Mathematical analysis of energy efficiency optimality in multi‐user OFDM systems. Issue 3 (12th August 2014)

• Record Type: Journal Article
• Authors: Chien, Su Fong; Ting, T. O.; Yang, Xin‐She; Takahashi, Kenzo
• Is Part Of: Wireless communications and mobile computing. Volume 16:Issue 3(2016)
• Page Start: 252
• Page End: 263
• Publication Date: 2014-08-12
• Subjects: energy efficiency -- OFDMA -- optimization -- QoS -- resource allocation; Wireless communication systems -- Periodicals; Mobile communication systems -- Periodicals; 621.38205
• DOI: 10.1002/wcm.2516
• Languages: English
• ISSNs: 1530-8669

Abstract

Abstract: The strong need and global interests for green communications necessitate the maximum reduction of energy consumption. Hence, one of the major challenges is to optimize the resource allocation and to improve the energy efficiency in an orthogonal frequency division multiple access system. In this paper, we analyze the energy‐efficient resource allocation problem mathematically. Our analytical results show that the optimal resource allocation can be achieved by primarily assigning the user with either the best channel gain or the least optimal power. Furthermore, our detailed case studies show that such analytical results are consistent with the best result obtained from the exhaustive search method. This means that the proposed approach can provide quick and better resource allocation. It can be expected that real‐time in situ optimal resource allocation can be achieved by extending the current methodology. Copyright © 2014 John Wiley & Sons, Ltd. Abstract : This work analyzed the prominent resource allocation problem (determination of best subcarrier to a user) in the OFDMA system. The mathematical analysis showed that the optimal resource allocation can be achieved by choosing a subchannel with best channel‐to‐noise gain. The proposed method is quick and easy, as compared to time‐consuming exhaustive search. This has been validated in detail on a small system with four subchannels. Then, we applied this simple method to tackle larger systems comprising 32 users with 64 subchannels. Results are fast and feasible, and no violation encountered thus far.