Weighted ergodic sum-rate maximisation in uplink orthogonal frequency division multiple access and its achievable rate region

• Published in: IET communications Vol. 4; no. 18; pp. 2217 - 2229
• Main Authors: Yaacoub, E., El-Hajj, A.M., Dawy, Z.
• Format: Journal Article
• Language: English
• Published: Stevenage Institution of Engineering and Technology 17.12.2010; John Wiley & Sons, Inc
• Subjects: Applied sciences; Ergodic processes; Exact sciences and technology; Frequency division multiple access; Information, signal and communications theory; Multiplexing; Online; Optimization; Signal and communications theory; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Temporal logic; Transmission and modulation (techniques and equipments); Multiple access; On line processing; Frequency division multiple access; Equity; Orthogonal frequency division multiplexing; Ergodicity; Off line; Iterative method; Uplink; Optimization
• ISSN: 1751-8628; 1751-8636
• DOI: 10.1049/iet-com.2009.0722

The weighted ergodic sum-rate maximisation problem subject to per-user power and rate constraints in the orthogonal frequency division multiple access uplink is formulated and solved. The solution is found via dual optimisation techniques, and the duality gap between the primal and dual solutions is analysed. Ergodicity allows taking advantage of the temporal dimension in addition to the frequency and multiuser dimensions. The per-user rate constraints allow an improved fairness level in the system. The achievable rate region of the weighted ergodic sum-rate maximisation problem is determined, and the effect of the per-user rate constraints on this region is studied. Offline and online iterative techniques to obtain the Lagrangian parameters are presented, and the results show that online iterations converge to the offline solution within a limited time.