Abstract
Orthogonal frequency division multiple access (OFDMA) has been selected as the core physical layer access scheme for state-of-the-art and next-generation wireless communications standards. In these systems, scheduling and resource allocation algorithms, jointly assigning transmission data rates, bandwidth and power, become crucial to optimize the resource utilization while providing support to multimedia applications with heterogeneous quality of service (QoS) requirements. In this article, a unified framework for channeland queue-aware QoS-guaranteed cross-layer scheduling and resource allocation algorithms for heterogeneous multiservice OFDMA wireless networks is presented. The framework encompasses different types of traffic, uniform and continuous power allocation, discrete and continuous rate allocation, and protocols with different amounts of channel- and queue-awareness. System parameters and QoS requirements are projected into utility functions and the optimization problem is then formulated as a constrained utility maximization problem. Optimal solutions for this problem are obtained for the uniform power allocation schemes, and novel quasioptimal algorithms are proposed for the adaptive power allocation strategies. Remarkably, these techniques exhibit complexities that are linear in the number of resource units and users. Simulation results demonstrate the validity and merits of the proposed cross-layer unified approach.
Highlights
Due to its high spectral efficiency, inherent robustness against frequency-selective fading and flexibility in resource allocation, orthogonal frequency division multiple access (OFDMA), combined with multiple-input multiple-output (MIMO) strategies, has been chosen as the multiple access technique for state-of-the-art and next-generation wireless communications standards such as IEEE 802.16e/m-based WiMAX systems [1] and Third Generation Partnership Project (3GPP) technologies based on the long-term evolution (LTE) and LTEadvanced (LTE-A)a [2]
This study introduces a framework able to account for different types of traffic, different allocation strategies (e.g., continuous and discrete rate allocation (DRA), uniform and adaptive power allocation (APA)), protocols with different amounts of channel- and queue-awareness, and different utility functions measuring user’s satisfaction in terms of, for instance, throughput, queue length and/or service time
7 Conclusions The emergence of state-of-the-art and next-generation wireless communications networks based on adaptive MIMO-OFDMA physical layer (PHY) access schemes, will enable the support of a wide range of multimedia applications with heterogeneous quality of service (QoS) requirements
Summary
Due to its high spectral efficiency, inherent robustness against frequency-selective fading and flexibility in resource allocation, orthogonal frequency division multiple access (OFDMA), combined with multiple-input multiple-output (MIMO) strategies, has been chosen as the multiple access technique for state-of-the-art and next-generation wireless communications standards such as IEEE 802.16e/m-based WiMAX systems [1] and Third Generation Partnership Project (3GPP) technologies based on the long-term evolution (LTE) and LTEadvanced (LTE-A)a [2]. A prediction of the HOL delay at the end of time slot t can be readily obtained as
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
