scholarly journals Statistical analysis of the best relay location in a random two‐way relay network with multi‐slope path loss

2021 ◽  
Author(s):  
Mehrdad Salimnejad ◽  
Amir Masoud Rabiei
Keyword(s):  
Statistical Analysis ◽  
Path Loss ◽  
Relay Network ◽  
Relay Location

scholarly journals Factorial Design Analysis for Localization Algorithms

2018 ◽  
Vol 8 (12) ◽  
pp. 2654
Author(s):  
Joaquin Mass-Sanchez ◽  
Erica Ruiz-Ibarra ◽  
Ana Gonzalez-Sanchez ◽  
Adolfo Espinoza-Ruiz ◽  
Joaquin Cortez-Gonzalez
Keyword(s):  
Statistical Analysis ◽  
Noise Level ◽  
Performance Metrics ◽  
Extreme Values ◽  
Path Loss ◽  
Propagation Model ◽  
Path Loss Exponent ◽  
Localization Algorithms ◽  
Accuracy And Precision ◽  
The Impact

Localization is a fundamental problem in Wireless Sensor Networks, as it provides useful information regarding the detection of an event. There are different localization algorithms applied in single-hop or multi-hop networks; in both cases their performance depends on several factors involved in the evaluation scenario such as node density, the number of reference nodes and the log-normal shadowing propagation model, determined by the path-loss exponent (η) and the noise level (σdB) which impact on the accuracy and precision performance metrics of localization techniques. In this paper, we present a statistical analysis based on the 2k factorial methodology to determine the key factors affecting the performance metrics of localization techniques in a single-hop network to concentrate on such parameters, thus reducing the amount of simulation time required. For this proposal, MATLAB simulations are carried out in different scenarios, i.e., extreme values are used for each of the factors of interest and the impact of the interaction among them in the performance metrics is observed. The simulation results show that the path-loss exponent (η) and noise level (σdB) factors have the greatest impact on the accuracy and precision metrics evaluated in this study. Based on this statistical analysis, we recommend estimating the propagation model as close to reality as possible to consider it in the design of new localization techniques and thus improve their accuracy and precision metrics.

scholarly journals Investigation on Mutual Contention Bandwidth Request Mechanisms in Two-Hop Relay Network with ITU-R Path Loss Models

2013 ◽  
Vol 2013 ◽  
pp. 1-13
Author(s):  
Rajesh Anbazhagan ◽  
Nakkeeran Rangaswamy
Keyword(s):  
Path Loss ◽  
Contention Window ◽  
Relay Network ◽  
Failure Model ◽  
Bandwidth Request ◽  
Channel Error ◽  
Mobile Stations ◽  
Failure Models ◽  
Loss Models ◽  
Transmission Failures

The performance of two-hop contention based bandwidth request (BR) mechanism for WiMAX relay networks is investigated under ITU-R path loss models. In conventional WiMAX systems, the mobile stations (MS) update their contention window irrespective of their transmission failures. Those systems update their contention window on collision and due to channel error or unavailability of bandwidth. Further, these failure models have been suggested for single hop networks. The failure model in two-hop systems becomes complex since it may include additional failure events such as improper detection of codes and channel error due to varying path loss. Interestingly, these failure events (collision, channel error, unavailability of bandwidth, and improper detection of codes) do not occur evenly for both hops of a link. Hence, to set the contention window effectively, unique failure models are developed by considering the characteristics of BR mechanism and hop at which the BR is performed. In the proposed system, the two-hop BR is carried out with all combinations of message and code bandwidth request schemes. Among them, the message-code BR mechanism performs better under suburban fixed and outdoor to indoor or pedestrian environment, and code-code BR scheme performs better for vehicular environment.

scholarly journals Optimal UAV Deployment and Resource Management in UAV Relay Networks

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6878
Author(s):  
Sang Ik Han ◽  
Jaeuk Baek
Keyword(s):  
Resource Allocation ◽  
Three Dimensional ◽  
Optimal Solution ◽  
Relay Node ◽  
Base Station ◽  
Computational Effort ◽  
Relay Network ◽  
Relay Location ◽  
Aerial Vehicle ◽  
A Cell

UAV equipped three-dimensional (3D) wireless networks can provide a solution for the requirements of 5G communications, such as enhanced Mobile Broadband (eMBB) and massive Machine Type Communications (mMTC). Especially, the introduction of an unmanned aerial vehicle (UAV) as a relay node can improve the connectivity, extend the terrestrial base station (BS) coverage and enhance the throughput by taking advantage of a strong air-to-ground line of sight (LOS) channel. In this paper, we consider the deployment and resource allocation of UAV relay network (URN) to maximize the throughput of user equipment (UE) within a cell, while guaranteeing a reliable transmission to UE outside the coverage of BS. To this end, we formulate joint UAV deployment and resource allocation problems, whose analytical solutions can be hardly obtained, in general. We propose a fast and practical algorithm to provide the optimal solution for the number of transmit time slots and the UAV relay location in a sequential manner. The transmit power at BS and UAV is determined in advance based on the availability of channel state information (CSI). Simulation results demonstrate that the proposed algorithms can significantly reduce the computational effort and complexity to determine the optimal UAV location and transmit time slots over an exhaustive search.

scholarly journals Impact of engineering parameters on performance of relay-assisted network

2020 ◽  
Vol 20 (1) ◽  
pp. 248
Author(s):  
Issam Maaz ◽  
Jean-Marc Conrat ◽  
Jean-Christophe Cousin ◽  
Samer Alabed
Keyword(s):  
Path Loss ◽  
Relay Node ◽  
Urban Environments ◽  
Full Duplex ◽  
Relay Nodes ◽  
Decode And Forward ◽  
Capacity Enhancement ◽  
Relay Location ◽  
Engineering Parameters ◽  
Loss Models

<span>This paper compares the performance of a relay assisted network to the performance given by a classical macrocell network without the presence of relay node schemes. The capacity enhancement provided by a relaying system as a function of the relay antenna height and the propagation environment surrounding the relay nodes is analyzed and discussed in details. The analysis in this work is based on the theoretical Shannon capacity where both measured/experimental path loss and calibrated path loss models are taken into consideration. In this work, we assume a decode and forward scheme, a full-duplex relaying protocol and an optimized relay location is investigated. A 30 % of improvement in the macrocell capacity is achieved with the usage of relaying scenario compared to a classical macrocell network. Furthermore, increasing the relay antenna height from 4 meters to 12 meters can significantly increase the relay capacity to more than 20 % in suburban and moderate urban environments.</span>

Optimal Beamforming and Performance Analysis of Wireless Relay Networks with Unmanned Aerial Vehicle

Frequenz ◽  
2015 ◽  
Vol 69 (3-4) ◽  
Author(s):  
Jian Ouyang ◽  
Min Lin
Keyword(s):  
Performance Analysis ◽  
Unmanned Aerial Vehicle ◽  
Large Scale ◽  
Path Loss ◽  
Base Station ◽  
Relay Network ◽  
Rician Fading ◽  
Amplify And Forward ◽  
Aerial Vehicle ◽  
Optimal Beamforming

AbstractIn this paper, we investigate a wireless communication system employing a multi-antenna unmanned aerial vehicle (UAV) as the relay to improve the connectivity between the base station (BS) and the receive node (RN), where the BS–UAV link undergoes the correlated Rician fading while the UAV–RN link follows the correlated Rayleigh fading with large scale path loss. By assuming that the amplify-and-forward (AF) protocol is adopted at UAV, we first propose an optimal beamforming (BF) scheme to maximize the mutual information of the UAV-assisted dual-hop relay network, by calculating the BF weight vectors and the power allocation coefficient. Then, we derive the analytical expressions for the outage probability (OP) and the ergodic capacity (EC) of the relay network to evaluate the system performance conveniently. Finally, computer simulation results are provided to demonstrate the validity and efficiency of the proposed scheme as well as the performance analysis.

scholarly journals Optimized Power Allocation and Relay Location Selection in Cooperative Relay Networks

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jianrong Bao ◽  
Jiawen Wu ◽  
Chao Liu ◽  
Bin Jiang ◽  
Xianghong Tang
Keyword(s):  
Outage Probability ◽  
Power Allocation ◽  
Relay Selection ◽  
Relay Network ◽  
Total Power ◽  
Selection Strategy ◽  
Relay Location ◽  
Single Relay ◽  
Equal Power Allocation ◽  
Equal Power

An incremental selection hybrid decode-amplify forward (ISHDAF) scheme for the two-hop single relay systems and a relay selection strategy based on the hybrid decode-amplify-and-forward (HDAF) scheme for the multirelay systems are proposed along with an optimized power allocation for the Internet of Thing (IoT). Given total power as the constraint and outage probability as an objective function, the proposed scheme possesses good power efficiency better than the equal power allocation. By the ISHDAF scheme and HDAF relay selection strategy, an optimized power allocation for both the source and relay nodes is obtained, as well as an effective reduction of outage probability. In addition, the optimal relay location for maximizing the gain of the proposed algorithm is also investigated and designed. Simulation results show that, in both single relay and multirelay selection systems, some outage probability gains by the proposed scheme can be obtained. In the comparison of the optimized power allocation scheme with the equal power allocation one, nearly 0.1695 gains are obtained in the ISHDAF single relay network at a total power of 2 dB, and about 0.083 gains are obtained in the HDAF relay selection system with 2 relays at a total power of 2 dB.

Sign in / Sign up

Export Citation Format

Share Document