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Proceedings ArticleDOI

Performance Evaluation of Full-Duplex Energy Harvesting Relaying Networks Using PDC Self-Interference Cancellation

01 Dec 2018-pp 1-6
TL;DR: To achieve a high throughput along with a good error performance in the full-duplex energy harvesting relaying system, a combined selection of a high signal-to-noise ratio and a suitable energy harvesting time is required.
Abstract: In this paper, throughput and bit error performance of an in-band full duplex (IBFD) relaying system assisted by the radio frequency energy harvesting technique and the polarization-enabled digital self-interference cancellation (PDC) scheme are investigated. In particular, the relay node harvests power from the wireless radio frequency signal transmitted from the source node and uses this power to amplify and forward signals to the destination. Meanwhile, the PDC scheme is used at the relay node to cancel the self-interference signal in order to facilitate the concurrent in-band transmission and reception. The impact of both energy harvesting and self-interference cancellation on the throughput and the error performance of the system is evaluated. Our simulation results show that the full-duplex energy harvesting relaying system almost doubles the system throughput, compared to the half-duplex energy harvesting relaying system, at the cost of about 5 dB inferior error performance, partially because of the noise effect of the PDC scheme. We also show that to achieve a high throughput along with a good error performance in the full-duplex energy harvesting relaying system, a combined selection of a high signal-to-noise ratio and a suitable energy harvesting time is required.

Summary (2 min read)

I. INTRODUCTION

  • In a system where there is no direct link between the source node and the destination node, the assistance of other nodes is needed to forward information to the destination.
  • This paper assumes a perfect self-interference cancellation mechanism, thus ignoring the influence of the self-interference cancellation circuitry.
  • In a full-duplex relaying system, the signal received at the relay from the distant transmitter is referred to the desired signal, while the transmitted signal from the local relaying transmitter is the self-interference signal.
  • The authors investigate the throughput of an in-band fullduplex relaying system assisted by RF energy harvesting and the PDC self-interference cancellation.
  • It is revealed that, for the same SNR, the BER performance of the system only improves slightly when α increases.

II. SYSTEM MODEL

  • The dual-hop in-band full-duplex relaying system with energy harvesting at the relay node is considered.
  • Then, the relay uses the harvested energy as a source of transmitting power to amplify and forward the source information to the destination within the duration (1-α)T. Besides, the PDC scheme is activated during this period to cancel the SI signal.
  • SIGNAL MODEL Define x( ) and z( ) as the desired signal from the source and the self-interference signal from the relay transmitter at the time instant n, respectively.
  • Denote the polarization states (PS) of the desired signal and self-interference signal as S and I respectively.
  • The PDC scheme has two steps, namely oblique projection and scalarization.

IV. SIMULATION RESULTS

  • Simulation results are presented to reveal the throughput and BER performances of both half-duplex harvesting relaying system and full-duplex energy harvesting relaying system.
  • Ps and P present the source and the relay transmission powers, respectively.
  • The source transmission rate is set as R1 = 2 bps for BPSK modulation and R2 = 4 bps for QPSK modulation, hence, the total numbers of transmitted symbols in both BPSK and QPSK cases are the same.
  • Besides, the authors assume that the signal channel and the selfinterference channel satisfy Rayleigh flat fading.

A. Throughput performances

  • The system outage probability can be calculated as EQUATION ) where γ is the instantaneous SNR per symbol of the received signal at the destination and γ is the SNR threshold.
  • Recall that the transmission rate of BPSK modulation is R1 while that of the QPSK modulation is R2.
  • This means the relay transmission powers per symbol P of FD is half of HD, which decrease the throughput by 0.4 times.
  • Thirdly, when SNR is larger, the maximum throughput appears at a lower α value.
  • Besides, the modulation method also has an influence on the BER performance as detailed in the following section.

B. Bit error rate

  • The authors quantify the self-interference cancellation performance of the PDC scheme in the FD system and compare it with the HD system.
  • Without the PDC scheme, the desired signal cannot be detected as it is seriously corrupted by the self-interference signal.
  • Fig. 6 examines the impact of the time fraction α on BER of the full-duplex energy harvesting relaying system using QPSK modulation.
  • The value of α decides the total harvested energy.
  • From Figs. 5 and 6 , when SNR increases, the BER decreases.

V. CONCLUSION

  • The authors considered an in-band full-duplex relaying system where the relay node harvests the RF energy from the source node to amplify and forward the signals.
  • This high throughput in the FD system come at the cost of an inferior BER performance due to the characteristic of their energy harvesting system that the full-duplex system uses the same harvested energy as in the HD one to transmit doubled amount of information.
  • The error performance inferiority is partially because of the additional noise introduced by the PDC scheme.
  • This paper has addressed the independent flat fading channels and a single antenna system.
  • Half-duplex energy harvesting relaying system vs. full-duplex energy harvesting relaying system associated with PDC for α = 0.2.

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University of Wollongong University of Wollongong
Research Online Research Online
Faculty of Engineering and Information
Sciences - Papers: Part B
Faculty of Engineering and Information
Sciences
2018
Performance Evaluation of Full-Duplex Energy Harvesting Performance Evaluation of Full-Duplex Energy Harvesting
Relaying Networks Using PDC Self-Interference Cancellation Relaying Networks Using PDC Self-Interference Cancellation
Jiaman Li
University of Wollongong
, jl797@uowmail.edu.au
Le Chung Tran
University of Wollongong
, lctran@uow.edu.au
Farzad Safaei
University of Wollongong
, farzad@uow.edu.au
Follow this and additional works at: https://ro.uow.edu.au/eispapers1
Part of the Engineering Commons, and the Science and Technology Studies Commons
Recommended Citation Recommended Citation
Li, Jiaman; Tran, Le Chung; and Safaei, Farzad, "Performance Evaluation of Full-Duplex Energy Harvesting
Relaying Networks Using PDC Self-Interference Cancellation" (2018).
Faculty of Engineering and
Information Sciences - Papers: Part B
. 2410.
https://ro.uow.edu.au/eispapers1/2410
Research Online is the open access institutional repository for the University of Wollongong. For further information
contact the UOW Library: research-pubs@uow.edu.au

Performance Evaluation of Full-Duplex Energy Harvesting Relaying Networks Performance Evaluation of Full-Duplex Energy Harvesting Relaying Networks
Using PDC Self-Interference Cancellation Using PDC Self-Interference Cancellation
Abstract Abstract
In this paper, throughput and bit error performance of an in-band full duplex (IBFD) relaying system
assisted by the radio frequency energy harvesting technique and the polarization-enabled digital self-
interference cancellation (PDC) scheme are investigated. In particular, the relay node harvests power from
the wireless radio frequency signal transmitted from the source node and uses this power to amplify and
forward signals to the destination. Meanwhile, the PDC scheme is used at the relay node to cancel the
self-interference signal in order to facilitate the concurrent in-band transmission and reception. The
impact of both energy harvesting and self-interference cancellation on the throughput and the error
performance of the system is evaluated. Our simulation results show that the full-duplex energy
harvesting relaying system almost doubles the system throughput, compared to the half-duplex energy
harvesting relaying system, at the cost of about 5 dB inferior error performance, partially because of the
noise effect of the PDC scheme. We also show that to achieve a high throughput along with a good error
performance in the full-duplex energy harvesting relaying system, a combined selection of a high signal-
to-noise ratio and a suitable energy harvesting time is required.
Keywords Keywords
energy, harvesting, relaying, networks, pdc, full-duplex, self-interference, performance, cancellation,
evaluation
Disciplines Disciplines
Engineering | Science and Technology Studies
Publication Details Publication Details
J. Li, L. Tran & F. Safaei, "Performance Evaluation of Full-Duplex Energy Harvesting Relaying Networks
Using PDC Self-Interference Cancellation," in 12th International Conference on Signal Processing and
Communication Systems (ICSPCS'2018), 2018, pp. 1-6.
This conference paper is available at Research Online: https://ro.uow.edu.au/eispapers1/2410

Performance Evaluation of Full-Duplex Energy
Harvesting Relaying Networks Using PDC Self-
Interference Cancellation
Jiaman Li
School of Electrical, Computer and
Telecommunication Engineering
University of Wollongong
jl797@uowmail.edu.au
Le Chung Tran
School of Electrical, Computer and
Telecommunication Engineering
University of Wollongong
lctran@uow.edu.au
Farzad Safaei
School of Electrical, Computer and
Telecommunication Engineering
University of Wollongong
farzad@uow.edu.au
AbstractIn this paper, throughput and bit error
performance of an in-band full duplex (IBFD) relaying system
assisted by the radio frequency energy harvesting technique and
the polarization-enabled digital self-interference cancellation
(PDC) scheme are investigated. In particular, the relay node
harvests power from the wireless radio frequency signal
transmitted from the source node and uses this power to amplify
and forward signals to the destination. Meanwhile, the PDC
scheme is used at the relay node to cancel the self-interference
signal in order to facilitate the concurrent in-band transmission
and reception. The impact of both energy harvesting and self-
interference cancellation on the throughput and the error
performance of the system is evaluated. Our simulation results
show that the full-duplex energy harvesting relaying system
almost doubles the system throughput, compared to the half-
duplex energy harvesting relaying system, at the cost of about 5
dB inferior error performance, partially because of the noise
effect of the PDC scheme. We also show that to achieve a high
throughput along with a good error performance in the full-
duplex energy harvesting relaying system, a combined selection
of a high signal-to-noise ratio and a suitable energy harvesting
time is required.
Keywords—Full-duplex relaying, self-interference
cancellation, energy harvesting, throughput, bit error rate.
I. I
NTRODUCTION
In a system where there is no direct link between the
source node and the destination node, the assistance of other
nodes is needed to forward information to the destination.
Thus, relaying networks and their characteristics are important
to investigate. Meanwhile, energy harvesting, which harvests
energy from radio frequency (RF) electromagnetic radiation,
has attracted a significant interest, since it prolongs the
lifetime of wireless sensor nodes. For example, the work in
[1], [2] investigates relaying systems with wireless energy
harvesting. The relay node converts the energy from the
source into its own energy to forward the signal to the
destination, but the relay is limited to the half-duplex (HD)
mechanism. In [3], a full-duplex (FD) relaying network is
investigated, which allows simultaneous transmission and
reception in the same frequency band. The network provides
higher spectrum efficiency compared to time division duplex
and frequency division duplex. However, this paper assumes
a perfect self-interference cancellation mechanism, thus
ignoring the influence of the self-interference cancellation
circuitry. In a full-duplex relaying system, the signal received
at the relay from the distant transmitter is referred to the
desired signal, while the transmitted signal from the local
relaying transmitter is the self-interference signal. Because
transmission and reception in a full-duplex system occur at the
same time and in the same frequency band, the self-
interference signal is mixed with the desired signal, leading to
a signal corruption at the receiver of the relay. Thus, it is
crucial that the self-interference signal is suppressed in the
relay node before the desired signal is amplified and
forwarded to the destination. By now many techniques to
suppress self-interference signals have been researched. In the
pioneering work by Everett et al. [4], passive self-interference
cancellations, including directional isolation, absorptive
shielding and cross-polarization, are studied. Besides, self-
interference techniques in the RF domain for different
transmission bandwidths are investigated in [5–9]. In the
digital domain, self-interference techniques to handle residual
self-interference after the analog-to-digital converter are
considered in [10–12]. Most of the existing cancellation
methods depend on the reconstruction of the self-interference
(SI) signal and then subtracting it from the received signal to
extract the desired signal. In contrast, the polarization-enabled
digital self-interference cancellation (PDC) scheme proposed
by Liu et al. [13] distinguishes the self-interference signal
from the desired signal in the polarized domain and cancels
the self-interference using an oblique projection. However,
this proposal does not consider the energy harvesting
mechanism and is not applied to relaying systems. To the best
of our knowledge, no works, especially in the polarized
domain, have considered the performance of self-interference
cancellation methods in the full-duplex relaying system with
RF energy harvesting. Given that both full-duplex
communications and RF energy harvesting are important
emerging technologies for 5G systems, performance
evaluation of full-duplex energy harvesting relaying networks
is of considerable importance. This is the motivation of our
paper.
In this paper, we consider a dual-hop full-duplex relaying
system, where the relaying node harvests the RF energy from
the source node, then uses this energy to amplify and forward
the signal to the destination. We assume there is no direct link
between the source node and the destination node. Thus, the
relay is used to assist the transmission from the source to the
destination. We also assume that the time switching method
[3], [14] is used at the relay to harvest the RF energy and the
PDC scheme is used to cancel self-interference at the relay.
The main contributions of the paper are summarized as
follow:
We investigate the throughput of an in-band full-
duplex relaying system assisted by RF energy
harvesting and the PDC self-interference
cancellation. We consider the throughput based on
the fraction of time α used to harvest energy for a

range of SNR and modulation methods. We show
that the maximum throughput appears at a lower
range of α values for a higher SNR, while this
optimal α is invariant for different modulation
methods. This observation means that, to achieve a
high throughput, a joint combination of a high SNR
value and a low α value is expected.
We examine the system bit error rate (BER)
performance under the impacts of RF energy
harvesting and the PDC self-interference
cancellation. It is revealed that, for the same SNR,
the BER performance of the system only improves
slightly when α increases. Combined with the above
observation, this result means that the energy
harvesting scheme can be optimized to improve
significantly the system throughput without
impacting the BER performance of the PDC self-
interference cancellation scheme.
We quantify the impact of the energy harvesting and
PDC scheme on the BER performance in comparison
with the half-duplex energy harvesting relaying
system. Our results show that the PDC scheme can
effectively cancel the self-interference in the full-
duplex system at the cost of a slight increase of noise.
In particular, if the relay transmission power (per
symbol) is the same in both full-duplex and half-
duplex systems, the BER performance curve of the
former is within 2 dB inferior compared to that of the
latter. Thus, applying the PDC cancellation scheme
to achieve a high throughput and reasonable BER for
our full-duplex energy harvesting relaying systems
seems feasible.
The rest of paper is organized as follows. In Section ,
the system model is presented. In Section , the signal model
for the polarization-enabled digital self-interference
cancellation scheme is described. The simulation results and
performance analysis are presented in Section . Section
concludes the paper.
II. S
YSTEM
M
ODEL
In this paper, the dual-hop in-band full-duplex relaying
system with energy harvesting at the relay node is considered.
We assume that there is no direct link between the source node
and the destination node. Thus, an intermediate relay is used
to assist the transmission from the source to the destination as
shown in Fig. 1. The system has a single source node, a relay
node, and a destination node. Denote a
1
to a
4
as orthogonally
dual-polarized antennas, in which the antennas a
1
and a
3
are
used for transmission, while a
2
and a
4
are used for reception.
The flat-fading channel gains from the source to the relay and
from the relay to the destination are denoted as h

and h

,
and the distances between them are presented as d
1
and d
2
respectively. As the system is a full duplex one, the relay is
able to receive signals from the source while transmitting
signals to the destination at the same time in the same
frequency band. Thus the local transmit antenna a
3
generates
self-interference (SI) signals in the same frequency band,
which will be mixed with the desired signal at the receive
antenna a
2
. Denoteh

as the propagation coefficient of the SI
channel which is assumed to follow a Rayleigh distribution.
The PDC scheme [13] is applied at the relay to cancel self-
interference signals.
In addition, the relay node is equipped with the time
switching-based relaying (TSR) protocol [3], [14] for energy
harvesting and information processing. The full-duplex TSR
protocol is depicted in Fig. 2. The whole signal block lasting
T (seconds) is divided into an energy harvesting section and
an information transmitting section. We define α, where 0 < α
< 1, as the fraction of time in which the relay harvests the
energy from its received signals. Thus, αT time is used for the
energy harvesting and the remaining block time (1-α)T is used
to transmit the desired signal in a full-duplex transmission
mode. The intermediate relay harvests energy from the RF
signal transmitted from the source within the duration αT. We
assume that energy harvesting is carried out without any limit
on the minimum power level of the received RF signal. Then,
the relay uses the harvested energy as a source of transmitting
power to amplify and forward the source information to the
destination within the duration (1-α)T. Besides, the PDC
scheme is activated during this period to cancel the SI signal.
After SI cancellation, the resulting signal is amplified by the
relay before being forwarded to the destination. Finally, the
received signal at the destination is detected by the maximum
ratio combining (MRC) method.
III. S
IGNAL
M
ODEL
Define x() and z() as the desired signal from the source
and the self-interference signal from the relay transmitter at
the time instant n, respectively. Define n
() as the additive
white Gaussian noise at the relay with the variance of σ
2
.
Denote m as the path loss exponent, P
as the source transmit
power, and P
i
as the interference power at the receive antenna
of the relay. The channel coefficients are presented in Fig.1.
Then, in a conventional non-polarized full-duplex system, the
received temporal signal
r
() at the relay is
r
() =
P
h

x
(
)
+
P
h

z() + n
() (1)
However, in this paper, since the orthogonally dual-
polarized antennas are used to transmit and receive the
polarized signals, the relay receives the polarized signals, each
of which has a horizontally polarized component (H) and a
vertically polarized component (V). Denote the polarization
states (PS) of the desired signal and self-interference signal as
S and I respectively. The bold letters in this paper represent
vectors.
Fig. 1. Full-duplex relaying system model
Fig. 2. Full-duplex TSR protocol for energy harvesting and information
processing

= [cos (
) sin (
)exp (j
)]
= [H
i
V
i
]
T
(2)
= [cos (
) sin (
)exp (j
)]
T
= [H
s
V
s
]
T
(3)
where ε
i/s
[0,π/2] is the polarized angle and
i/s
[0,2π]
describes the phase difference between the horizontal
polarized component and the vertical polarized one. Clearly,
and I
are unit vectors, i.e.,
=1 and
=1, where (.)
T
represents transpose and (.)
H
represents Hermitian
transposition. Thus, in the polarized system, the polarized
received signal at the relay node, namely the input signal of
the PDC scheme, can be written as
Y() = X() + Z() + N()
=
P
h

x
(
)
+
P
h

z() +󰇣
n
n
󰇤 (4)
where n
is the horizontal component of n
() and n
is its
vertical component. The component n
and n
are
independent complex Gaussian random variables with zero
mean and the variance of σ
2
/2.
The signal Y() is then processed by the PDC scheme. The
PDC scheme has two steps, namely oblique projection and
scalarization. The objective of the oblique projection is to
cancel the self-interference. The scalarization aims to
transform a signal vector to a scalar form. The oblique
projection operator 

is derived as [13]


=
󰇟

󰇠
󰇣


󰇤
󰇣
󰇤
=(
H
+
)
−1
H
+
(5)
where P
I
+
= E – I (I
H
I)
-1
I
H
, (.)
+
represents pseudo-inverse, E
represents an identity matrix, and 0 is a zero vector. It is
proved in [13] that 

has the property of


󰇟
,
󰇠
=
󰇟

󰇠
(6)
Thus,


Y() = 

(X() + Z() + N())
= 

P
s
h
sr
x()
+
P
i
h
si
z()
+
()
=
P
h

x()+ 

() (7)
In order to transform the polarization vector to the scalar form,
both sides of (7) are multiplied with
and note that
=
1. The output signal y() of the PDC scheme is
y()=
(

Y())
=
P
h

x()+


() (8)
Then, the signal y() is amplified and forwarded by the
relay node to the destination. Since the relay node is powered
by the energy harvesting technique, the transmission power P
of the relay node depends on the energy harvesting time αT
and the source transmission power P
. Denote the unit-power
signal transmitted from the source node as s
(), the received
signal
e
() at the relay during the harvesting time is
e
(
)
=
P
h

s
() + n
() (9)
Hence, using (9), the harvested energy at the relay within
duration αT can be expressed as
E
αT
󰇡

|

|
+
σ
p
2
󰇢
(10)
where 0 <η< 1 is the energy conversion efficiency and σ
is
the variance of the noise


() in (8).
The transmit power P
of the relay in the remaining duration
(1α)T in the full-duplex system is calculated as
P
=
()
=

()
󰇡

|

|
p
2
󰇢
(11)
The PDC output signal y
(
)
in Eq. (8) is amplified to the
power P
by the relay.
The transmitted signal at the relay
x
() is
x
() =
()
|

|

=


()
h

x()+

()


() (12)
The received signal y
() at the destination is
y
() =

h

x
(
)
+ n
()
=


()
h

h

x()
+

()
h
rd


()+ n
() (13)
where n
() is the AWGN at the destination with the variance
of σ
2
.
The signal y
(
)
is then processed by the maximum ratio
combining (MRC) detection method. Denote (.)* as the
complex conjugate, the resulting signal y

() used for
demodulation is
y

() = h

h

y
()
=h

h

ηαP
s
(1−α)d
1
m
d
2
m
h
sr
h
rd
x()
+ h

h


ηα
(1−α)d
2
m
h




()+n
() (14)
IV. S
IMULATION
R
ESULTS
In this section, simulation results are presented to reveal
the throughput and BER performances of both half-duplex
harvesting relaying system and full-duplex energy harvesting
relaying system. In Part A, we investigate the impact of SNR
and modulation scheme on the system throughput when the

Citations
More filters
Journal ArticleDOI
03 Jan 2020-Sensors
TL;DR: Experimental results validate the theoretical analyses presented in previous publications on the ALMS loop behaviors and propose a practical structure and presents an implementation of the AlMS loop.
Abstract: Self-interference (SI) is the key issue that prevents in-band full-duplex (IBFD) communications from being practical. Analog multi-tap adaptive filter is an efficient structure to cancel SI since it can capture the nonlinear components and noise in the transmitted signal. Analog least mean square (ALMS) loop is a simple adaptive filter that can be implemented by purely analog means to sufficiently mitigate SI. Comprehensive analyses on the behaviors of the ALMS loop have been published in the literature. This paper proposes a practical structure and presents an implementation of the ALMS loop. By employing off-the-shelf components, a prototype of the ALMS loop including two taps is implemented for an IBFD system operating at the carrier frequency of 2.4 GHz. The prototype is firstly evaluated in a single carrier signaling IBFD system with 20 MHz and 50 MHz bandwidths, respectively. Measured results show that the ALMS loop can provide 39 dB and 33 dB of SI cancellation in the radio frequency domain for the two bandwidths, respectively. Furthermore, the impact of the roll-off factor of the pulse shaping filter on the SI cancellation level provided by the prototype is presented. Finally, the experiment with multicarrier signaling shows that the performance of the ALMS loop is the same as that in the single carrier system. These experimental results validate the theoretical analyses presented in our previous publications on the ALMS loop behaviors.

13 citations

Journal ArticleDOI
TL;DR: Analysis and simulation results show that the proposed FD relaying system by utilizing a proper time split fraction can boost the system throughput significantly over an appreciable range of transmitting SNR values, compared to half-duplex (HD) relaying systems.
Abstract: In this article, we consider a dual-hop full-duplex (FD), amplify-and-forward, orthogonal frequency division multiplexing (OFDM) relaying network, where the relay operates based on a time-switching architecture to harvest energy from radio frequency signals. We use a polarization-enabled digital self-interference cancellation (PDC) scheme to cancel the self-interference signal at the relay in order to achieve FD communications. The paper provides a comprehensive analysis of the system performances in terms of outage probability and throughput over multipath Rayleigh fading channels. Furthermore, the optimal time split between the duration of energy harvesting and signal transmission to maximize the system throughput is numerically calculated. We also derive the asymptotic lines to simplify the expressions of outage probability and throughput at high transmit signal-to-noise ratios (SNR). Our analysis and simulation results show that the proposed FD relaying system by utilizing a proper time split fraction can boost the system throughput significantly over an appreciable range of transmitting SNR values, compared to half-duplex (HD) relaying systems.

5 citations


Cites background or methods from "Performance Evaluation of Full-Dupl..."

  • ...However, [18] does not derive the analytical expressions of outage probability and throughput and only considers flat-fading channels with a single carrier system....

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  • ...The work in [18] simulates the throughput and BER performances of a FDEH relaying system in comparisonwith those of a HD EH relaying system....

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  • ...To enable FD communication in our system, we adopt the FD time switching-based relaying (TSR) protocol in [14], [18], hence the whole communication process includes two phases as shown in Fig....

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Proceedings ArticleDOI
01 Sep 2019
TL;DR: In this paper, the performance of in-band full- duplex OFDM relaying systems with energy- harvesting and self-interference cancellation in the polarization domain is analyzed and it is revealed that the optimal time splitting factor should be less than 0.3 to maximize the full-duplex system throughput.
Abstract: In this paper, the performance of in-band full- duplex OFDM relaying systems with energy- harvesting and self-interference cancellation in the polarization domain is analyzed. Specifically, we use the time switching-based relaying protocol to implement energy harvesting. The harvested energy is used by the relay to forward the transmitted information from the source. To cancel the self-interference, the polarization-enabled digital self-interference cancellation scheme is deployed at the relay. Our simulation results show that the full-duplex OFDM energy harvesting relaying system almost doubles the throughput, while maintaining the same bit error performance by a modest increase in the signal-to-noise ratio compared to the half-duplex OFDM energy harvesting relaying system. It is also revealed that the optimal time splitting factor should be less than 0.3 to maximize the full-duplex system throughput.

3 citations


Cites background from "Performance Evaluation of Full-Dupl..."

  • ...However, [8], [9] do not consider the multipath propagation and OFDM mechanism....

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  • ...The proposed polarization-enabled digital self-interference cancellation (PDC) scheme in [8], [9] is efficient to cancel the interference in FD systems, which distinguishes and cancels the unexpected SI signal from the desired information signal....

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  • ...Denote Pr as the average harvested power per symbol at the relay [9], and ....

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Journal ArticleDOI
TL;DR: In this paper, the authors investigated a two-hop communication system in which the source utilizes radio frequency (RF) energy harvesting for the transmission of information and the intermediate relay works in a half-duplex (HD) mode in the energy harvesting (EH) phase to provide energy to the source.
Abstract: In this paper, we investigate a two-hop communication system in which the source utilizes radio frequency (RF) energy harvesting for the transmission of information. An intermediate relay works in a half-duplex (HD) mode in the energy harvesting (EH) phase to provide energy to the source. In the information transmission phase, the relay works in a full-duplex (FD) mode to receive information signals from the source and simultaneously transmit information signals to the destination in the same frequency band. The paper provides the analysis of outage probability and throughput of a FD relaying system and two HD relaying systems. The first HD system ( $HD_{1}$ ) has the same EH duration as the FD system while the second HD one ( $HD_{2}$ ) has the same transmitting power from the source as the FD one. The results show that the throughput with respect to the time split between the EH phase and the information transmission one is a concave function and the optimal time split can be calculated numerically. Besides, the polarization dissimilarity factor of the antennas used has an influence on the system throughput, which is maximized when polarization states are orthogonal. The FD system can double the system throughput while having the outage probability as low as that of the $HD_{1}$ system, at a cost of adopting the extra polarization-enabled digital cancellation (PDC) scheme. Meanwhile, the FD system can nearly double the system throughput while having the outage probability superior to that of the $HD_{2}$ system. Simulations are run to confirm the above analyses.
References
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Journal ArticleDOI
TL;DR: The numerical analysis provides practical insights into the effect of various system parameters, such as energy harvesting time, power splitting ratio, source transmission rate, source to relay distance, noise power, and energy harvesting efficiency, on the performance of wireless energy harvesting and information processing using AF relay nodes.
Abstract: An emerging solution for prolonging the lifetime of energy constrained relay nodes in wireless networks is to avail the ambient radio-frequency (RF) signal and to simultaneously harvest energy and process information. In this paper, an amplify-and-forward (AF) relaying network is considered, where an energy constrained relay node harvests energy from the received RF signal and uses that harvested energy to forward the source information to the destination. Based on the time switching and power splitting receiver architectures, two relaying protocols, namely, i) time switching-based relaying (TSR) protocol and ii) power splitting-based relaying (PSR) protocol are proposed to enable energy harvesting and information processing at the relay. In order to determine the throughput, analytical expressions for the outage probability and the ergodic capacity are derived for delay-limited and delay-tolerant transmission modes, respectively. The numerical analysis provides practical insights into the effect of various system parameters, such as energy harvesting time, power splitting ratio, source transmission rate, source to relay distance, noise power, and energy harvesting efficiency, on the performance of wireless energy harvesting and information processing using AF relay nodes. In particular, the TSR protocol outperforms the PSR protocol in terms of throughput at relatively low signal-to-noise-ratios and high transmission rates.

1,644 citations


"Performance Evaluation of Full-Dupl..." refers background in this paper

  • ...The path loss exponent is m = 4, the source-relay distance d1 and relay-destination distance d2 are 1 meter, and the energy harvesting efficiency is set to be η = 1 [1], [2]....

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  • ...For example, the work in [1], [2] investigates relaying systems with wireless energy harvesting....

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Journal ArticleDOI
TL;DR: In this article, two relaying protocols, namely, time switching-based relaying (TSR) and power splitting-based relay (PSR), are proposed to enable energy harvesting and information processing at the relay.
Abstract: An emerging solution for prolonging the lifetime of energy constrained relay nodes in wireless networks is to avail the ambient radio-frequency (RF) signal and to simultaneously harvest energy and process information. In this paper, an amplify-and-forward (AF) relaying network is considered, where an energy constrained relay node harvests energy from the received RF signal and uses that harvested energy to forward the source information to the destination. Based on the time switching and power splitting receiver architectures, two relaying protocols, namely, i) time switching-based relaying (TSR) protocol and ii) power splitting-based relaying (PSR) protocol are proposed to enable energy harvesting and information processing at the relay. In order to determine the throughput, analytical expressions for the outage probability and the ergodic capacity are derived for delay-limited and delay-tolerant transmission modes, respectively. The numerical analysis provides practical insights into the effect of various system parameters, such as energy harvesting time, power splitting ratio, source transmission rate, source to relay distance, noise power, and energy harvesting efficiency, on the performance of wireless energy harvesting and information processing using AF relay nodes. In particular, the TSR protocol outperforms the PSR protocol in terms of throughput at relatively low signal-to-noise-ratios and high transmission rate.

1,443 citations

Proceedings ArticleDOI
01 Nov 2010
TL;DR: If the self-interference is cancelled in the analog domain before the interfering signal reaches the receiver front end, then the resulting full-duplex system can achieve rates higher than the rates achieved by a half-dulex system with identical analog resources.
Abstract: We study full-duplex wireless communication systems where same band simultaneous bidirectional communication is achieved via cancellation of the self-interfering signal Using off-the-shelf MIMO radios, we present experimental results that characterize the suppression performance of three self-interference cancellation mechanisms, which combine a different mix of analog and digital cancellation Our experimental results show that while the amount of self-interference increases linearly with the transmitted power, the self-interference can be sufficiently cancelled to make full-duplex wireless communication feasible in many cases Our experimental results further show that if the self-interference is cancelled in the analog domain before the interfering signal reaches the receiver front end, then the resulting full-duplex system can achieve rates higher than the rates achieved by a half-duplex system with identical analog resources

977 citations

Journal ArticleDOI
TL;DR: These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.
Abstract: Recent research results have demonstrated the feasibility of full-duplex wireless communication for short-range links. Although the focus of the previous works has been active cancellation of the self-interference signal, a majority of the overall self-interference suppression is often due to passive suppression, i.e., isolation of the transmit and receive antennas. We present a measurement-based study of the capabilities and limitations of three key mechanisms for passive self-interference suppression: directional isolation, absorptive shielding, and cross-polarization. The study demonstrates that more than 70 dB of passive suppression can be achieved in certain environments, but also establishes two results on the limitations of passive suppression: (1) environmental reflections limit the amount of passive suppression that can be achieved, and (2) passive suppression, in general, increases the frequency selectivity of the residual self-interference signal. These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.

794 citations


"Performance Evaluation of Full-Dupl..." refers background in this paper

  • ...[4], passive self-interference cancellations, including directional isolation, absorptive shielding and cross-polarization, are studied....

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Journal ArticleDOI
TL;DR: This paper proposes two tight SM capacity upper bounds and presents the solution of the optimal time split ratio for the maximum system throughput according to the proposed upper bound and conducts Monte-carlo simulations to reveal the throughput gain of the proposed SM-FD relaying protocol.
Abstract: We consider a dual-hop full-duplex relaying system, where the energy constrained relay node is powered by radio frequency signals from the source using the time-switching architecture, both the amplify-and-forward and decode-and-forward relaying protocols are studied. Specifically, we provide an analytical characterization of the achievable throughput of three different communication modes, namely, instantaneous transmission, delay-constrained transmission, and delay tolerant transmission. In addition, the optimal time split is studied for different transmission modes. Our results reveal that, when the time split is optimized, the full-duplex relaying could substantially boost the system throughput compared to the conventional half-duplex relaying architecture for all three transmission modes. In addition, it is shown that the instantaneous transmission mode attains the highest throughput. However, compared to the delay-constrained transmission mode, the throughput gap is rather small. Unlike the instantaneous time split optimization which requires instantaneous channel state information, the optimal time split in the delay-constrained transmission mode depends only on the statistics of the channel, hence, is suitable for practical implementations.

374 citations

Frequently Asked Questions (1)
Q1. What contributions have the authors mentioned in the paper "Performance evaluation of full-duplex energy harvesting relaying networks using pdc self-interference cancellation" ?

In this paper, throughput and bit error performance of an in-band full duplex ( IBFD ) relaying system assisted by the radio frequency energy harvesting technique and the polarization-enabled digital selfinterference cancellation ( PDC ) scheme are investigated. The authors also show that to achieve a high throughput along with a good error performance in the full-duplex energy harvesting relaying system, a combined selection of a high signalto-noise ratio and a suitable energy harvesting time is required.