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Energy efficient relay networks with wireless power transfer from a multi‐antenna base station
Author(s) -
Wang Xinhua,
Liu Ju,
Zhai Chao,
Ma Shuang,
Wang Qing
Publication year - 2016
Publication title -
transactions on emerging telecommunications technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.366
H-Index - 47
ISSN - 2161-3915
DOI - 10.1002/ett.2988
Subject(s) - relay , node (physics) , base station , wireless , energy harvesting , computer science , power (physics) , maximum power transfer theorem , transmitter power output , transmission (telecommunications) , energy (signal processing) , block (permutation group theory) , antenna (radio) , efficient energy use , electrical engineering , data transmission , computer network , electronic engineering , engineering , telecommunications , channel (broadcasting) , transmitter , mathematics , statistics , physics , structural engineering , geometry , quantum mechanics
In this paper, we investigate the energy efficiency (EE) of a decode‐and‐forward relay network with wireless energy harvesting. The data transmission between a multi‐antenna base station (BS) and its user equipment is assisted by an intermediate relay node, which operates with the wireless energy harvesting. The BS firstly transmits energy and information to the relay node, which can harvest the energy and retract the information simultaneously using the power‐splitting or time‐switching method. Then, the relay node forwards its decoded information to the user equipment using all the harvested energy. Through maximising the instantaneous EE for the power‐splitting‐based system, the optimal power‐splitting ratio and the optimal transmit power of the BS are derived in closed form for each time block. To maximise the instantaneous EE for the time‐switching‐based system, an optimisation algorithm is proposed to judiciously determine the harvesting time and the transmit power of the BS for each time block. Furthermore, we optimise the number of antennas N of the BS by taking into account the circuit power consumption, as it cannot be ignored when N is large. Finally, simulation results are presented to validate our derived closed‐form solutions and verify the efficiency of our proposed algorithm. Copyright © 2015 John Wiley & Sons, Ltd.