Novel non-square, Gray coded, 64-QAM constellations

This paper outlines a method whereby a Gray coded, square, Quadrature Amplitude Modulation 64 point constellation, modified by relocating the inner most four and outer most four constellation points to specific positions, results in Gray coded, non-square constellations, with reduced peak-to-average power ratio at the modulator output relative to that resulting from the square constellation. As a consequence, a higher average transmitter output power is possible. Further, though receiver threshold level is increased, this increase is measurably less than the increase achievable in average transmitter output power, leading to an achievable system gain that is higher by approximately 0.9 dB.