1,248 research outputs found
Information-Theoretic Analysis of an Energy Harvesting Communication System
In energy harvesting communication systems, an exogenous recharge process
supplies energy for the data transmission and arriving energy can be buffered
in a battery before consumption. Transmission is interrupted if there is not
sufficient energy. We address communication with such random energy arrivals in
an information-theoretic setting. Based on the classical additive white
Gaussian noise (AWGN) channel model, we study the coding problem with random
energy arrivals at the transmitter. We show that the capacity of the AWGN
channel with stochastic energy arrivals is equal to the capacity with an
average power constraint equal to the average recharge rate. We provide two
different capacity achieving schemes: {\it save-and-transmit} and {\it
best-effort-transmit}. Next, we consider the case where energy arrivals have
time-varying average in a larger time scale. We derive the optimal offline
power allocation for maximum average throughput and provide an algorithm that
finds the optimal power allocation.Comment: Published in IEEE PIMRC, September 201
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
Universally Near Optimal Online Power Control for Energy Harvesting Nodes
We consider online power control for an energy harvesting system with random
i.i.d. energy arrivals and a finite size battery. We propose a simple online
power control policy for this channel that requires minimal information
regarding the distribution of the energy arrivals and prove that it is
universally near-optimal for all parameter values. In particular, the policy
depends on the distribution of the energy arrival process only through its mean
and it achieves the optimal long-term average throughput of the channel within
both constant additive and multiplicative gaps. Existing heuristics for online
power control fail to achieve such universal performance. This result also
allows us to approximate the long-term average throughput of the system with a
simple formula, which sheds some light on the qualitative behavior of the
throughput, namely how it depends on the distribution of the energy arrivals
and the size of the battery.Comment: the proposed scheme is shown to be optimal both within constant
additive and multiplicative gaps; submitted to Journal on Selected Areas in
Communications - Series on Green Communications and Networking (Issue 3);
revised following reviewers' comment
Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey
Wireless sensor networks (WSNs) consist of autonomous and resource-limited
devices. The devices cooperate to monitor one or more physical phenomena within
an area of interest. WSNs operate as stochastic systems because of randomness
in the monitored environments. For long service time and low maintenance cost,
WSNs require adaptive and robust methods to address data exchange, topology
formulation, resource and power optimization, sensing coverage and object
detection, and security challenges. In these problems, sensor nodes are to make
optimized decisions from a set of accessible strategies to achieve design
goals. This survey reviews numerous applications of the Markov decision process
(MDP) framework, a powerful decision-making tool to develop adaptive algorithms
and protocols for WSNs. Furthermore, various solution methods are discussed and
compared to serve as a guide for using MDPs in WSNs
Smart Meter Privacy with an Energy Harvesting Device and Instantaneous Power Constraints
A smart meter (SM) periodically measures end-user electricity consumption and
reports it to a utility provider (UP). Despite the advantages of SMs, their use
leads to serious concerns about consumer privacy. In this paper, SM privacy is
studied by considering the presence of an energy harvesting device (EHD) as a
means of masking the user's input load. The user can satisfy part or all of
his/her energy needs from the EHD, and hence, less information can be leaked to
the UP via the SM. The EHD is typically equipped with a rechargeable energy
storage device, i.e., a battery, whose instantaneous energy content limits the
user's capability in covering his/her energy usage. Privacy is measured by the
information leaked about the user's real energy consumption when the UP
observes the energy requested from the grid, which the SM reads and reports to
the UP. The minimum information leakage rate is characterized as a computable
information theoretic single-letter expression when the EHD battery capacity is
either infinite or zero. Numerical results are presented for a discrete binary
input load to illustrate the potential privacy gains from the existence of a
storage device.Comment: To be published in IEEE ICC201
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