High Efficiency Resource Allocation in Multicast OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is regarded as a promising technique for the next generation wireless networks. In OFDM system, transmitter can provide high data rates by dividing channels into multiple orthogonal subcarriers and then allocates them to different users. But in the field of multicast, the conventional method ignores the differences of the channel condition between the users and therefore forces the modulation be adjusted to serve the worst user. The unique contribution of our work is to maximize the total throughput in a time efficient manner. In this paper, we propose a dynamic-programming-based algorithm to find the maximum capacity of system in a global manner after partitioning the available power into schedulable equal pieces. Experimental results demonstrate the effectiveness and efficiency of the proposed algorithm, the system throughput gap between the proposed dynamic-programming-based algorithm and the optimal algorithm is within about 2%, and significantly outperform the lowest channel gain method as well as the previous works.