Optimal Resource Allocation for Multiuser MIMO-OFDM Systems With User Rate Constraints

• Published in: IEEE transactions on vehicular technology Vol. 58; no. 3; pp. 1190 - 1203
• Main Authors: Ho, W.W.L., Ying-Chang Liang
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Allocations; Applied sciences; Array signal processing; Complexity; Convex optimization; Demand; dual decomposition; dual proportional fairness (PF); Electrical engineering. Electrical power engineering; Electrical power engineering; Exact sciences and technology; Fading; Information, signal and communications theory; Lagrangian functions; MIMO; multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM); Multiplexing; multiuser; OFDM; Operation, maintenance, reliability; Operation. Load control. Reliability; Optimization; Organization, operation and development plans; Orthogonal Frequency Division Multiplexing; Pools; Power networks and lines; Radio spectrum management; Radiocommunications; Resource allocation; Resource management; Signal and communications theory; Studies; subcarrier selection; Subcarriers; System performance; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Throughput; Transmitters; resource allocation; dual decomposition; dual proportional fairness; MIMO-OFDM; convex optimization; multiuser; subcarrier selection; Performance evaluation; Wireless telecommunication; Resource allocation; Optimization method; Information rate; Multimedia communication; Subcarrier; Power allocation; Convex programming; Optimization; dual proportional fairness (PF); Subscriber; Optimal allocation; Convex optimization; multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM); Connectedness; Multimedia; MIMO system; Multiple access; Lagrangian; Frequency allocation; Information transmission; User requirement; Orthogonal frequency division multiplexing; Resource management; Service quality
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2008.927721

With the proliferation of wireless services, personal connectivity is quickly becoming ubiquitous. As the user population demands greater multimedia interactivity, data rate requirements are set to soar. Future wireless systems, e.g., multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM), need to cater to not only a burgeoning subscriber pool but also to a higher throughput per user. Furthermore, resource allocation for multiuser MIMO-OFDM systems is vital for the optimization of the subcarrier and power allocations to improve overall system performance. Using convex optimization techniques, this paper proposes an efficient solution to minimize the total transmit power subject to each user's data rate requirement. Using a Lagrangian dual decomposition, the complexity is reduced from one that is exponential in the number of subcarriers M to one that is only linear in M . To keep the complexity low, linear beamforming is incorporated at both the transmitter and the receiver. Although frequency-flat fading has been known to plague OFDM resource allocation systems, a modification, i.e., dual proportional fairness , seamlessly handles flat or partially frequency-selective fading. Due to the nonconvexity of the optimization problem, the proposed solution is not guaranteed to be optimal. However, for a realistic number of subcarriers, the duality gap is practically zero, and optimal resource allocation can be evaluated efficiently. Simulation results show large performance gains over a fixed subcarrier allocation.