A new MLC scheme with QAM constellations over AWGN and Rayleigh fading channels

Optimal multilevel codes (MLC) with QAM constellations are considered with focus on both AWGN and Rayleigh fading channels. With the proposition of three novel set partitioning rules for QAM constellations, a new MLC scheme with a very simple MSD (multistage decoding) structure comes into being, which is operated on the capacity rule. Compared with traditional MLC scheme the new MLC structure greatly reduces the calculation of the individual capacities in the MLC system because the new set partitioning rules ensure the independency of two dimension symbols. Furthermore the new system cannot cause any performance loss and the time delay is just 1/2 of that with traditional partitioning rules. As an example 64QAM constellation with three new set partitioning rules are provided. Their performance is simulated over AWGN and Rayleigh fading channels by choosing BCH codes as the component codes.