Abstract: “Resource allocation for multiuser OFDM relay systems is investigated in this paper. The separate power limits for the base station and the relay station is considered. The resource fairness problems for each user are also presented, including the subcarrier fairness and the proportional end-to-end throughput fairness. This paper introduces a hierarchical scheme to combine the maximum end-to-end throughput and minimum transmit power. The set of the switching levels for the modulation types is applied in this paper. The simulated annealing algorithm is introduced. The methods of the neighborhood search is discussed and compared with two heuristic allocation algorithms. Owing to the characteristic of the relay system, unbalanced throughput among hop links happened. This paper proposed a suitable bit loading approach using water-filling method applied to load bits optimally for each user under the power constraint and the fairness constraints. Each user’s hop links are guaranteed to have t”

Keywords: multihop relay, resource allocation, fairness problem, simulated annealing algorithm