Performance Bounds for Multilevel LDPC Coded Modulation

This paper investigates multilevel coded modulation with multistage decoding, where finite-length low-density parity check (LDPC) codes are used as component codes. The systems under consideration are different from the conventional multilevel coded modulation by the fact that more than one coded bit of a component code are mapped to the labeling bits of the signal constellation. The union bound on the bit error probability for each decoding stage is derived. The tightness of the bounds is verified against the simulation results on the error performance of the ordered statistic decoding (OSD) and sum-product decoding