A Feedback-Based Transmission for Wireless Networks with Energy and Secrecy Constraints
EURASIP Journal on Wireless Communications and Networking
Hindawi Publishing Corporation
A Feedback-Based Transmission for Wireless Networks with Energy and Secrecy Constraints
Ioannis Krikidis 1
John S. Thompson (EURASIP Member) 0
Steve McLaughlin (EURASIP Member) 0
Peter M. Grant (EURASIP Member) 0
Lin Cai
0 Institute for Digital Communications, The University of Edinburgh , Mayfield Road, Edinburgh EH9 3JL , UK
1 Department of Computer Engineering & Informatics, University of Patras , Rio, 26500 Patras , Greece
This paper investigates new transmission techniques for clustered feedback-based wireless networks that are characterized by energy and secrecy constraints. The proposed schemes incorporate multiuser diversity gain with an appropriate power allocation (PA) in order to support a defined Quality-of-Service (QoS) and jointly achieve lifetime maximization and confidentiality. We show that an adaptive PA scheme that adjusts the transmitted power using instantaneous feedback and suspends the transmission when the required power is higher than a threshold significantly prolongs the network lifetime without affecting the QoS of the network. In addition, the adaptation of the transmitted power on the main link improves the secrecy of the network and efficiently protects the source message from eavesdropper attacks. The proposed scheme improves network's confidentiality without requiring any information about the eavesdropper channel and is suitable for practical applications. Another objective of the paper is the energy analysis of networks by taking into account processing and maintenance energy cost at the transmitters. We demonstrate that the combination of PA with an appropriate switch-off mechanism, that allows the source to transmit for an appropriate fraction of the time, significantly extends the network lifetime. All the proposed protocols are evaluated by theoretical and simulation results.
1. Introduction
Recent studies have shown that the Base Station (BS) and
its associated operations are the main cause of power
consumption in the modern wireless networks [
1
]. This
result in combination with a continuing expansion of the
current networks increases the demands on energy sources
as well as some serious environmental issues like the increase
of CO2 emissions to the atmosphere [
1, 2
]. Therefore,
a network design that efficiently uses its available energy
resources is an urgent and important research topic. On the
other hand, due to the broadcast nature of the transmission,
the source message can be received from all the users that
are within the transmission range, and therefore secure
communication is also of importance. In this paper, we focus
on wireless networks with energy and secrecy constraints
and investigate some transmission techniques that improve
network lifetime and confidentiality for users.
Several physical (PHY) layer techniques that decrease
the network’s energy requirements and extend the network
lifetime have been proposed in the literature. In [
3, 4
]
the authors introduce multihop transmission in order to
reduce the energy consumption and they prove that short
intermediate transmissions can result in significant energy
savings. Accordingly, the channel capacity gain that arises
from the cooperative diversity concept also yields a decrease
in the required transmitted power. The energy efficiency
of different relaying techniques is discussed in [
5–8
], and
several relay selection metrics that incorporate instantaneous
channelfeedback with residual energy in order to achieve
lifetime improvements are presented in [
9
]. In addition,
appropriate resource allocation strategies can minimize the
energy consumption of a wireless network. The impact of
scheduling on the network lifetime for different levels of
channel knowledge is presented in [
10
], and several power
allocation (PA) techniques which minimize the average
transmission power for different network configurations are
discussed in [
11–13
]. On the other hand, in addition to
the energy cost associated with the transmission process,
data processing and system maintenance also contribute to
the energy consumption at the transmitters [
6
]. In [
14
],
the authors take into account the processing cost and they
prove that dedicated relaying (fixed relaying) is more energy
efficient than user cooperation (mobile relaying). Finally, a
burst transmission system that switches off the transmitter
for a fraction of time in order to reduce the processing
cost and accumulate energy for future transmissions is
analyzed in [
15, 16
] from an information theoretic
standpoint. However, the quality of the instantaneous link is not
taken into account, and PA as well as QoS issues are not
discussed.
As for secure communication, various PHY layer
techniques that increase the perfect secrecy capacity [
17, 18
] of a
wireless network have recently been investigated. In [19], the
authors propose a joint scheduli (...truncated)