scholarly journals Probabilistic model for the analysis of elastic session duration in wireless networks

2021 ◽  
Vol 2134 (1) ◽  
pp. 012029
Author(s):  
Eduard Sopin ◽  
Anastasia Daraseliya ◽  
Sergey Shorgin
Keyword(s):  
Wireless Networks ◽  
Probabilistic Model ◽  
Signal To Noise Ratio ◽  
Base Station ◽  
Cumulative Distribution ◽  
Rate Coefficients ◽  
Factors Affecting ◽  
User Session ◽  
Session Duration ◽  
Number Of Factors

Abstract In wireless networks, the bitrate received by a user session depends not only on the fraction of allocated resources of the base station but also on the number of factors affecting the signal-to-noise ratio. These factors include a distance between a mobile device and the base station, walls, buildings between them, etc. As a result, the bitrate of elastic sessions may differ tenfold. In this paper, we develop a probabilistic model that captures the main specifics of the data transmission through a wireless network by introducing the random serving rate coefficients concept. With the help of the model, we derived the cumulative distribution function of the elastic session duration.

scholarly journals Exact secure outage probability performance of uplinkdownlink multiple access network under imperfect CSI

2021 ◽  
Vol 10 (6) ◽  
pp. 3274-3281
Author(s):  
Dinh-Thuan Do ◽  
Minh-Sang Van Nguyen
Keyword(s):  
Outage Probability ◽  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Access Network ◽  
Base Station ◽  
High Signal ◽  
Secrecy Outage Probability ◽  
Factors Affecting ◽  
Secrecy Outage ◽  
The Right

In this paper, we study uplink-downlink non-orthogonal multiple access (NOMA) systems by considering the secure performance at the physical layer. In the considered system model, the base station acts a relay to allow two users at the left side communicate with two users at the right side. By considering imperfect channel state information (CSI), the secure performance need be studied since an eavesdropper wants to overhear signals processed at the downlink. To provide secure performance metric, we derive exact expressions of secrecy outage probability (SOP) and and evaluating the impacts of main parameters on SOP metric. The important finding is that we can achieve the higher secrecy performance at high signal to noise ratio (SNR). Moreover, the numerical results demonstrate that the SOP tends to a constant at high SNR. Finally, our results show that the power allocation factors, target rates are main factors affecting to the secrecy performance of considered uplink-downlink NOMA systems.

scholarly journals A Comparative Study of 3D UE Positioning in 5G New Radio with a Single Station

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1178
Author(s):  
Bo Sun ◽  
Bo Tan ◽  
Wenbo Wang ◽  
Elena Simona Lohan
Keyword(s):  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Time Estimation ◽  
Satellite System ◽  
Base Station ◽  
Rectangular Array ◽  
Single Station ◽  
5G Network ◽  
Autonomous Machines ◽  
3D Positioning

The 5G network is considered as the essential underpinning infrastructure of manned and unmanned autonomous machines, such as drones and vehicles. Besides aiming to achieve reliable and low-latency wireless connectivity, positioning is another function provided by the 5G network to support the autonomous machines as the coexistence with the Global Navigation Satellite System (GNSS) is typically supported on smart 5G devices. This paper is a pilot study of using 5G uplink physical layer channel sounding reference signals (SRSs) for 3D user equipment (UE) positioning. The 3D positioning capability is backed by the uniform rectangular array (URA) on the base station and by the multiple subcarrier nature of the SRS. In this work, the subspace-based joint angle-time estimation and statistics-based expectation-maximization (EM) algorithms are investigated with the 3D signal manifold to prove the feasibility of using SRSs for 3D positioning. The positioning performance of both algorithms is evaluated by estimation of the root mean squared error (RMSE) versus the varying signal-to-noise-ratio (SNR), the bandwidth, the antenna array configuration, and multipath scenarios. The simulation results show that the uplink SRS works well for 3D UE positioning with a single base station, by providing a flexible resolution and accuracy for diverse application scenarios with the support of the phased array and signal estimation algorithms at the base station.

Impact of climatic conditions on the parameters of failure flow of military vehicles

2021 ◽  
pp. 095440702110202
Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys
Keyword(s):  
Climatic Factors ◽  
Armed Forces ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Technical Equipment ◽  
Factors Affecting ◽  
Military Vehicles ◽  
Equipment Reliability ◽  
Number Of Factors ◽  
The Impact

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.

Implementation of Machine Learning Algorithms for Prediction of Fluidelastic Instability in Tube Arrays

2021 ◽  
Vol 143 (2) ◽  
Author(s):  
Joaquin E. Moran ◽  
Yasser Selima
Keyword(s):  
Machine Learning ◽  
Logistic Regression ◽  
Learning Algorithm ◽  
Machine Learning Algorithms ◽  
Two Phase ◽  
Factors Affecting ◽  
Logistic Regression Models ◽  
Number Of Factors ◽  
Tube Arrays ◽  
Fluidelastic Instability

Abstract Fluidelastic instability (FEI) in tube arrays has been studied extensively experimentally and theoretically for the last 50 years, due to its potential to cause significant damage in short periods. Incidents similar to those observed at San Onofre Nuclear Generating Station indicate that the problem is not yet fully understood, probably due to the large number of factors affecting the phenomenon. In this study, a new approach for the analysis and interpretation of FEI data using machine learning (ML) algorithms is explored. FEI data for both single and two-phase flows have been collected from the literature and utilized for training a machine learning algorithm in order to either provide estimates of the reduced velocity (single and two-phase) or indicate if the bundle is stable or unstable under certain conditions (two-phase). The analysis included the use of logistic regression as a classification algorithm for two-phase flow problems to determine if specific conditions produce a stable or unstable response. The results of this study provide some insight into the capability and potential of logistic regression models to analyze FEI if appropriate quantities of experimental data are available.

PORTFOLIO ANALYSIS IN THE DEVELOPMENT OF CORPORATE STRATEGY

2021 ◽  
Vol 2 (10) ◽  
pp. 13-20
Author(s):  
Ekaterina A. Egorova ◽  
◽  
Polina V. Syrovatkina ◽  
Tatiana F. Chernova ◽  
Irina S. Brikoshina ◽  
...  
Keyword(s):  
Strategic Management ◽  
Corporate Strategy ◽  
Portfolio Analysis ◽  
Point Of View ◽  
Factors Affecting ◽  
Number Of Factors ◽  
Market Situation

This article reveals the specifics of developing a corporate strategy using portfolio analysis, taking into account the current market situation, which has created a number of factors affecting labor produc-tivity, internal and external policies of organizations, using the example of the work of the "Vishnevii sad" theater. The information about portfolio analysis in the development of corporate strategy is presented from the point of view of strategic management. Both theoretical and practical data are given, including different ways of constructing portfolio analysis, rules and methods that can be implemented. Proposals for modifica-tion and improvement of internal processes taking into account the influence of extraneous factors, possible goals and results are presented.

scholarly journals Motivating factors affecting the individual energy consumption behavior

2021 ◽  
Vol 124 ◽  
pp. 08003
Author(s):  
Jalal ud Din Akbar ◽  
Muhammad Ridhuan Tony Lim Abdullah
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Human Behavior ◽  
Clean Energy ◽  
Daily Routine ◽  
Factors Affecting ◽  
Number Of Factors ◽  
Development Goals ◽  
The Government ◽  
The Individual

Global challenges of climate change and environmental deterioration helped in formulating seventeen sustainable development goals through United Nation. Achieving these sustainable goals, Malaysia initiated and track progress towards affordable and clean energy. The natural environment and climate are mostly influenced by human behavior. Due to the role of human behavior in climate change, a strong tendency towards the pursuit of energy sustainability exists. Attention is paid to strengthen the human behavior from general acts of doing things to carrying specific actions by adopting a responsible behavior into daily routine. A number of factors were identified through literature such as social structure, institution, and education for understanding the individual behavior for sustainability with regard to energy consumption. Many experts related to the field of energy were engaged to sort and prioritize these factors with respect to their importance by using multi-criteria decision making tool of analytical hierarchy process (AHP). The experts were selected from different sectors such as academia, NGOs and industry. With the help of experts, a framework of individual energy consumption behaviour is developed to allow the government and other stakeholders to make policies accordingly to achieve energy sustainable.

scholarly journals Effective Capacity Analysis of Reconfigurable Intelligent Surfaces Aided NOMA Network

2021 ◽  
Author(s):  
Geng Li ◽  
Huiling Liu ◽  
Gaojian Huang ◽  
Xingwang Li ◽  
Bichu Raj ◽  
...  
Keyword(s):  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Analytical Approximation ◽  
Base Station ◽  
Effective Capacity ◽  
Green Communication ◽  
Time Service ◽  
Delay Sensitive ◽  
Sixth Generation ◽  
Evaluation Metric

Abstract The future sixth generation (6G) is going to face the significant challenges of massive connections and green communication. Recently, reconfigurable intelligent surfaces (RIS) and non-orthogonal multiple access (NOMA) have been proposed as two key technologies to address the above problems. Motivated by this fact, we consider a downlink RIS-aided NOMA system, where the base station seeks to communicate with two NOMA users with the aid of a RIS. Considering future network supporting real-time service, we investigate the system performance with the view of effective capacity (EC), which is an important evaluation metric of sensitive to delay sensitive system. Based on this basis, we derive the analytical expressions of the EC of the near and far users. To obtain more useful insights, we deduce the analytical approximation expressions of the EC in the low signal-to-noise-ratio (SNR) approximation by utilizing Taylor expansion. In order to compare, we provide the results of orthogonal multiple access (OMA). It is found that 1) The number of RIS components and the transmission power of the base station have important effects on the performance of the considered system model. 2) Compared with OMA, NOMA system has higher effective capacity due to the short transmission time.

scholarly journals MmWave V2X Cooperative Diversity Relay Channel with Feedback Delay and Link Blockage

2021 ◽  
Author(s):  
Elyes Balti
Keyword(s):  
Cooperative Diversity ◽  
Signal To Noise Ratio ◽  
Base Station ◽  
Maximal Ratio Combining ◽  
High Signal ◽  
Relay Channel ◽  
Framework Analysis ◽  
Decode And Forward ◽  
Multiple Transmit ◽  
To Receive

In this work, we present a framework analysis of a millimeter wave (mmWave) vehicular communications systems. Communications between vehicles take place through a cooperative relay which acts as an intermediary base station (BS). The relay is equipped with multiple transmit and receive antennas and it employs decode-and-forward (DF) to process the signal. Also, the relay applies maximal ratio combining (MRC), and maximal ratio transmission (MRT), respectively, to receive and forward the signal.As the vehicles' speeds are relative high, the channel experiences a fast fading and this time variation is modeled following the Jake's autocorrelation model. We also assume narrowband fading channel. Closed-form expressions of the reliability metrics such as the outage probability and the mean rate are derived. Capitalizing on these performances, we derive the high signal-to-noise-ratio (SNR) asymptotes to get full insights into the system gains such as the diversity and coding gains.

scholarly journals About estimation of base station output power in GSM like systems under real conditions

2020 ◽  
Vol 30 (1) ◽  
pp. 109-119
Author(s):  
Aleksandar Lebl ◽  
Dragan Mitic ◽  
Zarko Markov ◽  
Verica Vasiljevic
Keyword(s):  
Computer Simulation ◽  
Output Power ◽  
Mobile User ◽  
Base Station ◽  
Cumulative Distribution ◽  
Real Case ◽  
The Real ◽  
The Mean

The output power of traffic channels in one cell of GSM like systems is estimated in this paper. We consider the real case: the number of users is much higher than the number of channels, the output power of one channel depends on the cube of the distance between a mobile user and the base station, and the distribution of users in the cell is uniform. We derive the expressions for cumulative distribution of output power of one channel and for the mean output power of the whole base station. Results of the calculation are confirmed by computer simulation.

scholarly journals Performance Analysis of Rate Splitting in Massive MIMO Systems with Low Resolution ADCs/DACs

2021 ◽  
Vol 11 (20) ◽  
pp. 9409
Author(s):  
Roger Kwao Ahiadormey ◽  
Kwonhue Choi
Keyword(s):  
Mimo Systems ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Quantization Noise ◽  
High Signal ◽  
Low Resolution ◽  
Rate Splitting ◽  
Noise Ratio

In this paper, we propose rate-splitting (RS) multiple access to mitigate the effects of quantization noise (QN) inherent in low-resolution analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). We consider the downlink (DL) of a multiuser massive multiple-input multiple-output (MIMO) system where the base station (BS) is equipped with low-resolution ADCs/DACs. The BS employs the RS scheme for data transmission. Under imperfect channel state information (CSI), we characterize the spectral efficiency (SE) and energy efficiency (EE) by deriving the asymptotic signal-to-interference-and-noise ratio (SINR). For 1-bit resolution, the QN is very high, and the RS scheme shows no rate gain over the non-RS scheme. As the ADC/DAC resolution increases (i.e., 2–3 bits), the RS scheme achieves higher SE in the high signal-to-noise ratio (SNR) regime compared to that of the non-RS scheme. For a 3-bit resolution, the number of antennas can be reduced by 27% in the RS scheme to achieve the same SE as the non-RS scheme. Low-resolution DACs degrades the system performance more than low-resolution ADCs. Hence, it is preferable to equip the system with low-resolution ADCs than low-resolution DACs. The system achieves the best SE/EE tradeoff for 4-bit resolution ADCs/DACs.

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