Fair resource allocation in OFDMA based relayed transmission

In this work we consider the problem of fair resource allocation in Orthogonal Frequency Division Multiplexing (OFDM) based relayed downlink transmission. A transmission frame is divided into two subframes. Base and Relay Stations transmit in the first and second subframe respectively. Resources are divided into subchannels and time slot and allocated to users in a max-min fair manner. Contrary to an Amplify and Forward assumption in the literature, we assume Decode and Forward relays and hence subchannel duration also becomes an optimization parameter. The problem is formulated and solved as a linear programming problem. A heuristic algorithm is also proposed. Simulation results prove that Decode and Forward relaying provides significant performance improvement with respect to Amplify and Forward relaying.