As many digital terrestrial broadcasting stations have been installed and are now broadcasting, the problem of poor reception has become serious even though the receiving powers are high. Although we had developed a interference canceller for broadcast-wave relay stations, an adaptive array is desirable to be more robust against low-D/U multipath environment as a receiver for the service area. In this paper, we propose a weighting coefficient optimization algorithm for post-FFT adaptive array using the reciprocals of weighting coefficients. Numerical examples show the effectiveness of the proposed method.