Cross-layer and Semi-distributed Resource Allocation for Delay Utility Maximization in a Wireless Relay-aided OFDMA Network

In this paper, we consider a wireless relay-aided Orthogonal Frequency Division Multiple Access (OFDMA) network, where there are a Base Station (BS), multiple Relay Stations (RSs) and Mobile Stations (MSs). we assume that individual MS is already allocated to its serving sector which is served by BS directly or through RSs. To maximize the total sum of utility functions of average packet delays of MSs, we first consider queue dynamics of MSs and estimate expected average packet delays. And then, we formulate an optimization problem to maximize delay utility under some resource allocation constraints. To solve the optimization problem, we propose a cross-layer and semi-distributed subchannel and service rate allocation scheme, where RSs participate in resource allocation procedure to maximize delay utility and to reduce feedback overheads. Simulation results show the performance benefits of our proposed scheme.