Abstract
We present a framework for designing a class of concatenated codes based on low-density parity-check component codes that we call parallel concatenated Gallager codes (PCGC). The iterative decoding trajectories technique is used to explain the performance of PCGC. Simulation results show an enhanced performance in the practical E/sub b//N/sub 0/ range in both AWGN and flat Rayleigh fading channels. The reduced decoding complexity of the proposed coding scheme along with its good performance makes it an attractive candidate in delay sensitive applications.