Practical Approaches to Adaptive Resource Allocation in OFDM Systems

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2008
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Mcode
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Language
en
Pages
1-10
Series
EURASIP Journal on Wireless Communications and Networking, Volume 2008
Abstract
Whenever a communication system operates in a time-frequency dispersive radio channel, the link adaptation provides a benefit in terms of any system performance metric by employing time, frequency, and, in case of multiple users, multiuser diversities. With respect to an orthogonal frequency division multiplexing (OFDM) system, link adaptation includes bit, power, and subcarrier allocations. While the well-known water-filling principle provides the optimal solution for both margin-maximization and rate-maximization problems, implementation complexity often makes difficult its application in practical systems. This paper presents a few suboptimal (low-complexity) adaptive loading algorithms for both single- and multiuser OFDM systems. We show that the single-user system performance can be improved by suitable power loading and an algorithm based on the incomplete channel state information is derived. At the same time, the power loading in a multiuser system only slightly affects performance while the initial subcarrier allocation has a rather big impact. A number of subcarrier allocation algorithms are discussed and the best one is derived on the basis of the order statistics theory.
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Keywords
adaptive control, fading, OFDM
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Citation
Ermolova , N & Makarevitch , B 2008 , ' Practical Approaches to Adaptive Resource Allocation in OFDM Systems ' , EURASIP Journal on Wireless Communications and Networking , vol. 2008 , 160307 , pp. 1-10 . https://doi.org/10.1155/2008/160307