A convergence pattern selection unit (10A) sequentially generates a plurality of different patterns based on designated initial conditions, selects, as a convergence pattern, a pattern in which evaluation value has converged to an extreme value, and repeatedly executes selection of the convergence pattern by changing the initial conditions every time the convergence pattern is selected. A transmission pattern determination unit (10B) selects, as an optimum transmission pattern, one of the convergence patterns obtained by the convergence pattern selection unit (10A), which has the highest evaluation value. This allows searches for an optimum transmission pattern having a better evaluation value.