179 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
Communicating Using an Energy Harvesting Transmitter: Optimum Policies Under Energy Storage Losses
In this paper, short-term throughput optimal power allocation policies are
derived for an energy harvesting transmitter with energy storage losses. In
particular, the energy harvesting transmitter is equipped with a battery that
loses a fraction of its stored energy. Both single user, i.e. one
transmitter-one receiver, and the broadcast channel, i.e., one
transmitter-multiple receiver settings are considered, initially with an
infinite capacity battery. It is shown that the optimal policies for these
models are threshold policies. Specifically, storing energy when harvested
power is above an upper threshold, retrieving energy when harvested power is
below a lower threshold, and transmitting with the harvested energy in between
is shown to maximize the weighted sum-rate. It is observed that the two
thresholds are related through the storage efficiency of the battery, and are
nondecreasing during the transmission. The results are then extended to the
case with finite battery capacity, where it is shown that a similar
double-threshold structure arises but the thresholds are no longer monotonic. A
dynamic program that yields an optimal online power allocation is derived, and
is shown to have a similar double-threshold structure. A simpler online policy
is proposed and observed to perform close to the optimal policy.Comment: Submitted to IEEE Transactions on Wireless Communications, August
201
Finite Horizon Online Lazy Scheduling with Energy Harvesting Transmitters over Fading Channels
Lazy scheduling, i.e. setting transmit power and rate in response to data
traffic as low as possible so as to satisfy delay constraints, is a known
method for energy efficient transmission.This paper addresses an online lazy
scheduling problem over finite time-slotted transmission window and introduces
low-complexity heuristics which attain near-optimal performance.Particularly,
this paper generalizes lazy scheduling problem for energy harvesting systems to
deal with packet arrival, energy harvesting and time-varying channel processes
simultaneously. The time-slotted formulation of the problem and depiction of
its offline optimal solution provide explicit expressions allowing to derive
good online policies and algorithms
Optimal Spectrum Access for a Rechargeable Cognitive Radio User Based on Energy Buffer State
This paper investigates the maximum throughput for a rechargeable secondary
user (SU) sharing the spectrum with a primary user (PU) plugged to a reliable
power supply. The SU maintains a finite energy queue and harvests energy from
natural resources, e.g., solar, wind and acoustic noise. We propose a
probabilistic access strategy by the SU based on the number of packets at its
energy queue. We investigate the effect of the energy arrival rate, the amount
of energy per energy packet, and the capacity of the energy queue on the SU
throughput under fading channels. Results reveal that the proposed access
strategy can enhance the performance of the SU.Comment: arXiv admin note: text overlap with arXiv:1407.726
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