Constant-power adaptive orthogonally multiplexed modulations under flat Rayleigh fading

Adaptive transmission technique adopting rectangularly-pulsed orthogonally multiplexed modulation (OMM) signals is studied for the flat Rayleigh fading channel. By choosing spectrally efficient OMM signals in accordance with channel status under an error rate constraint, constant-power adaptive OMM systems are shown to significantly outperform the conventional constant-power adaptive orthogonal frequency division multiplexing systems in average spectral efficiency.