On Performance of Combining Methods for Three-Node Relay Network

2012 ◽  
Vol 263-266 ◽  
pp. 1160-1164
Author(s):  
Wen Yuan Rao
Keyword(s):  
Relay Network ◽  
Estimation Accuracy ◽  
Diversity Order ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Channel Quality ◽  
Combining Methods ◽  
Better Than

We study the performance of the three-node relay network. Three combining methods for the Amplify-and-Forward (AF) protocol and the Decode-and-Forward (DF) protocol are compared. Simulations indicate that the AF protocol is better than DF under all these three combining methods. To combine the incoming signals the channel quality should be estimated as accuracy as possible, more estimation accuracy requires more resource. A very simple combining method can obtain the performance comparative with optimal combining methods approximately. At the same time, all three combining methods for both diversity protocols can achieve the maximum diversity order.

scholarly journals Energy Consumption Analysis of Beamforming and Cooperative Schemes for Aircraft Wireless Sensor Networks

2020 ◽  
Vol 10 (12) ◽  
pp. 4374
Author(s):  
Seung-Hwan Kim ◽  
Jae-Woo Kim ◽  
Dong-Seong Kim
Keyword(s):  
Wireless Sensor Networks ◽  
Energy Consumption ◽  
Sensor Networks ◽  
Channel Model ◽  
Path Loss ◽  
Wireless Sensor ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
International Telecommunication Union ◽  
Better Than

In this paper, the eight schemes for aircraft wireless sensor networks are investigated, which are single-hop array beamforming schemes (including analog beamforming (ABF), and digital beamforming (DBF)), non-cooperative schemes (including single-hop and multi-hop schemes), cooperative schemes (including amplify and forward (AF), decode and forward (DF)), and incremental cooperative schemes (incremental decode and forward (IDF), and incremental amplify and forward (IAF)). To set up the aircraft wireless communication environment, we design the aircraft channel model by referring to the experimental parameters of the ITU (International Telecommunication Union)-R M.2283, which is composed of path loss, shadowing fading, and multi-path fading channel responses. To evaluate the performance, the conditions energy consumption and throughput analysis are performed. Through simulation results, the incremental cooperative scheme outperformed by 66.8% better at spectral efficiency 2 than the DBF scheme in terms of the energy consumption metric. Whereas, in terms of throughput metric, overall SNR (signal-to-noise ratio) ranged from −20 to 30 dB the beamforming scheme had the best performance in which the beamforming scheme at SNR 0 dB achieved 85.4% better than the multi-hop scheme. Finally, in terms of normalized throughput metric in low SNR range between −20 and 1 dB the ABF scheme had the best performance over the others in which the ABF at SNR 0 dB achieved 75.4% better than the multi-hop scheme. Whereas, in high SNR range between 2 and 30 dB the IDF scheme had the best performance in which the IDF at SNR 10 dB achieved 62.2% better than the multi-hop scheme.

scholarly journals Asymptotic Capacity of Large Fading Relay Networks with Random Node Failures

2011 ◽  
Vol 59 (8) ◽  
pp. 2306-2315 ◽  
Author(s):  
Chuan Huang ◽  
Jinhua Jiang ◽  
Shuguang Cui
Keyword(s):  
Large Scale ◽  
Signal To Noise Ratio ◽  
Relay Node ◽  
Relay Network ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Attack Model ◽  
Random Node ◽  
Rate Loss ◽  
Node Failures

To understand the network response to large-scale physical attacks, we investigate the asymptotic capacity of a half-duplex fading relay network with random node failures when the number of relays N gets infinitely large. In this paper, a simplified independent attack model is assumed where each relay node fails with a certain probability. The noncoherent relaying scheme is considered, which corresponds to the case of zero forward-link channel state information (CSI) at the relays. Accordingly, the whole relay network can be shown equivalent to a Rayleigh fading channel, where we derive the ε-outage capacity upper bound according to the multiple access (MAC) cut-set, and the ε-outage achievable rates for both the amplify-and-forward (AF) and decode-and-forward (DF) strategies. Furthermore, we show that the DF strategy is asymptotically optimal as the outage probability ε goes to zero, with the AF strategy strictly suboptimal over all signal to noise ratio (SNR) regimes. Regarding the rate loss due to random attacks, the AF strategy suffers a less portion of rate loss than the DF strategy in the high SNR regime, while the DF strategy demonstrates more robust performance in the low SNR regime.

scholarly journals The Optimal Power Allocation with Hybrid Relaying Based on Channel Condition

2018 ◽  
Author(s):  
Junpyo Jeon ◽  
Yeonggyu Shim ◽  
Hyuncheol Park
Keyword(s):  
Power Allocation ◽  
Relay Network ◽  
Achievable Rate ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Transmit Power ◽  
Optimal Power ◽  
Af Relay

This paper considers a hybrid relay network consisting of the source, the amplify-and-forward (AF) relay, the decode-and-forward (DF) relay, and the destination. We propose the optimal power allocation schemes between two different relays which maximize the achievable rate under a sum relay power constraint for given channel gains and transmit power from source. By solving the optimization problem to maximize the achievable rate for each relay network, the transmit power values in closed-form are derived. When the channel gains are the same, the optimal power allocation scheme for AF-DF relay network proves that a more power should be allocated at the first relay to maximize the achievable rate. In case of the DF-AF relay network, we derive the optimal power allocation scheme for the possible four cases. Under the same SNR condition at the first hop, we show that the achievable rate of AF-DF relay network is greater than that of DF-AF relay network when the channel gain between two relays is higher than that between the second relay and destination. Simulation results show that the proposed power allocation schemes provide a higher achievable rate than the equal power allocation schemes.

scholarly journals Bi-directional relay network employing signal space diversity

2020 ◽  
Vol 71 (3) ◽  
pp. 203-209
Author(s):  
Mümtaz Yılmaz
Keyword(s):  
Rotation Angle ◽  
Symbol Error Rate ◽  
Relay Network ◽  
Space Diversity ◽  
Relay Channel ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Signal Space ◽  
Signal Space Diversity ◽  
Directional Relay

AbstractIn this work, signal space diversity (SSD) method is exploited for a simple two-way relay channel (TWRC) with two end users mutually exchanging information. In order to ensure simplicity, the same rotation angle and interleavers are used under SSD framework. Also the well known decode-and-forward (DF) and amplify-and-forward (AF) protocols are adapted for the proposed TWRC. The analytical symbol error rate (SER) performance of the proposed scheme is evaluated for DF and AF protocols individually and evaluated through simulation results. The proposed scheme is shown to improve the performance of TWRC in terms of SER for both two protocols.

Power Allocation of Relay Selection in Coordinated Channel Based on Channel Statistical Information

2014 ◽  
Vol 543-547 ◽  
pp. 796-799
Author(s):  
Yi Tian
Keyword(s):  
Relay Selection ◽  
Search Algorithm ◽  
Relay Node ◽  
Statistical Information ◽  
Relay Network ◽  
Selection Algorithm ◽  
Amplify And Forward ◽  
Relay Selection Algorithm ◽  
Full Search ◽  
Better Than

In order to balance between optimality and operation efficiency of relay selection algorithm, an efficient relay selection algorithm has been raised based on bit error rate (BER) in an amplify-and-forward (AF) collaborated relay network. The algorithm, based on characters of channel statistical information and system BER, adds gain parameter of equivalent channel, sets SNR as threshold, select relay node assembly in the condition of same power, so as to minimize system BER. This algorithm has equal performance with Full Search Algorithm but with simpler calculation. Performance of the relay selection calculation BER is better than other algorithm by forwarding and preselecting an optimal relay node.

scholarly journals Power Splitting and Source-Relay Selection in Energy Harvesting Wireless Network

2021 ◽  
Author(s):  
xiao jiang ◽  
Peng Li ◽  
ruchuan wang
Keyword(s):  
Energy Harvesting ◽  
Outage Probability ◽  
Relay Selection ◽  
Relay Network ◽  
Power Splitting ◽  
Multiple Sources ◽  
Decode And Forward ◽  
Optimal Power ◽  
Splitting Ratio ◽  
Better Than

Abstract In this paper, we consider an energy-harvesting (EH) relay network composing of multiple sources, a destination and multiple EH decode-and-forward (DF) relays. The EH relays all equip with a power splitter to divide the received signal power into two parts, one for information decoding and the remaining for signal relaying. The power splitting ratio (PSR) depicts the trade-off between the relaying energy and decoding energy. We propose an optimal power splitting and joint source-relay selection (OPS-JSRS) scheme where the optimal power-splitting ratio is obtained and the best source-relay pair is selected to transmit the message. For the purpose of comparison, we examine the optimal power splitting and round-robin (OPS-RR) scheme and the traditional power splitting and joint source-relay selection (TPS-JSRS) scheme. The exact and asymptotic closed-form expressions of outage probability for OPS-RR, TPS-JSRS and OPS-JSRS schemes are derived. Numerical results show that OPS-JSRS scheme is better than OPS-RR and TPS-JSRS schemes in terms of outage probability, explaining the superiority of the proposed OPS-JSRS scheme. Additionally, outage probability performance of OPS-JSRS scheme can be improved by increasing the number of sources and relays.

scholarly journals Hybrid Satellite-Terrestrial Relay Network: Proposed Model and Application of Power Splitting Multiple Access

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4296 ◽  
Author(s):  
Dinh-Thuan Do ◽  
Anh-Tu Le ◽  
Rupak Kharel ◽  
Adão Silva ◽  
Mohammad Abu Shattal
Keyword(s):  
Closed Form ◽  
Multiple Access ◽  
Driving Forces ◽  
Satellite Communications ◽  
Satellite Networks ◽  
Relay Network ◽  
Power Splitting ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Seamless Integration

The development of hybrid satellite-terrestrial relay networks (HSTRNs) is one of the driving forces for revolutionizing satellite communications in the modern era. Although there are many unique features of conventional satellite networks, their evolution pace is much slower than the terrestrial wireless networks. As a result, it is becoming more important to use HSTRNs for the seamless integration of terrestrial cellular and satellite communications. With this intent, this paper provides a comprehensive performance evaluation of HSTRNs employing non-orthogonal multiple access technique. The terrestrial relay is considered to be wireless-powered and harvests energy from the radio signal of the satellite. For the sake of comparison, both amplify-and-forward (AF) and decode-and-forward (DF) relaying protocols are considered. Subsequently, the closed-form expressions of outage probabilities and ergodic capacities are derived for each relaying protocol. Extensive simulations are performed to verify the accuracy of the obtained closed-form expressions. The results provided in this work characterize the outage and capacity performance of such a HSTRN.

scholarly journals Physical Layer Secrecy by Power Splitting and Jamming in Cooperative Multiple Relay Based on Energy Harvesting in Full-Duplex Network

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Nabila Sehito ◽  
Shouyi Yang ◽  
Esraa Mousa Ali ◽  
Muhammad Abbas Khan ◽  
Raja Sohail Ahmed Larik ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Full Duplex ◽  
Relay Network ◽  
Power Splitting ◽  
Amplify And Forward ◽  
Secrecy Rate ◽  
Decode And Forward ◽  
Time Switching ◽  
Source Signal ◽  
Multiple Relay

In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). In the presence of one eavesdropper, a signal is transferred from source to destination with the help of a relay. The source signal transmits in full-duplex (FD) mood, jamming the relay transfer signals to the destination. The relay and source employ Time Switching (TS) and Energy Harvesting (EH) techniques to obtain the power from the power beacon. In this study, we compared the Secrecy Rate of two Cooperative Schemes, Amplify and Forward (AF) and Decode and Forward (DF), for both designed systems with the established EH and PS system. The Secrecy Rate was improved by 50.5% in the AF scheme and by 44.2% in the DF scheme between the relay and eavesdropper at 40 m apart for the proposed system in EH and PS. This simulation was performed using the Monto Carlo method in MATLAB.

scholarly journals Evaluation and Analysis for Maximum Lifespan of Wireless Sensor Networks by Energy-Efficient Design

2021 ◽  
Vol 9 (4) ◽  
pp. 01-05
Author(s):  
Ms.Tejashri H. Mohite, Prof. Dr. Noorullah Shariff
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Environmental Parameters ◽  
Sensor Nodes ◽  
Relay Network ◽  
Wireless Sensor ◽  
Communication Link ◽  
Environment Monitoring ◽  
Amplify And Forward ◽  
Decode And Forward

Wireless Sensor Networks (WSNs) have used worldwide in the past few years and are now being used in health monitoring ,disaster management, defense, telecommunications, etc. Such networks are used in many industrial and consumer applications such as industrial process and environment monitoring, among others. A WSN network is a collection of specialized transducers known as sensor nodes with a communication link distributed randomly in any locations to monitor environmental parameters such as water level, and temperature. Each sensor node is equipped with a transducer, a signal processor, a power unit, and a transceiver. WSNs are now being widely used to monitor environmental parameters, including the amount of gas, water, temperature, humidity, oxygen level, dust, etc. The WSN for environment monitoring can be equivalently replaced by a multiple-input multiple-output (MIMO) relay network. Multi-hop relay networks have attracted significant research interest in recent years for their capability in increasing the coverage range. The network communication link from a source to a destination is implemented using the amplify-and-forward (AF) or decode-and-forward (DF) schemes. The AF relay receives information from the previous relay and simply amplifies the received signal and then forwards it to the next relay. On the other hand, the DF relay first decodes the received signal and then forwards it to the next relay in the second stage if it can perfectly decode the incoming signal. For analytical simplicity, in this thesis, we consider the AF relaying scheme and the results of this work can also be developed for the DF relay.

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