Resource allocation and frequency reusing for multihop relay systems

In this paper, an adaptive resource allocation (subframe, subcarrier, bit and power allocation) in a cellular multiuser OFDMA-based relay network is considered. We have studied a margin adaptive problem that satisfies link rate requirements with minimum total base station and relay stations power for a fixed set of discrete modulation levels. This problem has been solved by various optimization techniques such as integer programming algorithms, linear programming, suboptimal heuristic methods and finally greedy algorithm for adaptive bit loading. In our work, we have proposed a method for distributing the users randomly and uniformly in a network, a method for dynamic user selection in the central stations, an algorithm for subcarrier allocation in a relay-cellular network with frequency reusing to extend the coverage and minimize power consumption. Finally, we have compared the performance of our proposed algorithm with static methods and non-frequency reusing schemes and showed the prominent achievable gain.