scholarly journals Relaying Protocols for Wireless Energy Harvesting and Information Processing

2019 ◽  
Vol 9 (1) ◽  
pp. 1740-1746
Keyword(s):  
Relay Node ◽  
Optimization Techniques ◽  
Destination Node ◽  
Data Handling ◽  
Relaying Protocols ◽  
Hand Off ◽  
Source Signal ◽  
Wireless Relay ◽  
Point To Point ◽  
Hardware Circuit

Most of the ongoing exploration in wireless relay node networks and data preparing has considered point-to-point correspondence system. In remote helpful or then again sensor organizes, the hand-off or sensor relay node may have restricted battery holds and may need to depend on some outside charging component so as to stay dynamic in the system. Along these lines, vitality reaping in such systems is especially significant as it can empower data handing-off. In this thesis, we are worried about the issue of remote vitality collecting and data preparing in an intensify and-forward (AF) remote agreeable or sensor arrange. We consider the situation that a vitality obliged hand-off relay node harvests vitality from the RF sign communicated by a source node and utilizations that reaped vitality to advance the source signal to a destination node. We consider time switching (TS) and power switch (PS) scheme structures. we propose two transferring conventions: i) TS-based handing-off (TSR) convention and; ii) PS-based handing-off (PSR) convention for discrete data handling and vitality reaping at the vitality compelled wireless relay node. The primary commitments of this thesis are abridged as pursues: • We propose the TSR and the PSR conventions to empower remote vitality reaping and data handling at the vitality obliged transfer in remote AF transferring systems, in light of the TS and PS collector structures. • For the TSR and the PSR conventions, we determine logical articulations for the reachable throughput at the goal. • Comparing the TSR and the PSR conventions, our numerical investigation demonstrates that in postponement restricted transmission mode, the throughput execution of the TSR convention is better than the PSR convention at higher transmission rates, at generally lower signal-to-commotion proportion (SNR), and for lower vitality gathering productivity. • We propose the combination ATPSR system and demonstrate the optimal throughput for that system. • Finally, design and built the hardware circuit and using particle swarm optimization techniques to find the optimal value for the parameters.

scholarly journals Robust Relay in Narrow-Band Communications for Ubiquitous IoT Access

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Qinghe Du ◽  
Nan Lu ◽  
Li Sun ◽  
Xuelin Zhang ◽  
Bo Sun
Keyword(s):  
Narrow Band ◽  
Relay Node ◽  
Relay Network ◽  
Destination Node ◽  
Artificial Noise ◽  
Amplify And Forward ◽  
Limited Bandwidth ◽  
Wireless Relay ◽  
Core Idea ◽  
Untrusted Relay

We propose a robust wireless relay scheme in narrow-band communications for IoT access, which matches the typical features of IoT often carrying relatively low data rate with limited bandwidth. This framework is towards offering robustness in QoS guarantees with emphases on security and/or reliability, and we use the security-assured network as the typical scenario. In particular, we consider a dual-hop relay network including a transmitter, a receiver, an amplify-and-forward (AF) untrusted relay, and a jamming node. The jamming node is treated as a helper. Specifically, the jammer broadcasts artificial noise (AN), which in fact pollutes both the untrusted relay and the destination node’s signals. However, we show that such AN can be effectively mitigated after the destination node obtains the forwarded signal from the relay, while the untrusted relay node cannot do so. The core idea for robustness assurance is to exploit higher signal dimensions at the receiver over the untrusted relay node. Simulations and analyses are also conducted to demonstrate that our proposed scheme can make the performance at the untrusted relay an interference-limited manner while completely removing the interferences at the receiver, therefore corroborating our claim in robustness in terms of security and reliability.

scholarly journals Positioning of a Wireless Relay Node for Useful Cooperative Communication

2018 ◽  
Vol 10 (3) ◽  
pp. 959
Author(s):  
Tariq Muhamad Amjad ◽  
Elsheikh Mohamed Ahmed Elsheikh
Keyword(s):  
Relay Node ◽  
Cooperative Relaying ◽  
Maximal Ratio Combining ◽  
Destination Node ◽  
Relay Channel ◽  
Decode And Forward ◽  
Sustainable Solutions ◽  
Wireless Relay ◽  
Increasing Demand ◽  
The Impact

<span>Given the exorbitant amount of data transmitted and the increasing demand for data connectivity in the 21st century, it has become imperative to search for pro-active and sustainable solutions to the effectively alleviate the overwhelming burden imposed on wireless networks. In this study a Decode and Forward cooperative relay channel is analyzed, with the employment of Maximal Ratio Combining at the destination node as the method of offering diversity combining. The system framework used is based on a three-node relay channel with a source node, relay node and a destination node. A model for the wireless communications channel is formulated in order for simulation to be carried out to investigate the impact on performance of relaying on a node placed at the edge of cell. Firstly, an AWGN channel is used before the effect of Rayleigh fading is taken into consideration. Result shows that performance of cooperative relaying performance is always superior or similar to conventional relaying. Additionally, relaying is beneficial when the relay is placed closer to the receiver. </span>

An Efficient Distributed Single-hop Relay Supporting (EDSRS) MAC Protocol for Wireless Sensor Networks

2019 ◽  
Vol 9 (2) ◽  
pp. 153-164
Author(s):  
Arvind Kakria ◽  
Trilok Chand Aseri
Keyword(s):  
Energy Efficiency ◽  
Cooperative Communication ◽  
Mimo Systems ◽  
Mac Protocol ◽  
Multiple Input Multiple Output ◽  
Relay Node ◽  
Base Stations ◽  
Destination Node ◽  
Distributed Coordination ◽  
Hardware Complexity

Background & Objective: Wireless communication has immensely grown during the past few decades due to significant demand for mobile access. Although cost-effective as compared to their wired counterpart, maintaining good quality-of-service (QoS) in these networks has always remained a challenge. Multiple-input Multiple-output (MIMO) systems, which consists of multiple transmitter and receiver antennas, have been widely acknowledged for their QoS and transmit diversity. Though suited for cellular base stations, MIMO systems are not suited for small-sized wireless nodes due to their hardware complexity, cost, and increased power requirements. Cooperative communication that allows relays, i.e. mobile or fixed nodes in a communication network, to share their resources and forward other node’s data to the destination node has substituted the MIMO systems nowadays. To harness the full benefit of cooperative communication, appropriate relay node selection is very important. This paper presents an efficient single-hop distributed relay supporting medium access control (MAC) protocol (EDSRS) that works in the single-hop environment and improves the energy efficiency and the life of relay nodes without compensating the throughput of the network. Methods: The protocol has been simulated using NS2 simulator. The proposed protocol is compared with energy efficient cooperative MAC protocol (EECOMAC) and legacy distributed coordination function (DCF) on the basis of throughput, energy efficiency, transmission delay and an end to end delay with various payload sizes. Result and Conclusion: The result of the comparison indicates that the proposed protocol (EDSRS) outperforms the other two protocols.

scholarly journals Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Sana Ezzine ◽  
Fatma Abdelkefi ◽  
Jean Pierre Cances ◽  
Vahid Meghdadi ◽  
Ammar Bouallégue
Keyword(s):  
Channel Capacity ◽  
Orthogonal Frequency Division Multiplexing ◽  
Low Cost ◽  
Relay Node ◽  
Destination Node ◽  
Direct Link ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Maximum Ratio Combining ◽  
The Impact

Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC) channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC) system, in which Orthogonal Frequency Division Multiplexing (OFDM) is used, is considered in this paper. We derive and compare the PLC channel capacity and the end-to-end Average BER (ABER) for OFDM-based direct link (DL) BB-PLC system and for OFDM-based two-hop relaying BB-PLC system for Amplify and Forward (AF) and Decode and Forward (DF) protocols. We analyze the improvements when we consider the direct link in a cooperative communication when the relay node only transmits the correctly decoded signal. Maximum ratio combining is employed at the destination node to detect the transmitted signal. In addition, in this paper, we highlight the impact of the relay location on the channel capacity and ABER for AF and DF transmission protocols. Moreover, an efficient use of the direct link was also investigated in this paper.

scholarly journals Power Control Method for Energy Efficient Buffer-Aided Relay Systems

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3234
Author(s):  
Jingon Joung ◽  
Han Lim Lee ◽  
Jian Zhao ◽  
Xin Kang
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Control Method ◽  
Relay Node ◽  
Destination Node ◽  
Transmit Power ◽  
Channel Condition ◽  
Relay Systems ◽  
Fixed Power ◽  
Fitting Model

In this paper, a power control method is proposed for a buffer-aided relay node (RN) to enhance the energy efficiency of the RN system. By virtue of a buffer, the RN can reserve the data at the buffer when the the channel gain between an RN and a destination node (DN) is weaker than that between SN and RN. The RN then opportunistically forward the reserved data in the buffer according to channel condition between the RN and the DN. By exploiting the buffer, RN reduces transmit power when it reduces the transmit data rate and reserve the data in the buffer. Therefore, without any total throughput reduction, the power consumption of RN can be reduced, resulting in the energy efficiency (EE) improvement of the RN system. Furthermore, for the power control, we devise a simple power control method based on a two-dimensional surface fitting model of an optimal transmit power of RN. The proposed RN power control method is readily and locally implementable at the RN, and it can significantly improve EE of the RN compared to the fixed power control method and the spectral efficiency based method as verified by the rigorous numerical results.

scholarly journals DCAR: DTN Congestion Avoidance Routing Algorithm Based on Tokens in an Urban Environment

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Hezhe Wang ◽  
Hongwu Lv ◽  
Huiqiang Wang ◽  
Guangsheng Feng
Keyword(s):  
Network Performance ◽  
Routing Algorithm ◽  
Relay Node ◽  
Routing Algorithms ◽  
Buffer Size ◽  
Destination Node ◽  
Delivery Ratio ◽  
Movement Trajectory ◽  
Average Delay ◽  
Urban Scenario

When a delay/disruption tolerant network (DTN) is applied in an urban scenario, the network is mainly composed of mobile devices carried by pedestrians, cars, and other vehicles, and the node’s movement trajectory is closely related to its social relationships and regular life; thus, most existing DTN routing algorithms cannot show efficient network performance in urban scenarios. In this paper, we propose a routing algorithm, called DCRA, which divides the urban map into grids; fixed sink stations are established in specific grids such that the communication range of each fixed sink station can cover a specific number of grids; these grids are defined as a cluster and allocated a number of tokens in each cluster; the tokens in the cluster are controlled by the fixed sink station. A node will transmit messages to a relay node that has a larger remaining buffer size and encounters fixed sink stations or the destination node more frequently after it obtains a message transmit token. Simulation experiments are carried out to verify the performance of the DCAR under an urban scenario, and results show that the DCAR algorithm is superior to existing routing algorithms in terms of delivery ratio, average delay, and network overhead.

scholarly journals Individual Channel Estimation in a Diamond Relay Network Using Relay-Assisted Training

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Xianwen He ◽  
Gaoqi Dou ◽  
Jun Gao
Keyword(s):  
Channel Estimation ◽  
Relay Node ◽  
Spatial Diversity ◽  
Relay Network ◽  
Destination Node ◽  
Training Design ◽  
Amplify And Forward ◽  
Relay Nodes ◽  
Training Scheme ◽  
Data Signal

We consider the training design and channel estimation in the amplify-and-forward (AF) diamond relay network. Our strategy is to transmit the source training in time-multiplexing (TM) mode while each relay node superimposes its own relay training over the amplified received data signal without bandwidth expansion. The principal challenge is to obtain accurate channel state information (CSI) of second-hop link due to the multiaccess interference (MAI) and cooperative data interference (CDI). To maintain the orthogonality between data and training, a modified relay-assisted training scheme is proposed to migrate the CDI, where some of the cooperative data at the relay are discarded to accommodate relay training. Meanwhile, a couple of optimal zero-correlation zone (ZCZ) relay-assisted sequences are designed to avoid MAI. At the destination node, the received signals from the two relay nodes are combined to achieve spatial diversity and enhanced data reliability. The simulation results are presented to validate the performance of the proposed schemes.

scholarly journals Outage performance of underlay cognitive radio networks over mix fading environment

2021 ◽  
Vol 11 (3) ◽  
pp. 2019
Author(s):  
Nguyen Hong Nhu ◽  
Cuu_Ho Van ◽  
Van-Duc Phan ◽  
Tan N. Nguyen ◽  
Miroslav Voznak ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Fading Channels ◽  
System Performance ◽  
Relay Node ◽  
Ergodic Capacity ◽  
Radio Networks ◽  
Closed Form Expression ◽  
Destination Node ◽  
Secondary Source ◽  
Underlay Cognitive Radio

In this paper, the underlay cognitive radio network over mix fading environment is presented and investigated. A cooperative cognitive system with a secondary source node S, a secondary destination node D, secondary relay node Relay, and a primary node P are considered. In this model system, we consider the mix fading environment in two scenarios as Rayleigh/Nakagami-m and Nakagami-m/Rayleigh Fading channels. For system performance analysis, the closed-form expression of the system outage probability (OP) and the integral-formed expression of the ergodic capacity (EC) are derived in connection with the system's primary parameters. Finally, we proposed the Monte Carlo simulation for convincing the correctness of the system performance.

scholarly journals A Survey on Relay Selection in Cooperative Device-to-Device (D2D) Communication in 5G Cellular Networks

2017 ◽  
Author(s):  
Shamganth K ◽  
Said Shafi Abdullah Al-Shabibia
Keyword(s):  
Cellular Networks ◽  
Spectral Efficiency ◽  
Relay Selection ◽  
Relay Node ◽  
Cooperative Networks ◽  
Vital Role ◽  
D2d Communication ◽  
Destination Node ◽  
D2d Communications ◽  
Device To Device

Device-to-device (D2D) communications underlayed to a cellular infrastructure has recently been proposed to increase spectrum and energy efficiency. Relay selection plays a vital role in cooperative networks. In D2D communication, if the chosen relay is not the best relay, then the whole communication will not be successful from source node to destination node. Also to choose the optimal relays, if more feedback and time delay exists between the source nodes and relay node then it leads to degradation of spectral efficiency.  A survey on the relay selection techniques used with D2D communications and the challenges and design issues associated with the integration of D2D in 5G cellular network is presented.

scholarly journals Adaptive Downward/Upward Routing Protocol for Mobile-Sensor Networks

2019 ◽  
Vol 11 (1) ◽  
pp. 18 ◽  
Author(s):  
Jinpeng Wang ◽  
Gérard Chalhoub ◽  
Michel Misson
Keyword(s):  
Sensor Networks ◽  
Data Collection ◽  
Routing Protocol ◽  
Routing Protocols ◽  
Performance Metrics ◽  
Data Dissemination ◽  
Resource Constraints ◽  
Destination Node ◽  
Lossy Networks ◽  
Point To Point

Recently, mobility support has become an important requirement in various Wireless Sensor Networks (WSNs). Low-power and Lossy Networks (LLNs) are a special type of WSNs that tolerate a certain degree of packet loss. However, due to the strict resource constraints in the computation, energy, and memory of LLNs, most routing protocols only support static network topologies. Data collection and data dissemination are two basic traffic modes in LLNs. Unlike data collection, data dissemination is less investigated in LLNs. There are two sorts of data-dissemination methods: point-to-multipoint and point-to-point. In this paper, we focus on the point-to-point method, which requires the source node to build routes to reach the destination node. We propose an adaptive routing protocol that integrates together point-to-point traffic and data-collection traffic, and supports highly mobile scenarios. This protocol quickly reacts to the movement of nodes to make faster decisions for the next-hop selection in data collection and dynamically build routes for point-to-point traffic. Results obtained through simulation show that our work outperforms two generic ad hoc routing protocols AODV and flooding on different performance metrics. Results also show the efficiency of our work in highly mobile scenarios with multiple traffic patterns.

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