scholarly journals Tradeoff-HARQ Scheme for Full-Duplex SWIPT DF Relay

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiaoye Shi ◽  
Haiting Zhu ◽  
Fei Ding ◽  
Zhaowei Zhang ◽  
Nan Bao
Keyword(s):  
Transition Probability ◽  
Transmission Efficiency ◽  
The State ◽  
Full Duplex ◽  
Total Power ◽  
Energy Transmission ◽  
Total Transmission ◽  
Total Data ◽  
Power Limit ◽  
Slot Structure

The SWIPT (simultaneous wireless information and power transfer) DF (decoding and forwarding) relay system could achieve the purpose of both increasing revenue and reducing expenditure. By analysing the system model and transmission characteristics of full-duplex relay, this paper optimizes the retransmission slot structure to enhance the system performance. Firstly, the state transition model is established based on the analysis of the retransmission slot structure. Secondly, the state probability of each state and the transition probability between states are calculated to obtain the total data passing rate, energy transmission efficiency, and total transmission time. Thirdly, in order to compare the performance of various HARQ (hybrid automatic repeat request) schemes more effectively, JNTP (joint normalized throughput of information transmission and energy transmission) is constructed. Monte Carlo simulations finally confirm that the proposed tradeoff-HARQ scheme outperforms the regular-HARQ scheme in terms of JNTP: the performance of the tradeoff-HARQ scheme is 0.03883 higher than that of the regular-HARQ scheme when the total power limit is 20 dB and 0.00651 higher than that of the regular-HARQ scheme when the total power limit is 30 dB.

Improving the efficiency of oilfield electric power distribution

2019 ◽  
pp. 79-87
Author(s):  
Yu. F. Yu. F. Romaniuk ◽  
О. V. Solomchak ◽  
М. V. Hlozhyk
Keyword(s):  
Power Distribution ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Active Power ◽  
Oil Field ◽  
Total Power ◽  
Simultaneous Increase ◽  
Active Load ◽  
Step Down

The issues of increasing the efficiency of electricity transmission to consumers with different nature of their load are considered. The dependence of the efficiency of the electric network of the oil field, consisting of a power line and a step-down transformer, on the total load power at various ratios between the active and reactive components of the power is analyzed, and the conditions under which the maximum transmission efficiency can be ensured are determined. It is shown by examples that the power transmission efficiency depends not only on the active load, but also largely on its reactive load. In the presence of a constant reactive load and an increase in active load, the total power increases and the power transmission efficiency decreases. In the low-load mode, the schedule for changing the power transmission efficiency approaches a parabolic form, since the influence of the active load on the amount of active power loss decreases, and their value will mainly depend on reactive load, which remains unchanged. The efficiency reaches its maximum value provided that the active and reactive components of the power are equal. In the case of a different ratio between them, the efficiency decreases. With a simultaneous increase in active and reactive loads and a constant value of the power factor, the power transmission efficiency is significantly reduced due to an increase in losses. With a constant active load and an increase in reactive load, efficiency of power transmission decreases, since with an increase in reactive load, losses of active power increase, while the active power remains unchanged. The second condition, under which the line efficiency will be maximum, is full compensation of reactive power.  Therefore, in order to increase the efficiency of power transmission, it is necessary to compensate for the reactive load, which can reduce the loss of electricity and the cost of its payment and improve the quality of electricity. Other methods are also proposed to increase the efficiency of power transmission by regulating the voltage level in the power center, reducing the equivalent resistance of the line wires, optimizing the loading of the transformers of the step-down substations and ensuring the economic modes of their operation.

scholarly journals Energy Rate Maximization with Sum-Rate Constraint for SWIPT in Multiple-Access Channels

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1525
Author(s):  
Yeonggyu Shim ◽  
Wonjae Shin
Keyword(s):  
Multiple Access ◽  
Transmission Rate ◽  
Closed Form Expression ◽  
Total Power ◽  
Power Splitting ◽  
Splitting Scheme ◽  
Energy Transmission ◽  
Energy Rate ◽  
Optimal Power ◽  
Sum Rate

This paper considers simultaneous wireless information and power transfer (SWIPT) systems in the two-user Gaussian multiple access channel (G-MAC). In SWIPT systems, for a transmit signal each transmitter consists of an information-carrying signal and energy-carrying signal. By controlling a different set of the power for the information transmission and power for the energy transmission under a total power constraint, the information sum-rate and energy transmission rate can be achieved. As the information carrying-to-transmit power ratio at transmitters and the information sum-rate increases, however, the energy transmission rate decreases. In other words, there is a fundamental trade-off between the information sum-rate and the energy transmission rate according to the power-splitting ratio at each transmitter. Motivated by this, this paper proposes an optimal power-splitting scheme that maximizes the energy transmission rate subject to a minimum sum-rate constraint. In particular, a closed-form expression of the power-splitting coefficient is presented for the two-user G-MAC under a minimum sum-rate constraint. Numerical results show that the energy rate of the proposed optimal power-splitting scheme is greater than that of the fixed power-splitting scheme.

scholarly journals Recombination Lasers in the XUV Spectral Region

1984 ◽  
Vol 86 ◽  
pp. 234-240
Author(s):  
G.J. Pert
Keyword(s):  
Transition Probability ◽  
Unit Length ◽  
Energy Levels ◽  
Ultra Violet ◽  
Statistical Weight ◽  
Laser Medium ◽  
Total Power ◽  
Spontaneous Transition ◽  
Spectral Bands ◽  
Conventional Laser

In a conventional laser operating in the near ultra-violet, optical or infra-red spectral bands the photon energies, not exceeding lOeV, are closely matched to the electronic or molecular energy levels of neutral and weakly ionised atoms. Consequently typical photon energies (~ eV), and transition lifetimes (~ ns) closely match the characteristics of fast electrical circuitry feeding a weakly ionised discharge which may be used to pump either directly or indirectly the laser medium.In a X-ray laser operating at about 10Å, photon energies are about 1 keV, and lifetimes about 10−14s (l0fs). In consequence the power required to pump the laser must be expected to increase rapidly as the wavelength decreases. The gain per unit length is given by:where ζ is the line shape factor, A the spontaneous transition probability, λ the wavelength, and Δν the width of the line, and (n2,g2) and (n3,g3) the population density and statistical weight of the lower and upper laser states respectively. The total power loss per unit area, p, of the medium must exceed that emitted by spontaneous decay of the laser transition.

Optimization Method of the Transcutaneous Energy Transmission System with Given Output Power

2012 ◽  
Vol 195-196 ◽  
pp. 1169-1174
Author(s):  
Liang Yu Bai ◽  
Yu Zheng ◽  
Hou Jun Tang
Keyword(s):  
Output Power ◽  
Magnetic Coupling ◽  
Optimization Method ◽  
Transmission Efficiency ◽  
Energy Transmission ◽  
Bifurcation Phenomenon ◽  
Design Variables ◽  
Transcutaneous Energy Transmission

Transcutaneous energy transmission (TET) systems are designed to deliver power from an in vitro primary power source to in vivo implantable secondary over relatively large air gaps via magnetic coupling. This paper proposes an optimization method with given output power to meet different practical application. The transmission efficiency is the objective function; primary and secondary coils are design variables; constraints are based on bifurcation phenomenon and components peak over-voltage and peak withstand current. We have used MATLAB/ SIMULINK to verify the analytical results.

scholarly journals A Full-Duplex MAC Tailored for 5G Wireless Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Lucas de Melo Guimarães ◽  
Jacir Luiz Bordim
Keyword(s):  
Mobile Networks ◽  
Mac Protocol ◽  
Full Duplex ◽  
Medium Access ◽  
High Data ◽  
Total Transmission ◽  
Fifth Generation ◽  
Half Duplex ◽  
5G Network ◽  
5G Mobile Networks

The increasing demands for high-data rate traffic stimulated the development of the fifth-generation (5G) mobile networks. The envisioned 5G network is expected to meet its challenge by devising means to further improve spectrum usage. Many alternatives to enhance spectrum usage are being researched, such as massive MIMO, operation in mmWave frequency, cognitive radio, and the employment of full-duplex antennas. Efficient utilization of the potential of any of these technologies faces a set of challenges related to medium access control (MAC) schemes. This work focuses on MAC schemes tailored for full-duplex antennas, since they are expected to play a major role in the foreseeable 5G networks. In this context, this paper presents a MAC layer technique to improve total transmission time when full-duplex antennas are employed. Several evaluations in different scenarios are conducted to assess the proposed MAC scheme. Numerical results show that the proposed scheme provides gains up to 156% when compared to a state-of-the-art full-duplex antenna MAC protocol. Compared to traditional half-duplex antenna MAC protocols, the proposed scheme yields gain up to 412%.

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