A novel design of QAM whose modulation index is not the nth power of 2

This paper proposed a novel and universal Quadrature Amplitude Modulation (QAM) design whose modulation index is not the integral power of 2; it also realized the QAM modulation in a higher resolution of modulation index by mapping consecutive constellations into bit sequences. The novel QAM design can reduce the gap of the performance between different modulations and enrich the choices of QAM in adaptive modulation. This paper took 28QAM as an example to state the method of design, mainly including the design of a mapping rule which made the 28 constellation points mapped into bit sequences and simulate its performances. The BER curve of 28QAM is in the middle between 24QAM and 32QAM.