Outage Probability and Power Efficiency of Quantize-and-Forward Relay in Multi-hop D2D Networks

Author(s):  
Nasaruddin Nasaruddin ◽  
Ernita Dewi Meutia ◽  
Ramzi Adriman
2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Jie Li ◽  
Jianrong Bao ◽  
Shenji Luan ◽  
Bin Jiang ◽  
Chao Liu

To improve the reliability and efficiency in cooperative communications, a power optimized single relay selection scheme is proposed by increasing the diversity effort with an improved link-adaptive-regenerative (ILAR) protocol. The protocol determines the forwarding power of a relay node by comparing the signal-to-noise ratio (SNR) at both sides of the node; thus it improves the power efficiency. Moreover, it also proposes a single relay selection strategy to maximize the instantaneous SNR product, which ensures the approximate best channel link quality for good relay forwarding. And the system adjusts the forwarding power in real time and also selects the best relay node participated in the cooperative forwarding. In addition, the cooperation in the protocol is analyzed and the approximate expression of the bit-error-rate (BER) and the outage probability at high SNRs are also derived. Simulation results indicate that the BER and outage probability of the relay selection scheme by the ILAR protocol outperform other contrast schemes of current existing protocols. At BER of 10−2, the proposed scheme with ILAR protocol outperforms those of the decoded-and-forward (DF), the selected DF (SDF), and the amplify-and-forward (AF) protocols by 3.5, 3.5 and 7 dB, respectively. Moreover, the outage probability of the relay system decreases with the growth of the relay number. Therefore, the proposed relay selection scheme with ILAR strategies can be properly used in cooperative communications for good reliability and high power efficiency.


2015 ◽  
Vol 135 (3) ◽  
pp. 114-115 ◽  
Author(s):  
Ryoto Sato ◽  
Daisuke Yasumatsu ◽  
Shinya Kumagai ◽  
Masaru Hori ◽  
Minoru Sasaki

Author(s):  
B. P. Khozyainov

The article carries out the experimental and analytical studies of three-blade wind power installation and gives the technique for measurements of angular rate of wind turbine rotation depending on the wind speeds, the rotating moment and its power. We have made the comparison of the calculation results according to the formulas offered with the indicators of the wind turbine tests executed in natural conditions. The tests were carried out at wind speeds from 0.709 m/s to 6.427 m/s. The wind power efficiency (WPE) for ideal traditional installation is known to be 0.45. According to the analytical calculations, wind power efficiency of the wind turbine with 3-bladed and 6 wind guide screens at wind speedsfrom 0.709 to 6.427 is equal to 0.317, and in the range of speed from 0.709 to 4.5 m/s – 0.351, but the experimental coefficient is much higher. The analysis of WPE variations shows that the work with the wind guide screens at insignificant average air flow velocity during the set period of time appears to be more effective, than the work without them. If the air flow velocity increases, the wind power efficiency gradually decreases. Such a good fit between experimental data and analytical calculations is confirmed by comparison of F-test design criterion with its tabular values. In the design of wind turbines, it allows determining the wind turbine power, setting the geometrical parameters and mass of all details for their efficient performance.


2009 ◽  
Vol E92-B (3) ◽  
pp. 1039-1042
Author(s):  
Nurilla AVAZOV ◽  
Yun Hee KIM ◽  
Iickho SONG
Keyword(s):  

Author(s):  
Rinkuben N. Patel ◽  
Nirav V. Bhatt

Background: WSN is a network of smart tiny electromechanical devices named as sensors. Sensors perform various tasks like sensing the environment as per its range, transmit the data using transmission units, store the data in the storage unit and perform an action based on captured data. As they are installed in an unfriendly environment, to recharge the sensors are not possible every time which leads to a limited lifetime of a network. To enhance the life of a sensor network, the network required energy-efficient protocols. Various energy-efficient MAC protocols are developed by Research community, but very few of them are integrated with the priority-based environment which performs the priority-based data transmission. Another challenge of WSN is, most of the WSN areas are delay-sensitive because it is implemented in critical fields like military, disaster management, and health monitoring. Energy, Delay, and throughput are major quality factors that affect the sensor network. Objective: In this paper, the aim is to design and develop a MAC Protocol for a field like the military where the system requires energy efficiency and priority-based data transmission. Method: In the proposed model, the cluster-based network with priority queues are formed that can achieve higher power efficiency and less delay for sensitive data. Results: In this research simulation of Proposed MAC, TMAC and SMAC are done with different numbers of nodes, same inter-packet intervals, and variant inter-packet intervals. Based on the script simulation, result graphs are generated. Conclusion: The proposed work achieves greater lifetime compared to TMAC and SMAC using priority-based data transmission.


Author(s):  
Xu He ◽  
Yuan Ding ◽  
Gaojian Huang

Background: A new wireless multiple access technology enabled by using Time Modulated Arrays (TMAs) is proposed in this paper. Methods: It benefits due to the requirement of only a single Radio Frequency (RF) chain, compared with other multiple-RF-chain schemes. Results: As a result, it is able to greatly reduce the system cost, energy consumption, and complexity. Conclusion: In addition, the signal through the single RF chain is narrow-band modulated, reducing the signal Peak-to-Average-Power-Ratio (PAPR), thus, further enhancing the power efficiency of the RF chain, especially for power amplifiers. The operation principle and synthesis approach are elaborated in this paper, and are demonstrated with two examples.


2018 ◽  
Vol 2 (1) ◽  
pp. 30
Author(s):  
Hisatsugu Kato ◽  
Yoichi Ishizuka ◽  
Kohei Ueda ◽  
Shotaro Karasuyama ◽  
Atsushi Ogasahara

This paper proposes a design technique of high power efficiency LLC DC-DC Converters for Photovoltaic Cells. The secondary side circuit and transformer fabrication of proposed circuit are optimized for overcoming the disadvantage of limited input voltage range and, realizing high power efficiency over a wide load range of LLC DC-DC converters. The optimized technique is described with theoretically and with simulation results. Some experimental results have been obtained with the prototype circuit designed for the 80 - 400 V input voltage range. The maximum power efficiency is 98 %.


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