scholarly journals Performance Analysis of Full-Duplex Amplify-and-Forward Relay System with Hardware Impairments and Imperfect Self-Interference Cancellation

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ba Cao Nguyen ◽  
Xuan Nam Tran
Keyword(s):  
Interference Cancellation ◽  
Signal To Noise Ratio ◽  
Relay Node ◽  
Analytical Framework ◽  
Full Duplex ◽  
High Signal ◽  
Amplify And Forward ◽  
Relay System ◽  
Hardware Impairments ◽  
The Impact

In this paper, we analyze the performance of a full-duplex (FD) amplify-and-forward (AF) relay system with imperfect hardware. Besides the aggregate hardware impairments of the imperfect transceiver, we also consider the impact of residual self-interference (RSI) due to imperfect cancellation at the FD relay node. An analytical framework for analyzing the system performance including exact outage probability (OP), asymptotic OP, and approximate symbol error probability (SEP) is developed. In order to tackle these impacts, we propose an optimal power allocation scheme which can improve the outage performance of the FD relay node, especially at the high signal-to-noise ratio (SNR) regime. Numerical results are presented for various evaluation scenarios and verified using the Monte Carlo simulations.

scholarly journals On Performance of Full-Duplex Decode-and-Forward Relay Systems with an Optimal Power Setting under the Impact of Hardware Impairments

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Ba Cao Nguyen ◽  
Xuan Nam Tran ◽  
Thi Thu Hang Nguyen ◽  
Dinh Tan Tran ◽  
Donatella Darsena
Keyword(s):  
Interference Cancellation ◽  
Exact Expression ◽  
Full Duplex ◽  
Power Calculation ◽  
Direct Link ◽  
Decode And Forward ◽  
Hardware Impairments ◽  
Relay Systems ◽  
Optimal Power ◽  
The Impact

In this paper, we analyze the performance of in-band full-duplex (IBFD) relay systems that use the decode-and-forward (DF) protocol at the relay under the impact of imperfect self-interference cancellation and hardware impairments. Three practical relay scenarios are considered in our analysis: (i) there is no direct link from the source to the destination; (ii) there is a direct link, but the signal from the source is considered interference; and (iii) there is a direct link, and the signal from the source is cooperatively combined with that from the relaying path. Specifically, we derive exact and asymptotic expressions for the outage probability (OP) of the IBFD system. Based on the OP, the exact expression for symbol error probability (SEP) is also derived. Moreover, in order to cope with the effect of imperfect self-interference cancellation (SIC) due to the full-duplex mode, we propose optimal and suboptimal power calculation methods for the relay to minimize the OP and SEP. A performance evaluation shows that the IBFD relay system is significantly affected by both imperfect SIC and hardware impairments. However, the optimal power values can help to improve the system performance, significantly.

scholarly journals Secrecy Performance Analysis of Half/Full Duplex AF/DF Relaying in NOMA Systems Over κ - μ Fading Channels

2021 ◽  
Author(s):  
Nesrine Zaghdoud ◽  
Adel Ben Mnaouer ◽  
Hatem Boujemaa ◽  
Farid Touati
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Full Duplex ◽  
High Signal ◽  
Secrecy Outage Probability ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Special Cases ◽  
Secrecy Outage

Abstract Although the progress in understanding 5G and beyond techniques such as Non-Orthogonal Multiple Access (NOMA) and full-duplex techniques has been overwhelming, still analyzing the security aspects of such systems under different scenarios and settings is an important concern that needs further exploration. In particular, when considering fading in wiretap channels and scenarios, achieving secrecy has posed many challenges. In this context, we propose to study the physical layer security (PLS) of cooperative NOMA (C-NOMA) system using the general fading distribution κ - μ. This distribution facilitates mainly the effect of light-of-sight as well as multipath fading. It also includes multiple distributions as special cases like: Rayleigh, Rice, Nakagami-m which help to understand the comportment of C-NOMA systems under different fading parameters. The use of Half-Duplex and Full-Duplex communication is also investigated for both Amplify-and-forward (AF) and Decode-and-Forward (DF) relaying protocols. To characterize the secrecy performance of the proposed C-NOMA systems, closed form expressions of the Secrecy Outage Probability (SOP) and the Strictly Positive Secrcey Capacity (SPSC) metrics for the strong and weak users are given for high signal-to-noise ratio (SNR) due to the intractable nature of the exact expressions. Based on the analytical analysis, numerical and simulation results are given under different network parameters.

scholarly journals Impact of Co-Channel Interference on Two-Way Relaying Networks with Maximal Ratio Transmission

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 392 ◽  
Author(s):  
Awfa Aladwani ◽  
Eylem Erdogan ◽  
Tansal Gucluoglu
Keyword(s):  
Signal To Noise Ratio ◽  
High Reliability ◽  
Symbol Error Rate ◽  
High Signal ◽  
Amplify And Forward ◽  
Estimation Errors ◽  
Channel Interference ◽  
Noise Ratio ◽  
The Impact ◽  
Ratio Transmission

Amplify-and-forward (AF) two-way relay networks (TWRNs) have become popular to provide spectrally efficient communication when range extension or energy efficiency is needed by utilizing a simple relay. However, their performance can be significantly degraded in practice due to co-channel interference (CCI) which is increasing due to growing number of wireless devices and recent cognitive and non-orthogonal multiple access techniques. With the motivation of improving the performance of AF-TWRNs, the use of maximal ratio transmission (MRT) is investigated to achieve high reliability while requiring low receiver complexity for the relay. First, the signal-to-interference-plus-noise ratio (SINR) expression is formulated and upper bounded. Then, tight lower bound expressions of outage probability (OP), sum symbol error rate (SSER), and upper bound ergodic sum rate (ESR) for each source and for the overall system are obtained. Besides, array and diversity gains are provided after deriving the asymptotic expressions of OP and SSER at high signal-to-noise ratio (SNR). Furthermore, the impact of channel estimation errors on the performance is also included. Finally, Monte Carlo simulation results which corroborate our theoretical findings are illustrated.

scholarly journals On the Capacity of Full-Duplex AF/DF Relay System with Energy Harvesting for Vehicle-to-Vehicle Communications

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ba Cao Nguyen ◽  
Xuan Hung Le ◽  
Van Duan Nguyen ◽  
Le The Dung
Keyword(s):  
Energy Harvesting ◽  
Rayleigh Fading ◽  
Base Station ◽  
Full Duplex ◽  
High Signal ◽  
Transmission Power ◽  
Time Duration ◽  
Relay System ◽  
Vehicle To Vehicle ◽  
The Impact

This paper studies the ergodic capacity (EC) of full-duplex (FD) amplify-and-forward (AF) and decode-and-forward (DF) relay system with energy harvesting (EH) for vehicle-to-vehicle (V2V) communications. Unlike previous works on FD-EH systems, we consider the case that both relay and destination are mobile vehicles while the source is a static base station. We mathematically derive the exact closed-form expressions of ECs of both AF and DF protocols of the considered FD-EH-V2V relay system over cascade (double) Rayleigh fading. Our numerical results show that the ECs in the case of the V2V communication system are reduced compared to those in the case of stationary nodes. Also, with a specific value of residual self-interference (RSI), the ECs of the considered FD-EH-V2V relay system can be higher or lower than those of half-duplex- (HD-) EH-V2V system, depending on the average transmission power of the source. Furthermore, when the transmission power of the source and RSI are fixed, the ECs of the considered system can achieve peak values by using optimal EH time duration. On the other hand, the ECs of both AF and DF protocols reach the capacity floors in the high signal-to-noise ratio (SNR) regime due to the RSI impact. Also, the effect of RSI dominates the impact of cascade Rayleigh fading in the high SNR regime. Finally, we validate our analysis approach through Monte-Carlo simulations.

scholarly journals A Comparative Study on the Performance of LLR- and SNR-Based Hybrid Relaying Schemes

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed El-Mahdy ◽  
Wassim Alexan
Keyword(s):  
Comparative Study ◽  
Signal To Noise Ratio ◽  
Relay Node ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Probability Of Error ◽  
Hybrid Schemes ◽  
Relay Location ◽  
The Impact ◽  
Hybrid Relaying

A comparative study on the theoretical bit error rate (BER) is presented for hybrid relaying schemes that toggle between adaptive decode-and-forward (ADF) and amplify-and-forward (AF) protocols, for a typical three-node wireless network. Toggling between the two forwarding protocols is based on the log-likelihood ratio (LLR) or the signal-to-noise ratio (SNR) of the received signal at the relay node. Closed-form expressions for the probability of error are presented, as well as the expressions of the proposed schemes’ gains over classical ADF and AF protocols. Comparisons are carried out among the two schemes and other hybrid schemes found in the literature. Moreover, the impact of relay location on the probability of error is investigated.

scholarly journals Energy-Efficient Dual-Iteration Power Allocation for Two-Phase Relay System with Massive Antennas

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Long Zhao ◽  
Wei Xiang ◽  
Jie Mei ◽  
Hui Zhao ◽  
Hang Long ◽  
...  
Keyword(s):  
Power Allocation ◽  
Relay Node ◽  
Spectrum Efficiency ◽  
Amplify And Forward ◽  
Zero Forcing ◽  
Channel State ◽  
Relay System ◽  
Two Phase ◽  
Massive Antennas ◽  
Equal Power Allocation

This paper considers the scenario where multiple source nodes communicate with multiple destination nodes simultaneously with the aid of an amplify-and-forward relay equipped with massive antennas. In order to achieve optimal energy efficiency (EE) of the entire relay system, this paper investigates the power allocation problem for the multiple pairs of nodes at both the source nodes and the relay node, where the relay employs the backward and forward zero-forcing filters. Since the EE optimization problem cannot be solved analytically, we propose a two-phase power allocation method. Given power allocation of one phase, the optimal power allocation is derived for the other phase. Furthermore, two dual-iteration power allocation (DIPA) algorithms with performance approaching that of optimal EE are developed based on the instantaneous and statistic channel state information, respectively. Numerical results show that the proposed DIPA algorithms can greatly improve EE while guaranteeing spectrum efficiency (SE) when compared with the equal power allocation algorithm. Moreover, both algorithms suggest that deploying a rational number of antennas at the relay node and multiplexing a reasonable number of node pairs can improve on the EE and SE.

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 Outage Performance of Bidirectional Full-Duplex Amplify-and-Forward Relay Network with Transmit Antenna Selection and Maximal Ratio Combining

2018 ◽  
Vol 1 ◽  
pp. 62-69
Author(s):  
R. Rajesh ◽  
P. G. S. Velmurugan ◽  
S. J. Thiruvengadam ◽  
P. S. Mallick
Keyword(s):  
Antenna Selection ◽  
Relay Node ◽  
Maximal Ratio Combining ◽  
Full Duplex ◽  
Relay Network ◽  
Amplify And Forward ◽  
Transmit Antenna Selection ◽  
Outage Performance ◽  
Half Duplex ◽  
Af Relay

In this paper, a bidirectional full-duplex amplify- and-forward (AF) relay network with multiple antennas at source nodes is proposed. Assuming that the channel state information is known at the source nodes, transmit antenna selection and maximal ratio combining (MRC) are employed when source nodes transmit information to the relay node and receive information from the relay node respectively, in order to improve the overall signal-to-interference plus noise ratio (SINR). Analytical expressions are derived for tight upper bound SINR at the relay node and source nodes upon reception. Further, losed form expressions are also derived for end-to-end outage probability of the proposed bidirectional full-duplex AF relay network in the Nakagami-m fading channel environment. Although self-interference at the relay node limits the performance of the full-duplex network, the outage performance of the proposed network is better than that of conventional bidirectional full-duplex and half-duplex AF relay networks, due to the selection diversity gain in TAS and diversity and array gain in MRC.

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