Multicast resource allocation with side information in multicarrier wireless networks

In this paper, we study the resource allocation problem for multicast in an Orthogonal Frequency Division Multiplexing (OFDM) based multicarrier wireless system. The objective is to find the subcarrier and power allocation for a set of multicast groups such that the receivers of each group can receive their intended packets. Due to frequency selective and time-varying fading wireless channels, some receivers may fail to receive their packets in the assigned subcarriers. On the other hand, these unsatisfied receivers may obtain side information about the packets of other groups by overhearing other subcarriers, which can be exploited to improve the transmission efficiency using the index coding technique. Based on this idea, we formulate the multicast resource allocation problem by incorporating with the side information. This problem can be transformed to the maximum coverage problem, and a greedy algorithm is designed that solve the problem efficiently with guaranteed approximation ratio. Simulation results show that our proposed schemes can provide substantial improvement under various conditions.