At a receiver side, to enhance the performance of concatenated LDPC and TCM coding, an iterative decoding between TCM decoder and LDPC decoder enables improvement in the reliability of received LLRs of each symbol after each iteration. A SOVA output of the TCM is used for LDPC decoding, and then the updated LLRs from LDPC decoder are further looped back to the TCM decoder for the next iteration. In such a manner, the decoding performance could be significantly improved after just several iterations.