- 标题
- 摘要
- 关键词
- 实验方案
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10?Gbps CPRI signals transmission impaired by intercore crosstalk in 5G network fronthauls with multicore fibers
摘要： The impact of intercore crosstalk (ICXT) of weakly-coupled multicore fibers (MCFs) on the transmission performance of a Common Public Radio Interface (CPRI) signal in 5G networks fronthaul is studied by numerical simulation. The results show that forward error correction-supported CPRI signals have more tolerance to ICXT due to the higher targeted bit error rate (of 10?3). For a receiver power penalty of 1 dB, an improvement of the tolerance of CPRI signals to ICXT, due to the increase of the MCF skew by about 1 dB, is observed. However, for the crosstalk levels that lead to 1 dB power penalty, we have shown that, the system is unavailable with a high probability. The crosstalk level required for an acceptable outage probability is about 10 dB lower than the crosstalk level leading to 1 dB power penalty.
关键词： 5G wireless networks,Multicore fiber,Common public radio interface,Outage probability,Intercore crosstalk,Bit error rate
更新于2025-09-23 15:23:52
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Physical Layer Security of Hybrid Satellite-FSO Cooperative Systems
摘要： In this paper, we study the physical layer secrecy performance of a hybrid satellite and free-space optical (FSO) cooperative system. The satellite links are assumed to follow the Shadowed-Rician fading distribution; and the channel of the terrestrial link between the relay and destination is assumed to experience the Gamma-Gamma fading. For the FSO communications, the effects of different types of detection techniques (i.e., heterodyne detection and intensity modulation with direct detection) as well as the pointing error are considered. We derive exact analytical expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) for both cases of Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying. The asymptotic analysis for the SOP is also conducted to provide more insights on the impact of FSO and satellite channels on secrecy performance. It is found that with the AF with fixed gain scheme, the secrecy diversity order of the investigated system is only dependent on the channel characteristics of the FSO link and the FSO detection type, whereas the secrecy diversity is zero when the relay node employs DF or AF with variable-gain schemes.
关键词： land mobile satellite (LMS) channel,secrecy outage probability,hybrid satellite free-space optical (FSO) cooperative system,Physical layer security,average secrecy capacity
更新于2025-09-23 15:22:29
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-Distribution Dual-Hop RF/FSO Systems
摘要： In this correspondence, we investigate the physical-layer security of a mixed radio frequency/free space optical (RF/FSO) dual-hop communication system for both fixed- and variable-gain relaying schemes. More specifically, we only assume that the eavesdropping happens at the RF link because the optical link has high security. We assume that all RF channels suffer from η–μ fading, while the FSO link experiences M-distributed fading. Then, we derive some analytical results for the average secrecy rate and the secrecy outage probability.
关键词： secrecy outage probability,Average secrecy rate,radio frequency-free space optical,M-distributed fading,η-μ fading,physical-layer security
更新于2025-09-23 15:22:29
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Energy Harvesting Wireless Communications || Power Allocation for Point-to-Point Energy Harvesting Channels
摘要： This chapter considers a point-to-point EH wireless channel when the transmitter and the receiver are powered by EH. Under this setup, we first maximize various system utilities (such as the end-to-end throughput and the non-outage probability) via adaptive power allocation over time subject to the EH constraints at the transmitter, where the accumulatively consumed energy should not exceed that accumulatively harvested at any time. Under various CSIT and ESIT assumptions, we discuss the respective optimal designs. For example, in the noncausal CSIT and ESIT case, the optimal offline power allocation is shown to follow a non-decreasing and piecewise-constant (or staircase-like) pattern for the Gaussian channel case, and the optimal transmit power corresponds to a staircase water-filling power allocation for the fading channel case. In the causal ESIT and CSIT case, applicable online optimization strategies include dynamic programming-based and heuristically designed power allocation strategies. We also point out several open problems under different ESIT and CSIT considerations. For example, the throughput maximization problems under the case with causal CSIT and noncausal ESIT and the case with no CSIT and noncausal/causal ESIT remain unsolved in general, while the outage probability minimization problems under causal CSIT and noncausal/causal ESIT are also open problems at large. Furthermore, we extend the power allocation policies to other scenarios by considering other practical constraints such as limited battery capacity and imperfect circuits. We show that in the noncausal CSIT and ESIT case, the staircase power allocation with Gaussian channel and the staircase water-filling power allocation with fading channels can be modified to take these new practical constraints into account. With imperfect circuits, the EH transmitter should employ an on-off power allocation, which turns the transmitter into a sleep mode to save power in order to transmit more energy efficiently in the wake-up mode to tradeoff between the transmit energy consumption versus the circuit energy consumption. These new offline power allocation strategies motivate new online power allocation approaches with only causal CSIT and ESIT. Finally, we provide discussions on the transmit and receive power allocations in the case with EH transmitter and EH receiver, where in addition to the transmitter, the receiver's power consumption is also subject to an EH constraint. Under such a scenario, it is essential for the transmitter and the receiver to jointly optimize the transmit power and the code rate (hence, control the receive power consumption) to improve the end-to-end utility. Note that the case of EH receiver has not been widely investigated in the literature and there are rich open problems (e.g. under causal CSIT and ESIT) worth being pursued in future work.
关键词： power allocation,outage probability minimization,battery capacity,EH receiver,imperfect circuits,ESIT,wireless communications,throughput maximization,CSIT,Energy harvesting
更新于2025-09-23 15:22:29
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Outage and BER performances of indoor relay-assisted hybrid RF/VLC systems
摘要： In this study, the authors analyse the outage performance of the indoor relay-assisted hybrid radio frequency (RF)/visible light communication (VLC) systems. They derive closed-form expressions for the outage probability of the end-to-end signal-to-noise ratio. Then they obtain the optimal approximation parameter with optimising the outage probability using the differential evolution algorithm. Moreover, they analysed the average bit error rate (BER) performance of the hybrid RF/optical system using pulse position modulation method while assuming the timing error in synchronisation. Finally, they present some numerical results utilising the newly derived exact closed-form expressions.
关键词： pulse position modulation,hybrid RF/VLC,BER,differential evolution algorithm,relay-assisted,outage probability
更新于2025-09-23 15:21:21
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Laser Pouch Motors: Selective and Wireless Activation of Soft Actuators by Laser-powered Liquid-to-gas Phase Change
摘要： A joint optimization problem of link-layer energy efficiency (EE) and effective capacity (EC) in a Nakagami-m fading channel under a delay-outage probability constraint and an average transmit power constraint is considered and investigated in this paper. First, a normalized multi-objective optimization problem (MOP) is formulated and transformed into a single-objective optimization problem (SOP), by applying the weighted sum method. The formulated SOP is then proved to be continuously differentiable and strictly quasiconvex in the optimum average input power, which turns out to be a cup shape curve. Furthermore, the weighted quasiconvex tradeoff problem is solved by first using Charnes–Cooper transformation and then applying Karush–Kuhn–Tucker (KKT) conditions. The proposed optimal power allocation, which includes the optimal strategy for the link-layer EE-maximization problem and the EC-maximization problem as extreme cases, is proved to be sufficient for the Pareto optimal set of the original EE–EC MOP. Moreover, we prove that the optimum average power level monotonically decreases with the importance weight, but strictly increases with the normalization factor, the circuit power and the power amplifier efficiency. Simulation results confirm the analytical derivations and further show the effects of fading severeness and transmission power limit on the tradeoff performance.
关键词： energy efficiency,weighted sum method,delay-outage probability constraint,Quality-of-service,effective capacity,multi-objective optimization problem
更新于2025-09-23 15:21:01
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Physical Layer Security For Dual-Hop VLC/RF Communication Systems
摘要： In this letter, we investigate the physical layer security of a mixed visible light communication (VLC)/radio frequency (RF) system. More specifically, the relay can extract the direct current (DC) component and collect energy from the optical signal in the VLC link, and then use this collected energy to retransmit data though the RF link. With this setup, the exact performance expressions for secure outage probability and average secrecy capacity are derived in closed-form. We also provide asymptotic results to investigate the effect of different system parameters on the system performance. Finally, we present numerical results to illustrate our analytical result.
关键词： Energy harvesting,physical layer security,visible light communication,secure outage probability
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Swat, Pakistan (2019.7.24-2019.7.25)] 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Modeling and Analysis of Novel Tandem Solar Cells
摘要： While relay-based cooperative networks (widely known in the literature as cooperative communication), where relays only forward signals from the sources to the destination, have been extensively researched, fully cooperative systems have not been thoroughly examined. Unlike relay networks, in a fully cooperative network, each node acts as both a source node sending its own data and a relay forwarding its partner’s data to the destination. Mutual cooperation between neighboring nodes is believed to improve the overall system error performance, especially when space-time codes are incorporated. However, a comprehensive performance analysis of space-time-coded fully cooperative communication from all three perspectives, namely error performance, outage probability, and energy efficiency, is still missing. Answers to the commonly asked questions of whether, in what conditions, and to what extent the space-time-coded fully cooperative communication is better than direct transmission are still unknown. Motivated by this fact and inspired by the increasing popularity of healthcare applications in wireless body area networks (WBANs), this paper derives for the first time a comprehensive performance analysis of a decode-and-forward space-time coded fully cooperative communication network in Rayleigh and Rician fading channels in either identically or non-identically distributed fading scenario. Numerical analysis of error performance, outage probability, and energy efficiency, validated by simulations, show that fully cooperative communication is better than direct transmission from all three aspects in many cases, especially at a low-power and low signal-to-noise ratio regime, which is a typical working condition in WBANs.
关键词： symbol error rates,energy efficiency,MIMO,space-time codes,Rician,decode-and-forward,outage probability,wireless body area networks,Cooperative communication,Rayleigh
更新于2025-09-23 15:19:57
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Moment-based Approach for Statistical and Simulative Analysis of Turbulent Atmospheric Channels in FSO Communication
摘要： Free Space Optical (FSO) or wireless optical communication networks involve atmosphere as the channel, which at times can be turbulent in nature, thus degrading the system performance. These turbulent channels can be analysed by introducing various channel models and modulation techniques. Various researchers have analysed the performance by presenting different approaches for each type of channel model. In this paper, we present a uni?ed approach for the performance analysis of Log-normal, Nakagami-n (Rician) and Rayleigh statistical models by deriving the exact closed form expressions for average bit error probability and the outage probability of each model. It is achieved by using alternative form of Q-function and Gauss-Hermite Quadrature approximation to the moment-generating function of the output Signal-to-Noise Ratio (SNR). Further, de?nite expressions for each type of modulation technique are also derived to describe the channel fading in FSO communication system. The system of interest includes M-ary Phase Shift Keying (M-PSK) and M-ary Quadrature Amplitude Modulation (M-QAM) techniques. Moreover, the average output SNR, average received irradiance and the amount of fading (fading strength) are also expressed in simple closed forms for above mentioned turbulent channels. In addition to this, the performance of FSO system in presence of atmospheric turbulence and pointing errors is also investigated. The statistical model is examined for zero and nonzero boresight point errors modelled by Rayleigh and Rician distributions in Log-normal fading channel. The composite Log-normal PDFs along with asymptotic error rate and outage probability are also presented for such system. The effect of Tikhonov distributed phase noise arised due to BPSK modulation on BER performance is evaluated on three turbulent channels by deriving its closed-form expression using moment based approach.The mathematical analysis is veri?ed by comparing numerical results with Monte-Carlo Simulated values and graphs.
关键词： Rayleigh,SNR,BER,phase noise,Log-normal,Nakagami-n,path loss,outage probability,pointing errors
更新于2025-09-19 17:15:36
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Suppression of Speckle Noise in Digital Holography With Spatial and Temporal Domain Depolarization
摘要： In this paper, we introduce transmit antenna selection/maximal-ratio combining (TAS/MRC) scheme in dual-hop randomize-and-forward (RaF) cognitive multiple-input multiple-output (MIMO) wiretap networks with outdated channel state information (CSI). In this network, the secondary transmitter adopts the TAS scheme to choose the antenna with the maximal received signal-to-noise ratio (SNR), while the secondary receiver and the eavesdropper adopt the MRC scheme to combine the received signals. To thoroughly assess the secrecy performance achieved by the TAS/MRC scheme and the impact of outdated CSI on the secrecy performance, we derive a new closed-form expression for the secrecy outage probability of dual-hop RaF cognitive MIMO wiretap networks. In order to achieve more insights on the application of TAS/MRC scheme, we further present tractable asymptotic secrecy outage probability at high SNR regimes under two distinct scenarios. From our analysis, several important concluding remarks are obtained as follows: 1) the RaF relaying strategy achieves better secrecy performance than that of the decode-and-forward relaying strategy for dual-hop cognitive MIMO wiretap networks; 2) outdated CSI decreases the secrecy diversity gain of the TAS/MRC scheme from NR min (NA, NB) to min (NR, NB); and 3) although TAS/MRC scheme cannot attain full secrecy diversity gain for the considered system with outdated CSI, it still can achieve an extra secrecy coding gain compared with the random antenna selection/MRC scheme.
关键词： Cognitive radio networks,secrecy outage probability,MIMO,outdated channel state information
更新于2025-09-19 17:13:59