Power-efficient M-QAM signal constellations to reduce the PMEPR in OFDM systems

In this paper, we consider the problem of peak to mean envelope power ratio (PMEPR) in orthogonal frequency division multiplexing (OFDM) systems. First, we propose a power-efficient 8-QAM signal constellation and extend it to higher order QAM signal constellations as well; and then we deploy these constellations to reduce the PMEPR in OFDM systems using the constellation expanding idea. All these constellations have less average power compared to the existing constellations like quadrature constellation and therefore are appropriate for PMEPR reduction in OFDM and other discrete multi-tone (DMT) techniques