Resource allocation algorithms for multiuser cooperative OFDMA systems with subchannel permutation

In this paper, we investigate resource allocation for a multi-user OFDMA cooperative system. Aiming at minimizing the total transmission power under target rate constraints for each user, we propose centralized and decentralized subchannel, bit, and power allocation schemes. First, assuming knowledge of the instantaneous channel gains for all links in the entire network, centralized resource allocation algorithms with subchannel permutation, in which the subchannels are reallocated at the relay nodes, are considered. Then, a decentralized resource allocation scheme is proposed for ad hoc network. Simulation results show that significant performance gains can be achieved, especially when subchannel permutation is employed.