8 research outputs found
Resource Allocation for Secure Communication in Systems with Wireless Information and Power Transfer
This paper considers secure communication in a multiuser multiple-input
single-output (MISO) downlink system with simultaneous wireless information and
power transfer. We study the design of resource allocation algorithms
minimizing the total transmit power for the case when the receivers are able to
harvest energy from the radio frequency. In particular, the algorithm design is
formulated as a non-convex optimization problem which takes into account
artificial noise generation to combat potential eavesdroppers, a minimum
required signal-to-interference-plus-noise ratio (SINR) at the desired
receiver, maximum tolerable SINRs at the potential eavesdroppers, and a minimum
required power delivered to the receivers. We adopt a semidefinite programming
(SDP) relaxation approach to obtain an upper bound solution for the considered
problem. The tightness of the upper bound is revealed by examining a sufficient
condition for the global optimal solution. Inspired by the sufficient
condition, we propose two suboptimal resource allocation schemes enhancing
secure communication and facilitating efficient energy harvesting. Simulation
results demonstrate a close-to-optimal performance achieved by the proposed
suboptimal schemes and significant transmit power savings by optimization of
the artificial noise generation.Comment: 7 pages, 5 figures, and 1 table. Submitted for possible conference
publicatio
Achievable Secrecy Rates of an Energy Harvesting Device with a Finite Battery
In this paper, we investigate the achievable secrecy rates in an Energy Harvesting communication system composed of one transmitter and multiple receivers. In particular, because of the energy constraints and the channel conditions, it is important to understand when a device should transmit or not and how much power should be used. We introduce the Optimal Secrecy Policy in several scenarios. We show that, if the receivers demand high secrecy rates, then it is not always possible to satisfy all their requests. Thus, we introduce a scheme that chooses which receivers should be discarded. Also, we study how the system is influenced by the Channel State Information and, in particular, how the knowledge of the eavesdropper's channel changes the achievable rates
Secure Beamforming For MIMO Broadcasting With Wireless Information And Power Transfer
This paper considers a basic MIMO information-energy (I-E) broadcast system,
where a multi-antenna transmitter transmits information and energy
simultaneously to a multi-antenna information receiver and a dual-functional
multi-antenna energy receiver which is also capable of decoding information.
Due to the open nature of wireless medium and the dual purpose of information
and energy transmission, secure information transmission while ensuring
efficient energy harvesting is a critical issue for such a broadcast system.
Assuming that physical layer security techniques are applied to the system to
ensure secure transmission from the transmitter to the information receiver, we
study beamforming design to maximize the achievable secrecy rate subject to a
total power constraint and an energy harvesting constraint. First, based on
semidefinite relaxation, we propose global optimal solutions to the secrecy
rate maximization (SRM) problem in the single-stream case and a specific
full-stream case where the difference of Gram matrices of the channel matrices
is positive semidefinite. Then, we propose a simple iterative algorithm named
inexact block coordinate descent (IBCD) algorithm to tackle the SRM problem of
general case with arbitrary number of streams. We proves that the IBCD
algorithm can monotonically converge to a Karush-Kuhn-Tucker (KKT) solution to
the SRM problem. Furthermore, we extend the IBCD algorithm to the joint
beamforming and artificial noise design problem. Finally, simulations are
performed to validate the performance of the proposed beamforming algorithms.Comment: Submitted to journal for possible publication. First submission to
arXiv Mar. 14 201
Transceiver design for wireless energy harvesting cooperative networks
In this thesis, the RF energy harvesting technique is studied in the cooperative wireless network, and different optimization studies are investigated. First, an energy-efficient optimization is considered in the cooperative system with the time switching relaying and power splitting relaying protocols. Then, a security issue in the cooperative network with energy harvesting is proposed, in which the optimization problem is designed to maximize the secrecy rate. We also consider the application of energy harvesting in the full-duplex relaying network with a self-energy recycling protocol. Finally, the energy harvesting is studied in the full-duplex cooperative cognitive radio network. The system performance of all studies is verified in the thesis with MATLAB simulation results