Adaptive radio resource allocation with frequency reusing for OFDMA cellular relay networks

A daptive radio resource allocation in a cellular and multiuser OFDMA-Based relay network is considered in this paper. We solve the problem with the objective function for minimizing total transmitted power and the constraints on the relay and user data rates. We have studied adaptive subframe and subcarrier allocation and greedy bit loading in a cellular scenario. Users are distributed randomly and uniformly i n the network and we present a method for assigning the users to the central stations. We assume that the transmissions experience path loss, Rayleigh fading and log-normal shadowing. In this paper we have proposed a dynamic algorithm for subcarrier allocation in the network and also considering frequency reusing in the relay transmissions. Performance of the algorithm in saving power is compared with the non frequency reusing and static methods for subcarrier allocation. Achievable gain of the presented algorithm specially with increasing the requested rate and number of users has been shown in the simulations. Proposed algorithm can be applicable in a real scenario with high demands of transmission rates.