Adaptive Relay Selection for Regenerative OFDMA Relay Networks with Fairness Constraints

We propose an adaptive relay selection scheme for a regenerative orthogonal frequency division multiplexing access (OFDMA) relay network with fairness constraints. The proposed scheme selects the best M relays out of a set of K potential relays to maximize the system capacity. Among these selected relays, subcarriers are reallocated to satisfy fairness constraints as well as to minimize the decrease of the system capacity. The simulation results show that the proposed scheme achieves significant performance improvement over direct transmission and opportunistic relaying with OFDM (OR-OFDM). In addition, multiuser diversity is achieved as the number of potential relays increases with proposed scheme.