Network Coding in Two-Relay OFDMA Networks Using Re-initialized Transmission Scheme

This paper introduces a collaborative coding algorithm and re-initialized transmission scheme to improve spectral efficiency of two-relay OFDMA networks. By broadcasting the network coded frames through the shared sub-carriers, with specific network coding and frame recovery at each relay node (RN), the proposed algorithm provides 1/3 higher spectral efficiency than the conventional, store-and-forward, relaying scheme. The proposed algorithm suffers from the error propagations in the data recovery at the destinations. To control this effect, re-initialization into the transmission scheme is proposed.