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Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Link adaptation for energy-efficient uplink coordinated multi-point receptions | Nam et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 184 EURASIP Journal on . http jwcn.eurasipjournals.eom content 20ii i i84 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Link adaptation for energy-efficient uplink coordinated multi-point receptions Young-Han Nam 1 Lingjia Liu1 2 Guowang Miao1 and Charlie Jianzhong Zhang1 Abstract We investigate link adaptation methods for energy-efficient uplink coordinated multi-point receptions. A system model for practical cellular networks is introduced in which only a subset of base stations participates in cooperative link adaptation and cooperative decoding for uplink transmissions. To cope with channel-state-information CSI mismatch incurred from the system model link adaptation controllers implementing rate back-off from the maximum achievable rate calculated with the mismatched CSI is introduced. From analytical and simulation results it is concluded that under a certain condition the rate back-off does not help to improve energy efficiency where for example the condition holds when the CSI errors are modeled as additive Gaussian random variables. Furthermore energy efficiency of multi-user spatial-division-multiple-access uplink transmissions is studied in isolated cooperative cellular networks. In this scenario an analytical expression for the optimal link adaptation achieving maximum energy efficiency is obtained. Keywords coordinated multipoint receptions CoMP energy efficiency 1 Introduction Spectral efficiency and energy efficiency are important metrics for wireless communication systems. While contemporary wireless telecommunications standards e.g. LTE-Advanced mainly focuses on enhancing spectral efficiency e.g. 1 there is growing interest in improving energy efficiency partly because the development of battery technology has not kept in pace with the demand of mobile communications 2 3 . Energy-efficient communications also tend to reduce .
