Low complexity margin adaptive resource allocation in downlink MIMO-OFDMA system

• Published in: IEEE transactions on wireless communications Vol. 8; no. 7; pp. 3365 - 3371
• Main Authors: Hassan, N., Assaad, M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive systems; Allocations; Applied sciences; Array signal processing; Beamforming; Complexity; Computer Science; Detection, estimation, filtering, equalization, prediction; Downlink; Exact sciences and technology; Frequency conversion; Information, signal and communications theory; Interference constraints; Iterative algorithms; margin adaptive; MIMO; Multiple input multiple output (MIMO); Multiplexing; Networking and Internet Architecture; Operation, maintenance, reliability; Optimization; orthogonal frequency division multiple access (OFDMA); Quality of service; Resource allocation; Resource management; Signal and communications theory; Signal to noise ratio; Signal, noise; Subcarriers; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); User groups; zeroforcing; Performance evaluation; Noise reduction; Base station; Resource allocation; Frequency division multiple access; Downlink; Subcarrier; Power allocation; Convex programming; Beam forming; orthogonal frequency division multiple access OFDMA; MIMO system; Multiple access; Frequency allocation; zeroforcing; Interference suppression; margin adaptive; Algorithm performance; Simulation; Adaptive resource allocation; Optimal solution; Orthogonal frequency division multiplexing; Signal processing; Resource management; beamforming; Service quality; Multiple input multiple output (MIMO)
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2009.080210

We study the downlink multiuser Multiple Input Multiple Output-Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) system for margin adaptive resource allocation where the base station (BS) has to satisfy individual quality of service (QoS) constraints of the users subject to transmit power minimization. Low complexity solutions involve beamforming techniques for multiuser inter-stream interference cancellation. However, when beamforming is introduced in the margin adaptive objective, it becomes a joint beamforming and resource allocation problem. We propose a sub-optimal two-step solution which decouples beamforming from subcarrier and power allocation. First a reduced number of user groups are formed and then the problem is formulated as a convex optimization problem. Finally an efficient algorithm is developed which allocates the best user group to each subcarrier. Simulation results reveal comparable performance with the hugely complex optimal solution.