scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Youssef Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Ahmed Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

scholarly journals ARQ: The Gateway from NOMA to NOM

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Youssef Iraqi
Keyword(s):  
Multiple Access ◽  
System Throughput ◽  
High Signal ◽  
Signal To Noise ◽  
System Complexity ◽  
Power Domain ◽  
Single User ◽  
Point To Point ◽  
Adaptation Scheme ◽  
New Framework

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

scholarly journals Cooperative Non-Orthogonal Multiple Access over Log-Normal Power Line Communication Channels

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1254
Author(s):  
Roger Kwao Ahiadormey ◽  
Prince Anokye ◽  
Kyoung-Jae Lee
Keyword(s):  
Outage Probability ◽  
Multiple Access ◽  
Power Line ◽  
System Throughput ◽  
Power Line Communication ◽  
High Signal ◽  
Second Phase ◽  
Power Domain ◽  
Log Normal ◽  
The Impact

In this paper, we analyze the performance of cooperative power domain non-orthogonal multiple access (NOMA) in power line communication (PLC) networks. Due to the high signal attenuation of the source to user links, a relay aids communication from the source to two users. With half-duplex transmission, the source transmits a superimposed symbol in the first phase. The relay utilizes amplify-and-forward (AF) and decode-and-forward (DF) protocol on the received superimposed signal and forwards it to the users in the second phase. We derive analytic expressions for the outage probability and the system throughput of the proposed system under a PLC log-normal channel with impulsive noise. Based on the results for AF NOMA relaying case, we analyze the system performance at high signal-to-noise ratio (SNR) and derive closed-form lower and upper bounds for the outage probability. Simulation results show an improvement in the outage probability and the system throughput performance of the AF and DF NOMA schemes compared to the NOMA without relaying transmission and conventional orthogonal multiple access scheme. Furthermore, the impact of the channel variance is highlighted in the results. It is shown that the DF NOMA has a better outage probability than the AF NOMA scheme for low channel variance scenarios (i.e., less branches and connected loads in the PLC network). However, as the channel variance increases, AF NOMA scheme has similar outage probability performance as the DF NOMA scheme. In addition, it is shown that the system throughput is enhanced when the relay employs DF relaying compared to AF relaying.

scholarly journals Time Switching Based Wireless Powered Relay Transmission with Uplink NOMA

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5467
Author(s):  
Zhihua Lin ◽  
Shihua Cao ◽  
Jianqing Li
Keyword(s):  
Multiple Access ◽  
Relay Node ◽  
Base Station ◽  
Spectrum Efficiency ◽  
Transmission Model ◽  
System Throughput ◽  
Time Switching ◽  
Power Domain ◽  
End Node ◽  
Save Energy

Non-orthogonal multiple access (NOMA) utilizes power domain multiplexing to improve spectrum efficiency compared with orthogonal multiple access (OMA). In the Internet of Things (IoT) uplink NOMA networks, if the channel between the far-end node and the base station is in deep fading, allocating larger transmitting power for this node cannot achieve higher spectrum efficiency and overall system throughput. Relay cooperative communication reduces the transmitting power at the far-end node but leads to extra energy expenditure at the relay node. Fortunately, simultaneous wireless information and power transfer (SWIPT) is advocated in energy-constrained IoT networks to save energy consumption. However, early works all focus on energy harvesting (EH) from one source node or one dedicated power supply station. In this paper, we propose a time switching based wireless powered relay transmission model with uplink NOMA where our EH technique can harvest energy from two simultaneously transmitting nodes. More importantly, by optimizing relay position more energy is harvested from the near-end node at the relay and relay signal attenuation to the destination is reduced as well. Furthermore, the closed-form expressions of outage probability and overall system throughput are derived, and numerical results prove that NOMA in our EH scheme achieves better performance compared to the traditional EH scheme and OMA by optimizing the position of the relay node, time switching factor and so on.

A compact guided-wave EMAT with pulsed electromagnet for ferromagnetic tube inspection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen
Keyword(s):  
Power Plants ◽  
Signal To Noise Ratio ◽  
Small Diameter ◽  
Performance Testing ◽  
Guided Wave ◽  
High Signal ◽  
Receiver Coil ◽  
Signal To Noise ◽  
Corrosion Defects

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes

2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dft Calculations ◽  
Photoinduced Electron Transfer ◽  
Density Functional ◽  
Embryonic Stem ◽  
High Sensitivity ◽  
Md Simulations ◽  
High Signal ◽  
Signal To Noise ◽  
Green Fluorescent

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>

A Review of Power Domain Non-Orthogonal Multiple Access in 5G Networks

2018 ◽  
Vol 10 (7) ◽  
Author(s):  
Aiman Kassir ◽  
◽  
Rudzidatul Akmam Dziyauddin ◽  
Hazilah Mad Kaidi ◽  
Mohd Azri Mohd Izhar ◽  
...  
Keyword(s):  
Multiple Access ◽  
5G Networks ◽  
Power Domain

Electroanalysis of Catecholamine Drugs using Graphene Modified Electrodes

2019 ◽  
Vol 15 (4) ◽  
pp. 443-466 ◽  
Author(s):  
Mahya Karami Mosammam ◽  
Mohammad Reza Ganjali ◽  
Mona Habibi-Kool-Gheshlaghi ◽  
Farnoush Faridbod
Keyword(s):  
Electrochemical Sensors ◽  
Modified Electrodes ◽  
Electrochemical Methods ◽  
High Signal ◽  
Signal To Noise ◽  
Low Level ◽  
Biological Studies

Background: Catecholamine drugs are a family of electroactive pharmaceutics, which are widely analyzed through electrochemical methods. However, for low level online determination and monitoring of these compounds, which is very important for clinical and biological studies, modified electrodes having high signal to noise ratios are needed. Numerous materials including nanomaterials have been widely used as electrode modifies for these families during the years. Among them, graphene and its family, due to their remarkable properties in electrochemistry, were extensively used in modification of electrochemical sensors. Objective: In this review, working electrodes which have been modified with graphene and its derivatives and applied for electroanalyses of some important catecholamine drugs are considered.

Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Wei-Nan Liu ◽  
Rui Chen ◽  
Wei-Yi Shi ◽  
Ke-Bo Zeng ◽  
Fu-Li Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Signal To Noise Ratio ◽  
Incident Angle ◽  
Design Strategy ◽  
Transmission Peak ◽  
High Signal ◽  
Waveguide Array ◽  
Signal To Noise ◽  
Center Wavelength ◽  
Noise Ratio

AbstractSelective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.

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