Resource Allocation in Multicast OFDM Systems: Lower/Upper Bounds and Suboptimal Algorithm

摘要

This letter studies generalized resource allocation in multiple description coding multicast (MDCM) orthogonal frequency division multiplexing (OFDM) systems, where many multicast groups are served simultaneously by base station (BS). Due to non-tractable nature, the problem is reformulated to weighted-capacity maximization by resource distribution among virtual multicast groups (VMGs). Then, the relaxation of exclusively-used constraints allows us to provide both upper and lower bounds for the original problem. A suboptimal algorithm is also proposed based on Newton's method to reduce the computational complexity. Simulation results show the proposed algorithm approximately reaches the optimal capacity within 2 iterations for multicast waterfilling, and MDCM is more bandwidth-efficient for multicast services than conventional multicast (CVM).