Fair Resource Allocation in OFDMA Two-Hop Cooperative Relaying Cellular Networks

This paper discusses on the fair resource allocation in OFDMA two-hop cooperative relaying cellular networks which consist of a single base station (BS), dedicated fixed relay stations (RSs) and user stations (USs). By assuming the relay strategy employed on each subcarrier is adaptively selected among direct transmission, amplify-and-forward (AF) and decode-and-forward (DF) according to different channel conditions, we formulate a fair subcarrier assignment, relay station and relay strategy selection problem with QoS constraints in terms of user´s minimum rate requirement. The formulated problem is a binary integer programming (BIP) problem which is NP-complete, so a simple suboptimal algorithm is proposed to manage the network resources. Simulations demonstrate the proposed algorithm obtains near optimal solution with low complexity and achieves a good tradeoff between the overall system performance and the fairness among users.