The error introduced by asymmetry of the antenna-feeder channel when measuring transmitted power

1975 ◽  
Vol 18 (5) ◽  
pp. 743-744
Author(s):  
L. M. Moldavskii
Keyword(s):  
Transmitted Power ◽  
Feeder Channel

scholarly journals Physical layer security transmission scheme based on artificial noise in cooperative SWIPT NOMA system

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yong Jin ◽  
Zhentao Hu ◽  
Dongdong Xie ◽  
Guodong Wu ◽  
Lin Zhou
Keyword(s):  
Interference Cancellation ◽  
Physical Layer Security ◽  
High Energy ◽  
Physical Layer ◽  
Base Station ◽  
Artificial Noise ◽  
Transmitted Power ◽  
Transmission Scheme ◽  
Convex Problem ◽  
Security Problem

AbstractAiming at high energy consumption and information security problem in the simultaneous wireless information and power transfer (SWIPT) multi-user wiretap network, we propose a user-aided cooperative non-orthogonal multiple access (NOMA) physical layer security transmission scheme to minimize base station (BS) transmitted power in this paper. In this scheme, the user near from BS is adopted as a friendly relay to improve performance of user far from BS. An energy harvesting (EH) technology-based SWIPT is employed at the near user to collect energy which can be used at cooperative stage. Since eavesdropper in the downlink of NOMA system may use successive interference cancellation (SIC) technology to obtain the secrecy information of receiver, to tackle this problem, artificial noise (AN) is used at the BS to enhance security performance of secrecy information. Moreover, semidefinite relaxation (SDR) method and successive convex approximation (SCA) technique are combined to solve the above non-convex problem. Simulation results show that in comparison with other methods, our method can effectively reduce the transmitted power of the BS on the constraints of a certain level of the secrecy rates of two users.

scholarly journals Waveguide divider design based on null of electric field

2021 ◽  
Author(s):  
Leonardo Zappelli
Keyword(s):  
Electric Field ◽  
Theoretical Approach ◽  
Initial Point ◽  
Transmission Band ◽  
Geometric Parameters ◽  
Transmitted Power ◽  
Matching Network ◽  
Large Bandwidth ◽  
Input Matching ◽  
Thin Band

AbstractNowadays, the design of dividers is based on electromagnetic software that optimizes some geometric parameters to obtain the required performance. The choice of the geometry of the discontinuities contained in the divider and of the optimization initial point is quite critical to satisfy the divider requirements. In the last years, it is quite rare to find in the literature a theoretical approach helping the designers in the choice of the divider geometry. Helpful suggestion can derive by the analysis of the electric field in a trial divider that satisfies power division among the output ports in a thin band. In fact, the electric field null can be filled with metallic septa that ensure the same behavior at any frequency. The optimization of the septa position/form with numerical electromagnetic software permits to obtain divider with large bandwidth. A further analysis of the electric field null in the divider permits to add lateral metallic septa that further enlarge the transmission band. Finally, the design of an input matching network increases the transmitted power to the desired value.

scholarly journals Accurate and Efficient Evaluation of Bit Error Rate for Dynamic Directional Modulation for Standard Modulation Schemes

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 776
Author(s):  
Josep Parrón ◽  
Edith Cabrera-Hernandez ◽  
Alan Tennant
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Physical Layer Security ◽  
Evaluation Method ◽  
Physical Layer ◽  
Observation Angle ◽  
Transmitted Power ◽  
Modulation Schemes ◽  
Wireless Transmissions ◽  
Directional Modulation

Directional modulation (DM) has been proposed as a technique to enhance physical layer security of wireless transmissions. In DM, the improvement of security is achieved by increasing the transmitted power in such a way that the bit error rate (BER) is degraded in the observation angles out of the desired secure direction. The performance of DM in terms of BER is typically evaluated by transmitting a stream of symbols for every observation angle, but this approach can be time consuming. In this communication, we propose an approach to evaluate, accurately and efficiently, the BER of dynamic DM (DDM) for standard modulation schemes. Several DDM configurations will be tested to illustrate the benefits and limitations of the evaluation method. The proposed approach is also used to present a non-iterative DDM synthesis with restrictions in the BER response.

Research on Vibration Isolation Parameters of Double-Deck Isolation System of Heat Water Pump

2013 ◽  
Vol 694-697 ◽  
pp. 316-320
Author(s):  
Xiang Jun Kong ◽  
Er Ming Song ◽  
Chang Zheng Chen
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Mass Effect ◽  
Transmitted Power ◽  
Intermediate Mass ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Upper Deck ◽  
Vibration Power Flow

Isolation system of the heat water pumps can be simplified as a double sources exciting and double output double-deck vibration isolation system model, expressions of transmitted power flow and vibration speed to the basement are deduced based on the double sources exciting and double output double-deck vibration isolation system electric-force(E-F) analog picture, the curves of power flow and vibration speed transmitted to basement how the upper deck vibration isolation and intermediate mass effect are drawn by using mat lab program. The results show that the adjusting the upper deck vibration isolation stiffness parameters has little effect on the amplitude of vibration power flow, increasing intermediate mass can move first peak to the low frequency, increasing intermediate mass can obviously reduce t transmitted power flow and transmitted vibration speed amplitude to the basement.

Analytical Model of the Efficiency of Spur Gears: Study of the Influence of the Design Parameters

2011 ◽  
Author(s):  
Miguel Pleguezuelos ◽  
Jose´ I. Pedrero ◽  
Miryam B. Sa´nchez
Keyword(s):  
Load Distribution ◽  
Gear Ratio ◽  
Design Parameters ◽  
Spur Gears ◽  
Transmitted Power ◽  
Power Losses ◽  
Contact Ratio ◽  
Complete Study ◽  
Uniform Model ◽  
Analytical Expressions

An analytic model to compute the efficiency of spur gears has been developed. It is based on the application of a non-uniform model of load distribution obtained from the minimum elastic potential criterion and a simplified non-uniform model of the friction coefficient along the path of contact. Both conventional and high transverse contact ratio spur gears have been considered. Analytical expressions for the power losses due to friction, for the transmitted power and for the efficiency are presented. From this model, a complete study of the influence of some design parameters (as the number of teeth, the gear ratio, the pressure angle, the addendum modification coefficient, etc.) on the efficiency is presented.

Analysis of the Influence and Number of Turns on the Smartphone Wireless Charger on the Output Power of the Wireless Charger

2020 ◽  
Vol 10 (1) ◽  
pp. 20-25
Author(s):  
Donny Firmansyah
Keyword(s):  
Output Power ◽  
Magnetic Induction ◽  
Secondary Coil ◽  
Wireless Charging ◽  
Transmitted Power ◽  
Primary Coil ◽  
Power Test ◽  
Transmission Distance ◽  
Coil Diameter

Charging the smartphone battery can be done via powerbank or default charger from the smartphone still using the cable for charging the electricity. Charging using a cable certainly limits the use of the smartphone when it is charging. Smartphone users can not be far from the electric socket which of course is troublesome if this happens in the middle of a room that has a few electrical sockets. To solve this problem, now many wireless charging smartphones or smartphones have been developed wireless charger. Behind the benefits obtained from a wireless charger, it also has disadvantages, namely the transmission distance is short, even there is no distance and the transmitted power is unstable. Wireless chargers are based on the principle of magnetic induction in which electricity is transferred between two objects through a coil. Wireless charger consists of the primary coil as a charger (usually in the form of a thin board or cylinder), and the secondary coil is located on the back of the cellphone. Based on the results, the output power is obtained. The largest wireless charger is 0.027W with a coil diameter of 8cm in all the number of primary coils, namely 40 turns, 50 turns, and 60 turns at a primary and secondary coil distance of 0cm to 1cm. The farthest distance from the wireless charger output power test is 6cm as well as the 8cm coil diameter for all the number of primary coil turns, namely 40 turns, 50 turns, and 60 turns.

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