nearby cell of the mobile station; a calculator that calculates a value for each acquired reception power, weighted by a coefficient of the nearby cell; and a selector that based on each value calculated by the calculator and from among the nearby cells, selects a cell of which the cooperative transmission is to be requested.