Improved adaptive bit-interleaved coded modulation for mobile radio OFDM systems aided by fading prediction

Adaptive bit-interleaved coded modulation (ABICM) is attractive for rapidly varying mobile radio channels due to its robustness to imperfect channel state information (CSI) at the transmitter. Novel ABCIM method based on the expurgated bound is proposed. This method improves upon previously investigated ABICM techniques since it is able to maintain the target bit error rate for diverse CSI conditions. Spectral efficiencies of the proposed ABICM method, adaptive trellis-coded modulation, and uncoded adaptive modulation are compared for an adaptive mobile radio orthogonal frequency division-multiplex (OFDM) system aided by the long-range fading prediction. It is demonstrated that ABICM is much less sensitive to prediction errors than the other two adaptive modulation techniques, which do not employ interleaving, but reliable fading prediction is still necessary to achieve high spectral efficiency of ABICM for practical channel conditions.