Optimal Max–Min Fair Resource Allocation in Multihop Relay-Enhanced WiMAX Networks

In this paper, an optimal resource allocation scheme is proposed for WiMAX networks that are enhanced with nontransparent relay stations (RSs). We first focus on two-hop relaying networks, because this scenario has the largest throughput gain. Furthermore, several researchers have proposed different resource allocation schemes in two-hop relaying networks, and thus, we can compare the performance of our proposed scheme with the following two well-known schemes in terms of cell throughput, outage rate, and computational time: 1) orthogonal and 2) overlapped . We then explore an extension of the proposed scheme to a general multihop relaying scenario by taking into account spatial reuse in both the access and relay zone periods. The numerical results show that the highest cell throughput can be achieved by the proposed optimal scheme while maintaining the fairness and lower outage performance of the orthogonal scheme at a higher computational cost. Moreover, the cell throughput degradation from increasing the number of hops from two to three hops, under the proposed optimal scheduling scheme, is only 12% and 19% when six and nine RSs are deployed, respectively.