scholarly journals Ergodic Capacity Analysis of Full Duplex Relaying in the Presence of Co-Channel Interference in V2V Communications

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 261 ◽  
Author(s):  
Khaled Eshteiwi ◽  
Georges Kaddoum ◽  
M. S. Alam

We analyze the ergodic capacity of a dual-hop full duplex amplify-and-forward (AF) vehicle-to-vehicle (V2V) cooperative relaying system over Nakagami-m fading channels. In this context, the impacts of self-interference (SI) at the relay and co-channel interference (CCI) at the destination are taken into account in this analysis. Precisely, based on the analysis of the moment generating function (MGF) of the signal-to-interference-plus-noise ratio (SINR), new exact and lower bound expressions for the ergodic capacity are derived. The ergodic capacity upper bound is also derived based on the asymptotic outage probability of the approximated SINR. Monte-Carlo simulation results are presented to corroborate the derived analytical results. Our results show the significant impact of the considered interferences on the system performance. It is shown that the ergodic capacity is degraded when the average SI at the relay and/or the average CCI at the destination is increased. This highlights the importance of taking these phenomena into account in the performance evaluation in order to assess the practical limit of full duplex relaying (FDR) cooperative wireless communications. Interestingly, it is also observed that FDR with SI and CCI still shows a higher ergodic capacity than the interference-free half duplex relaying, especially at medium to high signal-to-noise ratios (SNRs).

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1277
Author(s):  
Dong Qin ◽  
Yuhao Wang ◽  
Tianqing Zhou

The exact performance of amplify-and-forward (AF) bidirectional relay systems is studied in generalized and versatile Nakagami-m fading channels, where the parameter m is an arbitrary positive number. We consider three relaying modes: two, three, and four time slot bidirectional relaying. Closed form expressions of the moment generating function (MGF), higher order moments of signal-to-noise ratio (SNR), ergodic capacity, and average signal error probability (SEP) are derived, which are different from previous works. The obtained expressions are very concise, easy to calculate, and evaluated instantaneously without a complex summation operation, in contrast to the nested multifold numerical integrals and truncated infinite series expansions used in previous work, which lead to computational inefficiency, especially when the fading parameter m increases. Simulation results corroborate the correctness and tightness of the theoretical analysis.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dong Qin ◽  
Yuhao Wang ◽  
Tianqing Zhou

This paper investigates the maximal ratio combining (MRC) performance of an amplify and forward (AF) relay system in Nakagami-m fading environments. The study considers a general scenario with distinct m fading parameters for the following three links, source to relay link, and source to destination link and relay to destination link. We derive new closed form expressions for the statistics of important performance metrics, including the moment generating function, outage probability, higher order moments of equivalent signal to noise ratio (SNR), ergodic capacity, and average symbol error probability (SEP) of common modulation types. In particular, we focus on analytical SEP expressions in the context of an additive white generalized Gaussian noise (AWGGN). As an active area of research, generalized noise receives much attention for its flexible model. However, analytical performance of modulation scheme in generalized noise type has not been found in open literature for AF relaying with MRC despite its practical usefulness. Without the help of analytical solutions, the SEP in generalized noise can only be obtained by a large number of repeated simulation experiments. Therefore, we present the general SEP expression by using special Fox’s H function. Simulation results verify the accuracy of our theoretical analysis and show that the diversity order of MRC criterion linearly depends upon Nakagami parameters of three links.


2015 ◽  
Vol 9 (1) ◽  
pp. 82-90
Author(s):  
Weijun Cheng ◽  
Teng Chen

In this paper, we investigate the end-to-end performance of a dual-hop fixed gain relaying system with semiblind relay under asymmetric fading environments. In such environments, the wireless links of the considered system undergo asymmetric multipath/shadowing fading conditions, where one link is subject to only the Nakagami-m fading, the other link is subject to the composite Nakagami-lognormal fading which is approximated by using mixture gamma fading model. First, the cumulative distribution function (CDF), the moment generating function (MGF) and the moments of the end-to-end signal-to-noise ratio (SNR) are derived under two asymmetric scenarios. Then, novel closed-form expressions of the outage probability, the average end-to-end SNR, the symbol error rate and the ergodic capacity for the dual-hop system are obtained based on the CDF and the MGF, respectively. Finally, some numerical and simulation results are shown and discussed to validate the accuracy of the analytical results under different scenarios, such as varying average SNR, fading parameters per hop, the choice of the semi-blind gain and the location of relaying nodes.


2021 ◽  
Author(s):  
Nesrine Zaghdoud ◽  
Adel Ben Mnaouer ◽  
Hatem Boujemaa ◽  
Farid Touati

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.


Author(s):  
Nguyen Duy Nhat Vien

This paper investigates a multi-input multi-output (MIMO) multi-relay amplify-and-forward (AF) full-duplex (FD) network using optimal joint relay and antenna selection over Rayleigh block fading channels. For system performance analysis, outage probability (OP) is theoretically analyzed to obtain exact and asymptotic expressions of OP where asymptotic derivations using the assumption of high signal-to-noise rate (SNR) regime. Numerical results are provided to verify the validity of the derived OP expressions by comparing with the related empirical performance. The paper shows that under different scenarios the exact OP expression values are close the related empirical ones while the approximated OP expression values approach to the empirical OP under high SNR conditions.


2015 ◽  
Vol 719-720 ◽  
pp. 767-772
Author(s):  
Wei Jun Cheng

In this paper, we present the end-to-end performance of a dual-hop amplify-and-forward variablegain relaying system over Mixture Gamma distribution. Novel closed-form expressions for the probability density function and the moment-generation function of the end-to-end Signal-to-noise ratio (SNR) are derived. Moreover, the average symbol error rate, the average SNR and the average capacity are found based on the above new expressions, respectively. These expressions are more simple and accuracy than the previous ones obtained by using generalized-K (KG) distribution. Finally, numerical and simulation results are shown to verify the accuracy of the analytical results.


Author(s):  
B Barua ◽  
MZI Sarkar

This paper is concerned with the analysis of exact symbol error probability (SEP) for cooperative diversity using amplify-and-forward (AF) relaying over independent and non-identical Nakagami-m fading channels. The mathematical formulations for Probability Density Function (pdf) and Moment Generating Function (MGF) of a cooperative link have been derived for calculating symbol error probability with well-known MGF based approach taking M-ary Phase Shift Keying (MPSK) signals as input. The numerical results obtained from this research have been compared with different fading conditions. It is observed that the existence of the diversity link in a relay network plays a dominating role in error performance. Keywords: Symbol Error Probability; Probability Density Function; Moment Generating Function; Nakagami-m fading. DOI: http://dx.doi.org/10.3329/diujst.v6i2.9338 DIUJST 2011; 6(2): 1-5


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Phu Tran Tin ◽  
Phan Van-Duc ◽  
Tan N. Nguyen ◽  
Le Anh Vu

In this paper, we investigate the full-duplex (FD) decode-and-forward (DF) cooperative relaying system, whereas the relay node can harvest energy from radiofrequency (RF) signals of the source and then utilize the harvested energy to transfer the information to the destination. Specifically, a hybrid time-power switching-based relaying method is adopted, which leverages the benefits of time-switching relaying (TSR) and power-splitting relaying (PSR) protocols. While energy harvesting (EH) helps to reduce the limited energy at the relay, full-duplex is one of the most important techniques to enhance the spectrum efficiency by its capacity of transmitting and receiving signals simultaneously. Based on the proposed system model, the performance of the proposed relaying system in terms of the ergodic capacity (EC) is analyzed. Specifically, we derive the exact closed form for upper bound EC by applying some special function mathematics. Then, the Monte Carlo simulations are performed to validate the mathematical analysis and numerical results.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ba Cao Nguyen ◽  
Xuan Nam Tran

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.


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