1,479 research outputs found
Resource Allocation in Wireless Networks with RF Energy Harvesting and Transfer
Radio frequency (RF) energy harvesting and transfer techniques have recently
become alternative methods to power the next generation of wireless networks.
As this emerging technology enables proactive replenishment of wireless
devices, it is advantageous in supporting applications with quality-of-service
(QoS) requirement. This article focuses on the resource allocation issues in
wireless networks with RF energy harvesting capability, referred to as RF
energy harvesting networks (RF-EHNs). First, we present an overview of the
RF-EHNs, followed by a review of a variety of issues regarding resource
allocation. Then, we present a case study of designing in the receiver
operation policy, which is of paramount importance in the RF-EHNs. We focus on
QoS support and service differentiation, which have not been addressed by
previous literatures. Furthermore, we outline some open research directions.Comment: To appear in IEEE Networ
Application of Smart Antenna Technologies in Simultaneous Wireless Information and Power Transfer
Simultaneous wireless information and power transfer (SWIPT) is a promising
solution to increase the lifetime of wireless nodes and hence alleviate the
energy bottleneck of energy constrained wireless networks. As an alternative to
conventional energy harvesting techniques, SWIPT relies on the use of radio
frequency signals, and is expected to bring some fundamental changes to the
design of wireless communication networks. This article focuses on the
application of advanced smart antenna technologies, including multiple-input
multiple-output and relaying techniques, to SWIPT. These smart antenna
technologies have the potential to significantly improve the energy efficiency
and also the spectral efficiency of SWIPT. Different network topologies with
single and multiple users are investigated, along with some promising solutions
to achieve a favorable trade-off between system performance and complexity. A
detailed discussion of future research challenges for the design of SWIPT
systems is also provided
Energy-Efficient NOMA Enabled Heterogeneous Cloud Radio Access Networks
Heterogeneous cloud radio access networks (H-CRANs) are envisioned to be
promising in the fifth generation (5G) wireless networks. H-CRANs enable users
to enjoy diverse services with high energy efficiency, high spectral
efficiency, and low-cost operation, which are achieved by using cloud computing
and virtualization techniques. However, H-CRANs face many technical challenges
due to massive user connectivity, increasingly severe spectrum scarcity and
energy-constrained devices. These challenges may significantly decrease the
quality of service of users if not properly tackled. Non-orthogonal multiple
access (NOMA) schemes exploit non-orthogonal resources to provide services for
multiple users and are receiving increasing attention for their potential of
improving spectral and energy efficiency in 5G networks. In this article a
framework for energy-efficient NOMA H-CRANs is presented. The enabling
technologies for NOMA H-CRANs are surveyed. Challenges to implement these
technologies and open issues are discussed. This article also presents the
performance evaluation on energy efficiency of H-CRANs with NOMA.Comment: This work has been accepted by IEEE Network. Pages 18, Figure
Wireless-Powered Communication Assisted by Two-Way Relay with Interference Alignment Underlaying Cognitive Radio Network
This study investigates the outage performance of an under-laying
wireless-powered secondary system that reuses the primary users (PU) spectrum
in a multiple-input multiple-output (MIMO) cognitive radio (CR) network. Each
secondary user (SU) harvests energy and receives information simultaneously by
applying power splitting (PS) protocol. The communication between SUs is aided
by a two-way (TW) decode and forward (DF) relay. We formulate a problem to
design the PS ratios at SUs, the power control factor at the secondary relay,
and beamforming matrices at all nodes to minimize the secondary network's
outage probability. To address this problem, we propose a two-step solution.
The first step establishes closedform expressions for the PS ratios at each SU
and secondary relay's power control factor. Furthermore, in the second step,
interference alignment (IA) is used to design proper precoding and decoding
matrices for managing the interference between secondary and primary networks.
We choose IA matrices based on the minimum mean square error (MMSE) iterative
algorithm. The simulation results demonstrate a significant decrease in the
outage probability for the proposed scheme compared to the benchmark schemes,
with an average reduction of more than two orders of magnitude achieved
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