On two cross-layer assisted resource allocation schemes in multiuser multicarrier systems

Resource allocation (RA) is a crucial task in the operation of wireless communication systems, which in many cases aims at meeting the users´ quality of service (QoS) requirements with the minimum amount of resources. In this work, we consider the QoS-provisioning RA problem at the downlink of a multicarrier system, where the total transmit power consumption is to be minimized. Two RA schemes, one employing Lagrange dual methods and a greedy primal recovery scheme, and the other heuristic with a three-step approach, are proposed under the same cross-layer framework, where power allocation, adaptive modulation and coding as well as retransmission protocols are jointly modeled. Though both suboptimal, the two schemes are advantageous for their low complexity and small amount of online computations required. Their performances are illustrated and compared based on simulation results. The work also provides a quantitative comparison on the two commonly used retransmission protocols, namely automatic repeat request (ARQ) and hybrid automatic repeat request (HARQ).