Journal ArticleDOI
Opportunistic relay selection with outdated CSI: outage probability and diversity analysis
TLDR
It is demonstrated that the diversity order of the system is reduced to 1 when CSI is outdated, being this behavior independent of the level of CSI accuracy.Abstract:
In this paper, we analyze the outage probability and diversity order of opportunistic relay selection in a scenario based on decode and forward and where the available channel state information (CSI) is outdated. The study is conducted analytically by obtaining a closed-form expression for the outage probability, which is defined as the probability that the instantaneous capacity is below a target value. We derive high-SNR approximations for the outage probability. By doing so, we demonstrate that the diversity order of the system is reduced to 1 when CSI is outdated, being this behavior independent of the level of CSI accuracy. A physical explanation for this extreme loss of diversity is provided along with numerical results to support the analytical study.read more
Citations
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Journal ArticleDOI
Channel Modeling for Diffusive Molecular Communication—A Tutorial Review
TL;DR: This paper provides a tutorial review on mathematical channel modeling for diffusive MC systems and provides the channel models for time-varying MC systems with moving transmitters and receivers, which are relevant for advanced applications such as smart drug delivery with mobile nanomachines.
Journal ArticleDOI
Amplify-and-Forward Relay Selection with Outdated Channel Estimates
TL;DR: It is shown that it may be preferable, in terms of outage and symbol error probability, not to include links in the relay selection process that experience a sufficiently high maximum Doppler shift, since in those cases partial relay selection outperforms best relay selection.
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Decision-Theoretic Distributed Channel Selection for Opportunistic Spectrum Access: Strategies, Challenges and Solutions
TL;DR: This article analyzes the challenges facing OSA systems globally, which mainly include interactions among multiple users, dynamic spectrum opportunity, tradeoff between sequential sensing cost and expected reward, and tradeoffs between exploitation and exploration in the absence of prior statistical information.
Journal ArticleDOI
Relay Selection Schemes for Dual-Hop Networks under Security Constraints with Multiple Eavesdroppers
TL;DR: This paper considers three opportunistic relay selection schemes to reduce the overheard information at the eavesdroppers by choosing the relay having the lowest instantaneous signal-to-noise ratio (SNR) to them, and examines the ratio between the SNR of a relay and the maximum among the corresponding SNRs to the eaves droppers.
Journal ArticleDOI
Asymptotic Analysis of Cooperative Diversity Systems With Relay Selection in a Spectrum-Sharing Scenario
TL;DR: Three low-complexity relay-selection strategies, namely, selective amplify and forward, selective decode and forward (S-DF), and amplified and forward with partial relay selection (PRS-AF) in a spectrum-sharing scenario are studied and the diversity and coding gains are derived and compared.
References
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Book
Table of Integrals, Series, and Products
TL;DR: Combinations involving trigonometric and hyperbolic functions and power 5 Indefinite Integrals of Special Functions 6 Definite Integral Integral Functions 7.Associated Legendre Functions 8 Special Functions 9 Hypergeometric Functions 10 Vector Field Theory 11 Algebraic Inequalities 12 Integral Inequality 13 Matrices and related results 14 Determinants 15 Norms 16 Ordinary differential equations 17 Fourier, Laplace, and Mellin Transforms 18 The z-transform
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Cooperative diversity in wireless networks: Efficient protocols and outage behavior
TL;DR: Using distributed antennas, this work develops and analyzes low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks and develops performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading.
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User cooperation diversity. Part I. System description
TL;DR: Results show that, even though the interuser channel is noisy, cooperation leads not only to an increase in capacity for both users but also to a more robust system, where users' achievable rates are less susceptible to channel variations.
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