6,285 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
Capacity of Fading Gaussian Channel with an Energy Harvesting Sensor Node
Network life time maximization is becoming an important design goal in
wireless sensor networks. Energy harvesting has recently become a preferred
choice for achieving this goal as it provides near perpetual operation. We
study such a sensor node with an energy harvesting source and compare various
architectures by which the harvested energy is used. We find its Shannon
capacity when it is transmitting its observations over a fading AWGN channel
with perfect/no channel state information provided at the transmitter. We
obtain an achievable rate when there are inefficiencies in energy storage and
the capacity when energy is spent in activities other than transmission.Comment: 6 Pages, To be presented at IEEE GLOBECOM 201
Source-Channel Coding under Energy, Delay and Buffer Constraints
Source-channel coding for an energy limited wireless sensor node is
investigated. The sensor node observes independent Gaussian source samples with
variances changing over time slots and transmits to a destination over a flat
fading channel. The fading is constant during each time slot. The compressed
samples are stored in a finite size data buffer and need to be delivered in at
most time slots. The objective is to design optimal transmission policies,
namely, optimal power and distortion allocation, over the time slots such that
the average distortion at destination is minimized. In particular, optimal
transmission policies with various energy constraints are studied. First, a
battery operated system in which sensor node has a finite amount of energy at
the beginning of transmission is investigated. Then, the impact of energy
harvesting, energy cost of processing and sampling are considered. For each
energy constraint, a convex optimization problem is formulated, and the
properties of optimal transmission policies are identified. For the strict
delay case, , waterfilling interpretation is provided. Numerical
results are presented to illustrate the structure of the optimal transmission
policy, to analyze the effect of delay constraints, data buffer size, energy
harvesting, processing and sampling costs.Comment: 30 pages, 15 figures. Submitted to IEEE Transactions on Wireless
Communication
Secure Communication with a Wireless-Powered Friendly Jammer
In this paper, we propose to use a wireless-powered friendly jammer to enable
secure communication between a source node and destination node, in the
presence of an eavesdropper. We consider a two-phase communication protocol
with fixed-rate transmission. In the first phase, wireless power transfer is
conducted from the source to the jammer. In the second phase, the source
transmits the information-bearing signal under the protection of a jamming
signal sent by the jammer using the harvested energy in the first phase. We
analytically characterize the long-time behavior of the proposed protocol and
derive a closed-form expression for the throughput. We further optimize the
rate parameters for maximizing the throughput subject to a secrecy outage
probability constraint. Our analytical results show that the throughput
performance differs significantly between the single-antenna jammer case and
the multi-antenna jammer case. For instance, as the source transmit power
increases, the throughput quickly reaches an upper bound with single-antenna
jammer, while the throughput grows unbounded with multi-antenna jammer. Our
numerical results also validate the derived analytical results.Comment: accepted for publication in IEEE Transactions on Wireless
Communication
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