ofdm receiver having a llr metrics based on Csi

In a wireless communication system for digital video broadcast, the receiver device comprises a Viterbi decoder. The Viterbi decoder as inputs require log likelihood ratio. Respect fading channel, the fading strength, can be taken into account to calculate the log-likelihood ratio. In mobile environments, the movement of the receiver, the fading intensity changes. The receiver apparatus 1 of the present invention, depending on the estimation of the interference power being determined individually for each subcarrier, determines the log likelihood ratio. Therefore, log likelihood ratio can be calculated with accurate and improved performance.