Performance comparison of hard and soft-decision turbo coded OFDM systems

This paper compares the performance of hard and soft-decision turbo coded Orthogonal Frequency Division Multiplexing systems with Quadrature Phase Shift Keying (QPSK) and 16-Quadrature Amplitude Modulation (16-QAM). The results show that the soft-decision method greatly outperforms the hard-decision method. Using simplified algorithm for the soft-output demapper in the 16-QAM constellation, the complexity of the demapper is greatly simplified.