756 research outputs found
Optimal Energy Allocation For Delay-Constrained Traffic Over Fading Multiple Access Channels
In this paper, we consider a multiple-access fading channel where users
transmit to a single base station (BS) within a limited number of time slots.
We assume that each user has a fixed amount of energy available to be consumed
over the transmission window. We derive the optimal energy allocation policy
for each user that maximizes the total system throughput under two different
assumptions on the channel state information. First, we consider the offline
allocation problem where the channel states are known a priori before
transmission. We solve a convex optimization problem to maximize the
sum-throughput under energy and delay constraints. Next, we consider the online
allocation problem, where the channels are causally known to the BS and obtain
the optimal energy allocation via dynamic programming when the number of users
is small. We also develop a suboptimal resource allocation algorithm whose
performance is close to the optimal one. Numerical results are presented
showing the superiority of the proposed algorithms over baseline algorithms in
various scenarios.Comment: IEEE Global Communications Conference: Wireless Communications
(Globecom2016 WC
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
Optimal Energy Allocation for Wireless Communications with Energy Harvesting Constraints
We consider the use of energy harvesters, in place of conventional batteries
with fixed energy storage, for point-to-point wireless communications. In
addition to the challenge of transmitting in a channel with time selective
fading, energy harvesters provide a perpetual but unreliable energy source. In
this paper, we consider the problem of energy allocation over a finite horizon,
taking into account channel conditions and energy sources that are time
varying, so as to maximize the throughput. Two types of side information (SI)
on the channel conditions and harvested energy are assumed to be available:
causal SI (of the past and present slots) or full SI (of the past, present and
future slots). We obtain structural results for the optimal energy allocation,
via the use of dynamic programming and convex optimization techniques. In
particular, if unlimited energy can be stored in the battery with harvested
energy and the full SI is available, we prove the optimality of a water-filling
energy allocation solution where the so-called water levels follow a staircase
function.Comment: 27 pages, 6 figures, accepted for publications at IEEE Transactions
on Signal Processin
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