Modulation Adaptation for OFDM Packet Radio Transmissions

Adaptive modulation can improve the performance and reliability of orthogonal frequency division multiplexing (OFDM) packet transmissions over dynamic fading channels. For this to occur, the modulation must be selected to match the subchannel conditions as they evolve over time, which requires that subchannel state information be collected and routinely updated. In this study we develop and evaluate a method for modulation adaptation that does not rely on traditional channel measurements to assess subchannel quality.