Inter
national
J
our
nal
of
Electrical
and
Computer
Engineering
(IJECE)
V
ol.
11,
No.
6,
December
2021,
pp.
5588
5600
ISSN:
2088-8708,
DOI:
10.11591/ijece.v11i6.pp5588-5600
r
5588
Efficient
radio
r
esour
ce
allocation
scheme
f
or
5G
netw
orks
with
de
vice-to-de
vice
communication
F
ar
eha
Nizam
1
,
Mardeni
Roslee
2
,
Zubaida
Y
usoff
3
,
Prince
Ugochukwu
Nmenme
4
,
K
eshvinder
Singh
5
,
Hafizal
Mohamad
6
,
Anwar
F
aizd
Bin
Osman
7
,
Ibraheem
Abdullah
Mohammed
Shay
ea
8
1,2,3,4,5
F
aculty
of
Engineering,
Multimedia
Uni
v
ersity
,
Cyberjaya,
Malaysia
6
F
aculty
of
Engineering
and
Built
En
vironment,
Uni
v
ersiti
Sains
Islam
Malaysia
7
Spectre
Solutions
Sdn
Bhd,
Malaysia
8
F
aculty
of
Electrical
and
Electronics
Eng.
Electronics
and
Communication
Eng.
Dep.
Istanb
ul
T
echnical
Uni
v
ersity
(ITU),
Istanb
ul,
T
urk
e
y
Article
Inf
o
Article
history:
Recei
v
ed
Oct
24,
2020
Re
vised
Mar
24,
2021
Accepted
Jun
8,
2021
K
eyw
ords:
De
vice
to
de
vice
communication
FFR
Hung
arian
Interference
minimization
L
TE
ABSTRA
CT
A
vital
technology
in
the
ne
xt-generation
cellul
ar
netw
ork
is
de
vice-to-de
vice
(D2D)
communication.
Cellular
user
enabled
with
D2D
communication
pro
vides
high
spec-
tral
ef
ficienc
y
and
further
increas
es
the
co
v
erage
area
of
the
cell,
especially
for
the
end-cell
users
and
blind
spot
areas.
Ho
we
v
er
,
the
im
plementation
of
D2D
commu-
nication
increases
interference
among
the
cellular
and
D2D
users.
In
t
his
paper
,
we
proposed
a
ra
dio
resource
allocation
(RRA)
algorithm
to
manage
the
interference
using
fractional
frequenc
y
reuse
(FFR)
scheme
and
Hung
arian
algorithm.
The
proposed
al-
gorithm
is
di
vided
into
three
parts.
First,
the
FFR
scheme
allocates
dif
ferent
frequenc
y
bands
among
the
cell
(inner
and
outer
re
gion)
for
both
the
cellular
and
the
D2D
users
to
reduce
the
int
erference.
Second,
the
Hung
arian
weighted
bipartite
matching
algo-
rithm
is
used
to
allocate
the
resources
to
D2D
users
with
the
minimum
total
system
interference,
while
maintaining
the
total
system
sum
rate.
The
cellular
users
share
the
resources
with
more
than
one
D2D
pair
.
Lastly
,
the
local
search
technique
of
sw
apping
is
used
for
further
allocation
to
minimize
the
interference.
W
e
implemented
tw
o
types
of
assignments,
f
air
multiple
assignment,
and
restricted
multiple
assignment.
W
e
com-
pared
our
results
w
ith
e
xisting
algorithms
which
v
erified
that
our
proposed
algorithm
pro
vides
outstanding
results
in
aspe
cts
lik
e
interference
reduction
and
system
sum
rate.
F
or
restricted
multiple
assignment,
60-70%
of
the
D2D
users
are
allocated
in
a
v
erage
cases.
This
is
an
open
access
article
under
the
CC
BY
-SA
license
.
Corresponding
A
uthor:
Mardeni
bin
Roslee
F
aculty
of
Engineering
Multimedia
Uni
v
ersity
Persiaran
Multimedia
63100,
Cyberjaya,
Selangor
Email:
mardeni.roslee@mmu.edu.my
1.
INTR
ODUCTION
An
e
xponential
boost
in
the
subscriber
base
and
multimedia
services
are
e
vident
in
the
last
tw
o
decades
which
moti
v
ated
the
de
v
elopment
of
ne
w
technologies
such
as
massi
v
e
MI
MOs,
small
cells
and
millimeter
w
a
v
es
in
order
to
boost
the
speed
and
data
rate,
and
decrease
the
latenc
y
of
the
system
[1]-[4].
One
of
the
k
e
y
technology
being
discussed
under
3rd
generation
partnership
program
(3GPP)
is
de
vice-to-de
vice
(D2D)
communication.
This
ne
w
paradigm
enables
tw
o
de
vices
to
connect
to
one
another
without
transv
ersing
from
J
ournal
homepage:
http://ijece
.iaescor
e
.com
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5589
the
e
v
ol
v
ed
node
base
station
(eNb).
This
deli
v
ers
high
system
throughput,
lo
w
load
at
the
eNB,
impro
v
ement
in
spectral
ef
ficienc
y
,
and
lo
w
consumption
of
transmit
po
wer
,
all
of
which
are
desirable
features
of
long
tern
e
v
olution-adv
anced
(L
TE-A)
[5]-[9].
Figure
1
sho
ws
the
D2D
communication
in
multi-tier
cells
in
HetNets.
The
spectrum
allocation
in
D2D
communication
is
cate
gorized
into
tw
o
modes:
underlay
and
o
v
erlay
.
The
main
objecti
v
e
of
underlay
communication
mode
is
to
permit
the
D2D
users
to
reuse
of
cellular
user
resource.
Deplo
yment
of
such
communication
mode
impro
v
es
the
spectrum
ef
ficienc
y
,
ener
gy
ef
ficienc
y
as
well
as
co
v
erage
area,
b
ut
increases
the
interference
among
cellular
and
D2D
users,
and
between
D2D
users
which
becomes
a
b
urden
on
the
netw
ork
[10]-[12].
Ov
erlay
communication
mode
grants
the
D2D
users
to
share
the
orthogonal
resources
of
the
cellular
users
in
a
w
ay
that
the
spectrum
is
di
vided
to
optimally
allocate
resources
among
the
cellular
and
the
D2D
users.
Although
there
is
minimal
interference
in
this
mode,
there
is
a
w
astage
of
the
spectrum
if
proper
radio
resource
allocation
(RRA)
scheme
is
not
implemented
in
the
netw
ork
[10],
[12]-[14].
Figure
1.
D2D
communication
in
multi-tier
cells
in
heterogeneous
netw
orks
Interference
management
is
the
main
moti
v
ation
when
considering
the
underlay
spectrum
[15].
The
reuse
of
the
spectrum
by
D2D
pairs
interposes
and
imposes
interference
to
w
ards
the
eNb
and
the
cellular
users.
The
cellular
users
can
also
introduce
the
interference
to
w
ards
the
D2D
pairs
which
af
fects
the
ef
ficienc
y
and
connecti
vity
between
D2D
links.
This
interference
relies
on
the
shared
channel
of
the
cellular
users
which
is
in
do
wnlink
(DL)
and
uplink
(UL)
phases.
The
as
signment
of
the
channel,
therefore,
is
compulsory
for
interference
management
in
D2D
communication.
Currently
,
numerous
open-ended
projects
are
in
progress
which
are
considering
distinct
aspects
of
the
D2D
communication
lik
e
increasing
the
sum
rate
of
the
system,
minimizing
the
system
interf
erence,
and
maintaining
the
transmit
po
wer
of
the
D2D
transmitter
[16]-[19].
Ne
v
ertheless,
the
cellular
users
are
preferred
o
v
er
the
D2D
users
by
the
netw
ork
pro
vider
to
lo
wer
the
interference
caused
to
the
cellular
users
[20].
In
order
to
resolv
e
this
concern,
an
ef
fecti
v
e
RRA
technique
must
be
e
x
ecuted
for
assignment
of
resource
blocks
(RBs)
to
the
D2D
pairs.
The
proposed
algorithms
in
the
recent
res
earch
of
RRA
concluded
that
when
the
resources
of
the
cellular
user
is
shared
with
D2D
p
a
irs,
the
sum
rate
of
the
user
is
impro
v
ed
[21]-[23].
Ho
we
v
er
,
these
techniques
may
also
minimize
the
system’
s
total
sum
rate
[24]-[25].
Considering
all
the
w
ork
done
pre
viously
,
this
paper
aims
to
manage
the
interference
in
the
underlay
spectrum
D2D-aided
cellular
netw
orks.
The
system
model
aims
to
opportunistically
assigns
radio
resources
such
that;
i)
The
cellular
netw
ork
maintains
the
system’
s
tar
get
sum
rate,
ii)
The
system
reduces
the
interference.
The
major
contrib
utions
of
this
paper
are
as
follo
ws:
a.
W
e
implemented
fractional
frequenc
y
reuse
(FFR)
scheme
in
the
D2D-aided
cellular
netw
ork
with
se
v
en
cells
for
the
purpose
of
allocating
cellular
users
resources
to
the
D2D
pairs
with
minimum
interference.
b
.
W
e
considered
f
air
as
well
as
restricted
multiple
assignment
schemes.
In
the
f
air
multiple
assignment,
the
system
allocates
all
the
D2D
users
present
in
the
system
at
that
moment
to
ce
llular
users
while
in
the
restricted
multiple
assignment,
the
D2D
users
will
be
block
ed
in
case
the
total
sum
rate
of
the
system
is
lesser
than
the
tar
get
sum
rate.
c.
W
e
implemented
a
Hung
arian-weighted
bipartite
matching
allocation
algorithm
for
one-to-one
matching
to
mitig
ate
the
interference
further
while
maintaining
the
sum
rate.
In
the
case
where
the
sum
rate
is
Ef
ficient
r
adio
r
esour
ce
allocation
sc
heme
for
5G
networks
with...
(F
ar
eha
Nizam)
Evaluation Warning : The document was created with Spire.PDF for Python.
5590
r
ISSN:
2088-8708
not
maintained,
we
applied
one-to-man
y
matching
to
increase
the
sum
rate.
Finally
,
we
applied
a
local
technique
kno
wn
as
sw
apping
to
impro
v
e
the
result
from
the
pre
vious
phase.
This
paper
is
further
or
g
anised
as
follo
ws:
Section
2
gi
v
es
an
o
v
ervie
w
of
resource
allocation
in
D2D-aided
cellular
netw
ork
and
frame
w
ork
of
the
proposed
algorithm.
Section
3
discusses
the
simulation
outcomes
for
performance
e
v
aluation,
in
v
arious
aspects,
of
the
algorithm
proposed.
Lastly
,
section
4
presents
the
conclusion
of
this
paper
.
2.
O
VER
VIEW
OF
RESOURCE
ALLOCA
TION
IN
D2D-AIDED
CELLULAR
NETW
ORKS
The
main
aim
of
resource
allocation
in
D2D
communication
is
to
distrib
ute
the
cellular
user
resources
to
D2D
users
ef
ficiently
and
ef
fecti
v
ely
.
This
section
sho
ws
the
proposed
system
model
of
resource
allocation.
2.1.
D2D
communication
system
model
In
our
system
m
odel
scenario,
underlay
D2D-aided
cellular
netw
ork
w
as
deplo
yed,
that
reuses
the
fre-
quenc
y
spectrum
of
the
cellular
users
in
the
UL
communication.
The
eNb
and
the
D2D
recei
v
er
will
encounter
the
interference
by
the
D2D
transmitter
and
the
cellular
users,
respecti
v
ely
.
W
e
considered
se
v
en
he
xagonal
cells
with
a
eNb
situated
in
the
centre
of
each
cell.
F
or
the
reduction
of
interference,
FFR
scheme
is
also
con-
sidered.
Each
cell
is
partitioned
into
outer
and
inner
cell
re
gions.
The
frequenc
y
band,
F
,
is
di
vided
into
four
se
gments:
F
1
,
F
2
,
F
3
,
and
F
4
with
each
se
gment
corresponding
to
a
bandwidth:
f
1
,
f
2
,
f
3
,
and
f
4
,
respecti
v
ely
.
The
eNb
assigns
the
resources
to
the
each
de
vice
present
in
the
cell’
s
inner
and
outer
re
gion
with
the
frequenc
y
reuse
f
actor
(FRF):
1
and
3,
respecti
v
ely
.
The
system
supports
the
cellular
and
D2D
users,
where
the
cellular
users
are
>
the
D2D
de
vices.
T
o
minimize
the
interference
caused
by
the
neighboring
cells,
F
1
frequenc
y
is
utilized
by
the
cellul
ar
users
present
in
the
cell’
s
inner
re
gion
while
F
2
,
F
3
,
or
F
4
is
used
by
the
cellular
user
present
in
the
cell’
s
outer
re
gion.
The
set
of
the
cellular
users
are
labeled
a
s
N
=
f
n
1
;
n
2
;
n
3
;
:::::;
n
n
g
while
the
set
of
D2D
pairs
are
defined
as
R
=
f
r
1
;
r
2
;
r
3
;
:::::;
r
n
g
.
T
ables
1
and
2
sho
ws
the
parameters
considered
and
list
of
abbre
viations
used
in
the
paper
,
respecti
v
ely
.
RRA
for
D2D
users
is
implemented
in
dif
ferent
w
ays
based
on
the
position
of
the
users.
T
able
1.
Simulation
parameters
P
arameter
V
alue
Radius
of
the
cell
1
km
Cellular
users
250
FRF
-
inner
re
gion
1
FRF
-
outer
re
gionF
3
D2D
pairs
10
-
200
(increment
of
20)
Distance
between
D2D
pairs
(max)
15
meters
Bandwidth,
B
180
kHz
Base
station
transmission
po
wer
46
dBm
D2D
user
transmission
po
wer
20
dBm
Cellular
user
transmitting
po
wer
20
dBm
Frequenc
y
1.7
GHz
T
ar
get
Sum
rate
Sum
rate
(optimal
achie
v
able)
[9]
A
WGN
-174
dBm
2.1.1.
Outer
r
egion-D2D
users
In
the
outer
part
of
the
cell,
the
D2D
pairs
are
assigned
to
reuse
the
cellular
users’
resources
that
are
currently
present
in
the
cell’
s
inner
part
only
.
Only
F
1
can
be
utilized
by
the
D2D
users
present
in
the
cell’
s
outer
re
gion.
The
interference
to
these
D2D
pairs
are
from
all
the
cellular
and
D2D
users
present
at
the
cell’
s
outer
and
inner
re
gion
(co-channel
interference),
respecti
v
ely
.
2.1.2.
Inner
r
egion-D2D
users
In
the
inner
part
of
the
cell
,
the
D2D
pairs
currently
present
in
the
e
xperience
interference
from
three
re
gions;
i)
From
the
co-channel
D2D
pairs
in
the
same
cell,
ii)
the
co-channel
D2D
pairs
in
the
inner
part
of
the
tw
o
third
of
the
other
cells
and
iii)
the
co-channel
cellular
users
present
in
the
outer
part
of
the
one
third
of
the
other
cells.
In
this
w
ork,
Rayleigh
f
ading
model
w
as
considered.
Orthogonal
channels
and
separate
RBs
for
each
cellular
user
were
implemented.
W
e
e
xpressed
cellular
and
D2D
pairs
as
n
i
and
r
j
,
respecti
v
ely
.
Note:
1
i
n
and
1
j
r
.
Int
J
Elec
&
Comp
Eng
,
V
ol.
11,
No.
6,
December
2021
:
5588
–
5600
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5591
T
able
2.
T
able
of
abbre
viation
Abbre
viation
Description
d
distance
between
the
D2D
transmitter
and
recei
v
er
f
c
transmission
frequenc
y
P
m;n
path
loss
between
de
vice:
m
and
n
m
and
n
the
transmitting
de
vice
and
recei
ving
de
vice
respecti
v
ely
I
nt
system
interference
T
S
system
sum
rate
(total)
W
i;j
a
binary
channel
allocation
decision
matrix
P
n
i
cellular
user
transmitting
po
wer
P
r
j
t
)
D2D
user
transmitting
po
wer
C
hannel
Gain
n
i
;eN
B
channel
g
ain
(cellular
user
to
the
base
station)
C
hannel
Gain
r
j
t
;eN
B
channel
g
ain
(interference
by
the
D2D
transmitter
to
the
base
station)
C
hann
el
Gain
r
j
t
;r
j
r
channel
g
ain
(D2D
transmitter
-
D2D
recei
v
er)
C
hannel
Gain
n
i
;r
j
r
the
channel
g
ain
(cellular
user
and
-
D2D
recei
v
er)
B
bandwidth
of
the
channel
n
i
;r
j
SINR
(eNB)
n
i
;
0
SINR
for
the
cellular
users
who
are
allo
wing
the
sharing
of
resources
with
an
y
D2D
user
,
r
j
;n
i
SINR
for
D2D
recei
v
er
when
reusing
the
resources)
P
ath
loss
model
used
is
(1):
P
=
36
:
7
log
10
(
d
)
+
26
log
10
(
f
c
)
+
22
:
7
(1)
Achie
v
able
channel
g
ain
for
the
transmission
can
be
written
as
(2):
C
hannel
Gain
(
m;n
)
=
10
(
P
m;n
=
10)
(2)
2.2.
Pr
oblem
f
ormulation
The
FFR
scheme
using
the
assignment
algorithm
for
the
UL
RRA
is
proposed.
The
assignment
scheme
indicates
the
assignment
of
each
D2D
pair
with
a
resource
of
the
cellular
user
.
In
(3)
sho
ws
the
objecti
v
e
of
our
paper
,
which
is
to
mitig
ate
the
interference
of
the
system
concerning
the
constraints
(4),
(5),
(6)
and
(7).
minimiz
e
k
X
i
=1
l
X
j
=1
Y
i;j
I
n
t
n
i
;r
j
(3)
subject
to,
T
S
T
ar
g
etsumr
ate;
(4)
l
X
j
=1
W
i;j
2;
8
n
i
2
N
(5)
k
X
i
=1
W
i;j
=
1;
8
r
j
2
R
(6)
k
X
i
=1
W
i;j
1;
8
r
j
2
R
(7)
W
i;j
=
(
1
r
j
reused
the
resource
of
n
i
0
r
j
reused
the
resource
of
n
i
(8)
Although
the
e
xisting
algorithms
deal
with
the
same
problem
formulation,
the
y
consider
only
a
single
cell
interference
and
use
one
D2D
user
that
reuses
the
resource
of
one
cellular
user
in
order
to
a
v
oid
the
generation
of
higher
interference.
The
cellular
users
can
share
t
he
resources
to
a
maximum
of
tw
o
D2D
pairs
as
depicted
in
constraint
(5).
A
single
cellul
ar
user
must
share
the
resource
to
the
D2D
user
as
present
in
constraint
Ef
ficient
r
adio
r
esour
ce
allocation
sc
heme
for
5G
networks
with...
(F
ar
eha
Nizam)
Evaluation Warning : The document was created with Spire.PDF for Python.
5592
r
ISSN:
2088-8708
(6).
D2D
pair
can
reuse
the
resource
of
one
cellular
user
only
,
or
else,
the
D2D
pair
will
not
be
ass
igned
to
an
y
resource
as
sho
wn
in
constraint
(7).
In
our
system,
we
present
tw
o
types
of
assignments,
f
air
and
restricted.
Constraint
(5)
declares
that
the
system
implie
s
f
air
multiple
assignment
of
RRA,
where
all
the
D2D
pairs
are
assigned
to
cellular
users,
which
indicates
the
f
airness
feature
of
the
system.
Ho
we
v
er
,
in
some
cases
the
constraint
(5)
does
not
satisfy
,
thus
constraint
(6)
presents
the
res
tricted
multiple
assignment
where
the
system
assigns
the
D2D
users
with
cellular
user
resources
only
if
the
sum
rate
is
maintained.
Hence,
the
D2D
pair
is
allocated
resource
blocks
of
the
cellular
user
or
the
y
remain
unassigned
to
satisfy
the
total
system
sum
rate.
Signal
to
interference
plus
noise
ratio
(SINR)
for
the
uplink,
at
the
eNB,
while
the
D2D
pairs
reused
the
cellular
users
RBs
is
(9),
n
i
;r
j
=
P
n
i
C
h
an
nel
Gain
n
i
;eN
B
+
P
r
j
t
C
hannel
Gain
r
j
t
;eN
B
;
(9)
The
cellular
users
who
are
sharing
of
resources,
the
SINR
is:
n
i
;
0
=
P
n
i
C
h
an
nel
Gain
n
i
;eN
B
;
(10)
In
(11),
the
SINR
at
the
D2D
recei
v
er
is
sho
wn
in
cases
where
the
D2D
user
reused
the
resources.
r
j
;n
i
=
P
r
j
t
C
ha
n
nel
Gain
r
j
t
;r
j
r
+
P
n
i
C
hannel
Gain
n
i
;r
j
r
;
(11)
The
total
interference
that
is
produced
in
the
system
when
RBs
are
shared
to
the
D2D
users
is
presented
in
(12).
I
n
t
n
i
;r
j
=
P
r
j
t
C
h
an
nel
Gain
r
j
t
;eN
B
+
P
n
i
C
hannel
Gain
n
i
;r
j
r
(12)
Using
the
Shannon
capacity
formula,
we
calculated
the
system
sum
rate
(13),
in
ca
ses
when
D2D
pairs
reused
the
resource.
S
R
t
n
i
;r
j
=
B
l
og
2
(1
+
n
i
;r
j
)
+
B
l
og
2
(1
+
r
j
;n
i
)
(13)
The
sum
rate
when
the
resources
are
not
reused
is:
S
R
t
n
i
;
0
=
B
l
og
2
(1
+
n
i
;
0
)
(14)
T
aking
(13)
and
(14),
we
measured
the
o
v
erall
system
sum
rate.
T
S
=
k
X
i
=1
(1
l
X
j
=1
W
i;j
)
S
R
t
n
i
;
0
N
n
i
+
k
X
i
=1
l
X
j
=1
W
i;j
S
R
t
n
i
;d
j
N
n
i
(15)
2.3.
Pr
oposed
r
esour
ce
allocation
algorithm
f
or
D2D
communication
In
this
paper
,
we
proposed
the
RRA
assignment
using
the
FFR
sche
me
follo
wed
by
the
Hung
arian
weighted
bipartite
matching
approach
for
mitig
ation
of
interference
in
the
system.
In
this
part,
we
displayed
the
calculation
o
f
the
FFR,
the
de
v
elopment,
and
calcul
ation
of
the
weight
biparti
te
matching
graph,
and
the
algorithm
proposed
for
both,
f
air
multiple
assignment
as
well
as
restricted
multiple
assignment.
The
graph
compromises
of
tw
o
disjoints.
The
sets
of
v
ertices
are
N
=
f
n
1
;
n
2
;
n
3
;
:::::;
n
n
g
and
R
=
f
r
1
;
r
2
;
r
3
;
:::::;
r
n
g
.
Shannon
capacity
sum
rate
and
interference
in
the
system
are
the
edge
between
both
the
v
ertices.
The
D2D
pairs
and
the
cellular
users
are
the
columns
and
ro
ws
for
the
weigh
matrix,
respecti
v
ely
,
W
e
included
n
x
n
matrix
called
A
.
Only
a
square
matrix
is
considered
in
the
weight
bipartite
matrix.
The
cellular
user
>>
the
D2D
us
ers
hence,
we
introduced
dummy
D2D
users
that
will
not
influence
the
final
assignment
of
the
allocation.
F
or
the
f
air
multiple
assignment,
the
initial
m
columns
represent
the
interference
that
is
introduced
because
of
the
resource
sharing
between
D2D
pairs
and
cellular
users.
The
remaining
dummy
pairs
is
assigned
zero
v
alue
so
that
it
does
not
match
the
final
allocation.
F
or
the
restricted
multiple
assignment,
the
remaining
D2D
pairs
are
assigned
zero
v
alue,
so
that
it
does
not
match
the
final
solution.
Int
J
Elec
&
Comp
Eng
,
V
ol.
11,
No.
6,
December
2021
:
5588
–
5600
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5593
Lik
e
wise,
the
weight
matrix
for
the
sum
rate
maximizat
ion,
we
included
a
matrix:
m
x
m
called
B
.
F
or
the
f
air
multiple
assignment,
the
first
m
columns
presents
the
system
sum
rate
when
the
D2D
pair
reuse
the
resource
of
the
cellular
user
.
The
remaining
dummy
pairs
are
assigned
with
the
v
alue
of
the
sum
rate
calculated
in
(14),
which
implies
that
the
sum
rate
will
not
af
fect
the
final
allocation.
F
or
the
restricted
multiple
assignment,
the
remaining
D2D
pair
is
assigned
the
v
alue
of
the
sum
rate
calculated
in
(14).
This
ensures
that
the
matching
is
a
v
oided
with
the
dummy
pairs.
Algorithm
1
RRA-part
one
1:
Assigning
N
(
n
1
;
n
2
;
:::;
n
n
)
,
R
(
r
1
;
r
2
;
:::;
r
n
)
and
T
ar
g
etsumr
ate
2:
Consider
matrix
A
[
n;
n
]
and
matrix
B
[
n;
n
]
as
weight
matrix
for
the
weight
bipartite
matching
3:
A
i;j
=
S
R
n
i
;r
j
4:
B
i;j
=
I
n
i
;r
j
5:
f
or
all
i
2
C
do
6:
f
or
all
j
2
D
do
7:
Measure
the
interference
8:
end
f
or
9:
end
f
or
10:
Measure
T
S
using
Hung
arian
Minimization
Algorithm
(
B
i;j
)
11:
if
T
ar
g
etS
umr
ate
T
S
then
12:
Allocate
r
j
to
n
i
to
all
v
alues
of
(
B
i;j
)
13:
else
14:
Allocate
2
D2D
users
to
1
cellular
user
15:
Measure
ne
w
T
S
16:
end
if
17:
if
T
ar
g
etS
umr
ate
T
S
then
18:
Assign
r
j
ton
i
to
all
the
v
alues
of
(
B
i;j
)
19:
else
f
Measure
the
T
S
through
bipartite
weight
A
i;j
for
specific
f
air
or
restricted
multiple
assignment
g
20:
end
if
21:
if
T
ar
g
etS
umr
ate
Hung
arian
Maximization
Graph(A
i;j
)
then
22:
Allocate
r
j
to
n
i
for
all
the
v
alues
of
(
A
i;j
)
23:
end
if
2.3.1.
Interfer
ence
minimization
using
FFR
In
t
he
first
part
of
the
algorithm,
we
de
v
eloped
a
RRA
algorithm
for
D2D
communication
using
FFR.
In
e
v
ery
cell,
an
eNb
is
deplo
yed.
Ev
ery
cell
is
then
di
vided
into
the
inner
and
outer
parts.
The
cellular
user
present
in
the
inner
part
used
one
part
of
the
frequenc
y
band
while
the
users
in
the
outer
part
used
the
remaining
one
third.
T
aking
the
location
of
the
D2D
pair
in
the
cell,
the
resources
are
allocated.
The
outer
part’
s
D2D
user
reuse
the
resource
of
the
cellular
user
present
in
the
inner
part
and
vice
v
ersa.
The
frequenc
y
allocation
is
described
in
section
2.1.
2.3.2.
Minimizing
interfer
ence
in
the
system
using
Hungarian
appr
oach
Firstly
,
tw
o
sets
of
disjoint
v
alue
are
used
as
follo
ws:
N
(
n
1
;
n
2
;
:::;
n
n
)
and
R
(
r
1
;
r
2
;
:::;
r
n
)
.
The
total
interference
in
the
system
w
as
measured
using
these
disjoint
v
alues.
A
matrix
A
w
as
created
in
the
third
line.
W
e
ran
the
Hung
arian
algorithm
to
measure
the
total
interference.
The
edges
of
the
weight
presents
the
interference
of
the
system
when
D2D
users
reuse
the
resources
of
cellular
users.
The
calculati
o
n
of
the
inter
-
ference
is
done
based
on
the
selection
of
assignment,
that
is,
f
air
or
restrict
ed
multiple
assignment.
According
to
the
Hung
arian
algorithm,
the
D2D
pairs
are
then
assigned
to
the
cellular
users.
This
result
is
considered
the
final
allocation
unless
the
sum
rate
is
not
achie
v
ed.
Thus,
in
the
ne
xt
phase,
we
use
Hung
arian
maximization
to
increase
the
system
sum
rate.
This
is
done
to
check
the
allocation
for
an
y
assignment
where
the
sum
rate
is
increased.
W
e
introduce
a
matrix
B
to
measure
the
maximum
sum
rate.
The
Hung
arian
algorithm
then
allocates
the
D2D
to
the
cellular
users
if
the
sum
rate
is
maintained.
Assuming
that
the
tar
get
sum
rate
is
<
=
to
the
acquired
sum
rate,
we
will
tak
e
the
result
as
the
final
allocation,
otherwise,
we
confirm
that
there
is
no
solution.
The
allocation
is
t
hen
passed
to
the
ne
xt
part
of
the
algorithm,
where
the
initial
allocation
is
further
check
ed
to
reduce
the
system
interference.
After
multiple
Ef
ficient
r
adio
r
esour
ce
allocation
sc
heme
for
5G
networks
with...
(F
ar
eha
Nizam)
Evaluation Warning : The document was created with Spire.PDF for Python.
5594
r
ISSN:
2088-8708
sharing,
i
f
the
sum
rate
is
still
less,
the
Hung
arian
maximiz
ation
algorithm
is
implemented.
This
calculates
the
highest
sum
rate
for
that
case
to
get
the
optimal
solution.
In
case
of
an
optimal
solution,
we
consider
this
as
the
final
allocation
else
the
pre
vious
allocation
is
considered
final.
The
algorithm
is
sho
wn
in
algorithm:
RRA-part
one.
2.3.3.
Minimizing
interfer
ence
in
the
system
using
swapping
appr
oach
After
the
initial
assignment
of
the
D2D
users,
we
propose
a
local
sw
apping
approach
technique
to
minimize
the
interference
further
.
In
this
part,
we
considered
tw
o
D2D-cell
u
l
ar
user’
s
allocations
and
sw
ap
the
D2D
pairs
to
check
for
the
interference,
for
e
xample,
tw
o
user
n
1
,
n
2
and
r
1
,
r
2
.
W
e
sw
ap
the
D2D
pairs
with
each
ot
her
and
m
easured
the
interference
of
the
system
and
achie
v
ed
sum
rate.
If
the
interference
is
minimized,
the
system
ensures
that
the
sum
rate
is
greater
than
or
equal
to
the
tar
get
sum
rate.
If
both,
interference
and
the
sum
rate,
assignment
is
done
as
follo
ws:
n
1
to
r
2
,
and
n
2
to
r
1
.
This
allocation
is
considered
final,
otherwise,
the
allocation
in
the
pre
vious
step
is
considered
as
the
final
solution.
This
is
sho
wn
in
algorithm
for
sw
apping
approach-part
tw
o.
Algorithm
2
Algorithm
for
sw
apping
approach-part
tw
o
1:
f
or
entire
N
i;j
and
R
i;j
do
2:
sw
apping
n
i
r
i
and
n
j
r
j
to
n
i
r
j
and
n
j
r
i
3:
Measure
the
interference
4:
end
f
or
5:
if
T
ar
g
etS
umr
ate
<
=
update
sum
rate
then
6:
Allocate
n
i
to
r
j
and
n
j
to
r
i
7:
Re
vise
the
updated
system
interference
8:
end
if
3.
PERFORMANCE
EV
ALU
A
TION
3.1.
Pr
e
vious
algorithms
f
or
perf
ormance
obser
v
ation
The
same
problem
formulation
is
used
in
MIKIRA
[24].
The
authors
used
knapsack
based
interference
a
w
are
RRA.
MIKIRA
satisfies
the
constraints,
b
ut
the
assignment
is
not
f
air
for
the
D2D
user
.
Once
the
sum
rate
is
maintained,
the
system
blocks
the
RRA
for
the
D2D
pairs,
hence
lea
ving
a
gre
at
number
of
D2D
pairs
unassigned.
T
AFIRA
[25]
is
an
algorithm
using
the
same
problem
formulation.
The
authors
de
v
eloped
the
auction-based
algorithm.
Although
the
interference
is
minimized
and
the
sum
rate
is
maintained,
there
are
instances
where
the
algorithm
f
ails
to
pro
vide
an
y
feasible
solution,
although
the
solution
e
xists.
D2D
pairs
are
randomly
assigned
to
cellular
users
without
implementing
an
y
interference
management
schemes.
3.2.
System
description
The
parameters
sho
wn
earlier
is
follo
wed
for
the
system
setup.
W
e
manipulated
with
se
v
eral
parame-
ters
to
v
erify
the
results.
In
the
setup,
we
used
7
cells.
Each
cell
radius
is
1000
m.
In
15
m
w
as
the
maximum
distance
between
the
D2D
link
(long
di
stances
minimize
the
benefits
of
implementing
D2D
communication).
Using
[9],
we
calculated
the
tar
get
sum
rate.
Ho
we
v
er
,
the
netw
ork
pro
vider
can
set
there
o
wn
tar
get
sum
rate.
The
result
of
multiple
iteration’
s
a
v
erages
w
as
used
for
each
result.
W
e
fix
ed
the
cellular
user
to
250
for
all
the
scenarios.
Ho
we
v
er
,
we
v
aried
the
cellular
users
to
v
erify
the
results.
It
w
as
observ
ed
that
the
results
were
consistent.
3.3.
System
interfer
ence
perf
ormance
of
D2D
communication
without
FFR
scheme
Belo
w
are
the
results
that
present
the
comparison
between
the
e
xisting
and
the
propos
ed
algorithm.
In
Figures
2(a)
and
2(b),
a
comparison
of
the
results
of
our
proposed
algorithm
of
only
one
cell
is
sho
wn.
The
results
are
compared
without
FFR.
Figure
2(a)
presents
that
the
system
interference
of
our
algorithm
is
much
lesser
than
T
AFIRA.
When
the
number
of
D2D
pairs
were
10,
the
total
system
interference
of
our
algorithm
w
as
-20
dBm,
while
for
T
AFIRA
and
random
allocation,
the
interference
is
-18
dBm
and
-14
dBm,
respecti
v
ely
.
As
the
number
of
D2D
pairs
is
increased,
it
can
be
observ
ed
that
the
interference
is
increased
as
well.
Ho
we
v
er
,
throughout
the
graph
pattern,
it
can
be
noted
t
hat
in
most
cases
our
algorithm
outperforms
other
algorithms.
The
circles
in
the
T
AFIRA
sho
w
the
instances
where
there
e
xist
a
feasible
results
b
ut
the
T
AFIRA
f
ailed
to
allocate
the
D2D
Int
J
Elec
&
Comp
Eng
,
V
ol.
11,
No.
6,
December
2021
:
5588
–
5600
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5595
users
while
maintaining
the
sum
rate.
In
the
proposed
algorithm,
all
the
D2D
users
were
assigned
resources.
In
Figure
2(b),
the
graph
sho
ws
the
comparison
of
interference
of
restricted
multiple
assignment,
MIKIRA,
and
random
al
location.
The
results
pro
v
e
that
e
v
en
without
FFR,
the
proposed
algorithm
is
sho
wing
better
results
than
the
e
xisting
algori
thms.
The
mark
ed
circles
sho
w
that
MIKIRA
does
not
pro
vide
feasible
solutions
e
v
en
when
the
solutions
e
xist.
These
results
prioritize
our
algorithm
since
our
algorithm
assigns
the
D2D
pair
for
all
the
e
xisting
solutions.
(a)
(b)
Figure
2.
Interference
in
the
system,
(a)
proposed
algorithm
vs
f
air
multiple
assignment,
(b)
proposed
algorithm
vs
restricted
multiple
assignment
3.4.
System
sum
rate
perf
ormance
of
D2D
communication
with
FFR
scheme
In
Figures
3(a)
and
3(b),
the
results
sho
w
the
normalized
system
sum
rate
of
our
algorithm.
The
comparison
in
this
section
e
v
aluates
that
the
system
sum
rate
has
boosted
when
the
number
of
D2D
pairs
w
as
increased
from
10
t
o
200.
Our
algorithm
outperformed
T
AFIRA
and
random
allocation
algorithm
for
the
f
air
multiple
assignment
(where
we
ensure
that
all
the
D2D
users
are
assigned
to
one
cellular
user)
and
MIKIRA
and
random
allocation
algorithm
for
the
restricted
multiple
assignment
(where
we
ensure
that
the
D2D
users
are
assigned
to
one
cellular
user
if
the
sum
rate
is
maintained
else
the
D2D
pair
remains
unassigned).
The
dif
ference
between
the
sum
rate
between
our
algorithm
and
T
AFIRA
is
v
ery
high.
In
Figure
3(a),
for
10
D2D
pairs,
the
normalized
system
sum
rate
is
1,
while
for
T
AFIRA
and
random
allocation
algorithm
normalized
sum
rate
is
0.924
and
0.917,
respecti
v
ely
.
Furthermore,
in
man
y
instances,
T
AFIRA
and
MIKIRA
f
ailed
to
allocate
the
feasible
solution
e
v
en
when
the
solution
e
xisted.
In
some
cases,
D2D
pairs
remain
unassigned
to
an
y
cellular
users
because
sharing
of
those
resources
with
the
D2D
pair
decreases
the
sum
rate.
The
simulation
ran
multiple
times
and
it
is
noticeable
that
for
restricted
multiple
assignment,
Figure
3(b),
about
60
to
70%
of
D2D
pairs
a
re
allocated
in
a
v
erage
cases.
It
is
also
noted
that
the
f
air
multiple
assignment
pro
vides
much
higher
interference
than
restricted
multiple
assignments.
This
is
due
to
the
f
act
that
in
restricted
multiple
assignment
some
of
the
D2D
pairs
are
not
allocated
to
the
cellular
users,
hence
minimizing
the
system
interference.
The
shape
of
the
graph
is
not
smooth
becaus
e
of
t
he
random
di
strib
ution
of
users
around
the
cell.
An
a
v
erage
for
20
runs
w
as
done
to
plot
the
graph
on
a
single
case
scenario.
The
single
plot
presents
multiple
cases.
3.5.
P
erf
ormance
of
D2D
pair
allocation
W
e
further
analyzed
our
system
to
check
for
the
al
location
of
D2D
links
in
the
restricted
multiple
as-
signment.
In
Figure
4(a)
(see
in
appendix),
we
compared
the
results
with
MIKIRA
and
our
proposed
algorithm,
with
and
without
FFR
scheme.
It
can
be
noted
that
in
all
the
cases,
our
algorithm
with
FFR
assigned
more
D2D
pairs
to
the
cellul
ar
user
,
while
maintaining
the
sum
rate
and
decreasing
the
interference,
than
MIKIRA.
In
all
the
cases,
e
v
en
the
algorithm
without
FFR
sho
ws
higher
results.
Ef
ficient
r
adio
r
esour
ce
allocation
sc
heme
for
5G
networks
with...
(F
ar
eha
Nizam)
Evaluation Warning : The document was created with Spire.PDF for Python.
5596
r
ISSN:
2088-8708
(a)
(b)
Figure
3.
T
otal
sum
rate,
(a)
proposed
algorithm
vs
f
air
multiple
assignment,
(b)
proposed
algorithm
vs
restricted
multiple
assignment
3.6.
P
erf
ormance
of
D2D
pair
allocation
at
the
cell-edge
In
Figure
4(b)
(se
e
in
appendix),
we
analyzed
the
cell-edge
D2D
pairs
to
v
erify
the
performance
of
the
system.
W
e
increased
the
D2D
pairs
present
at
the
cell-edge
to
compare
the
results
of
RR
A.
The
graph
sho
ws
that
our
algorithm
al
w
ays
allocates
most
of
the
D2D
pairs
with
our
propose
d
algorithm
with
FFR
scheme.
F
or
all
the
cases,
the
allocation
of
our
algorithm
without
FFR
is
still
higher
than
MIKIRA.
This
sho
ws
that
our
algorithm
sho
ws
superior
results
for
the
cell-edge
D2D
pairs.
4.
CONCLUSION
D2D
communication
is
a
technology
with
great
importance
for
future
communication
netw
orks.
Ho
w-
e
v
er
,
interference
management
is
crucial
for
introducing
this
paradigm
into
the
mark
et.
V
arious
algorithms
are
proposed
for
minimizing
interference,
increasing
the
data
rate,
and
impro
ving
spectral
ef
ficienc
y
.
RRA
algo-
rithm
using
the
FFR
scheme
along
with
the
Hung
arian
minimization/maximization
algorithm
for
mitig
ation
of
the
interference
while
controlling
the
sum
rate
is
proposed
in
this
paper
.
W
e
used
f
air
multiple
assignment
and
restricted
multiple
assignment
to
allocate
the
D2D
users
to
the
resources
of
the
cellular
users.
The
simulation
results
sho
ws
that
FFR
greatly
influence
the
throughput
of
the
system.
The
proposed
algorithm
minimized
the
Int
J
Elec
&
Comp
Eng
,
V
ol.
11,
No.
6,
December
2021
:
5588
–
5600
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5597
interference
while
the
sum
rate
w
as
maintained.
Most
of
the
cell-edge
users
were
co
v
ered
when
FFR
scheme
w
as
applied
with
our
proposed
algorithm
unlik
e
con
v
entional
algorithms.
F
or
the
future
w
ork,
we
plan
on
as-
signing
multiple
D2D
pairs
to
one
cellular
user
and
one
D2D
pai
r
to
multiple
cellular
users
to
further
increase
the
sum
rate.
Ho
we
v
er
,
this
will
require
comple
x
interference
management
techniques.
APPENDIX
(a)
(b)
Figure
4.
Comparison
of
proposed
restricted
multiple
assignment
and
MIKIRA,
(a)
D2D
users,
(b)
cell
Egde
D2D
users
A
CKNO
WLEDGMENT
This
w
ork
is
supported
and
funded
by
the
Fundamental
Research
Grant
Scheme-FRGS
/1/2017/ICT03
/MMU/02/3,
Ministry
of
Higher
Education,
Malaysia.
REFERENCES
[1]
M.
Noura
and
R.
Nordin,
“
A
surv
e
y
on
interference
management
for
De
vice-to-De
vice
(D2D)
communication
and
its
challenges
in
5G
netw
orks,
”
J
ournal
of
Network
and
Computer
Applications,
v
ol.
71,
pp.
130-150,
2016,
doi:
10.1016/j.jnca.2016.04.021.
Ef
ficient
r
adio
r
esour
ce
allocation
sc
heme
for
5G
networks
with...
(F
ar
eha
Nizam)
Evaluation Warning : The document was created with Spire.PDF for Python.