Orthogonal frequency division multiple access (OFDMA) has been selected as the core physical layer access\r\nscheme for state-of-the-art and next-generation wireless communications standards. In these systems, scheduling\r\nand resource allocation algorithms, jointly assigning transmission data rates, bandwidth and power, become crucial\r\nto optimize the resource utilization while providing support to multimedia applications with heterogeneous quality\r\nof service (QoS) requirements. In this article, a unified framework for channeland queue-aware QoS-guaranteed\r\ncross-layer scheduling and resource allocation algorithms for heterogeneous multiservice OFDMA wireless networks\r\nis presented. The framework encompasses different types of traffic, uniform and continuous power allocation,\r\ndiscrete and continuous rate allocation, and protocols with different amounts of channel- and queue-awareness.\r\nSystem parameters and QoS requirements are projected into utility functions and the optimization problem is then\r\nformulated as a constrained utility maximization problem. Optimal solutions for this problem are obtained for the\r\nuniform power allocation schemes, and novel quasioptimal algorithms are proposed for the adaptive power\r\nallocation strategies. Remarkably, these techniques exhibit complexities that are linear in the number of resource\r\nunits and users. Simulation results demonstrate the validity and merits of the proposed cross-layer unified\r\napproach.
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