1,243 research outputs found
Power Allocation and Scheduling for SWIPT Systems with Non-linear Energy Harvesting Model
In this paper, we design a resource allocation algorithm for multiuser
simultaneous wireless information and power transfer systems for a realistic
non-linear energy harvesting (EH) model. In particular, the algorithm design is
formulated as a non-convex optimization problem for the maximization of the
long-term average total harvested power at EH receivers subject to quality of
service requirements for information decoding receivers. To obtain a tractable
solution, we transform the corresponding non-convex sum-of-ratios objective
function into an equivalent objective function in parametric subtractive form.
This leads to a computationally efficient iterative resource allocation
algorithm. Numerical results reveal a significant performance gain that can be
achieved if the resource allocation algorithm design is based on the non-linear
EH model instead of the traditional linear model.Comment: Accepted for presentation at the IEEE ICC 201
Energy-Efficient Resource Allocation in Multiuser OFDM Systems with Wireless Information and Power Transfer
In this paper, we study the resource allocation algorithm design for
multiuser orthogonal frequency division multiplexing (OFDM) downlink systems
with simultaneous wireless information and power transfer. The algorithm design
is formulated as a non-convex optimization problem for maximizing the energy
efficiency of data transmission (bit/Joule delivered to the users). In
particular, the problem formulation takes into account the minimum required
system data rate, heterogeneous minimum required power transfers to the users,
and the circuit power consumption. Subsequently, by exploiting the method of
time-sharing and the properties of nonlinear fractional programming, the
considered non-convex optimization problem is solved using an efficient
iterative resource allocation algorithm. For each iteration, the optimal power
allocation and user selection solution are derived based on Lagrange dual
decomposition. Simulation results illustrate that the proposed iterative
resource allocation algorithm achieves the maximum energy efficiency of the
system and reveal how energy efficiency, system capacity, and wireless power
transfer benefit from the presence of multiple users in the system.Comment: 6 pages. The paper has been accepted for publication at the IEEE
Wireless Communications and Networking Conference (WCNC) 2013, Shanghai,
China, Apr. 201
Dynamic Scheduling for Delay Guarantees for Heterogeneous Cognitive Radio Users
We study an uplink multi secondary user (SU) system having statistical delay
constraints, and an average interference constraint to the primary user (PU).
SUs with heterogeneous interference channel statistics, to the PU, experience
heterogeneous delay performances since SUs causing low interference are
scheduled more frequently than those causing high interference. We propose a
scheduling algorithm that can provide arbitrary average delay guarantees to SUs
irrespective of their statistical channel qualities. We derive the algorithm
using the Lyapunov technique and show that it yields bounded queues and satisfy
the interference constraints. Using simulations, we show its superiority over
the Max-Weight algorithm.Comment: Asilomar 2015. arXiv admin note: text overlap with arXiv:1602.0801
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