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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Engineering

TÜBİTAK

Journal

2019

Energy efficiency

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Antenna Selection And Transmission Power For Energy Efficiency In Downlink Massive Mimo Systems, Adeeb Salh, Lukman Audah, Nor Shahida Mohd Shah, Shipun Anuar Hamzah, Hasan Saeed Mir Jan 2019

Antenna Selection And Transmission Power For Energy Efficiency In Downlink Massive Mimo Systems, Adeeb Salh, Lukman Audah, Nor Shahida Mohd Shah, Shipun Anuar Hamzah, Hasan Saeed Mir

Turkish Journal of Electrical Engineering and Computer Sciences

Massive multiinput-multioutput (M-MIMO) systems are crucial for maximizing energy efficiency (EE) in fifth-generation (5G) wireless networks. A M-MIMO system's achievable high data rate is highly related to the number of antennas, but increasing the number of antennas the system raises energy consumption. In this paper, we derive ergodic EE based on the optimal transmit power and joint optimization antenna selection (AS) with impact pilot reuse sequences (PRSs). We apply Newton's method and the Lagrange multiplier to derive jointly optimized AS and optimal transmission power under the effect of PRSs. The proposed algorithm prevents repeated searching for joint optimal AS and …


Increasing Bluetooth Low Energy Communication Efficiency By Presetting Protocol Parameters, Dusan Hatvani, Dominik Macko Jan 2019

Increasing Bluetooth Low Energy Communication Efficiency By Presetting Protocol Parameters, Dusan Hatvani, Dominik Macko

Turkish Journal of Electrical Engineering and Computer Sciences

Standard protocols are important regarding the compatibility of devices provided by different vendors. However, specific applications have various requirements and do not always need all features offered by standard protocols, making them inefficient. This paper focuses on standard Bluetooth Low Energy modifications, reducing control overhead for the intended healthcare application. Specifically, the connection establishment, device pairing, and connection parameter negotiations have been targeted. The simulation-based experiments showed over 20 times reduction of control-overhead time preceding a data transmission. It does not just directly increase the energy efficiency of communication; it also prolongs the time for sensor-based end devices to spend …