scholarly journals Rate Fairness and Power Consumption Optimization for NOMA-Assisted Downlink Networks

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 58
Author(s):  
Kha-Hung Nguyen ◽  
Hieu V. Nguyen ◽  
Mai T. P. Le ◽  
Tuan X. Cao ◽  
Oh-Soon Shin
Keyword(s):  
Graph Theory ◽  
Power Consumption ◽  
System Performance ◽  
Multiple Access ◽  
Relaxation Method ◽  
Low Complexity ◽  
Joint Optimization ◽  
Power Consumption Optimization ◽  
Inner Approximation

This paper considers a non-orthogonal multiple access (NOMA) downlink network, where a hybrid of NOMA and beamforming designs is developed to enhance the channel capacity. We aim to improve the system performance in terms of rate fairness and power consumption. Hence, a multi-objective problem with a joint optimization of user equipment pairing, power control, and quality-of-service requirements is addressed. To efficiently solve the problem, we propose two low-complexity algorithms based on the inner-approximation method, with the first algorithm using the relaxation method and the second one using graph theory. Numerical results are provided to demonstrate the effectiveness of the two proposed algorithms in comparison with the exhaustive search and existing methods.

scholarly journals Joint optimization of computing ratio and access points’ density for mixed mobile edge/cloud computing

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Tianqi Jing ◽  
Shiwen He ◽  
Fei Yu ◽  
Yongming Huang ◽  
Luxi Yang ◽  
...  
Keyword(s):  
Cloud Computing ◽  
Coverage Probability ◽  
Optimization Problem ◽  
Mobile Cloud Computing ◽  
Low Complexity ◽  
Mixed Integer ◽  
Joint Optimization ◽  
Mobile Cloud ◽  
Convex Problem

AbstractCooperation between the mobile edge computing (MEC) and the mobile cloud computing (MCC) in offloading computing could improve quality of service (QoS) of user equipments (UEs) with computation-intensive tasks. In this paper, in order to minimize the expect charge, we focus on the problem of how to offload the computation-intensive task from the resource-scarce UE to access point’s (AP) and the cloud, and the density allocation of APs’ at mobile edge. We consider three offloading computing modes and focus on the coverage probability of each mode and corresponding ergodic rates. The resulting optimization problem is a mixed-integer and non-convex problem in the objective function and constraints. We propose a low-complexity suboptimal algorithm called Iteration of Convex Optimization and Nonlinear Programming (ICONP) to solve it. Numerical results verify the better performance of our proposed algorithm. Optimal computing ratios and APs’ density allocation contribute to the charge saving.

Joint Optimization of Quality of Experience and Power Consumption in OFDMA Multicell Networks

2016 ◽  
Vol 20 (2) ◽  
pp. 380-383 ◽  
Author(s):  
Hua Shao ◽  
Wenpeng Jing ◽  
Xiangming Wen ◽  
Zhaoming Lu ◽  
Haijun Zhang ◽  
...  
Keyword(s):  
Power Consumption ◽  
Quality Of Experience ◽  
Joint Optimization ◽  
Multicell Networks

scholarly journals QoS Enabled IoT Based Low Cost Air Quality Monitoring System with Power Consumption Optimization

2020 ◽  
Vol 20 (2) ◽  
pp. 122-140
Author(s):  
Virendra Barot ◽  
Viral Kapadia ◽  
Sharnil Pandya
Keyword(s):  
Quality Of Service ◽  
Air Quality ◽  
Power Consumption ◽  
Monitoring System ◽  
Topology Design ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Power Consumption Optimization ◽  
Indoor And Outdoor

AbstractAir pollution has emerged as a major concern of the current century. In recent times, fellow researchers have conducted numerous researches in the area of air quality monitoring. Still, air quality monitoring remains an open research area due to various challenges such as sophisticated topology design, privacy and security, power backup, large memory requirements and deployment of such systems at resource-constrained sites. The proposed research work is an attempt to address the issues of communication topology design, assessment of the Quality of Service (QoS) levels against accuracy, sensing throughput and power consumption optimization. In the undertaken work, the proposed IoT based Air Quality Monitoring system has been deployed at indoor and outdoor sites to measure air quality parameters such as PM10, PM2.5, carbon monoxide, temperature and humidity. The proposed system is also tested at variety of quality of service levels at the indoor and outdoor sites. The conducted experiments have also recorded accuracy in terms of reliable delivery of the messages under employed protocol.

Estimating OLED Display Device Lifetime from pixel and screen brightness and its application

2019 ◽  
Vol 2019 (1) ◽  
pp. 331-338 ◽  
Author(s):  
Jérémie Gerhardt ◽  
Michael E. Miller ◽  
Hyunjin Yoo ◽  
Tara Akhavan
Keyword(s):  
Image Processing ◽  
Power Consumption ◽  
Model Parameters ◽  
Display Device ◽  
Image Processing Algorithm ◽  
Pixel Value ◽  
Device Lifetime ◽  
The Impact ◽  
Oled Display

In this paper we discuss a model to estimate the power consumption and lifetime (LT) of an OLED display based on its pixel value and the brightness setting of the screen (scbr). This model is used to illustrate the effect of OLED aging on display color characteristics. Model parameters are based on power consumption measurement of a given display for a number of pixel and scbr combinations. OLED LT is often given for the most stressful display operating situation, i.e. white image at maximum scbr, but having the ability to predict the LT for other configurations can be meaningful to estimate the impact and quality of new image processing algorithms. After explaining our model we present a use case to illustrate how we use it to evaluate the impact of an image processing algorithm for brightness adaptation.

UNDER-GRADUATE STUDENTS AND THE ROLE OF E- LIBRARIES TO UPLIFT THE QUALITY OF HIGHER EDUCATION

2018 ◽  
Vol 6 (26) ◽  
Author(s):  
Dharambeer Singh
Keyword(s):  
Graduate Students ◽  
Digital Libraries ◽  
Rural Areas ◽  
Multiple Access ◽  
Information Needs ◽  
Quality Of Higher Education ◽  
Brick And Mortar ◽  
Education Status

Digital libraries, designed to serve people and their information needs in the same way as traditional libraries, present distinct advantages over brick and mortar facilities: elimination of physical boundaries, round-the-clock access to information, multiple access points, networking abilities, and extended search functions. As a result, they should be especially well-suited for the disables. However, minorities, those affected by lower income and education status, persons living in rural areas, the physically challanged, and developing countries as a whole consistently suffer from a lack of accessibility to digital libraries. This paper evaluates the effectiveness and relevance of digital libraries currently in place and discusses what could and should be done to improve accessibility to digital libraries for under-graduate students.

scholarly journals Fuzzy-Based Thermal Management Scheme for 3D Chip Multicores with Stacked Caches

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 346 ◽  
Author(s):  
Lili Shen ◽  
Ning Wu ◽  
Gaizhen Yan
Keyword(s):  
Power Consumption ◽  
Thermal Management ◽  
System Performance ◽  
Control Policy ◽  
Three Dimension ◽  
Processor Core ◽  
Management Scheme ◽  
And Performance ◽  
On Chip ◽  
Silicon Vias

By using through-silicon-vias (TSV), three dimension integration technology can stack large memory on the top of cores as a last-level on-chip cache (LLC) to reduce off-chip memory access and enhance system performance. However, the integration of more on-chip caches increases chip power density, which might lead to temperature-related issues in power consumption, reliability, cooling cost, and performance. An effective thermal management scheme is required to ensure the performance and reliability of the system. In this study, a fuzzy-based thermal management scheme (FBTM) is proposed that simultaneously considers cores and stacked caches. The proposed method combines a dynamic cache reconfiguration scheme with a fuzzy-based control policy in a temperature-aware manner. The dynamic cache reconfiguration scheme determines the size of the cache for the processor core according to the application that reaches a substantial amount of power consumption savings. The fuzzy-based control policy is used to change the frequency level of the processor core based on dynamic cache reconfiguration, a process which can further improve the system performance. Experiments show that, compared with other thermal management schemes, the proposed FBTM can achieve, on average, 3 degrees of reduction in temperature and a 41% reduction of leakage energy.

scholarly journals Enhanced Spectral Amplitude Coding OCDMA System Utilizing a Single Photodiode Detection

2018 ◽  
Vol 8 (10) ◽  
pp. 1861 ◽  
Author(s):  
Somia Abd El-Mottaleb ◽  
Heba Fayed ◽  
Ahmed Abd El-Aziz ◽  
Mohamed Metawee ◽  
Moustafa Aly
Keyword(s):  
System Performance ◽  
Multiple Access ◽  
Group Velocity Dispersion ◽  
Single Mode ◽  
Fiber Amplifier ◽  
Single Mode Fiber ◽  
Spectral Amplitude ◽  
Erbium Doped Fiber Amplifier ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

In this paper, the performance of a spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system is investigated utilizing a single photodiode (SPD) detection technique. The proposed system uses enhanced double weight (EDW) codes as signature codes with three simultaneous users to overcome both phase-induced intensity noise (PIIN) and multiple access interference (MAI). In addition, a dispersion compensating fiber (DCF) is used in order to decrease the group velocity dispersion (GVD) caused in the single mode fiber. An erbium-doped fiber amplifier (EDFA) is used to overcome the attenuation. The use of both DCF and EDFA leads to an appreciable enhancement in the system performance. The system performance is evaluated through its bit error rate (BER), Q-factor, and received power. A comparison between the EDW codes and modified double weight (MDW) codes on the SAC-OCDMA system is demonstrated. Simulation is carried out through Optisystem ver. 7. The simulation results show that: (a) using an avalanche photodiode (APD) over PIN photodiode allows data transmission over longer distances; (b) the use of DCF improves the system BER;(c) using MDW codes gives better BER than using EDW codes.

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