In this paper, we propose an energy-efficient power control scheme for device-to-device(D2D) communications underlaying cellular networks, where multiple D2D pairs reuse the same resource blocks allocated to one cellu...In this paper, we propose an energy-efficient power control scheme for device-to-device(D2D) communications underlaying cellular networks, where multiple D2D pairs reuse the same resource blocks allocated to one cellular user. Taking the maximum allowed transmit power and the minimum data rate requirement into consideration, we formulate the energy efficiency maximization problem as a non-concave fractional programming(FP) problem and then develop a two-loop iterative algorithm to solve it. In the outer loop, we adopt Dinkelbach method to equivalently transform the FP problem into a series of parametric subtractive-form problems, and in the inner loop we solve the parametric subtractive problems based on successive convex approximation and geometric programming method to obtain the solutions satisfying the KarushKuhn-Tucker conditions. Simulation results demonstrate the validity and efficiency of the proposed scheme, and illustrate the impact of different parameters on system performance.展开更多
Aiming at the energy consumption of long-distance device-to-device(D2D) devices for two-way communications in a cellular network,this paper proposes a strategy that combines two-way relay technology(TWRT) and simultan...Aiming at the energy consumption of long-distance device-to-device(D2D) devices for two-way communications in a cellular network,this paper proposes a strategy that combines two-way relay technology(TWRT) and simultaneous wireless information and power transfer(SWIPT) technology to achieve high energy efficiency(EE) communication.The scheme first establishes a fractional programming problem to maximize EE of D2D,and transforms it into a non-fractional optimization problem that can be solved easily.Then the problem is divided into three sub-problems:power control,power splitting ratios optimization,and relay selection.In order to maximize EE of the D2D pair,the Dinkelbach iterative algorithm is used to optimize the transmitted power of two D2D devices simultaneously;the one-dimensional search algorithm is proposed to optimize power splitting ratios;an improved optimal relay selection scheme based on EE is proposed to select relay.Finally,experiments are carried out on the Matlab simulation platform.The simulation results show that the proposed algorithm has faster convergence.Compared with the one-way relay transmission and fixed relay algorithms,the proposed scheme has higher EE.展开更多
水提法从蜜环菌 Am 99- 1菌株人工发酵菌体分离得到蜜环菌多糖 Am 1,以低能 N+ 离子束为诱变源 ,黑腹果蝇为受试动物 ,检测 Am 1对离子束诱变果蝇的恢复功能。实验结果经统计学分析表明 ,1.0 %和 1.5 %浓度的蜜环菌多糖 Am 1可以提高受...水提法从蜜环菌 Am 99- 1菌株人工发酵菌体分离得到蜜环菌多糖 Am 1,以低能 N+ 离子束为诱变源 ,黑腹果蝇为受试动物 ,检测 Am 1对离子束诱变果蝇的恢复功能。实验结果经统计学分析表明 ,1.0 %和 1.5 %浓度的蜜环菌多糖 Am 1可以提高受试果蝇蛹的孵出率和降低当代及 F2代果蝇突变率。这说明蜜环菌多糖对于低能离子束诱变有一定程度的防护作用。展开更多
基金supported by National Natural Science Foundation of China (No.61501028)Beijing Institute of Technology Research Fund Program for Young Scholars
文摘In this paper, we propose an energy-efficient power control scheme for device-to-device(D2D) communications underlaying cellular networks, where multiple D2D pairs reuse the same resource blocks allocated to one cellular user. Taking the maximum allowed transmit power and the minimum data rate requirement into consideration, we formulate the energy efficiency maximization problem as a non-concave fractional programming(FP) problem and then develop a two-loop iterative algorithm to solve it. In the outer loop, we adopt Dinkelbach method to equivalently transform the FP problem into a series of parametric subtractive-form problems, and in the inner loop we solve the parametric subtractive problems based on successive convex approximation and geometric programming method to obtain the solutions satisfying the KarushKuhn-Tucker conditions. Simulation results demonstrate the validity and efficiency of the proposed scheme, and illustrate the impact of different parameters on system performance.
基金Supported by the National Natural Science Foundation of China (No.61561031)。
文摘Aiming at the energy consumption of long-distance device-to-device(D2D) devices for two-way communications in a cellular network,this paper proposes a strategy that combines two-way relay technology(TWRT) and simultaneous wireless information and power transfer(SWIPT) technology to achieve high energy efficiency(EE) communication.The scheme first establishes a fractional programming problem to maximize EE of D2D,and transforms it into a non-fractional optimization problem that can be solved easily.Then the problem is divided into three sub-problems:power control,power splitting ratios optimization,and relay selection.In order to maximize EE of the D2D pair,the Dinkelbach iterative algorithm is used to optimize the transmitted power of two D2D devices simultaneously;the one-dimensional search algorithm is proposed to optimize power splitting ratios;an improved optimal relay selection scheme based on EE is proposed to select relay.Finally,experiments are carried out on the Matlab simulation platform.The simulation results show that the proposed algorithm has faster convergence.Compared with the one-way relay transmission and fixed relay algorithms,the proposed scheme has higher EE.
基金We would like to thank Chen Xiaohong for her technical assistance.This work was supported by the National Natural Science Foundation of China(Grant No.30230200)the Ministry of Education of China and Guangdong Province(Grant No.IRT0447,NSF-05200303)the National Basic Research Program(Grant No.2005CB724600).
文摘水提法从蜜环菌 Am 99- 1菌株人工发酵菌体分离得到蜜环菌多糖 Am 1,以低能 N+ 离子束为诱变源 ,黑腹果蝇为受试动物 ,检测 Am 1对离子束诱变果蝇的恢复功能。实验结果经统计学分析表明 ,1.0 %和 1.5 %浓度的蜜环菌多糖 Am 1可以提高受试果蝇蛹的孵出率和降低当代及 F2代果蝇突变率。这说明蜜环菌多糖对于低能离子束诱变有一定程度的防护作用。
