A receiving device comprises a signal detection unit, a reliability unit coupled to the signal detection unit and a decoding unit coupled to the signal detection unit and the reliability unit. The signal detection unit is for receiving a plurality of compensated symbols on a plurality of subcarriers, to generate a plurality of soft information and a plurality demodulated symbols of the plurality of compensated symbols according to the plurality of compensated symbols. The reliability unit is for generating a plurality of weights of the plurality of soft information according to a plurality of reliability information of the plurality of subcarriers. The decoding unit is for decoding the plurality of demodulated symbols according to the plurality of soft information and the plurality of weights, to generate a plurality of decoded bits.