Future wireless video transmission systems will consider OFDM (orthogonal frequency division multiplexing) as the basic modulation technique due to its robustness and low complexity implementation in the presence of frequency selective channels. Adaptive bit loading techniques have been applied to OFDM showing good performance gains in cable transmission systems. In this paper adaptive loading techniques are applied to a HIPERLAN2-like wireless system at 5 GHz for efficient multimedia traffic transmission. Moreover, the classical water-filling algorithm is extended to the multi-layer case. The semi-analytical results obtained show a large improvement respect to the non-adaptive case, also taking different channel state information up-date rates into account. The impact of this technique in terms of video quality is also evaluated for MPEG-4 video transmission.
['Davide Dardari', 'Maria G. Martini', 'Marco Milantoni', 'Marco Chiani']
MPEG-4 video transmission in the 5 GHz band through an adaptive OFDM wireless scheme