Cross-layer resource allocation approach in OFDMA systems with multi-class QoS services and users queue status

The design of an efficient and dynamic radio resource management (RRM) scheme is crucial for optimizing the resource utilization and providing QoS in wireless networks. Given the broad range of applications supported, high data rate required and low latency promised, the RRM scheme is indispensable for newly emerging air interface technologies such as WiMAX and LTE standards. The cross-layer information comes handy when judicious resource allocation and performance improvement are considered. This study proposes a cross-layer design for optimized resource allocation with quality of services (QoS) support that aims to balance between service provider´s revenue and subscriber´s satisfaction. The paper considers OFDMA system, which has been adopted in both WiMax and LTE, and presents a cross-layer design optimization for subchannel and power allocations with the objective of maximizing the capacity (in bits/sec/Hz) subject to fairness parameters and QoS requirement as constraints. The optimization does not only consider users´ channel conditions but also queue status of each user as well as different QoS requirements. The QoS classes adopted by the IEEE 802.16e standard, for WiMax technology, have been utilized in this study. In the proposed framework, the problem of power allocation is solved analytically while the subchannel allocation is solved using integer programming exhaustive search. The simulation and numerical results obtained in this paper have shown improved system performance as compared to other optimization schemes known in literature.