Cross-Layer Design for OFDMA Wireless Systems With Heterogeneous Delay Requirements

• Published in: IEEE transactions on wireless communications Vol. 6; no. 8; pp. 2872 - 2880
• Main Authors: Hui, D.S.W., Lau, V.K.N., Wong Hing Lam
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01.08.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Allocations; Applied sciences; Base stations; Cross layer design; Delay; Delay effects; Delay systems; Design engineering; Dynamical systems; Dynamics; Exact sciences and technology; Information theory; Optimization; Organization, operation and development plans; Physical layer; Policies; Power system modeling; Queueing analysis; Radiocommunications; Statistics; Subcarriers; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teletraffic; Throughput; Transmission and modulation (techniques and equipments); Base station; Wireless telecommunication; Frequency division multiple access; Information rate; Subcarrier; Power allocation; Modeling; Optimal allocation; Linear complexity; Traffic control; Delay time; Multilevel system; Frequency allocation; Teletraffic; Delay-sensitive cross-layer scheduling; Scheduling; Information transmission; Simulation; Queueing system; Power control; Traffic management; Orthogonal frequency division multiplexing; orthogonal frequency division multiple access (OFDMA); heterogeneous applications; subcarrier allocation; Information theory
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2007.05716

This paper proposes a cross-layer scheduling scheme for OFDMA wireless systems with heterogeneous delay requirements. We shall focus on the cross-layer design which takes into account both queueing theory and information theory in modeling the system dynamics. We propose a delay-sensitive cross-layer design, which determines the optimal subcarrier allocation and power allocation policies to maximize the total system throughput, subject to the individual user's delay constraint and total base station transmit power constraint. The delay-sensitive power allocation was found to be multilevel water-filling in which urgent users have higher water-filling levels. The delay-sensitive subcarrier allocation strategy has linear complexity with respect to number of users and number of subcarriers. Simulation results show that substantial throughput gain is obtained while satisfying the delay constraints when the delay-sensitive jointly optimal power and subcarrier allocation policy is adopted.