OFDM Turbo DeCodulation with exit optimized bit loading and signal constellations

We propose the combination of orthogonal frequency division multiplexing (OFDM) and turbo decodulation (TDeC) - a multiple turbo process consisting of iterative demodulation and iterative source-channel decoding - for transmission of correlated source codec parameters over wireless frequency-selective broadband fading channels. As OFDM systems split up frequency-selective fading channels into orthogonal flat-fading channels, individual modulation signal constellations sets with different bit mapping rules can be assigned to subcarriers taking into account the iterative reception and decoding process. The superior performance of the proposed OFDM-TDeC system is demonstrated by analyzing the achieved residual bit error rate (BER) and parameter signal-to-noise ratio (SNR).