Robustness of LDPC codes on periodic fading channels

Root and Variya (1968) proved the existence of codes that can communicate reliably over any member of a set of linear Gaussian channels where each member exceeds a given amount of mutual information. In this paper we show that LDPC codes are such codes and that their performance lies within 0.1 bits of the Root and Variya capacity for a large family of periodic Gaussian channels. specifically, the robustness of LDPC codes to periodic fading is demonstrated through the consistency of their mutual information performance across period-2 and period-256 fading profiles. The latter case implies that these codes are ideal candidates for coding in OFDM.