5 research outputs found
Cost minimization for fading channels with energy harvesting and conventional energy
In this paper, we investigate resource allocation strategies for a
point-to-point wireless communications system with hybrid energy sources
consisting of an energy harvester and a conventional energy source. In
particular, as an incentive to promote the use of renewable energy, we assume
that the renewable energy has a lower cost than the conventional energy. Then,
by assuming that the non-causal information of the energy arrivals and the
channel power gains are available, we minimize the total energy cost of such a
system over fading slots under a proposed outage constraint together with
the energy harvesting constraints. The outage constraint requires a minimum
fixed number of slots to be reliably decoded, and thus leads to a mixed-integer
programming formulation for the optimization problem. This constraint is
useful, for example, if an outer code is used to recover all the data bits.
Optimal linear time algorithms are obtained for two extreme cases, i.e., the
number of outage slot is or . For the general case, a lower bound
based on the linear programming relaxation, and two suboptimal algorithms are
proposed. It is shown that the proposed suboptimal algorithms exhibit only a
small gap from the lower bound. We then extend the proposed algorithms to the
multi-cycle scenario in which the outage constraint is imposed for each cycle
separately. Finally, we investigate the resource allocation strategies when
only causal information on the energy arrivals and only channel statistics is
available. It is shown that the greedy energy allocation is optimal for this
scenario.Comment: to appear in IEEE Transactions on Wireless Communication
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 Scheduling for Energy Harvesting Transmitters with Hybrid Energy Storage
Abstract—We consider data transmission with an energy harvesting transmitter which has a hybrid energy storage unit composed of a perfectly efficient super-capacitor (SC) and an inefficient battery. The SC has finite space for energy storage while the battery has unlimited space. The transmitter can choose to store the harvested energy in the SC or in the battery. The energy is drained from the SC and the battery simultaneously. In this setting, we consider the offline throughput maximization problem by a deadline over a point-to-point channel. In contrast to previous works, the hybrid energy storage model with finite and unlimited storage capacities imposes a generalized set of constraints on the transmission policy. As such, we show that the solution generalizes that for a single battery and is obtained by applying directional water-filling algorithm multiple times. I