767 research outputs found
Performance Analysis of a Dual-Hop Cooperative Relay Network with Co-Channel Interference
This paper analyzes the performance of a dual-hop amplify-and-forward (AF) cooperative relay network in the presence of direct link between the source and destination and multiple co-channel interferences (CCIs) at the relay. Specifically, we derive the new analytical expressions for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR) and the average symbol error rate (ASER) of the relay network. Computer simulations are given to confirm the validity of the analytical results and show the effects of direct link and interference on the considered AF relay network
Filter-And-Forward Distributed Beamforming in Relay Networks with Frequency Selective Fading
A new approach to distributed cooperative beamforming in relay networks with
frequency selective fading is proposed. It is assumed that all the relay nodes
are equipped with finite impulse response (FIR) filters and use a
filter-and-forward (FF) strategy to compensate for the transmitter-to-relay and
relay-to-destination channels.
Three relevant half-duplex distributed beamforming problems are considered.
The first problem amounts to minimizing the total relay transmitted power
subject to the destination quality-of-service (QoS) constraint. In the second
and third problems, the destination QoS is maximized subject to the total and
individual relay transmitted power constraints, respectively. For the first and
second problems, closed-form solutions are obtained, whereas the third problem
is solved using convex optimization. The latter convex optimization technique
can be also directly extended to the case when the individual and total power
constraints should be jointly taken into account. Simulation results
demonstrate that in the frequency selective fading case, the proposed FF
approach provides substantial performance improvements as compared to the
commonly used amplify-and-forward (AF) relay beamforming strategy.Comment: Submitted to IEEE Trans. on Signal Processing on 8 July 200
Principles of Physical Layer Security in Multiuser Wireless Networks: A Survey
This paper provides a comprehensive review of the domain of physical layer
security in multiuser wireless networks. The essential premise of
physical-layer security is to enable the exchange of confidential messages over
a wireless medium in the presence of unauthorized eavesdroppers without relying
on higher-layer encryption. This can be achieved primarily in two ways: without
the need for a secret key by intelligently designing transmit coding
strategies, or by exploiting the wireless communication medium to develop
secret keys over public channels. The survey begins with an overview of the
foundations dating back to the pioneering work of Shannon and Wyner on
information-theoretic security. We then describe the evolution of secure
transmission strategies from point-to-point channels to multiple-antenna
systems, followed by generalizations to multiuser broadcast, multiple-access,
interference, and relay networks. Secret-key generation and establishment
protocols based on physical layer mechanisms are subsequently covered.
Approaches for secrecy based on channel coding design are then examined, along
with a description of inter-disciplinary approaches based on game theory and
stochastic geometry. The associated problem of physical-layer message
authentication is also introduced briefly. The survey concludes with
observations on potential research directions in this area.Comment: 23 pages, 10 figures, 303 refs. arXiv admin note: text overlap with
arXiv:1303.1609 by other authors. IEEE Communications Surveys and Tutorials,
201
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