3 research outputs found
Energy Efficiency Maximization for SWIPT Enabled Two-Way DF Relaying
This paper focuses on the design of an optimal resource allocation scheme to
maximize the energy efficiency (EE) in a simultaneous wireless information and
power transfer (SWIPT) enabled two-way decode-and-forward (DF) relay network
under a non-linear energy harvesting model. In particular, we formulate an
optimization problem by jointly optimizing the transmit powers of two source
nodes, the power-splitting (PS) ratios of the relay, and the time for the
source-relay transmission, under multiple constraints including the transmit
power constraints at sources and the minimum rate requirement. Although the
formulated problem is non-convex, an iterative algorithm is developed to obtain
the optimal resource allocation. Simulation results verify the proposed
algorithm and show that the designed resource allocation scheme is superior to
other benchmark schemes in terms of EE.Comment: This paper has been accepted by IEEE Signal Processing Letter
System Outage Probability of PS-SWIPT Enabled Two-Way AF Relaying with Hardware Impairments
In this paper, we investigate the system outage probability of a simultaneous
wireless information and power transfer (SWIPT) based two-way
amplify-and-forward (AF) relay network considering transceiver hardware
impairments (HIs), where the energy-constrained relay node processes the
received signals based on a power splitting protocol and the two terminals
employ a selection combining (SC) scheme to exploit the signals from the direct
and relaying links. Assuming independent but non-identically distributed
Nakagami-m fading channels, we derive the system outage probability in a
closed-form, which enables us to identify two crucial ceiling effects on the
system outage probability caused by HIs in the high data rate regions, i.e.,
relay cooperation ceiling (RCC) and overall system ceiling (OSC). Specifically,
the RCC prevents the relaying link from participating in cooperative
communications, while the OSC leaves the overall system in outage. Furthermore,
we derive the achievable diversity gain of the considered network, which shows
that the diversity gain equals either the shape parameter of the direct link or
zero. Computer simulations are provided to validate the correctness of our
analytical results, and study the effects of various system parameters on the
system outage performance and the optimal power splitting ratio, as well as the
energy efficiency.Comment: This paper has been submitted for potential journal publicatio
System Outage Performance for Three-Step Two-Way Energy Harvesting DF Relaying
Wireless energy harvesting (WEH) has been recognized as a promising technique
to prolong the lifetime of energy constrained relay nodes in wireless sensor
networks. Its application and related performance study in three-step two-way
decode-and-forward (DF) relay networks are of high interest but still lack
sufficient study. In this paper we propose a dynamic power splitting (PS)
scheme to minimize the system outage probability in a three-step two-way energy
harvesting DF relay network and derive an analytical expression for the system
outage probability with respect to the optimal dynamic PS ratios. In order to
further improve the system outage performance, we propose an improved dynamic
scheme where both the PS ratios and the power allocation ratio at the relay are
dynamically adjusted according to instantaneous channel gains. The
corresponding system performance with the improved dynamic scheme is also
investigated. Simulation results show that our proposed schemes outperform the
existing scheme in terms of the system outage performance and the improved
dynamic scheme is superior to the dynamic PS scheme