69,527 research outputs found
Energy Harvesting Wireless Communications: A Review of Recent Advances
This article summarizes recent contributions in the broad area of energy
harvesting wireless communications. In particular, we provide the current state
of the art for wireless networks composed of energy harvesting nodes, starting
from the information-theoretic performance limits to transmission scheduling
policies and resource allocation, medium access and networking issues. The
emerging related area of energy transfer for self-sustaining energy harvesting
wireless networks is considered in detail covering both energy cooperation
aspects and simultaneous energy and information transfer. Various potential
models with energy harvesting nodes at different network scales are reviewed as
well as models for energy consumption at the nodes.Comment: To appear in the IEEE Journal of Selected Areas in Communications
(Special Issue: Wireless Communications Powered by Energy Harvesting and
Wireless Energy Transfer
Secure Layered Transmission in Multicast Systems with Wireless Information and Power Transfer
This paper considers downlink multicast transmit beamforming for secure
layered transmission systems with wireless simultaneous information and power
transfer. We study the power allocation algorithm design for minimizing the
total transmit power in the presence of passive eavesdroppers and energy
harvesting receivers. The algorithm design is formulated as a non-convex
optimization problem. Our problem formulation promotes the dual use of energy
signals in providing secure communication and facilitating efficient energy
transfer. Besides, we take into account a minimum required power for energy
harvesting at the idle receivers and heterogeneous quality of service (QoS)
requirements for the multicast video receivers. In light of the intractability
of the problem, we reformulate the considered problem by replacing a non-convex
probabilistic constraint with a convex deterministic constraint. Then, a
semidefinite programming relaxation (SDR) approach is adopted to obtain an
upper solution for the reformulated problem. Subsequently, sufficient
conditions for the global optimal solution of the reformulated problem are
revealed. Furthermore, we propose two suboptimal power allocation schemes based
on the upper bound solution. Simulation results demonstrate the excellent
performance and significant transmit power savings achieved by the proposed
schemes compared to isotropic energy signal generation.Comment: 7 pages, 3 figures, accepted for presentation at the IEEE
International Conference on Communications (ICC), Sydney, Australia, 201
Constrained Codes for Joint Energy and Information Transfer
In various wireless systems, such as sensor RFID networks and body area
networks with implantable devices, the transmitted signals are simultaneously
used both for information transmission and for energy transfer. In order to
satisfy the conflicting requirements on information and energy transfer, this
paper proposes the use of constrained run-length limited (RLL) codes in lieu of
conventional unconstrained (i.e., random-like) capacity-achieving codes. The
receiver's energy utilization requirements are modeled stochastically, and
constraints are imposed on the probabilities of battery underflow and overflow
at the receiver. It is demonstrated that the codewords' structure afforded by
the use of constrained codes enables the transmission strategy to be better
adjusted to the receiver's energy utilization pattern, as compared to classical
unstructured codes. As a result, constrained codes allow a wider range of
trade-offs between the rate of information transmission and the performance of
energy transfer to be achieved.Comment: 27 pages, 14 figures, Submitted Submitted in IEEE Transactions on
Communication
Optimal Online Transmission Policy for Energy-Constrained Wireless-Powered Communication Networks
This work considers the design of online transmission policy in a
wireless-powered communication system with a given energy budget. The system
design objective is to maximize the long-term throughput of the system
exploiting the energy storage capability at the wireless-powered node. We
formulate the design problem as a constrained Markov decision process (CMDP)
problem and obtain the optimal policy of transmit power and time allocation in
each fading block via the Lagrangian approach. To investigate the system
performance in different scenarios, numerical simulations are conducted with
various system parameters. Our simulation results show that the optimal policy
significantly outperforms a myopic policy which only maximizes the throughput
in the current fading block. Moreover, the optimal allocation of transmit power
and time is shown to be insensitive to the change of modulation and coding
schemes, which facilitates its practical implementation.Comment: 7 pages, accepted by ICC 2019. An extended version of this paper is
accepted by IEEE TW
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
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