993 research outputs found
Link Selection for Secure Cooperative Networks with Buffer-Aided Relaying
This paper investigates the secure communication in a two-hop cooperative
wireless network, where a buffer-aided relay is utilized to forward data from
the source to destination, and a passive eavesdropper attempts to intercept
data transmission from both the source and relay. Depending on the availability
of instantaneous channel state information of the source, two cases of
transmission mechanisms, i.e., adaptive-rate transmission and fixed-rate
transmission are considered. To enhance the security of the system, novel link
selection policies are proposed for both cases to select source-to-relay,
relay-to-destination, or no link transmission based on the channels qualities.
Closed-form expressions are derived for the end-to-end secrecy outage
probability (SOP), secrecy outage capacity (SOC), and exact secrecy throughput
(EST), respectively. Furthermore, we prove the condition that EST reaches its
maximum, and explore how to minimize the SOP and maximize the SOC by optimizing
the link selection parameters. Finally, simulations are conducted to
demonstrate the validity of our theoretical performance evaluation, and
extensive numerical results are provided to illustrate the efficiency of the
proposed link selection polices for the secure communication in two-hop
cooperative networks.Comment: 13 pages, 10 figure
Mimicking Full-Duplex Secure Communications for Buffer-Aided Multi-Relay Systems
This paper considers secure communication in buffer-aided cooperative
wireless networks in the presence of one eavesdropper, which can intercept the
data transmission from both the source and relay nodes. A new max-ratio
relaying protocol is proposed, in which different relays are chosen for
reception and transmission according to the ratio of the legitimate channels to
the eavesdropper channels, so that the relay selected for reception and the
relay selected for transmission can receive and transmit at the same time. It
is worth noting that the relay employs a randomize-and-forward (RF) strategy
such that the eavesdropper can only decode the signals received in the two hops
independently. Theoretical analysis of the secrecy throughput of the proposed
scheme is provided and the approximate closed-form expressions are derived,
which are verified by simulations. Through numerical results, it is shown that
the proposed scheme achieves a significant improvement in secrecy throughput
compared with existing relay selection policies.Comment: 8 pages, 4 figure
Buffer-Aided Relay Selection Algorithms for Physical-Layer Security in Wireless Networks
In this work, we consider the use of buffer-aided relays, linear precoding
techniques and multiple antennas for physical-layer security in wireless
networks. We develop relay selection algorithms to improve the secrecy-rate
performance of cooperative multi-user multiple-antenna wireless networks. In
particular, we propose a novel finite buffer-aided relay selection algorithm
that employs the maximum likelihood (ML) criterion to select sets of relays
which fully exploit the flexibility offered by relay nodes equipped with
buffers. Numerical results show the benefits of the proposed techniques as
compared to prior art.Comment: 5 pages, 3 figures in WSA 201
Effective Capacity in Wireless Networks: A Comprehensive Survey
Low latency applications, such as multimedia communications, autonomous
vehicles, and Tactile Internet are the emerging applications for
next-generation wireless networks, such as 5th generation (5G) mobile networks.
Existing physical-layer channel models, however, do not explicitly consider
quality-of-service (QoS) aware related parameters under specific delay
constraints. To investigate the performance of low-latency applications in
future networks, a new mathematical framework is needed. Effective capacity
(EC), which is a link-layer channel model with QoS-awareness, can be used to
investigate the performance of wireless networks under certain statistical
delay constraints. In this paper, we provide a comprehensive survey on existing
works, that use the EC model in various wireless networks. We summarize the
work related to EC for different networks such as cognitive radio networks
(CRNs), cellular networks, relay networks, adhoc networks, and mesh networks.
We explore five case studies encompassing EC operation with different design
and architectural requirements. We survey various delay-sensitive applications
such as voice and video with their EC analysis under certain delay constraints.
We finally present the future research directions with open issues covering EC
maximization
Achievable Rates for the Fading Half-Duplex Single Relay Selection Network Using Buffer-Aided Relaying
In the half-duplex single relay selection network, comprised of a source,
half-duplex relays, and a destination, only one relay is active at any given
time, i.e., only one relay receives or transmits, and the other relays are
inactive, i.e., they do not receive nor transmit. The capacity of this network,
when all links are affected by independent slow time-continuous fading and
additive white Gaussian noise (AWGN), is still unknown, and only achievable
average rates have been reported in the literature so far. In this paper, we
present new achievable average rates for this network which are larger than the
best known average rates. These new average rates are achieved with a
buffer-aided relaying protocol. Since the developed buffer-aided protocol
introduces unbounded delay, we also devise a buffer-aided protocol which limits
the delay at the expense of a decrease in rate. Moreover, we discuss the
practical implementation of the proposed buffer-aided relaying protocols and
show that they do not require more resources for channel state information
acquisition than the existing relay selection protocols.Comment: Published in IEEE Transactions on Wireless Communication
Study of Opportunistic Cooperation Techniques using Jamming and Relays for Physical-Layer Security in Buffer-aided Relay Networks
In this paper, we investigate opportunistic relay and jammer cooperation
schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks.
The network consists of one source, an arbitrary number of relay nodes,
legitimate users and eavesdroppers, with the constraints of physical layer
security. We propose an algorithm to select a set of relay nodes to enhance the
legitimate users' transmission and another set of relay nodes to perform
jamming of the eavesdroppers. With Inter-Relay interference (IRI) taken into
account, interference cancellation can be implemented to assist the
transmission of the legitimate users. Secondly, IRI can also be used to further
increase the level of harm of the jamming signal to the eavesdroppers. By
exploiting the fact that the jamming signal can be stored at the relay nodes,
we also propose a hybrid algorithm to set a signal-to-interference and noise
ratio (SINR) threshold at the node to determine the type of signal stored at
the relay node. With this separation, the signals with high SINR are delivered
to the users as conventional relay systems and the low SINR performance signals
are stored as potential jamming signals. Simulation results show that the
proposed techniques obtain a significant improvement in secrecy rate over
previously reported algorithms.Comment: 8 pages, 3 figure
Alternate Distributed Beamforming for Buffer-Aided Multi-Antenna Relay Systems
In this paper, link selection is investigated in half-duplex (HD) dual-hop
cooperative systems with multiple antennas at the relays. Alternate distributed
beamforming (ADB) scheme is revisited for buffer-aided multi-antenna relay
systems, in which the relays are divided into two groups, with one group
receiving the same information broadcast from the source and the other group
transmitting the common messages to the destination via distributed beamforming
in each time slot. It is worth noting that the relays used for reception and
transmission are determined without the need of instantaneous channel state
information (CSI). Theoretical analysis of the achievable throughput of the
proposed scheme in Rayleigh fading is provided and the approximate closed-form
expressions are derived. Simulation results are given to verify the theoretical
analysis. Through numerical results, it is shown that compared with existing
link selection policies, the fixed scheduling ADB scheme achieves a significant
improvement in achievable throughput. It is also shown that for the ADB scheme,
the throughput performance of increasing the number of antennas equipped at
each relay is better than that of increasing the number of relays equipped with
a single antenna when the total number of antennas at the relays is fixed.Comment: 8 pages, 7 figures. arXiv admin note: substantial text overlap with
arXiv:1910.0395
Study of Relay Selection for Physical-Layer Security in Buffer-Aided Relay Networks Based on the Secrecy Rate Criterion
In this paper, we investigate an opportunistic relay and jammer scheme along
with relay selection algorithms based on the secrecy rate criterion in
multiple-input multiple-output buffer-aided down link relay networks, which
consist of one source, a number of relay nodes, legitimate users and
eavesdroppers, with the constraints of physical layer security. The
opportunistic relay and jammer scheme is employed to improve the transmission
rate and different relay selection policies are performed to achieve better
secrecy rate with the consideration of eavesdroppers. Among all the
investigated relay selection policies, a relay selection policy which is
developed to maximize the secrecy rate based on exhaustive searches outperforms
other relay selection policies in terms of secrecy rate. Based on the secrecy
rate criterion, we develop a relay selection algorithm without knowledge of the
channels of the eavesdroppers. We also devise a greedy search algorithm based
on the secrecy rate criterion to reduce the computational complexity of the
exhaustive search technique. Simulations show the superiority of the secrecy
rate criterion over competing approaches.Comment: 6 pages, 3 figure
Secrecy Rate Maximization with Outage Constraint in Multihop Relaying Networks
In this paper, we study the secure transmission in multihop wireless networks
with randomize-and-forward (RaF) relaying, in the presence of randomly
distributed eavesdroppers. By considering adaptive encoder with on-off
transmission (OFT) scheme, we investigate the optimal design of the wiretap
code and routing strategies to maximize the secrecy rate while satisfying the
secrecy outage probability (SOP) constraint. We derive the exact expressions
for the optimal rate parameters of the wiretap code. Then the secure routing
problem is solved by revising the classical Bellman-Ford algorithm. Simulation
results are conducted to verify our analysis.Comment: 4 pages, 2 figures, 1 table, Accepted for publication at the IEEE
Communications Lette
Effective Capacity of Buffer-Aided Full-Duplex Relay Systems with Selection Relaying
In this work, the achievable rate of three-node relay systems with selection
relaying under statistical delay constraints, imposed on the limitations of the
maximum end-to-end delay violation probabilities, is investigated. It is
assumed that there are queues of infinite size at both the source and relay
node, and the source can select the relay or destination for data reception.
Given selection relaying policy, the effective bandwidth of the arrival
processes of the queue at the relay is derived. Then, the maximum constant
arrival rate can be identified as the maximum effective capacity as a function
of the statistical end-to-end queueing delay constraints, signal-to-noise
ratios (SNR) at the source and relay, the fading distributions of the links,
and the relay policy. Subsequently, a relay policy that incorporates the
statistical delay constraints is proposed. It is shown that the proposed relay
policy can achieve better performance than existing protocols. Moreover, it is
demonstrated that buffering relay model can still help improve the throughput
of relay systems in the presence of statistical delay constraints and
source-destination link.Comment: submitted for publication. arXiv admin note: text overlap with
arXiv:1411.427
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