In this paper, we propose a simple design of LDPC codes which combines the good properties of multilevel coding (MLC) and bit-interleaved coded modulation (BICM) schemes with Gray-mapped PAM constellations and one-shot demodulation. Through simulations, we show that it performs better than MLC/parallel independent decoding for short-medium lengths, which is required for most applications, on AWGN and block-fading channels. Since 2<sup>m</sup>-PAM represents one quadrature component of 2<sup>2m</sup>-QAM, the optimization holds true for QAM too. In general, this idea can be extended to other modulation schemes like 2<sup>m</sup>-PSK very easily.
Global Telecommunications Conference, 2004. GLOBECOM '04. IEEE; 01/2004