Robust Beamforming and Artificial Noise Design in K-User
Interference Channel with Simultaneous Wireless
Information and Power Transfer
Yuan Ren, Jian Zhou, and Hui Gao
School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing
100876, China
Email: {renyuan, huigaod}@bupt.edu.cn; jiannzhou@163.com
Abstract—In this paper, we investigate the robust beamforming
and artificial noise design for simultaneous wireless information
and power transfer in K-user interference channel, where a
secure user is wiretapped by an energy receiver (external
eavesdropper). With only imperfect Eavesdropper's Channel
State Information (ECSI) at the transmitters, we aim to
maximize the worst-case secrecy rate of the secure user, while
guaranteeing the individual power constraint at each transmitter,
the quality of service requirements at the wiretap-free nodes and
the energy harvesting requirement at the energy receiver.
Adopting the ellipsoidal uncertainty model of imperfect ECSI,
our design goal is reformulated as a two-stage optimization
problem, which can be solved efficiently with the help of rank
relaxation and one-dimensional line search. Simulation results
verify the effectiveness of the proposed design in different
scenarios.
Index Terms—Robust beamforming, artificial noise,
interference channel, simultaneous wireless information and
power transfer
I. INTRODUCTION
Green communications have attracted a lot of
attentions of both academia and industry. Energy
Harvesting (EH) has been considered as a promising
technique to expand the lifetime of network, and ambient
Radio-Frequency (RF) signals can be the energy source
for Energy Receivers (ERs). RF signal is able to carry
information and energy at the same time, and the scheme
named Simultaneous Wireless Information and Power
Transfer (SWIPT) comes into being [1], [2]. However,
the messages intended to the Information Receivers (IRs)
may be at risk of being eavesdropped by the ERs, which
brings great challenges to the security of the SWIPT
systems.
Recently, there are growing interests on Physical Layer
Security (PLS), which is able to guarantee the perfect
secrecy communication from the information-theoretic
perspective [3]. In particular, the MIMOME wiretap
Manuscript received April 25, 2016; revised August 23, 2016
This work is financially supported by the National Natural Science
Foundation of China (NSFC) (Grant No. 61271188 and Grant No.
61401041), the National High Technology Research and Development
Program of China (863 Program) (Grant No. 2015AA01A706).
Corresponding author email: renyuan@bupt.edu.cn.
doi:10.12720/jcm.11.8.740-747
channel in a three nodes scenario is investigated in [4],
[5], which reveals that using multiple antennas at the
transmitter can improve the secrecy performance of the
system effectively. Based on the PLS technologies, the
secure communication with SWIPT has been considered
in relay systems [6] and cognitive radio networks [7],
respectively. Up to now, most of the research works of
the secure communication for SWIPT focus on the
Broadcast Channel (BC) [8]-[12]. In particular, [8]
investigates the three-node single-input single-output
(SISO) SWIPT BC, and an Artificial Noise (AN) aided
transmission scheme is proposed to facilitate the secrecy
information transmission. In [9], the authors study both
the secrecy rate maximization problem and sum harvested
energy maximization problem for multiuser Multiple-
Input Single-Output (MISO) SWIPT BC. [10] proposes a
secure multicast scheme to minimize the total power by
using the techniques of rank-two beamformed Alamouti
coding. In [11], the authors study the multicast transmit
beamforming for secure layered transmission in MISO
SWIPT BC. The research on the secure transmission for
SWIPT is further extended to the Multiple-Input
Multiple-Output (MIMO) BC in [12], and the
beamforming matrix is designed to maximize the
achievable secrecy rate subject to a total power constraint
and an energy harvesting constraint.
However, all the above mentioned designs [6]-[12]
assume the knowledge of perfect Eavesdropper’s Channel
State Information (ECSI). Practically, the ECSI collected
at the transmitter may not be perfect because of the delay
error, the quantization error and the limited capacity of
feedback channel. Considering the imperfect ECSI, the
robust secure beamforming in the multiuser SWIPT BC is
investigated in [13], [14]. Recently, the jointly
information and energy transmit beamforming scheme in
SWIPT BC with imperfect ECSI and colluding ERs is
addressed in [15]. In [16], the authors propose a robust
AN-aided secure transmission design with consideration
of the channel uncertainties from the transmitter to IR,
ER and eavesdroppers. To the best of our knowledge, the
topics on secure communication in SWIPT K-user
interference channel (IFC) with ER trying to intercept the
secure transmitter have not been studied. Due to the
existence of the co-channel interference, the previous
works cannot be extended into K-user IFC
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©2016 Journal of Communications
of Communications Vol. 11, No. 8, August 2016