Methods and apparatuses for generating optimized LDPC codes are proposed. One of the methods is a method for generating an optimized LDPC code for an asymmetric transmis¬ sion channel. The method includes receiving an initial LDPC code for the asymmetric transmission channel. Further, the method includes performing a density evolution threshold optimization for the initial LDPC code in order to obtain the optimized LDPC code for the asymmetric transmission channel. A uniformly mixed symmetric channel density for the asymmetric transmission channel is used in the density evolution threshold optimization.