A resource allocation scheme for the heterogeneous OFDMA system with Ad Hoc relay

In this paper, we present a heterogeneous network framework involved an orthogonal frequency division multiple access (OFDMA) network with an out-of-band Ad Hoc network. In this heterogeneous system, the mobile stations (MSs) are dual-mode, with both cellular OFDMA and Ad Hoc radios. MSs communicate with the base station (BS) by cellular OFDMA mode and communicate with each other by Ad Hoc mode. An active MS is free to choose an inactive MS as its relay station (RS). Partner selection, subcarrier, power, and rate allocation schemes for the uplink of the heterogeneous system are considered. To maximize the system capacity under individual rate and transmit power constraints, a fair and efficient resource allocation scheme for the heterogeneous OFDMA system with Ad Hoc relay is proposed. Numerical results show that the proposed resource allocation scheme achieves significant improvement on the performance in terms of the system capacity and the outage probability, while imposing little complexity on the MSs and consuming negligible power in the Ad Hoc network.