Approaching the shannon limit through parallel concatenation of regular LDGM codes

We propose a parallel concatenated coding scheme in which the constituent codes are regular systematic linear codes with low-density generator matrix (LDGM codes). The proposed system provides a simple way to reduce the error floors characteristic of single regular LDGM codes, and leads to a performance similar to that of turbo and irregular LDPC codes with less encoding/decoding complexity. Although the whole concatenated code is in fact a single irregular LDGM code, its interpretation as a parallel scheme facilitates the design, allowing the implementation of good irregular LDGM codes in a very simple manner. The system performance is studied through density evolution and validated by simulation results