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1
Content available Half-duplex Two-way Relaying for Wireless Sensor Networks with Adaptive Coding Rate : A Performance Optimization Framework
Ngo The-Anh, Le Viet-Thanh, Nguyen Thien P., Ha Duy-Hung
Journal of Telecommunications and Information Technology
|
2025
|
nr 4
69--76
EN
In this paper, a novel framework to enhance the reliability of wireless sensor networks (WSNs) by addressing the high probability of outage (OP) resulting from limited energy resources and unreliable channels. The framework integrates three techniques: half-duplex two-way relaying (HD-TWR), digital network coding (DNC), and rateless codes. Although these techniques have been extensively studied in isolation, a comprehensive analysis of their joint performance is provided as the main contribution. The proposed scheme leverages the energy efficiency of HD-TWR, the transmission reduction capability of DNC, and the retransmission-free resilience of rateless codes. Simulation results show that the integrated framework significantly reduces OP, offering a robust and practical solution to enhance the reliability enhancement. Furthermore, the impact of optimal relay node placement is investigated through parameter adjustments in the simulation stage to maximize performance gains.
2
Content available Analysis of relay-assisted device-to-device communication over Fisher–Snedecor F fading channels
Mehdi Haider, Hussain Zakir, Saleem Syed Muhammad Atif
Przegląd Elektrotechniczny
|
2024
|
R. 100, nr 3
162--165
EN
Outage and Success performances of an amplify-and-forward (AF) relay-assisted Device-to-Device (D2D) communication system over Fisher–Snedecor F composite fading channels in the presence of co-channel interference (CCI) are discussed in this work. The CCIs are assumed to degrade the quality of D2D data at relay as well as destination. Selection combining (SC) scheme is also incorporated at the D2D receiver to mitigate fading conditions. Analytical expressions for success and outage probabilities are derived with the help of characteristic function. These expressions depend on the path-loss exponents, distance between relay and the D2D source, distance between the D2D receiver and the relay, distances between CCI sources and the relay node, distances between the D2D receiver and CCI sources, and channel fading conditions. The numerical results for various scenarios are presented and discussed.
PL
W tym omówiono wydajność przestojów i sukcesów systemu komunikacji Device-to-Device (D2D) wspomaganego przez amplifikację i przekazywanie (AF) przez kompozytowe kanały zanikające Fisher-Snedecor F w obecności zakłóceń współkanałowych (CCI) praca. Zakłada się, że CCI obniżają jakość danych D2D zarówno w punkcie pośrednim, jak i docelowym. Schemat łączenia wyboru (SC) jest również wbudowany w odbiornik D2D w celu złagodzenia warunków zanikania. Wyrażenia analityczne dla prawdopodobieństw sukcesu i awarii wyprowadzane są za pomocą funkcji charakterystycznej. Wyrażenia te zależą od wykładników tłumienia ścieżki, odległości między przekaźnikiem a źródłem D2D, odległości między odbiornikiem D2D a przekaźnikiem, odległości między źródłami CCI a węzłem przekaźnikowym, odległości między odbiornikiem D2D a źródłami CCI, warunków zaniku kanału. Przedstawiono i omówiono wyniki liczbowe dla różnych scenariuszy.
3
Content available Performance Analysis of Antenna-Relay Selection in CNOMA Systems under Practical Impairments
Saber Menaa, Abdellatif Khelil
Journal of Telecommunications and Information Technology
|
2024
|
nr 3
7--16
EN
Selection strategies prove to be a valuable approach in mitigating complexity associated with antenna selection (AS) and relay selection (RS), optimizing signal transmission through a streamlined number of antennas/relays, and enhancing overall system performance. This paper offers a comprehensive analysis, deriving closed-form expressions for the outage probability (OP) and throughput in proposed scenarios that leverage the best relay selection (BRS) and transmit antenna selection (TAS) protocol for cooperative non-orthogonal multiple access (CNOMA), along with partial relay selection (PRS) and TAS protocol for CNOMA. The study extends to Rayleigh fading channels, considering practical impairments such as successful interference cancellation (SIC) error, channel estimation error (CEE), and feedback delay error. In comparing the proposed system to conventional CNOMA, our findings highlight the substantial impact of SIC, CEE, and feedback delay imperfections on the performance of both proposed scenarios. Notably, the application of BRS-based TAS protocol outperforms PRS-based TAS in terms of OP and throughput. The close alignment between analytical, asymptotic, and simulation results attests to the credibility of conducted analysis.
4
Content available Performance Analysis of Relay-Assisted Device-to-Device Communication
Hussain Zakir, Mehdi Haider, Saleem Syed Muhammad Atif, Mahboob Aashir
International Journal of Electronics and Telecommunications
|
2022
|
Vol. 68. No. 3
587--593
EN
Outage and Success performances of an amplify-and-forward relay-assisted D2D communication system over a κ-μ shadowed fading wireless link are presented here. Co-channel interference (CCI) is assumed to affect the D2D signals at relay and destination nodes. The system is analyzed with two scenarios, namely, with diversity combining and without diversity combining. Selection combining (SC) based diversity scheme is incorporated at the D2D receiver to combat fading conditions. The expressions for success and outage probabilities are presented by using the characteristic function approach. The expressions are functions of path-loss exponents, wireless link length between relay and D2D source node, wireless link length between the receiver node and relay, distances between interferers and the relay node, CCI distances from various devices of the system, fading channel. The numerical analysis for various scenarios is presented and analyzed.
5
Content available remote Performance Evaluation Of Multi-Hop Relaying IoTs Networks Using Hop-By-Hop Cooperative Transmission Under Impact of Co-channel Interference
An Ngo Hoang, Van Dong Doan, Son Nguyen Ngoc, Tu Lam-Thanh, Sang Nguyen Quang, Duy Tran Trung
Annals of Computer Science and Information Systems
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2022
|
Vol. 33
63--68
EN
The performance of the multi-hop relaying networks applied to Internet of Things (IoT) networks is investigated in the present work. To ameliorate the reliability of the whole network, for each hop, we employ cooperative communications subject to co-channel interference. In particular, several cooperative schemes are applied in the present work namely, incremental relaying, selection combining, and maximal ratio combining. In this context, we derive the exact closed-form expressions of end-to-end (e2e) outage probability (OP) of the whole systems over Rayleigh fading distribution. Numerical results based on the Monte-Carlo method are then employed to not only confirm the accuracy of the proposed mathematical framework but also to illustrate the advantages of the considered schemes compared with the conventional multi-hop relaying without using cooperative communications.
6
Content available remote Outage Probability and Intercept Probability Of Cognitive IoTs Networks With Relay Selection, Passive Eavesdropper and Hardware Noises
Minh Pham Xuan, Hien Nguyen Van, Hop Pham Quoc, Duy Trang Trung, Phu Le Quang, Hieu Nguyen Trung
Annals of Computer Science and Information Systems
|
2022
|
Vol. 33
165--170
EN
In this paper, we measure outage probability (OP) and intercept probability (IP) of a secondary secure network in an underlay spectrum-sharing cognitive radio (USS-CR). In the considered scheme, one of secondary relays is selected at a cooperative phase to provide the highest signal-to-noise ratio (SNR) at a secondary destination. We consider a practical scenario, where channel state information (CSI) of the secondary eavesdropping links is not available. OP and IP of the considered scheme are evaluated via mathematical analysis and computer simulations, under impact of hardware noises, over Rayleigh fading channels.
7
Content available Enabling Power Beacons and Wireless Power Transfers for Non-Orthogonal Multiple Access Networks
Le Chi-Bao, Nguyen Nhan Duc
Journal of Telecommunications and Information Technology
|
2021
|
nr 3
1--9
EN
This paper studies downlink cellular networks relying on non-orthogonal multiple access (NOMA). Specifically, the access point (AP) is able to harvest wireless power from the power beacon (PB). In the context of an AP facilitated with multiple antennas, the transmit antenna selection procedure is performed to process the downlink signal, with the transmission guaranteed by energy harvesting. Therefore, a wireless power transfer-based network is introduced to overcome power outages at the AP. In particular, an energy-constrained AP harvests energy from the radio frequency signals transmitted by the PB in order to assist in transmitting user data. Outage performance and ergodic capacity are evaluated with the use of closed-form expressions. In order to highlight some insights, approximate computations are provided. Finally, numerical simulations are performed to confirm the benefits of combining the downlink NOMA transmission and the transmit power scheme at the AP in order to serve a multitude of users.
8
Content available An Inclusive Performance Analysis of Single-branch Single-relay AF Transmission in a Mixed Rayleigh-Nakagami-m Fading Environment
Benmahmoud Slimane
Journal of Telecommunications and Information Technology
|
2019
|
nr 3
39--48
EN
In this paper, the end-to-end performance of a single-branch two-hop amplify-and-forward (AF) relaying network in a mixed Rayleigh-Nakagami-m fading environment, is investigated. Four different fading scenarios and three standard relay configurations for each scenario are considered. Exact analytical expressions for the outage probability and tight upper bounds for the ergodic capacity are derived. Results of Monte Carlo simulations are provided to verify the accuracy of the analytical results.
9
Content available Full-duplex Cognitive Radio NOMA Networks : Outage and Throughput Performance Analysis
Tran Thanh-Nam, Do Dinh-Thuan, Voznak Miroslav
International Journal of Electronics and Telecommunications
|
2019
|
Vol. 65, No. 1
103--109
EN
A novel non-orthogonal multiple access (NOMA) scheme is proposed to improve the throughput and the outage probability of the cognitive radio (CR) inspired system which has been implemented to adapt multiple services in the next-generation network (5G). In the proposed scheme, the primary source (PS) had sent a superposition code symbol with a predefined power allocation to relays, it decoded and forwarded (DF) a new superposition coded symbol to the destination with the other power allocation. By using a dual antenna at relays, it will be improved the bandwidth efficiency in such CR NOMA scheme. The performance of the system is evaluated based on the outage probability and the throughput with the assumption of the Rayleigh fading channels. According to the results obtained, it is shown that the outage probability and throughput of the proposed full-duplex (FD) in CR-NOMA with reasonable parameters can be able deploy in practical design as illustration in numerical results section.
10
Content available Closed-form Distribution and Analysis of a Combined Nakagami-lognormal Shadowing and Unshadowing Fading Channel
Singh R., Rawat M.
Journal of Telecommunications and Information Technology
|
2016
|
nr 4
81--87
EN
The realistic wireless channels face combined (time shared) Nakagami-lognormal shadowing and unshadowing fading because of time varying nature of radio channel and mobile user. These channels can be modeled as time-shared sum of multipath-shadowing and unshadowing Rician distributions. These fading create severe problems in long distance wireless systems where multipath fading is superim-posed on shadowing fading (called multipath-shadowing fading). The multipath effect can be modeled using Rayleigh, Rician, Nakagami-m or Weibull distribution and shadowing effect is modeled using lognormal distribution. In this paper, authors present a new closed-form probability distribution function of a Nakagami-lognormal fading channel. Using this result, the closed-form expression of combined Nakagami-lognormal shadowing and unshadowing fading is presented. The obtained closed-form result facilitates to derive the important performance metrics of a communication system such as amount of fading, outage probability, and average channel capacity in closed-form expressions.
11
Optimal combiners in pre-amplified optical wireless systems under medium-to-strong atmospheric turbulence
Sagias N. A., Boucouvalas A. C., Yiannapoulos K., Uysal M., Ghassemlooy Z.
Image Processing & Communications
|
2016
|
Vol. 21, no. 1
23--32
EN
In this work we analytically investigate optimal combiners for pre-amplified diversity receivers that operate under medium-tostrongatmosphericturbulence. We first demonstrate that the combi ner performance is strongly affected by the existence of a signal-amplified spontaneous emission beat noise at the output of the photodetector. Due to the Signac dependent nature of noise, the optimal combi ner can be classified as a hybridone,of which performance is between the well-known equalgain and maximal-ratio combiner architectures. Having established the optimal design, we further assess the proposed combiner performance over gamma-gamma and negative-exponential fading environments.
12
Content available remote Outage probability of the SSC/SC combiner at two time instants in the presence of lognormal fading
Stefanović M., Nikolić P., Krstić D., Doljak V.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 3a
237-240
EN
The outage probability of the Switch and Stay Combining/Selection Combining (SSC/SC) combiner output signal at two time instants, in the presence of log-normal fading, is determined in this paper. The probability density function (PDF) of the combiner output signal is derived. Then, the outage probability is numerically calculated using this PDF. The results are shown graphically to compare performances of the SSC/SC combiner with regard to classical SSC and SC combiners at one time instant.
PL
W artykule analizuje się prawdopodobieństwo przerw połączenia SSC/SC w obecności zaników o rozkładzie logarytmicznonormalnym. Prawdopodobieństwo to jest liczone na podstawie krzywej gęstości prawdopodobieństwa PDF. Porównano połączenia SSC/SC z klasycznymi SSC i SC.
13
Content available remote Outage probability of dual-hop semi-blind relaying with interference at the relay
Cvetković A. M., Dordević G., Stefanovic M. C.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 12a
325-327
EN
In this paper a novel expression for the gain of semi-blind relay in the presence of multiple interferences at the relay is derived. Using this expression for the gain of relay, closed-form expression for outage probability of signal-to-interference and noise ratio (SINR) is derived for dual-hop semi-blind relaying in interference-limited relay environment over Rayleigh fading conditions. Monte Carlo simulation is used to verify the theoretical expression for the outage probability.
PL
W artykule opisano nowy sposób wyznaczenia wzmocnienia przesyłu typu semi-blind w obecności różnorodnych zakłóceń. Na podstawie otrzymanego wyrażenia, określono wzór jawny na prawdopodobieństwo awarii i zmiany względnego wskaźnika poziomu szumów dla dwu-stopniowego przekazywania semi-blind w środowisku o ograniczonych zakłóceniach, w warunkach zanikania Rayleigh’a. Weryfikacji dokonano metodą Monte Carl.
14
Content available remote Spatial Multiplexing in Random Wireless Networks
Stamatiou K., Proakis J. G., Zeidler J. R.
Advances in Electronics and Telecommunications
|
2010
|
Vol. 1, no. 1
5--12
EN
We consider a network of transmitters, each with a receiver at a fixed distance, and locations drawn independen tly according to a homogeneous Poisson Point Process (PPP). The transmitters and the receivers are equipped with multiple a ntennas. Under a channel model that includes Rayleigh fading and path-loss, and an outage model for packet successes, we examine the rformance of various spatial multiplexing techniques, namely zero-forcing (ZF), ZF with successive interference cancellation (ZF-SIC or VBLAST) and DBLAST. In each case, we determine the number of streams that maximizes the transmission capacity, defined as the maximum network throughput per unit area such that a constraint on the outage probability is satisfied. Numerical results showcase the benefit of DBLAS Tover ZF and VBLAST in terms of the transmission capacity. In all cases, the transmission capacity scales linearly in the number of antennas.
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