References of "Cheffena, Michael"
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See detailHybrid automatic repeat request‐based intelligent reflecting surface‐assisted communication system
Ai, Yun; Mohamed, M.; Kong, Long UL et al

in Electronics Letters (2021)

The intelligent reflecting surface (IRS) is an emerging technique to extend wireless coverage. In this letter, the performance of the hybrid automatic repeat request (hybrid ARQ) for an IRS‐assisted ... [more ▼]

The intelligent reflecting surface (IRS) is an emerging technique to extend wireless coverage. In this letter, the performance of the hybrid automatic repeat request (hybrid ARQ) for an IRS‐assisted system is analysed. More specifically, the outage performance of the IRS‐aided system using hybrid ARQ protocol with chase combining is studied. The asymptotic analysis also shows that the outage performance is better and improves linearly by increasing the number of reflectors of the IRS‐aided system. The results also verify the potential of combining the ARQ scheme in the link layer of the IRS‐aided system and demonstrate that a very small change of path loss condition can impact the performance largely. [less ▲]

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See detailComprehensive Physical Layer Security Analysis of FSO Communications over Malaga Channels
Ai, Yun; Mathur, Aashish; Verma, Gyan Deep et al

in IEEE Photonics Journal (2020)

In this paper, we study the physical layer security of free-space optical (FSO) communications under different eavesdropping scenarios. More specifically, the secrecy performance of FSO communication ... [more ▼]

In this paper, we study the physical layer security of free-space optical (FSO) communications under different eavesdropping scenarios. More specifically, the secrecy performance of FSO communication employing intensity modulation/direct detection detection is analyzed for the well-established Mlaga channels. Three different realistic scenarios of eavesdropping are considered by assuming different placement locations for the eavesdropper in the paper. Novel expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) are derived for the considered scenarios, and useful insights are also provided through asymptotic analysis. The results show: (i) When the eavesdropper is placed near the transmitter, atmospheric condition imposes a less significant impact on secrecy performance; (ii) Certain level of correlation can potentially enhance the secrecy performance for FSO communications; (iii) The correlation imposes opposite impacts on the ASC and SOP of FSO communications; and the secrecy performance metrics exhibit a non-monotonic impact with the increase of correlation; (v) When the correlation of the FSO links is too small or too large (i.e., the correlation parameter around 0 or 1), the correlation plays a more significant impact on secrecy performance; and (vi) The asymptotic slope of the SOP is 0.5 for all eavesdropping scenarios under practical FSO channels. [less ▲]

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See detailEffective Throughput Analysis of α-η-κ-μ Fading Channels
Ai, Yun; Mathur, Aashish; Kong, Long UL et al

in IEEE Access (2020)

The α-η-κ-µ fading model is a very useful instrument to accurately describe various radio wave propagation scenarios. In this paper, we study the effective throughput performance of communication systems ... [more ▼]

The α-η-κ-µ fading model is a very useful instrument to accurately describe various radio wave propagation scenarios. In this paper, we study the effective throughput performance of communication systems over the α-η-κ-µ fading channels. Novel and exact expressions for the effective throughput over α-η-κ-µ channels are derived, and the effective throughput of multiple-input single-output (MISO) and multiple-input multiple-output (MIMO) systems over some widely used small-scale fading models are presented based on the derived results. To obtain more understandings on the impact of physical channel characteristics and system configuration on the effective throughput, closed-form expressions for the asymptotic effective throughput at high signal-to-noise ratio (SNR) regimes are also obtained. The results reveal the underlying connections between different physical channel parameters (e.g., scattering level, phase correlation, channel nonlinearity, multipath clustering, and channel imbalance) and the effective throughput. It is found that the effective throughput improves with the increase of channel nonlinearity and number of multipath clusters, and the high-SNR slope is only dependent on the channel nonlinearity and the number of multipath clusters present in the physical channel. [less ▲]

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See detailOn Performance Characterization of Cascaded Multiwire-PLC/MIMO-RF Communication System
Ai, Yun; Kong, Long UL; Cheffena, Michael et al

E-print/Working paper (2020)

Detailed reference viewed: 15 (2 UL)
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See detailSecure Vehicular Communications through Reconfigurable Intelligent Surfaces
Ai, Yun; Figueiredo, Felipe A. P. de; Kong, Long UL et al

E-print/Working paper (2020)

Detailed reference viewed: 16 (3 UL)