689 research outputs found
Real-time Optimal Resource Allocation for Embedded UAV Communication Systems
We consider device-to-device (D2D) wireless information and power transfer
systems using an unmanned aerial vehicle (UAV) as a relay-assisted node. As the
energy capacity and flight time of UAVs is limited, a significant issue in
deploying UAV is to manage energy consumption in real-time application, which
is proportional to the UAV transmit power. To tackle this important issue, we
develop a real-time resource allocation algorithm for maximizing the energy
efficiency by jointly optimizing the energy-harvesting time and power control
for the considered (D2D) communication embedded with UAV. We demonstrate the
effectiveness of the proposed algorithms as running time for solving them can
be conducted in milliseconds.Comment: 11 pages, 5 figures, 1 table. This paper is accepted for publication
on IEEE Wireless Communications Letter
Max-min Fair Beamforming for SWIPT Systems with Non-linear EH Model
We study the beamforming design for multiuser systems with simultaneous
wireless information and power transfer (SWIPT). Employing a practical
non-linear energy harvesting (EH) model, the design is formulated as a
non-convex optimization problem for the maximization of the minimum harvested
power across several energy harvesting receivers. The proposed problem
formulation takes into account imperfect channel state information (CSI) and a
minimum required signal-to-interference-plus-noise ratio (SINR). The globally
optimal solution of the design problem is obtained via the semidefinite
programming (SDP) relaxation approach. Interestingly, we can show that at most
one dedicated energy beam is needed to achieve optimality. Numerical results
demonstrate that with the proposed design a significant performance gain and
improved fairness can be provided to the users compared to two baseline
schemes.Comment: Invited paper, IEEE VTC 2017, Fall, Toronto, Canad
Finite Horizon Throughput Maximization for a Wirelessly Powered Device over a Time Varying Channel
In this work, we consider an energy harvesting device (EHD) served by an
access point with a single antenna that is used for both wireless power
transfer (WPT) and data transfer. The objective is to maximize the expected
throughput of the EHD over a finite horizon when the channel state information
is only available causally. The EHD is energized by WPT for a certain duration,
which is subject to optimization, and then, EHD transmits its information bits
to the AP until the end of the time horizon by employing optimal dynamic power
allocation. The joint optimization problem is modeled as a dynamic programming
problem. Based on the characteristic of the problem, we prove that a time
dependent threshold type structure exists for the optimal WPT duration, and we
obtain closed form solution to the dynamic power allocation in the uplink
period.Comment: arXiv admin note: substantial text overlap with arXiv:1804.0183
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