scholarly journals Link and System-Level NOMA Simulator: The Reproducibility of Research

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2388
Author(s):  
Arsla Khan ◽  
Muhammad Arslan Usman ◽  
Muhammad Rehan Usman ◽  
Muneeb Ahmad ◽  
Soo-Young Shin
Keyword(s):  
Spectral Efficiency ◽  
Channel Coding ◽  
Multiple Access ◽  
Performance Metrics ◽  
Fold Increase ◽  
System Level ◽  
Intercell Interference ◽  
The Many ◽  
Level Analysis

This study focuses on the design of a MATLAB platform for non-orthogonal multiple access (NOMA) based systems with link-level and system-level analyses. Among the different potential candidates for 5G, NOMA is gaining considerable attention owing to the many-fold increase in spectral efficiency as compared to orthogonal multiple access (OMA). In this study, a NOMA simulator is presented for two and more than two users in a single cell for link-level analysis; whereas, for system-level analysis, seven cells and 19 cells scenarios were considered. Long-term evolution (LTE) was used as the baseline for the NOMA simulator, while bit error rate (BER), throughput and spectral efficiency are used as performance metrics to analyze the simulator performance. Moreover, we demonstrated the application of the NOMA simulator for different simulation scenarios through examples. In addition, the performance of multi-carrier NOMA (MC-NOMA) was evaluated in the presence of AWGN, impulse noise, and intercell interference. To circumvent channel impairments, channel coding with linear precoding is suggested to improve the BER performance of the system.

scholarly journals Countrywide Mobile Spectrum Sharing with Small Indoor Cells for Massive Spectral and Energy Efficiencies in 5G and Beyond Mobile Networks

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3825 ◽  
Author(s):  
Rony Kumer Saha
Keyword(s):  
Energy Efficiency ◽  
Mobile Networks ◽  
Spectral Efficiency ◽  
Spectrum Sharing ◽  
Performance Metrics ◽  
Interference Management ◽  
Mobile Network ◽  
System Level ◽  
Small Cells ◽  
Generic Model

In this paper, we propose a technique to share the licensed spectrums of all mobile network operators (MNOs) of a country with in-building small cells per MNO by exploiting the external wall penetration loss of a building and introducing the time-domain eICIC technique. The proposed technique considers allocating the dedicated spectrum Bop per MNO only its to outdoor macro UEs, whereas the total spectrum of all MNOs of the country Bco to its small cells indoor per building such that technically any small indoor cell of an MNO can have access to Bco instead of merely Bop assigned only to the MNO itself. We develop an interference management strategy as well as an algorithm for the proposed technique. System-level capacity, spectral efficiency, and energy efficiency performance metrics are derived, and a generic model for energy efficiency is presented. An optimal amount of small indoor cell density in terms of the number of buildings L carrying these small cells per MNO to trade-off the spectral efficiency and the energy efficiency is derived. With the system-level numerical and simulation results, we define an optimal value of L for a dense deployment of small indoor cells of an MNO and show that the proposed spectrum sharing technique can achieve massive indoor capacity, spectral efficiency, and energy efficiency for the MNO. Finally, we demonstrate that the proposed spectrum sharing technique could meet both the spectral efficiency and the energy efficiency requirements for 5G mobile networks for numerous traffic arrival rates to small indoor cells per building of an MNO.

scholarly journals On Developing Techniques for Sharing Satellite Spectrum with Indoor Small Cells in 5G

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 748
Author(s):  
Rony Saha
Keyword(s):  
Energy Efficiency ◽  
Mobile Networks ◽  
Spectral Efficiency ◽  
Spectrum Sharing ◽  
Performance Metrics ◽  
Interference Management ◽  
Optimal Number ◽  
System Level ◽  
Small Cells ◽  
Mobile System

In this paper, we present two spectrum sharing techniques for a multisystem, incorporating an integrated satellite-mobile system and an autonomous terrestrial-mobile system (iSMS/aTMS), namely orthogonal spectrum sharing (OSS) and non-orthogonal spectrum sharing (nOSS) techniques. aTMS consists of numerous small cells deployed in several buildings, and iSMS consists of a satellite station integrated with complementary ground component (CGC) stations deployed within buildings. By exploiting the high external wall penetration loss of a building, the iSMS spectrum is shared with small cells per building in OSS, and small cells per 3-dimensional (3D) cluster per building in nOSS. An interference management scheme, to avoid interference in apartments with collocated CGC stations and small cells, was developed and an optimal number of almost blank subframes (ABSs) per ABS pattern period (APP) was defined. System-level capacity, spectral efficiency, and energy efficiency performance metrics were derived. Furthermore, we present an algorithm for both OSS and nOSS techniques. With extensive simulation and numerical analysis, it is shown that the proposed nOSS significantly outperforms OSS in terms of spectral efficiency and energy efficiency, and both techniques can meet the expected spectral efficiency and energy efficiency requirements for the fifth-generation (5G) mobile networks.

scholarly journals Analysis of handover decision making in downlink Long Term Evolution networks

2015 ◽  
Author(s):  
◽  
Israel Oludayo Elujide
Keyword(s):  
Spectral Efficiency ◽  
System Performance ◽  
Long Term Evolution ◽  
Physical Layer ◽  
System Level ◽  
Handover Decision ◽  
Local Averaging ◽  
Term Evolution ◽  
Filtering Technique

This dissertation reports on handover in downlink Long Term Evolution (LTE) networks. The LTE is seen as the technology that will bring about Fourth Generation (4G) mobile broadband experience. The necessity to maintain quality of service for delay sensitive data services and applications used by mobile users makes mobility and handover between base stations in the downlink LTE very critical. Unfortunately, several handover schemes in LTE are based on Reference Symbols Received Power (RSRP) which include measurement error due to limited symbols in downlink packets. However, prompt and precise handover decision cannot be based on inaccurate measurement. Therefore, the downlink LTE intra-system handover is studied with focus on user measurement report. The study centers on preparation stage of the LTE handover procedure. Two different types of physical layer filtering technique namely linear averaging and local averaging are focused upon among others investigated. The performance of LTE conventional physical layer filtering technique, linear filtering, is compared with an alternative technique called local averaging. The output of each physical layer filtering is then used for LTE standardized radio resource layer filtering (otherwise called L3 filtering). The analysis of results from handover decision is based on simulations performed in an LTE system-level simulator. The performance metrics for the results are evaluated in terms of overall system and mobility-related performance. The system performance is based on spectral efficiency and throughput while mobility-related performance is based on handover failure. The performance comparison of the results shows that local averaging technique provides improved system performance of about 51.2 % for spectral efficiency and 42.8% cell-edge throughput for high speed users. Local averaging also produces a reduction of about 26.95% in average number of handover failure when L 3 filtering is applied for low speed mobile terminal. This result confirms that both averaging techniques are suitable for LTE network. Moreover, in the case of high mobility local averaging tends to be better than linear averaging.

scholarly journals Spectral efficiency analysis of two-user Downlink PD-NOMA with LTE modulation and coding schemes

2021 ◽  
Vol 2134 (1) ◽  
pp. 012023
Author(s):  
Ya. V. Kryukov ◽  
D. A. Pokamestov ◽  
R. R. Abenov ◽  
S. M. Mukhamadiev ◽  
I. Kanatbekuli
Keyword(s):  
Spectral Efficiency ◽  
Multiple Access ◽  
High Efficiency ◽  
Signal To Noise Ratio ◽  
Time Frequency ◽  
Coding Schemes ◽  
Power Domain ◽  
Real Performance ◽  
Practical Performance

Abstract Non-orthogonal multiple access (NOMA) is a promising user multiplexing technique for future wireless networks that allows increasing their spectral efficiency (SE). Power-Domain NOMA (PD-NOMA) is one of the most perspective techniques in the NOMA group. It makes it possible to perform the transmission of information symbols of several users within the same time-frequency resource segment (RS) without a spreading code. Many research works show the high efficiency of PD-NOMA compared to the orthogonal multiple access (OMA). However, these results are obtained analytically using Shannon’s formula and not taking into account the real performance of existing modulation and coding schemes (MCS). The issue is that it is impossible to obtain the achievable practical performance of PD-NOMA systems in this way. We obtain the SE in RS of a PD-NOMA system with Long Term Evolution (LTE) MCS’s and compare it with OMA. As a result, we conclude that PD-NOMA gains the system SE when the multiplexed user’s signal-to-noise ratio (SNR) outreaches the threshold of the highest performing MCS provided for the transmission by a MCS table.

Application of AI-based techniques for system-level analysis of Space Station Freedom

1991 ◽  
Author(s):  
KENNETH LASKEY ◽  
ALFRED KROMHOLZ
Keyword(s):  
Space Station ◽  
System Level ◽  
Space Station Freedom ◽  
Level Analysis

Comparative assessment of morphological mechanisms of maintaining structural liver homeostasis in the dynamics of exposure to coal-rock dust and sodium fluoride on the body

2020 ◽  
pp. 189-194
Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova
Keyword(s):  
Sodium Fluoride ◽  
Morphological Changes ◽  
The Body ◽  
System Level ◽  
Production Factor ◽  
Coal Rock ◽  
The Impact ◽  
Structural Homeostasis ◽  
Rock Dust

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.

The Many Faces of Socioeconomic Change

2017 ◽  
Author(s):  
John Toye
Keyword(s):  
Socioeconomic Development ◽  
Adam Smith ◽  
First Century ◽  
Social Progress ◽  
Long Time ◽  
The Face ◽  
Scientific Expertise ◽  
The Many ◽  
Century Development

This book provides a survey of different ways in which economic sociocultural and political aspects of human progress have been studied since the time of Adam Smith. Inevitably, over such a long time span, it has been necessary to concentrate on highlighting the most significant contributions, rather than attempting an exhaustive treatment. The aim has been to bring into focus an outline of the main long-term changes in the way that socioeconomic development has been envisaged. The argument presented is that the idea of socioeconomic development emerged with the creation of grand evolutionary sequences of social progress that were the products of Enlightenment and mid-Victorian thinkers. By the middle of the twentieth century, when interest in the accelerating development gave the topic a new impetus, its scope narrowed to a set of economically based strategies. After 1960, however, faith in such strategies began to wane, in the face of indifferent results and general faltering of confidence in economists’ boasts of scientific expertise. In the twenty-first century, development research is being pursued using a research method that generates disconnected results. As a result, it seems unlikely that any grand narrative will be created in the future and that neo-liberalism will be the last of this particular kind of socioeconomic theory.

scholarly journals Intelligent long-term performance analysis in power electronics systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Peyghami ◽  
Tomislav Dragicevic ◽  
Frede Blaabjerg
Keyword(s):  
Performance Indicator ◽  
Thermal Characteristics ◽  
Operating Conditions ◽  
System Level ◽  
Power Electronic ◽  
Reliability Modeling ◽  
Artificial Neural Network Ann ◽  
Long Term Performance ◽  
Term Performance

AbstractThis paper proposes a long-term performance indicator for power electronic converters based on their reliability. The converter reliability is represented by the proposed constant lifetime curves, which have been developed using Artificial Neural Network (ANN) under different operating conditions. Unlike the state-of-the-art theoretical reliability modeling approaches, which employ detailed electro-thermal characteristics and lifetime models of converter components, the proposed method provides a nonparametric surrogate model of the converter based on limited non-linear data from theoretical reliability analysis. The proposed approach can quickly predict the converter lifetime under given operating conditions without a further need for extended, time-consuming electro-thermal analysis. Moreover, the proposed lifetime curves can present the long-term performance of converters facilitating optimal system-level design for reliability, reliable operation and maintenance planning in power electronic systems. Numerical case studies evaluate the effectiveness of the proposed reliability modeling approach.

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