I
n
t
e
r
n
at
ion
al
Jou
r
n
al
of
E
lec
t
r
ical
an
d
Com
p
u
t
e
r
E
n
gin
e
e
r
in
g
(
I
JE
CE
)
Vol.
15
,
No.
1
,
F
e
br
ua
r
y
20
25
,
pp.
480
~
492
I
S
S
N:
2088
-
8708
,
DO
I
:
10
.
11591/i
jec
e
.
v
15
i
1
.
pp
4
80
-
492
480
Jou
r
n
al
h
omepage
:
ht
tp:
//
ij
e
c
e
.
iaes
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c
om
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e
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gl
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ay a
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ip
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ase
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Chet
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a
De
vi
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1
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alod
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Vis
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wanat
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P
an
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u
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Rao
2
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D
e
pa
r
tm
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nt
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ngi
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r
in
g, F
a
c
ul
ty
of
E
ngi
ne
e
r
in
g
a
nd
T
e
c
hnol
ogy,
J
A
I
N
(
D
e
e
me
d
-
to
-
be
U
ni
ve
r
s
it
y)
,
B
e
nga
lu
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ndi
a
2
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e
pa
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tm
e
nt
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g, F
a
c
ul
ty
of
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ngi
ne
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r
in
g
a
nd
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e
c
hnol
ogy, J
A
I
N
(
D
e
e
me
d
-
to
-
be
U
ni
ve
r
s
it
y
)
,
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e
nga
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I
ndi
a
Ar
t
icle
I
n
f
o
AB
S
T
RA
CT
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r
ti
c
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h
is
tor
y
:
R
e
c
e
ived
J
un
6,
2024
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e
vis
e
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4,
2024
Ac
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m
fo
r
G
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o
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red
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ce
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l
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h
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So
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-
b
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y
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effi
ci
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an
d
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rce
s
.
Co
mp
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s
s
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o
w
s
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h
at
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e
p
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p
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s
ed
me
t
h
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d
es
m
o
re
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e
d
s
am
p
l
e
s
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few
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d
ro
p
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s
am
p
l
e
s
,
an
d
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er
d
at
a
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s
s
rat
e,
c
o
n
f
i
rmi
n
g
i
t
s
effec
t
i
v
en
e
s
s
i
n
b
o
o
s
t
i
n
g
G
N
SS
s
i
g
n
a
l
p
ro
ce
s
s
i
n
g
rel
i
ab
i
l
i
t
y
an
d
eff
i
ci
e
n
cy
.
K
e
y
w
o
r
d
s
:
B
a
s
e
ba
nd
pr
oc
e
s
s
ing
F
ield
-
pr
ogr
a
mm
a
ble
ga
te
a
r
r
a
y
Globa
l
na
vigation
s
a
telli
te
s
ys
tem
S
ignal
a
c
quis
it
ion
S
of
twa
r
e
-
de
f
ined
r
a
dio
S
ys
tem
-
on
-
c
hip
T
r
a
c
king
a
c
c
ur
a
c
y
Th
i
s
i
s
a
n
o
p
en
a
c
ces
s
a
r
t
i
c
l
e
u
n
d
e
r
t
h
e
CC
B
Y
-
SA
l
i
ce
n
s
e.
C
or
r
e
s
pon
din
g
A
u
th
or
:
C
he
tna
De
vi
Kh
De
pa
r
tm
e
nt
of
E
lec
tr
onics
E
ng
inee
r
ing,
F
a
c
ult
y
of
E
nginee
r
ing
a
nd
T
e
c
hnology
,
J
AI
N
(
De
e
med
-
to
-
b
e
Unive
r
s
it
y)
45
th
km
,
NH
-
209,
J
a
kka
s
a
ndr
a
P
os
t,
B
e
nga
lur
u
-
Ka
na
ka
pur
a
R
d,
B
e
nga
lur
u
,
Ka
r
na
taka
562112
,
I
n
dia
E
mail:
c
hois
iwon.
kh@gmail
.
c
om
1.
I
NT
RODU
C
T
I
ON
T
he
global
na
vigation
s
a
telli
te
s
ys
tem
(
GN
S
S
)
ha
s
be
c
ome
a
f
unda
menta
l
c
omponent
of
c
ontempor
a
r
y
na
vigation
a
nd
pos
it
ioni
ng
s
ys
tems
,
e
nc
ompas
s
ing
a
wide
r
a
nge
of
a
ppli
c
a
ti
ons
,
f
r
o
m
pe
r
s
ona
l
na
vigation
de
vice
s
to
the
moni
tor
ing
o
f
e
s
s
e
nti
a
l
inf
r
a
s
tr
uc
tur
e
[
1]
.
GN
S
S
tec
hnology
unde
r
pins
va
r
ious
c
r
it
ica
l
f
unc
t
ions
in
our
e
ve
r
yda
y
li
ve
s
,
includ
ing
tr
a
ns
por
tation
,
tele
c
omm
unica
ti
ons
,
a
nd
e
m
e
r
ge
nc
y
s
e
r
vice
s
,
e
ns
ur
ing
de
pe
nda
ble
a
nd
p
r
e
c
is
e
loca
ti
on
inf
o
r
mation
[
2]
.
As
r
e
li
a
nc
e
on
GN
S
S
incr
e
a
s
e
s
,
t
he
r
e
is
a
c
or
r
e
s
ponding
ne
e
d
f
o
r
e
nha
nc
e
d
pe
r
f
or
manc
e
,
pr
e
c
is
ion,
a
nd
r
e
s
il
ienc
e
in
GN
S
S
r
e
c
e
iver
s
.
s
of
twa
r
e
-
de
f
ined
r
a
dio
(
S
DR
)
ha
s
ga
ined
popular
it
y
a
s
a
f
lexible
a
nd
e
f
f
icie
nt
method
f
or
s
ignal
pr
oc
e
s
s
ing,
of
f
e
r
in
g
notable
be
ne
f
it
s
in
ter
ms
o
f
a
da
ptabili
ty
,
ve
r
s
a
ti
li
ty,
a
nd
c
os
t
-
e
f
f
e
c
ti
ve
ne
s
s
[
3]
.
S
DR
tec
hnology
a
ll
ows
the
im
pleme
ntation
of
r
a
dio
ha
r
dwa
r
e
c
a
pa
bil
it
ies
thr
o
ugh
s
of
twa
r
e
,
f
a
c
il
it
a
ti
ng
e
f
f
or
tl
e
s
s
upgr
a
de
s
a
nd
r
e
vis
ions
Evaluation Warning : The document was created with Spire.PDF for Python.
I
nt
J
E
lec
&
C
omp
E
ng
I
S
S
N:
2088
-
8708
E
nhanc
e
d
global
nav
igat
ion
s
atelli
te
s
y
s
tem
s
igna
l
pr
oc
e
s
s
ing
us
ing
.
.
.
(
C
he
tna
De
v
i
K
h)
481
without
r
e
quir
ing
a
ny
ha
r
dwa
r
e
a
lt
e
r
a
ti
ons
.
T
his
f
lexibil
it
y
is
pa
r
ti
c
ular
ly
a
dva
ntage
ous
f
or
GN
S
S
a
ppli
c
a
ti
ons
,
whe
r
e
it
is
c
r
uc
ial
to
a
da
pt
to
va
r
ious
s
ignal
c
ondit
ions
a
nd
r
e
quir
e
ments
.
T
he
ba
s
e
ba
nd
pr
oc
e
s
s
ing
unit
is
a
c
r
uc
ial
e
le
ment
in
a
GN
S
S
r
e
c
e
iver
,
pe
r
f
or
mi
ng
e
s
s
e
nti
a
l
f
unc
ti
ons
s
uc
h
a
s
s
ignal
a
c
qui
s
it
ion,
tr
a
c
king,
d
e
modul
a
ti
on,
a
nd
de
c
oding
of
na
vigation
da
ta
[
4]
.
T
he
e
f
f
icie
nc
y
of
the
ba
s
e
ba
nd
pr
oc
e
s
s
or
dir
e
c
tl
y
inf
l
ue
nc
e
s
the
ove
r
a
ll
e
f
f
e
c
ti
ve
ne
s
s
of
the
GN
S
S
r
e
c
e
iver
[
5]
.
T
r
a
dit
ionally,
a
ppli
c
a
ti
on
-
s
pe
c
if
ic
int
e
gr
a
ted
c
ir
c
u
it
s
(
ASI
C
s
)
or
digi
tal
s
ignal
p
r
oc
e
s
s
or
s
(
DSP
s
)
ha
ve
be
e
n
us
e
d
f
or
ba
s
e
ba
nd
pr
oc
e
s
s
ing
[
6]
.
How
e
ve
r
,
thes
e
methodologi
e
s
a
r
e
c
ons
tr
a
ined
by
thei
r
in
f
lexibil
i
ty,
high
powe
r
c
ons
umpt
ion,
a
nd
lengthy
de
ve
lopm
e
nt
ti
mes
.
f
ield
-
pr
ogr
a
mm
a
ble
ga
te
a
r
r
a
ys
(
F
P
G
As
)
a
r
e
incr
e
a
s
ingl
y
c
ons
ider
e
d
a
viable
opti
on
f
or
im
pleme
nti
ng
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hms
in
GN
S
S
r
e
c
e
iver
s
[
7]
.
F
P
GA
s
of
f
e
r
a
unique
c
ombi
na
ti
on
o
f
ha
r
dwa
r
e
e
f
f
icie
nc
y
a
nd
s
of
twa
r
e
a
da
ptabili
ty
,
making
th
e
m
idea
l
f
or
de
manding
s
ignal
pr
oc
e
s
s
ing
tas
k
s
.
T
he
r
e
pr
o
gr
a
mm
a
bil
it
y
of
F
P
GA
s
a
ll
ows
them
to
a
da
pt
to
va
r
ious
a
lgor
it
hms
a
nd
s
ignal
c
ondit
ions
,
pr
ovidi
ng
a
l
e
ve
l
of
f
lexibil
it
y
that
AS
I
C
s
or
c
onve
nti
ona
l
ha
r
dwa
r
e
s
olut
ions
c
a
nnot
matc
h
[
8]
.
Additi
ona
ll
y,
F
P
GA
s
c
a
n
a
c
hieve
high
leve
ls
of
pa
r
a
ll
e
li
s
m,
e
na
bli
ng
c
ompl
e
x
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hms
to
r
un
quickly
a
nd
ha
ndle
mor
e
da
ta
pr
oc
e
s
s
ing
powe
r
.
T
o
f
ull
y
ha
r
ne
s
s
the
be
ne
f
it
s
of
ut
il
izing
F
P
GA
s
f
or
GN
S
S
ba
s
e
ba
nd
pr
oc
e
s
s
ing,
it
is
ne
c
e
s
s
a
r
y
to
ove
r
c
ome
s
e
ve
r
a
l
obs
tac
les
.
I
mpl
e
menting
GN
S
S
ba
s
e
ba
nd
a
lgor
it
hms
on
F
P
GA
s
r
e
quir
e
s
a
t
hor
ough
unde
r
s
tanding
of
both
the
a
lgor
it
h
ms
thems
e
lves
a
nd
the
F
P
GA
ha
r
dwa
r
e
a
r
c
hit
e
c
tur
e
.
T
he
int
r
ica
te
na
tur
e
of
the
a
lgor
it
hms
,
a
long
with
the
li
mi
tations
im
pos
e
d
by
the
F
P
GA
ha
r
dwa
r
e
,
mi
ght
p
r
ovide
di
f
f
iculti
e
s
in
the
de
s
ign
a
nd
opti
mi
z
a
ti
on
pr
oc
e
s
s
.
One
big
pr
oble
m
is
ge
tt
ing
the
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hms
to
wor
k
pr
ope
r
ly
on
the
F
P
GA
f
a
br
ic
.
T
his
mea
ns
making
a
lgor
it
hms
that
make
the
be
s
t
us
e
of
F
P
GA
r
e
s
ou
r
c
e
s
li
ke
logi
c
c
omponents
,
memor
y
blocks
,
a
nd
DSP
s
li
c
e
s
while
mi
nim
izing
powe
r
us
e
a
nd
de
lay.
T
o
f
ind
thi
s
ba
lanc
e
,
one
mus
t
c
a
r
e
f
ull
y
c
ons
ider
the
pr
os
a
n
d
c
ons
of
dif
f
e
r
e
nt
de
s
ign
opti
ons
,
li
ke
picking
be
twe
e
n
f
ixed
-
point
a
nd
f
loating
-
point
math,
pipelini
ng
a
nd
pa
r
a
ll
e
li
s
m,
a
nd
ba
lanc
ing
pe
r
f
o
r
manc
e
with
r
e
s
our
c
e
a
ll
oc
a
ti
on.
Anothe
r
c
ha
ll
e
nge
is
ve
r
if
ying
a
nd
va
li
da
ti
ng
the
im
pleme
ntation
ba
s
e
d
on
F
P
GA
s
.
I
t
is
e
s
s
e
nti
a
l
to
ve
r
i
f
y
that
the
im
p
leme
nted
a
lgor
i
thm
s
s
a
t
is
f
y
the
ne
c
e
s
s
a
r
y
pe
r
f
or
manc
e
a
nd
a
c
c
ur
a
c
y
c
r
it
e
r
ia,
pa
r
ti
c
ular
ly
f
or
a
ppli
c
a
ti
ons
that
invol
ve
s
a
f
e
ty
-
c
r
it
ica
l
ope
r
a
ti
ons
.
T
his
ne
c
e
s
s
it
a
tes
thor
ough
s
im
ula
ti
on
a
nd
tes
ti
ng,
a
long
with
the
e
s
tablis
hment
of
r
e
s
il
ient
ve
r
if
ica
ti
on
p
r
oc
e
dur
e
s
.
T
h
e
m
a
i
n
g
oa
l
o
f
t
his
p
r
o
jec
t
is
to
c
r
e
a
te
a
nd
a
pp
ly
e
f
f
e
c
t
iv
e
ba
s
e
ba
nd
p
r
o
c
e
s
s
in
g
a
l
go
r
it
h
ms
f
o
r
GN
S
S
r
e
c
e
i
ve
r
s
ut
il
iz
in
g
F
P
GA
tec
hn
ol
og
y
.
I
de
n
ti
f
y
a
nd
c
h
oos
e
a
p
p
r
o
p
r
i
a
te
ba
s
e
ba
nd
p
r
oc
e
s
s
i
ng
a
l
go
r
it
h
ms
f
o
r
G
NS
S
r
e
c
e
iv
e
r
s
a
nd
m
od
i
f
y
t
he
m
f
o
r
e
f
f
ic
ie
nt
i
mp
le
me
nt
a
t
io
n
on
F
P
G
As
.
De
v
e
l
op
a
n
d
e
n
ha
n
c
e
the
c
h
os
e
n
a
lg
o
r
i
th
ms
f
o
r
F
P
GA
d
e
p
lo
ym
e
n
t
,
w
it
h
a
p
r
im
a
r
y
e
m
ph
a
s
is
on
i
m
pr
ov
in
g
e
f
f
i
c
i
e
nc
y
,
m
in
i
mi
z
i
ng
r
e
s
o
u
r
c
e
u
t
il
iz
a
t
io
n
,
a
nd
g
ua
r
a
nt
e
e
in
g
lo
w
p
ow
e
r
c
ons
um
pt
io
n
.
E
va
lu
a
te
t
he
e
f
f
i
c
a
c
y
of
t
he
i
mp
le
me
nt
e
d
a
l
go
r
i
t
hms
b
y
s
c
r
ut
in
iz
in
g
c
r
uc
ial
me
t
r
i
c
s
s
u
c
h
a
s
la
te
nc
y
,
t
h
r
o
ug
hp
u
t
,
r
e
s
o
u
r
c
e
ut
i
li
z
a
t
i
on
,
a
nd
po
we
r
c
ons
um
pt
i
on
.
T
his
r
e
s
e
a
r
c
h
is
im
por
tant
f
or
mul
ti
ple
r
e
a
s
ons
.
F
ir
s
tl
y,
it
tac
kles
the
incr
e
a
s
ing
r
e
quir
e
ment
f
or
GN
S
S
r
e
c
e
iver
s
that
a
r
e
both
high
-
pe
r
f
or
m
ing
a
nd
a
da
ptable
,
a
s
they
a
r
e
c
r
uc
ial
f
o
r
a
va
r
iety
of
a
ppl
ica
ti
ons
[
9]
.
B
y
uti
li
z
ing
the
f
lexibil
it
y
a
nd
pa
r
a
ll
e
l
p
r
oc
e
s
s
ing
c
a
pa
bil
it
ies
of
F
P
GA
s
,
thi
s
r
e
s
e
a
r
c
h
a
im
s
to
im
pr
ove
the
pe
r
f
or
manc
e
a
nd
a
da
ptabili
ty
o
f
GN
S
S
ba
s
e
ba
nd
pr
oc
e
s
s
or
s
.
T
his
e
nha
nc
e
ment
will
e
na
ble
thes
e
pr
oc
e
s
s
or
s
to
mee
t
the
r
e
quir
e
ments
of
c
ontempor
a
r
y
GN
S
S
a
ppli
c
a
ti
ons
.
F
ur
ther
mor
e
,
thi
s
r
e
s
e
a
r
c
h
e
nha
nc
e
s
the
f
ield
of
S
DR
by
s
howc
a
s
ing
the
pr
a
c
ti
c
a
li
ty
a
nd
a
dva
ntage
s
of
incor
por
a
ti
ng
int
r
ica
te
s
ignal
pr
oc
e
s
s
ing
a
lgor
it
hms
on
F
P
GA
platf
o
r
ms
.
T
his
r
e
s
e
a
r
c
h
e
xpa
nds
it
s
inf
luenc
e
be
yond
GN
S
S
r
e
c
e
iver
s
by
a
pplyi
ng
it
s
a
c
quir
e
d
knowle
dge
to
va
r
ious
ot
he
r
S
DR
a
ppli
c
a
ti
ons
.
Ul
ti
mate
ly,
thi
s
r
e
s
e
a
r
c
h
of
f
e
r
s
s
igni
f
ica
nt
knowle
dge
a
nd
a
ppr
oa
c
he
s
f
o
r
c
r
e
a
ti
n
g
a
nd
e
nha
nc
ing
F
P
GA
-
ba
s
e
d
s
ignal
pr
oc
e
s
s
ing
s
ys
tems
.
Othe
r
F
P
GA
-
ba
s
e
d
s
ys
tems
c
a
n
uti
li
z
e
the
de
s
ign
a
nd
opti
mi
z
a
ti
on
tec
hniques
de
ve
loped
in
th
is
s
tudy,
ther
e
by
making
a
va
luable
c
ontr
ibut
ion
to
the
wide
r
domain
o
f
digi
tal
s
ignal
pr
oc
e
s
s
ing
a
nd
F
P
GA
de
s
ign.
T
he
r
e
s
e
a
r
c
h
pr
e
s
e
nted
in
thi
s
s
tudy
c
ont
r
ibut
e
s
s
i
gnif
ica
ntl
y
to
the
f
ield
of
GN
S
S
s
ignal
pr
oc
e
s
s
ing.
I
t
a
c
hieve
s
thi
s
by
e
mpl
oying
F
P
GA
a
nd
s
ys
tem
-
on
-
c
hip
(
S
oC
)
-
ba
s
e
d
s
of
twa
r
e
r
e
c
e
iver
s
,
w
hich
a
r
e
ins
tr
umenta
l
in
im
p
r
oving
GN
S
S
s
ignal
pr
oc
e
s
s
ing.
T
he
f
i
r
s
t
a
s
pe
c
t
of
thi
s
wo
r
k
is
the
int
r
oduc
ti
on
of
a
nove
l
a
ppr
oa
c
h
to
im
pleme
nti
ng
GN
S
S
S
DR
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hms
on
F
P
GA
platf
or
ms
.
T
he
p
r
opos
e
d
method
uti
li
z
e
s
the
c
omput
a
ti
ona
l
powe
r
a
nd
f
lexibil
it
y
of
F
P
GA
s
to
im
pr
ove
the
pe
r
f
or
ma
nc
e
a
nd
a
da
ptabili
ty
of
GN
S
S
r
e
c
e
iver
s
.
T
his
e
na
bles
e
f
f
icie
nt
ha
ndli
ng
o
f
high
da
ta
r
a
tes
a
nd
c
ompl
e
x
s
ignal
pr
oc
e
s
s
ing
tas
k
s
,
whic
h
a
r
e
c
r
uc
ial
f
or
a
c
c
ur
a
te
GN
S
S
s
ignal
a
c
quis
it
ion
a
nd
tr
a
c
king.
T
he
r
e
s
e
a
r
c
h
dis
c
us
s
e
s
the
pr
oc
e
s
s
of
int
e
gr
a
ti
ng
the
AD
F
M
C
OM
M
S
3
-
E
B
Z
R
F
f
r
ont
e
nd
with
the
Z
ynq
7000
S
oC
boa
r
d
us
ing
a
high
-
s
pe
e
d
pa
r
a
ll
e
l
I
/O
int
e
r
f
a
c
e
.
T
his
int
e
gr
a
ti
o
n
is
de
s
c
r
ibed
in
de
tail.
T
he
in
tegr
a
ti
on
de
s
c
r
ib
e
d
he
r
e
f
a
c
il
it
a
tes
the
e
f
f
icie
nt
ha
ndli
ng
of
high
-
s
pe
e
d
s
a
mpl
e
d
da
ta,
r
e
s
ult
ing
in
a
de
pe
nda
ble
a
nd
r
e
s
il
ie
nt
GN
S
S
s
ignal
pr
oc
e
s
s
ing
s
y
s
tem.
T
he
us
e
of
the
S
P
I
in
c
onf
igur
a
ti
on,
mana
ge
ment,
a
nd
moni
tor
ing
im
pr
ove
s
the
s
ys
tem's
ove
r
a
ll
pe
r
f
or
manc
e
a
nd
f
lexibil
it
y
.
T
he
c
ompar
a
ti
ve
a
na
lys
is
be
twe
e
n
the
ba
s
e
li
ne
a
nd
pr
opos
e
d
a
ppr
oa
c
he
s
r
e
ve
a
ls
notable
e
nha
nc
e
ments
in
GN
S
S
s
ignal
p
r
oc
e
s
s
ing
pe
r
f
or
manc
e
.
T
he
pr
opos
e
d
a
ppr
oa
c
h,
whic
h
a
c
hieve
s
higher
r
e
c
e
ived
s
a
mpl
e
r
a
tes
,
s
ig
nif
ica
ntl
y
f
e
we
r
dr
oppe
d
s
a
mpl
e
s
,
a
nd
a
lowe
r
d
a
ta
los
s
pe
r
c
e
ntage
,
c
onf
i
r
ms
the
e
f
f
e
c
ti
ve
ne
s
s
of
the
p
r
o
pos
e
d
method
in
im
pr
oving
the
r
e
li
a
bil
it
y
a
nd
a
c
c
ur
a
c
y
of
GN
S
S
r
e
c
e
iver
s
.
I
n
a
ddit
ion,
the
r
e
s
e
a
r
c
h
o
f
f
e
r
s
a
c
ompr
e
he
ns
ive
a
s
s
e
s
s
ment
of
the
pe
r
f
o
r
manc
e
of
the
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2088
-
8708
I
nt
J
E
lec
&
C
omp
E
ng
,
Vol
.
15
,
No.
1
,
F
e
br
ua
r
y
20
25
:
480
-
492
482
GN
S
S
r
e
c
e
iver
by
e
mpl
oying
dif
f
e
r
e
nt
metr
ics
,
including
a
c
quis
it
ion
ti
me,
tr
a
c
king
a
c
c
ur
a
c
y,
r
e
s
our
c
e
uti
li
z
a
ti
on,
a
nd
powe
r
c
ons
umpt
ion
.
T
he
e
xpe
r
i
menta
l
r
e
s
ult
s
c
onf
i
r
m
the
s
upe
r
ior
it
y
of
the
S
oC
-
ba
s
e
d
GN
S
S
r
e
c
e
iver
c
ompar
e
d
to
tr
a
dit
ional
P
C
-
ba
s
e
d
im
pleme
ntations
.
T
h
is
e
mphas
ize
s
the
potential
of
the
S
oC
-
ba
s
e
d
GN
S
S
r
e
c
e
iver
f
o
r
r
e
a
l
-
ti
me
GN
S
S
a
pp
li
c
a
ti
ons
.
2.
RE
L
AT
E
D
WORKS
S
DR
a
ppr
oa
c
he
s
of
f
e
r
a
f
lexible
a
lt
e
r
na
ti
ve
to
the
r
e
s
tr
icte
d
a
da
ptabili
ty
c
omm
only
e
nc
ounter
e
d
in
c
onve
nti
ona
l
GN
S
S
r
e
c
e
iver
s
[
10
]
.
S
DR
tec
hnology
e
na
bles
e
xa
c
t
c
us
tom
iza
ti
on
to
f
ulf
il
indi
vid
ua
l
us
e
r
r
e
quir
e
ments
be
c
a
us
e
of
it
s
pr
ogr
a
mm
a
ble
a
nd
a
da
ptable
na
tur
e
.
M
or
e
ove
r
,
S
DR
pr
ov
ides
c
ompl
e
te
a
c
c
e
s
s
t
o
the
GN
S
S
r
e
c
e
iver
's
s
ignal
pr
oc
e
s
s
ing
c
ha
in,
a
ll
owing
us
e
r
s
to
e
xa
mi
ne
a
nd
a
lt
e
r
it
us
ing
f
r
e
e
a
nd
ope
n
-
s
our
c
e
s
of
twa
r
e
(
F
OSS
)
.
T
his
f
e
a
tur
e
e
na
ble
s
us
e
r
s
to
tailor
the
s
ys
tem
to
their
unique
ne
e
ds
a
nd
c
a
r
r
y
out
thor
ough
ins
pe
c
ti
ons
a
nd
modi
f
ica
ti
ons
,
f
r
e
e
f
r
om
the
c
ons
tr
a
int
s
of
pr
opr
ieta
r
y
s
ys
tems
.
T
h
e
powe
r
c
ons
umpt
ion,
phys
ica
l
dim
e
ns
ions
,
a
nd
c
os
t
o
f
S
DR
r
e
c
e
iver
s
a
r
e
thei
r
main
dis
a
dva
ntage
s
[
11]
.
An
im
por
tant
wo
r
r
y
r
e
volves
a
r
ound
the
e
ne
r
gy
c
o
ns
umpt
ion
of
e
mbedde
d
de
vice
s
.
S
e
ve
r
a
l
S
DR
r
e
c
e
iver
s
’
f
unc
ti
on
by
e
xe
c
uti
ng
s
of
twa
r
e
on
ve
r
s
a
ti
le
pr
oc
e
s
s
or
c
or
e
s
,
r
e
s
ult
ing
in
e
leva
ted
powe
r
c
ons
umpt
ion.
T
his
is
a
s
igni
f
ica
nt
is
s
ue
,
e
s
pe
c
ially
whe
n
us
ing
the
b
a
tt
e
r
y
f
o
r
e
xtende
d
pe
r
iods
,
a
s
the
e
xe
c
uti
on
of
int
r
ica
te
a
lgor
it
hms
c
a
n
r
a
pidl
y
de
plete
the
ba
tt
e
r
y.
T
he
r
a
pid
pr
ogr
e
s
s
in
s
of
twa
r
e
a
nd
ha
r
dwa
r
e
tec
hnologi
e
s
ha
s
gr
e
a
tl
y
e
xpe
dit
e
d
the
gr
owth
of
s
of
twa
r
e
ba
s
e
d
GN
S
S
r
e
c
e
iver
s
.
T
his
t
r
e
nd
is
e
vident
in
the
in
c
r
e
a
s
ing
number
o
f
textbooks
a
nd
s
c
holar
ly
a
r
ti
c
les
s
pe
c
if
ica
ll
y
f
oc
us
e
d
on
the
s
ubjec
t.
M
os
t
textbooks
p
r
im
a
r
il
y
e
mphas
ize
the
theor
e
ti
c
a
l
a
nd
pr
a
c
ti
c
a
l
e
leme
nts
of
GP
S
r
e
c
e
iver
s
,
s
pe
c
if
ica
ll
y
s
tr
e
s
s
ing
the
be
ne
f
i
ts
of
the
S
DR
method
[
12]
.
T
he
s
e
mate
r
ials
f
r
e
que
ntl
y
c
ons
is
t
of
M
AT
L
AB
im
pleme
ntations
that
s
howc
a
s
e
the
f
ull
c
a
pa
bil
it
y
of
a
GPS
r
e
c
e
iver
,
o
f
f
e
r
ing
pr
a
c
ti
c
a
l
i
l
lus
tr
a
ti
ons
to
e
nha
nc
e
theor
e
ti
c
a
l
unde
r
s
tanding
[
13]
.
Lu
[
14]
p
r
ovides
a
n
ove
r
view
o
f
methods
f
or
dua
l
-
s
y
s
tem
s
of
twa
r
e
r
e
c
e
iver
s
that
make
us
e
o
f
both
B
e
idou
a
nd
GPS
.
On
the
othe
r
ha
nd
,
B
or
r
e
[
15]
f
oc
us
e
s
on
the
de
s
ign
a
nd
f
unc
ti
ona
li
ty
o
f
s
of
twa
r
e
r
e
c
e
iver
s
that
s
uppor
t
s
e
ve
r
a
l
GN
S
S
s
ys
tems
a
nd
f
r
e
que
nc
ies
,
e
mpl
oying
s
ophis
ti
c
a
ted
methodologi
e
s
.
S
e
ve
r
a
l
pu
b
li
c
a
t
i
ons
p
r
ov
id
e
c
o
mp
r
e
he
ns
ive
in
f
o
r
ma
ti
on
on
th
e
de
s
i
gn
,
i
ns
ta
ll
a
t
io
n
,
a
n
d
f
i
r
s
t
e
va
lu
a
t
io
n
o
f
GN
S
S
S
DR
r
e
c
e
ive
r
s
.
T
h
e
s
e
s
ys
te
ms
d
i
f
f
e
r
in
te
r
m
s
o
f
th
e
i
r
i
nt
e
n
de
d
us
e
s
a
nd
t
he
u
nd
e
r
l
yi
ng
t
e
c
hn
ol
og
y
us
e
d
in
th
e
i
r
d
e
v
e
l
op
me
nt
.
S
o
f
twa
r
e
a
l
on
e
o
pe
r
a
tes
a
s
ubs
ta
nt
ia
l
p
o
r
t
i
on
o
f
th
e
s
e
d
e
v
ice
s
on
p
e
r
s
o
na
l
c
om
pu
te
r
s
o
r
o
th
e
r
c
o
mp
ut
in
g
p
lat
f
o
r
ms
[
1
6
]
.
S
e
ve
r
a
l
s
t
ud
ies
ha
ve
f
o
c
us
e
d
on
ma
ki
ng
F
P
GA
-
b
a
s
e
d
pl
a
tf
o
r
ms
f
o
r
q
ui
c
k
ly
pr
o
to
ty
pi
ng
G
NS
S
r
e
c
e
i
ve
r
a
l
go
r
i
th
ms
[
1
7
]
,
a
s
we
ll
a
s
pla
t
f
o
r
ms
t
ha
t
m
ix
F
P
GA
s
w
it
h
DS
P
s
[
1
8
]
.
R
e
c
e
nt
ly
,
mu
lt
i
pl
e
s
t
ud
ies
h
a
ve
p
r
o
pos
e
d
the
ut
i
li
z
a
t
io
n
o
f
S
oC
F
P
GA
-
b
a
s
e
d
de
s
ig
ns
f
o
r
c
e
r
ta
in
a
pp
li
c
a
ti
ons
.
T
h
e
s
e
de
s
ig
ns
ut
i
li
z
e
the
p
owe
r
f
ul
pa
r
a
l
le
l
p
r
oc
e
s
s
in
g
c
a
p
a
b
il
i
ti
e
s
a
nd
e
n
e
r
gy
e
f
f
i
c
i
e
nc
y
o
f
F
P
GA
s
,
in
a
dd
i
ti
on
t
o
t
he
f
lex
i
bi
li
t
y
o
f
e
m
be
dd
e
d
c
e
nt
r
a
l
p
r
oc
e
s
s
i
ng
un
i
t
s
(
C
P
U
s
)
[
19
]
.
T
he
F
P
G
A
in
t
he
s
e
s
ys
te
ms
e
xe
c
ut
e
s
th
e
m
os
t
d
e
m
a
n
di
ng
c
o
mp
u
ta
ti
ona
l
op
e
r
a
t
io
ns
,
wh
il
e
t
he
S
oC
p
r
oc
e
s
s
o
r
pe
r
f
o
r
ms
c
r
uc
ia
l
c
a
lc
ul
a
t
i
ons
r
e
la
te
d
t
o
G
NS
S
mea
s
u
r
e
me
nts
a
nd
na
vi
ga
ti
on
s
o
lu
ti
ons
.
F
or
i
ns
tan
c
e
,
a
r
e
c
e
iv
e
r
ba
s
e
d
on
a
S
oC
F
P
G
A
w
a
s
a
bl
e
to
e
f
f
e
c
t
iv
e
l
y
a
c
qu
i
r
e
a
nd
t
r
a
c
k
G
P
S
L
1
C
/A
s
a
te
ll
it
e
s
b
y
u
t
il
iz
in
g
s
t
o
r
e
d
s
ig
na
ls
,
a
s
s
ho
wn
in
a
s
tud
y
[
2
0
]
.
D
e
v
e
l
op
in
g
ba
s
e
b
a
n
d
p
r
o
c
e
s
s
in
g
te
c
h
ni
qu
e
s
f
o
r
GN
S
S
-
S
DR
a
p
pl
ica
t
io
ns
p
r
e
s
e
n
ts
n
ume
r
ous
no
ta
bl
e
di
f
f
i
c
u
lt
ies
d
ue
to
th
e
c
om
pl
e
x
c
ha
r
a
c
t
e
r
is
ti
c
s
o
f
G
NS
S
s
ig
na
l
s
a
n
d
the
s
ig
n
if
ic
a
n
t
c
om
pu
ta
ti
on
a
l
r
e
qu
i
r
e
men
ts
o
f
s
ig
na
l
p
r
oc
e
s
s
i
ng
[
21
]
.
GN
S
S
r
e
c
e
i
ve
r
s
us
e
b
a
s
e
ba
n
d
p
r
oc
e
s
s
i
ng
te
c
h
ni
qu
e
s
tha
t
in
vo
lv
e
c
om
pu
ta
ti
on
a
l
ly
de
m
a
n
d
in
g
t
a
s
k
s
li
ke
s
ig
na
l
a
c
q
u
is
i
ti
on
,
t
r
a
c
ki
ng
,
de
mo
du
la
ti
on,
a
nd
n
a
v
ig
a
t
io
n
s
o
lu
ti
on
e
s
t
im
a
t
io
n
.
T
o
d
e
l
iv
e
r
a
c
c
u
r
a
t
e
a
n
d
r
e
li
a
b
le
po
s
i
ti
on
in
g
a
n
d
ti
mi
ng
s
o
lu
t
io
ns
,
ba
s
e
ba
n
d
p
r
o
c
e
s
s
in
g
a
lg
o
r
i
th
ms
m
us
t
e
f
f
e
c
ti
ve
ly
m
it
i
ga
t
e
th
e
s
e
e
f
f
e
c
ts
.
Ne
v
e
r
t
he
les
s
,
th
e
i
nc
lus
io
n
o
f
pow
e
r
f
u
l
s
i
g
na
l
p
r
o
c
e
s
s
in
g
t
e
c
h
n
iq
ue
s
tha
t
c
a
n
e
f
f
ic
ien
t
ly
m
i
ni
m
ize
i
n
te
r
f
e
r
e
nc
e
w
hi
le
ma
in
ta
in
in
g
s
ig
na
l
i
nt
e
g
r
it
y
in
t
r
o
d
uc
e
s
i
n
tr
ic
a
c
y
to
a
lg
o
r
i
th
m
e
x
e
c
u
t
io
n
,
th
e
r
e
b
y
in
c
r
e
a
s
in
g
t
he
c
om
pu
ta
ti
on
a
l
l
oa
d
.
G
NS
S
-
S
DR
p
la
tf
o
r
ms
,
li
ke
F
P
GA
s
a
n
d
e
m
be
d
de
d
C
P
Us
,
t
yp
ic
a
l
ly
ha
ve
l
i
m
it
e
d
c
om
pu
ta
t
io
na
l
r
e
s
o
u
r
c
e
s
[
22
]
.
T
he
s
e
r
e
s
o
u
r
c
e
s
i
nc
lu
de
p
r
o
c
e
s
s
in
g
c
or
e
s
,
me
mo
r
y
,
a
n
d
in
pu
t/
ou
tp
u
t
i
nt
e
r
f
a
c
e
s
.
F
P
GA
s
a
c
h
ie
ve
hi
gh
t
hr
ou
gh
pu
t
a
nd
l
ow
la
ten
c
y
b
y
dis
t
r
i
bu
t
in
g
p
r
o
c
e
s
s
in
g
a
c
t
iv
it
ies
t
hr
ou
gh
ou
t
the
F
P
G
A
f
a
b
r
ic
,
s
uc
c
e
s
s
f
u
ll
y
mee
ti
ng
th
e
r
e
a
l
-
t
im
e
de
ma
nds
o
f
GN
S
S
-
S
DR
a
p
pl
ic
a
t
io
ns
[
2
3]
.
T
he
s
e
ha
r
dwa
r
e
s
y
s
te
ms
a
r
e
e
x
t
r
e
m
e
l
y
f
le
xi
b
le
,
e
n
a
b
l
in
g
im
me
d
iat
e
a
d
jus
tm
e
n
t
a
n
d
m
od
i
f
i
c
a
t
i
on
t
o
m
e
e
t
e
v
ol
vi
ng
c
o
mpu
ta
t
io
na
l
r
e
qu
i
r
e
men
ts
,
s
i
gna
l
c
ir
c
u
ms
t
a
n
c
e
s
,
a
n
d
a
p
pl
ica
t
io
n
s
c
e
na
r
i
os
.
T
he
m
e
n
ti
on
e
d
s
t
ud
ies
[
2
4
]
,
[
2
5
]
i
n
vo
lv
e
d
r
e
s
e
a
r
c
h
e
r
s
wh
o
c
o
nd
uc
ted
a
n
e
va
l
ua
ti
on
to
c
om
pa
r
e
t
he
q
ua
li
t
y
o
f
GN
S
S
obs
e
r
va
bl
e
s
ob
ta
in
e
d
th
r
o
ug
h
S
DR
t
e
c
hn
ol
og
y
w
it
h
th
os
e
ob
ta
ine
d
u
t
il
iz
in
g
a
s
pe
c
ia
li
z
e
d
U
-
bl
o
x
l
ow
-
c
os
t
r
e
c
e
iv
e
r
[
26
]
.
T
he
ir
ob
je
c
t
iv
e
w
a
s
t
o
a
s
c
e
r
t
a
i
n
t
he
a
t
ta
in
a
b
le
p
e
r
f
o
r
m
a
nc
e
le
ve
l
us
i
ng
a
n
e
xt
r
e
me
l
y
in
e
x
pe
ns
i
ve
S
DR
f
o
r
s
in
gl
e
-
p
oi
nt
loc
a
t
ion
a
nd
to
c
om
pa
r
e
i
t
w
it
h
t
he
pe
r
f
o
r
man
c
e
of
a
b
ud
ge
t
-
f
r
ie
nd
ly
GN
S
S
r
e
c
e
i
ve
r
.
3.
DE
VE
L
OP
M
E
N
T
OF
GNS
S
T
RA
NSMI
T
T
E
R
AN
D
RE
CE
I
V
E
R:
S
DR
AP
P
ROAC
H
T
he
f
ir
s
t
s
tep
in
a
pplyi
ng
the
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hms
is
to
tr
a
ns
mi
t
the
GN
S
S
s
ignal.
I
nit
ially,
we
c
r
e
a
te
a
bit
s
tr
e
a
m
to
r
e
pr
e
s
e
nt
the
digi
tal
da
ta
we
int
e
nd
to
tr
a
ns
f
e
r
.
Ne
xt,
we
e
nc
ode
the
Evaluation Warning : The document was created with Spire.PDF for Python.
I
nt
J
E
lec
&
C
omp
E
ng
I
S
S
N:
2088
-
8708
E
nhanc
e
d
global
nav
igat
ion
s
atelli
te
s
y
s
tem
s
igna
l
pr
oc
e
s
s
ing
us
ing
.
.
.
(
C
he
tna
De
v
i
K
h)
483
bit
s
tr
e
a
m
onto
a
c
ompl
e
x
a
r
r
a
nge
ment
of
point
s
in
the
s
ignal
s
pa
c
e
,
a
s
s
hown
in
F
igur
e
1.
T
his
modu
lation
is
a
c
hieve
d
us
ing
the
c
ons
tellation
modul
a
tor
block
of
the
GN
U
r
a
dio
f
r
a
mew
or
k.
T
his
block
a
ll
ow
s
f
or
the
c
us
tom
iza
ti
on
of
s
e
ve
r
a
l
c
ha
r
a
c
ter
is
ti
c
s
,
s
uc
h
a
s
the
type
a
nd
a
r
r
a
nge
ment
o
f
the
c
ons
tellation,
e
na
bli
ng
e
f
f
e
c
ti
ve
modi
f
ica
ti
on
of
the
br
oa
dc
a
s
t
s
ignal.
A
n
e
s
s
e
nti
a
l
f
a
c
tor
to
c
ons
ider
dur
ing
th
is
pr
oc
e
du
r
e
is
the
number
of
s
a
mpl
e
s
pe
r
s
ymbol
(
S
P
S
)
.
T
o
maintai
n
s
ync
hr
oniza
ti
on
be
twe
e
n
the
tr
a
ns
mi
tt
e
d
bit
r
a
te
a
nd
the
ha
r
dwa
r
e
de
vice
’
s
s
a
mpl
ing
r
a
te,
it
is
c
r
uc
ial
to
li
mi
t
the
S
P
S
va
lue.
How
e
ve
r
,
it
s
hould
not
go
be
low
a
pa
r
ti
c
ular
thr
e
s
hold,
us
ua
ll
y
s
e
t
a
t
a
mi
nim
um
o
f
2.
W
hil
e
thi
s
s
tage
us
e
s
s
im
ulation
ins
tea
d
of
r
e
a
l
-
ti
me
tr
a
ns
mi
s
s
ion,
maintaining
the
S
P
S
pa
r
a
mete
r
is
e
s
s
e
nti
a
l
f
or
p
r
e
s
e
r
ving
c
ohe
r
e
nc
e
thr
oughou
t
the
f
l
owgr
a
ph.
T
his
im
pleme
ntation
us
e
s
a
n
S
P
S
va
lue
o
f
4.
T
h
is
va
lue
not
only
e
xc
e
e
ds
the
mi
nim
um
r
e
quir
e
ment
but
a
ls
o
pr
ovides
a
ddit
ional
gr
a
nular
it
y
,
whic
h
is
a
dva
nta
ge
ous
f
or
a
na
lyzing
the
s
ignal
a
c
r
os
s
dif
f
e
r
e
nt
d
omains
.
Although
a
lowe
r
S
P
S
may
be
a
c
c
e
ptable
,
s
e
lec
ti
ng
a
va
lue
o
f
4
im
pr
ove
s
the
c
lar
it
y
a
nd
e
xa
mi
na
ti
o
n
of
the
br
oa
dc
a
s
t
s
ignal’
s
qua
li
ti
e
s
.
T
his
s
olut
ion
s
tands
out
due
to
it
s
meticulous
planning
a
nd
e
xe
c
uti
on
of
the
GN
S
S
s
ignal
tr
a
ns
mi
s
s
ion
pr
oc
e
s
s
us
ing
the
GN
U
R
a
dio
f
r
a
mew
or
k,
whic
h
a
ll
ows
f
or
e
xtens
ive
c
us
tom
iza
ti
on
a
nd
opti
mi
z
a
ti
on.
T
he
a
ppr
oa
c
h
gua
r
a
ntee
s
e
f
f
e
c
ti
ve
a
nd
pr
e
c
is
e
s
ignal
modul
a
ti
on
by
meticulous
ly
c
ho
os
ing
a
nd
a
djus
ti
ng
the
c
ons
tellation
modul
a
tor
block
a
nd
ot
he
r
c
r
uc
ial
pa
r
a
mete
r
s
.
Util
izing
a
n
S
P
S
va
lue
of
4,
a
lbeit
be
yond
the
mi
nim
a
l
r
e
qui
r
e
ment,
of
f
e
r
s
im
pr
ove
d
pr
e
c
is
ion
f
o
r
v
is
ua
li
z
ing
a
nd
a
na
lyzing
s
ignals
,
whic
h
is
e
s
s
e
nti
a
l
f
or
c
omp
r
e
he
nding
a
nd
e
va
luating
the
f
e
a
tur
e
s
of
the
tr
a
ns
mi
tt
e
d
s
ignal.
Ke
e
ping
the
S
P
S
pa
r
a
mete
r
in
the
im
pleme
ntation
make
s
s
ur
e
that
the
f
l
owgr
a
ph
s
tays
c
ohe
r
e
nt,
whic
h
s
hows
how
i
mpor
tant
s
ync
hr
oniza
ti
on
is
in
digi
tal
c
omm
unica
ti
on
s
y
s
tems
.
T
he
c
a
r
e
f
ul
s
tudy
of
e
xtr
a
ba
ndwidth
a
nd
ga
in
pa
r
a
mete
r
s
s
hows
de
dica
ti
on
to
bui
ldi
ng
a
s
tr
on
g
a
nd
r
e
li
a
ble
s
ignal
t
r
a
ns
mi
s
s
ion
s
ys
tem
that
c
a
n
ha
ndle
nois
e
a
nd
c
ha
nne
l
dis
tor
ti
ons
.
F
igur
e
1.
C
onf
igur
a
ti
on
of
the
GN
S
S
s
ignal
tr
a
ns
m
it
ter
us
ing
the
GN
U
r
a
dio
f
r
a
mew
or
k
F
igur
e
2
dis
plays
the
s
tr
uc
tu
r
e
o
f
the
GN
S
S
r
e
c
e
iv
e
r
,
whic
h
include
s
many
e
s
s
e
nti
a
l
c
omponents
f
or
a
c
c
ur
a
tely
de
c
oding
a
nd
de
modul
a
ti
ng
dif
f
e
r
e
nti
a
ll
y
c
ode
d
s
ignals
.
T
he
dif
f
e
r
e
nti
a
l
de
c
ode
r
block
is
a
c
r
uc
ial
c
omponent
a
t
the
c
or
e
of
th
is
s
ys
tem.
I
t
is
r
e
s
pon
s
ibl
e
f
or
de
c
oding
s
ignals
that
ha
ve
unde
r
gone
dif
f
e
r
e
nti
a
l
e
nc
oding.
T
he
dif
f
e
r
e
nti
a
l
de
c
ode
r
di
f
f
e
r
s
f
r
om
t
r
a
dit
ional
de
c
ode
r
s
in
that
it
pr
io
r
it
ize
s
pha
s
e
tr
a
ns
it
ions
be
twe
e
n
c
ons
e
c
uti
ve
s
ymbol
s
ins
tea
d
of
r
e
lyi
ng
on
a
bs
olut
e
pha
s
e
inf
or
mation.
T
his
s
tr
a
tegy
is
e
s
pe
c
ially
he
lpf
ul
in
s
it
ua
ti
ons
whe
r
e
pha
s
e
unc
e
r
tainty
mi
ght
pr
e
s
e
nt
s
ubs
tantial
dif
f
iculti
e
s
.
A
ke
y
c
ha
ll
e
nge
in
GN
S
S
s
ignal
pr
oc
e
s
s
ing
i
s
the
de
modul
a
ti
on
of
dif
f
e
r
e
nt
ly
c
ode
d
s
ignals
.
I
n
c
a
s
e
s
whe
r
e
the
pha
s
e
r
e
f
e
r
e
nc
e
may
not
be
pr
e
c
is
e
ly
known,
the
d
if
f
e
r
e
nti
a
l
c
oding
a
p
pr
oa
c
h
r
e
duc
e
s
the
im
pa
c
t
o
f
pha
s
e
a
mbi
guit
y
a
nd
pr
ovides
de
pe
nda
ble
s
ignal
de
c
oding.
Ne
ve
r
thele
s
s
,
thi
s
a
ppr
oa
c
h
a
dds
a
leve
l
of
int
r
ica
c
y
to
the
de
mo
dulation
pr
oc
e
dur
e
,
a
s
it
ne
c
e
s
s
it
a
tes
meticulous
a
tt
e
nti
on
to
pha
s
e
tr
a
ns
it
ions
to
pr
e
c
is
e
ly
de
c
ipher
the
s
uppli
e
d
da
ta.
W
it
hin
the
domain
of
GN
S
S
r
e
c
e
iver
s
,
the
tas
k
of
dif
f
e
r
e
nti
a
l
de
c
oding
be
c
omes
pa
r
ti
c
ular
ly
a
r
duous
a
s
it
ne
c
e
s
s
it
a
te
s
the
int
e
r
pr
e
tation
of
s
ymbol
s
ba
s
e
d
on
their
tr
a
ns
it
ions
r
a
ther
than
their
a
bs
olut
e
va
lues
.
T
his
pr
oc
e
dur
e
e
ntails
ut
il
izing
e
xter
na
l
in
f
or
mation
to
a
c
c
ur
a
tely
c
o
r
r
e
late
the
pha
s
e
tr
a
ns
it
i
ons
with
their
c
or
r
e
s
ponding
s
ymbol
s
.
I
t
is
e
s
s
e
nti
a
l
to
pr
e
c
is
e
ly
unde
r
s
tand
thes
e
tr
a
ns
it
ion
s
to
s
uc
c
e
s
s
f
ull
y
de
modul
a
te
the
s
ignal
a
nd
r
e
c
ove
r
the
de
li
ve
r
e
d
da
ta.
T
o
tac
kle
thi
s
dif
f
iculty,
the
r
e
c
e
iver
a
r
c
hit
e
c
tur
e
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2088
-
8708
I
nt
J
E
lec
&
C
omp
E
ng
,
Vol
.
15
,
No.
1
,
F
e
br
ua
r
y
20
25
:
480
-
492
484
incor
por
a
tes
a
map
block
,
whic
h
ha
s
a
c
r
uc
ial
f
unc
ti
on
in
c
onve
r
t
ing
the
dif
f
e
r
e
nti
a
ll
y
de
c
ode
d
s
ymb
ols
ba
c
k
to
their
or
ig
inal
f
or
ms
.
T
he
M
a
p
block
us
e
s
pr
e
-
e
s
t
a
bli
s
he
d
mappings
,
take
n
f
r
om
the
we
ll
-
known
dif
f
e
r
e
nti
a
l
e
nc
oding
s
ys
tem,
to
a
c
c
ur
a
tely
tr
a
ns
f
o
r
m
pha
s
e
tr
a
ns
it
ions
int
o
the
a
ppr
opr
iate
s
ymbol
s
.
T
he
mapping
pr
oc
e
s
s
is
c
r
uc
ial
f
or
the
p
r
e
c
is
e
r
e
tr
ieva
l
of
the
s
e
nt
da
ta,
a
s
it
gua
r
a
ntee
s
the
a
c
c
ur
a
te
int
e
r
pr
e
tati
on
of
the
dif
f
e
r
e
ntl
y
de
c
ode
d
s
ignals
.
T
he
Unpa
c
k
B
it
s
block
take
s
ove
r
a
f
ter
r
e
s
tor
ing
the
s
ymbol
s
to
their
or
igi
na
l
s
ha
pe
s
.
T
his
block
br
e
a
ks
down
the
o
r
igi
na
l
s
ym
bols
,
typi
c
a
ll
y
r
a
nging
f
r
om
0
to
3
,
in
to
dis
c
r
e
te
bit
s
.
T
his
pr
oc
e
s
s
r
e
s
tor
e
s
the
or
igi
na
l
s
e
que
nc
e
of
da
ta
bit
s
s
e
nt.
T
his
pha
s
e
plays
a
c
r
uc
ial
r
ole
in
e
ns
ur
ing
the
r
e
c
e
iver
c
a
n
pr
e
c
is
e
ly
r
e
c
ons
tr
uc
t
a
nd
e
f
f
e
c
ti
ve
ly
uti
li
z
e
the
r
e
c
e
ived
da
ta.
T
he
r
e
c
e
iver
a
r
c
hit
e
c
tur
e
is
notable
f
or
it
s
e
f
f
e
c
ti
ve
mana
ge
ment
of
d
if
f
e
r
e
ntl
y
c
ode
d
s
ignals
a
nd
it
s
r
e
s
il
ient
de
modul
a
ti
on
pr
oc
e
s
s
.
T
he
a
r
c
hit
e
c
tur
e
doe
s
a
good
job
o
f
de
a
li
ng
with
the
p
r
oblems
that
c
ome
with
di
f
f
e
r
e
nti
a
l
de
c
oding
by
f
oc
us
ing
on
pha
s
e
tr
a
ns
it
ions
a
nd
us
ing
a
c
lea
r
mapping
mec
ha
nis
m.
F
ur
ther
mor
e
,
the
inclus
ion
of
the
Unpa
c
k
B
it
s
block
gua
r
a
ntee
s
pr
e
c
is
e
r
e
tr
ieva
l
of
the
ini
ti
a
l
bit
s
e
que
nc
e
,
ther
e
by
im
pr
oving
the
r
e
c
e
iver
's
ove
r
a
ll
de
pe
nda
bil
it
y
a
nd
e
f
f
icie
nc
y.
F
igur
e
2.
C
onf
igur
a
ti
on
of
the
GN
S
S
r
e
c
e
iver
us
in
g
the
GN
U
r
a
dio
f
r
a
mew
or
k
3.
1.
B
as
e
b
an
d
p
r
oc
e
s
s
in
g
T
his
s
e
c
ti
on
pr
e
s
e
nts
a
de
s
ign
c
onc
e
pt
f
o
r
a
r
e
a
l
-
ti
me
GN
S
S
s
of
twa
r
e
r
e
c
e
iver
ba
s
e
d
on
a
S
oC
.
T
he
pr
opos
a
l
leve
r
a
ge
s
the
be
ne
f
it
s
of
a
n
ope
n
-
s
our
c
e
GN
S
S
S
DR
f
r
a
mew
or
k
,
ini
t
ially
de
s
igned
f
o
r
pe
r
s
ona
l
c
omput
e
r
s
.
T
he
s
ugge
s
ted
de
s
ign
a
im
s
to
e
nha
nc
e
the
int
e
gr
a
ti
on
o
f
va
r
ious
r
a
dio
f
r
a
mew
or
k
(
RF
)
f
r
ont
e
nds
a
nd
s
im
pli
f
y
the
de
ve
lopm
e
nt
pr
oc
e
s
s
of
the
r
e
c
e
iver
c
ha
in
f
or
na
vigation
a
ppli
c
a
ti
ons
.
T
he
c
hos
e
n
f
r
a
mew
or
k,
obtaine
d
f
r
o
m
the
ope
n
-
s
our
c
e
GN
S
S
S
DR
c
omm
unit
y,
is
known
f
or
it
s
s
im
pli
c
it
y,
r
e
li
a
ble
pe
r
f
or
manc
e
,
a
nd
e
xtens
ive
c
ode
r
e
us
a
bil
it
y.
T
he
s
e
a
tt
r
ibut
e
s
make
it
a
n
idea
l
opti
on
f
or
a
da
ptation
in
S
oC
c
ontexts
,
whe
r
e
e
f
f
icie
nc
y
a
nd
f
lexibil
it
y
a
r
e
pa
r
a
mount
.
T
he
f
r
a
mew
or
k's
de
s
ign
f
a
c
il
it
a
tes
the
de
ve
lopm
e
nt
of
e
f
f
icie
nt
im
pleme
ntations
a
c
r
os
s
diver
s
e
ha
r
dwa
r
e
platf
or
ms
a
nd
ope
r
a
ti
ng
s
ys
tems
.
A
s
igni
f
ica
nt
f
e
a
tur
e
of
thi
s
ope
n
-
s
our
c
e
GN
S
S
S
DR
f
r
a
mew
or
k
is
it
s
modul
a
r
it
y
,
whic
h
a
ll
ows
f
or
the
s
e
a
ml
e
s
s
int
e
g
r
a
ti
on
of
dif
f
e
r
e
nt
R
F
f
r
ont
e
nds
.
T
he
modul
a
r
it
y
of
the
pr
opos
e
d
S
oC
-
ba
s
e
d
GN
S
S
r
e
c
e
iver
is
c
r
uc
ial,
e
ns
ur
ing
the
s
ys
tem's
a
da
ptabili
ty
to
va
r
ious
R
F
f
r
ont
-
e
nd
c
o
nf
igur
a
ti
ons
.
B
y
uti
l
izing
th
is
ve
r
s
a
ti
li
ty,
the
de
s
ign
c
a
n
a
c
c
omm
oda
te
a
wide
r
a
nge
of
s
ignal
c
ondit
ions
a
nd
r
e
quir
e
ments
,
ther
e
by
e
nha
nc
ing
the
ove
r
a
ll
pe
r
f
or
manc
e
a
nd
a
da
ptabili
ty
of
the
r
e
c
e
iver
.
T
he
pr
opos
e
d
mod
e
l
is
de
picte
d
in
F
igur
e
3
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
nt
J
E
lec
&
C
omp
E
ng
I
S
S
N:
2088
-
8708
E
nhanc
e
d
global
nav
igat
ion
s
atelli
te
s
y
s
tem
s
igna
l
pr
oc
e
s
s
ing
us
ing
.
.
.
(
C
he
tna
De
v
i
K
h)
485
F
igur
e
3.
T
he
s
tr
uc
tur
e
o
f
the
GN
S
S
r
e
c
e
iver
im
pl
e
menta
ti
on
with
F
P
GA
T
he
nove
lt
y
o
f
thi
s
pr
opos
a
l
li
e
s
in
it
s
us
e
o
f
t
he
ope
n
-
s
our
c
e
f
r
a
mew
or
k
to
c
r
e
a
te
a
de
dica
ted
r
unti
me
e
nvir
onment
f
o
r
s
ignal
p
r
oc
e
s
s
ing
tas
ks
.
T
his
method
s
igni
f
ica
ntl
y
r
e
duc
e
s
the
a
moun
t
of
t
im
e
a
nd
c
ompl
e
xit
y
invol
ve
d
in
de
ve
lopm
e
nt
be
c
a
us
e
it
a
ll
ows
de
ve
loper
s
to
c
onc
e
ntr
a
te
on
e
nha
nc
ing
s
pe
c
if
ic
c
omponents
of
the
r
e
c
e
iver
c
ha
in
r
a
ther
than
c
ons
t
r
uc
ti
ng
the
e
nti
r
e
s
ys
tem
f
r
o
m
the
be
ginni
ng
.
R
e
u
s
ing
a
nd
ope
r
a
ti
ng
without
e
r
r
or
s
s
pe
e
ds
up
the
de
ve
lopm
e
nt
pr
oc
e
s
s
,
e
na
bli
ng
quick
c
r
e
a
ti
on
a
nd
im
pleme
n
tation
of
GN
S
S
r
e
c
e
iver
s
olut
ions
.
F
ur
ther
mo
r
e
,
the
f
r
a
mew
or
k’
s
f
lexibil
it
y
to
a
c
c
omm
oda
te
va
r
ious
ha
r
dwa
r
e
platf
or
ms
e
ns
ur
e
s
the
de
ploym
e
nt
of
the
s
ugge
s
ted
S
oC
r
e
c
e
iver
on
a
wide
r
a
nge
o
f
de
vic
e
s
,
f
r
om
e
ne
r
gy
-
e
f
f
icie
nt
e
mbedde
d
s
ys
tems
to
powe
r
f
ul
c
omput
ing
plat
f
or
ms
.
T
he
a
da
ptabili
ty
of
thi
s
tec
h
nology
is
e
s
pe
c
ially
a
dva
ntage
ou
s
in
the
f
ield
o
f
GN
S
S
a
ppli
c
a
ti
ons
,
a
s
it
is
c
r
uc
ial
to
be
a
ble
to
f
unc
ti
on
on
many
types
of
ha
r
dwa
r
e
to
c
a
ter
to
the
r
e
quir
e
ments
of
di
f
f
e
r
e
nt
us
e
r
s
a
nd
s
c
e
na
r
ios
.
T
he
S
ignal
S
our
c
e
modul
e
ge
ne
r
a
tes
a
n
unint
e
r
r
u
pted
f
low
of
unpr
oc
e
s
s
e
d
da
ta,
e
it
he
r
th
r
ough
a
n
R
F
f
r
ont
-
e
nd
or
f
r
om
pr
e
-
e
xis
ti
ng
f
il
e
s
.
T
he
s
ignal
c
ondit
ioner
a
c
ts
a
s
a
media
tor
be
twe
e
n
the
s
ignal
s
our
c
e
a
nd
the
c
ha
nne
l.
I
ts
p
r
im
a
r
y
tas
ks
a
r
e
to
f
il
ter
th
e
s
ignal
a
nd
a
djus
t
it
to
mee
t
the
c
ha
nne
l's
s
tanda
r
ds
.
T
he
c
ha
nne
l
is
r
e
s
pons
ibl
e
f
or
pr
oc
e
s
s
ing
the
GN
S
S
ba
s
e
ba
nd,
whic
h
include
s
de
c
ipher
ing
,
moni
to
r
i
ng,
a
nd
r
e
tr
ieving
na
vigation
da
ta.
E
a
c
h
c
ha
nne
l
is
r
e
s
pon
s
ibl
e
f
or
p
r
oc
e
s
s
ing
a
s
pe
c
if
ic
s
a
telli
te's
ba
s
e
ba
nd
s
ignals
,
a
nd
the
s
of
twa
r
e
a
ll
ows
f
or
the
c
onf
igu
r
a
ti
on
of
the
number
of
c
ha
nne
ls
.
T
he
Obs
e
r
va
ble
block
ga
ther
s
s
ync
hr
onize
d
da
ta
f
r
om
many
s
ignal
pr
oc
e
s
s
ing
blocks
to
c
r
e
a
te
e
s
s
e
nti
a
l
GN
S
S
met
r
ics
,
including
s
im
ulate
d
r
a
nge
,
c
a
r
r
ier
pha
s
e
,
a
nd
Dopple
r
s
hif
t.
How
e
ve
r
,
the
s
igni
f
ica
nt
c
omput
a
ti
ona
l
c
ompl
e
xit
y
of
de
pl
oying
a
s
of
twa
r
e
r
e
c
e
iver
on
a
hos
t
P
C
im
pos
e
s
li
mi
tations
.
M
or
e
ove
r
,
a
s
c
e
r
taining
the
s
tar
ti
ng
loca
ti
o
n
of
the
pr
ogr
a
m
r
e
c
e
iver
on
a
pe
r
s
ona
l
c
omput
e
r
ne
c
e
s
s
it
a
tes
s
ubs
tantial
e
xe
r
ti
on.
T
o
a
ddr
e
s
s
thes
e
li
mi
tations
,
we
s
ugge
s
t
the
a
dopti
on
of
a
S
oC
s
of
twa
r
e
r
e
c
e
iver
.
W
e
incor
por
a
te
the
r
e
c
e
iver
int
o
a
S
oC
a
r
c
hit
e
c
tur
e
,
whic
h
e
f
f
icie
ntl
y
c
a
ptur
e
s
r
e
a
l
-
ti
me
GN
S
S
s
ignals
us
ing
t
he
USR
P
N210
R
F
f
r
ont
-
e
nd
modul
e
.
T
he
Z
ynq
7
000
S
oC
boa
r
d
c
a
r
r
ies
out
the
c
omput
a
ti
ons
r
e
quir
e
d
f
or
pr
oc
e
s
s
ing
the
GPS
ba
s
e
ba
nd
a
lgor
i
thm
s
.
T
his
method
uti
li
z
e
s
the
e
f
f
e
c
ti
ve
ne
s
s
a
nd
f
lexibil
it
y
of
the
S
oC
a
r
c
hit
e
c
tur
e
,
pr
ovidi
ng
a
mor
e
f
e
a
s
ibl
e
a
lt
e
r
n
a
ti
ve
f
or
pr
oc
e
s
s
ing
r
e
a
l
-
ti
me
GN
S
S
s
ignals
.
3.
2.
Over
view
of
b
as
e
b
an
d
p
r
oc
e
s
s
in
g
B
a
s
e
b
a
n
d
pr
oc
e
s
s
i
ng
i
n
a
GN
S
S
r
e
c
e
i
ve
r
e
n
c
o
mpas
s
e
s
va
r
io
us
e
s
s
e
n
ti
a
l
o
pe
r
a
t
io
ns
,
in
c
l
ud
in
g
s
ig
na
l
a
c
q
uis
it
i
on
,
s
i
gna
l
t
r
a
c
ki
ng
,
d
e
m
od
ul
a
t
io
n
,
a
nd
d
a
ta
de
c
o
di
ng
.
T
he
s
e
f
u
nc
ti
on
s
a
r
e
c
r
u
c
ia
l
f
o
r
c
on
ve
r
t
i
ng
th
e
r
e
c
e
i
ve
d
R
F
s
ig
na
ls
i
n
to
p
os
it
io
n
,
v
e
l
oc
it
y
,
a
n
d
t
i
me
(
P
V
T
)
da
ta
.
W
e
pa
r
t
it
io
n
t
he
a
lg
o
r
i
th
m
in
to
mu
lt
ip
le
s
ta
ge
s
,
e
a
c
h
de
d
ic
a
t
e
d
t
o
a
s
p
e
c
if
ic
c
om
po
ne
nt
of
s
ig
na
l
p
r
o
c
e
s
s
in
g
.
S
ig
na
l
a
c
qu
is
i
t
io
n
is
t
he
f
i
r
s
t
s
t
a
ge
in
the
b
a
s
e
ba
n
d
p
r
oc
e
s
s
i
ng
c
h
a
i
n
.
T
h
e
ma
in
go
a
l
is
t
o
i
de
nt
i
f
y
t
he
e
x
is
t
e
nc
e
of
GN
S
S
s
ig
na
ls
a
nd
c
a
lc
ul
a
te
t
he
a
p
p
r
o
x
im
a
te
v
a
l
ue
s
o
f
t
he
c
a
r
r
ie
r
f
r
e
que
nc
y
a
nd
c
od
e
p
ha
s
e
.
T
he
f
o
l
low
i
ng
s
ta
ge
s
m
a
k
e
u
p
t
he
a
c
q
uis
i
ti
on
pr
oc
e
s
s
:
−
C
or
r
e
lation
:
W
e
c
ompar
e
the
incoming
s
ignal
w
it
h
a
loca
ll
y
pr
oduc
e
d
dupl
ica
te
of
a
GN
S
S
s
a
telli
te
s
ignal.
T
his
pr
oc
e
dur
e
e
ntails
mul
ti
plyi
ng
the
inc
omi
ng
s
ignal
with
a
dupli
c
a
te
a
nd
then
in
tegr
a
ti
n
g
the
r
e
s
ult
ove
r
a
p
r
e
de
ter
mi
ne
d
pe
r
iod
.
−
S
e
a
r
c
h
s
pa
c
e
:
T
he
pr
ogr
a
m
e
xplor
e
s
a
s
pe
c
tr
um
of
Dopple
r
s
hif
ts
a
nd
c
ode
pha
s
e
s
to
identif
y
the
opti
mal
matc
h,
whic
h
s
igni
f
ies
the
e
xis
tenc
e
of
a
s
a
telli
te
s
ignal.
−
P
e
a
k
d
e
t
e
c
t
i
on
:
A
f
te
r
o
bt
a
i
ni
ng
th
e
c
o
r
r
e
la
t
io
n
f
in
d
in
gs
,
t
he
pr
og
r
a
m
de
tec
ts
p
e
a
ks
t
ha
t
ma
tc
h
p
r
ob
a
b
le
s
a
te
ll
i
te
s
ig
na
ls
.
T
he
pe
a
k
w
i
th
th
e
g
r
e
a
tes
t
mag
n
it
ud
e
r
e
p
r
e
s
e
n
ts
th
e
c
o
de
's
e
s
ti
ma
te
d
f
r
e
q
ue
n
c
y
a
n
d
t
im
i
ng
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2088
-
8708
I
nt
J
E
lec
&
C
omp
E
ng
,
Vol
.
15
,
No.
1
,
F
e
br
ua
r
y
20
25
:
480
-
492
486
F
oll
owing
the
a
c
quis
it
ion,
the
s
ignal
tr
a
c
king
pr
oc
e
s
s
e
nha
n
c
e
s
the
a
c
c
ur
a
c
y
of
the
e
s
ti
mate
s
f
or
the
c
a
r
r
ier
f
r
e
que
nc
y,
c
ode
pha
s
e
,
a
nd
da
ta
bit
s
ync
hr
oniza
ti
on.
W
e
s
e
gment
the
tr
a
c
king
pr
oc
e
dur
e
int
o
two
pr
im
a
r
y
it
e
r
a
ti
ons
.
−
P
ha
s
e
l
oc
k
l
oop
(
P
L
L
)
:
T
he
P
L
L
moni
tor
s
a
nd
a
d
jus
ts
the
pha
s
e
a
nd
f
r
e
que
nc
y
o
f
the
r
e
c
e
ived
s
ign
a
l.
I
t
r
e
duc
e
s
the
loca
l
pha
s
e
dis
c
r
e
pa
nc
y
be
twe
e
n
th
e
s
ignal
r
e
c
e
ived
a
nd
the
c
a
r
r
ier
ge
ne
r
a
ted
,
e
ns
ur
ing
pr
e
c
is
e
s
ignal
de
modul
a
ti
on.
−
De
lay
l
oc
k
l
oop
(
DL
L
)
:
T
he
DL
L
moni
tor
s
a
nd
r
e
c
or
ds
the
c
ode
pha
s
e
of
the
ps
e
udo
-
r
a
ndom
nois
e
(
P
R
N)
c
ode
.
I
t
r
e
duc
e
s
the
ti
mi
ng
dis
c
r
e
pa
nc
y
be
t
we
e
n
the
c
ode
pha
s
e
of
the
r
e
c
e
ived
s
ignal
a
nd
the
c
ode
pha
s
e
c
r
e
a
ted
loca
ll
y,
e
ns
ur
ing
pr
e
c
is
e
c
ode
a
li
gn
ment.
T
he
f
inal
s
tage
of
the
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hm
invol
ve
s
de
c
oding
the
na
vigation
mes
s
a
ge
that
the
s
a
telli
te
t
r
a
ns
mi
ts
a
f
ter
de
modul
a
ti
on
.
T
his
c
omm
unica
ti
on
include
s
c
r
uc
ial
da
ta,
including
s
a
telli
te
e
phe
mer
is
,
c
lock
c
or
r
e
c
ti
ons
,
a
nd
a
lm
a
na
c
da
ta.
A
S
oC
platf
or
m
e
xe
c
utes
the
GN
S
S
S
DR
ba
s
e
ba
nd
pr
oc
e
s
s
ing
tec
hnique,
uti
li
z
ing
the
c
omput
a
ti
ona
l
c
a
pa
bil
it
ies
a
nd
a
da
ptabili
ty
of
F
P
GA
s
.
De
s
c
r
ibed
the
a
lgor
it
hm
us
ing
a
ha
r
dwa
r
e
de
s
c
r
ipt
ion
langu
a
ge
(
HD
L
)
li
ke
VH
DL
or
Ve
r
il
og
.
T
h
is
de
s
c
r
ipt
ion
e
nc
ompas
s
e
s
the
de
s
ign
of
c
or
r
e
lation,
tr
a
c
king
l
oops
,
a
nd
de
c
oding
blocks
.
W
e
s
im
ulate
a
nd
va
l
i
da
te
the
de
s
ign
us
ing
tes
t
be
nc
he
s
to
e
ns
ur
e
a
c
c
ur
a
te
f
un
c
ti
ona
li
ty.
T
he
ve
r
i
f
ica
ti
on
method
e
ntails
c
ompa
r
ing
the
F
P
GA
output
s
to
the
e
xpe
c
ted
outcome
s
de
r
ived
f
r
om
s
of
twa
r
e
s
im
ulations
.
T
he
S
oC
platf
or
m
incor
por
a
tes
the
s
ynthes
ize
d
de
s
ign
a
nd
tes
ts
it
us
e
s
r
e
a
l
GN
S
S
s
ignal.
C
onduc
ted
e
va
luations
on
pe
r
f
o
r
manc
e
mea
s
ur
e
s
s
uc
h
a
s
a
c
quis
it
ion
ti
me,
tr
a
c
king
a
c
c
ur
a
c
y,
a
nd
c
o
mput
ing
e
f
f
icie
nc
y.
3.
3.
I
m
p
lem
e
n
t
at
ion
of
wave
let
t
r
an
s
f
or
m
t
e
c
h
n
iq
u
e
s
T
he
dis
c
r
e
te
wa
ve
let
tr
a
ns
f
or
m
(
DW
T
)
wa
s
a
ppli
e
d
us
ing
the
Da
ube
c
hies
(
db4)
wa
ve
let,
s
e
lec
ted
f
or
it
s
a
bil
it
y
to
c
a
ptur
e
s
ignal
dis
c
onti
nuit
ies
,
making
it
we
ll
-
s
uit
e
d
f
or
GN
S
S
s
ignal
p
r
oc
e
s
s
ing.
T
he
s
ignal
wa
s
de
c
ompos
e
d
int
o
f
ive
leve
ls
,
whic
h
pr
ovided
a
n
e
f
f
e
c
ti
ve
ba
lanc
e
be
twe
e
n
f
i
lt
e
r
ing
out
high
-
f
r
e
que
nc
y
nois
e
a
nd
pr
e
s
e
r
ving
i
mpor
tant
lowe
r
-
f
r
e
que
nc
y
e
lem
e
nts
of
the
GN
S
S
s
ignal.
T
his
de
c
ompos
it
ion
l
e
ve
l
wa
s
c
hos
e
n
to
s
tr
ike
a
n
opti
mal
ba
lanc
e
be
twe
e
n
m
a
int
a
ini
ng
s
ignal
a
c
c
ur
a
c
y
a
nd
mana
ging
c
omput
a
ti
ona
l
c
ompl
e
xit
y.
A
s
of
t
thr
e
s
holdi
ng
tec
hnique
wa
s
us
e
d
dur
ing
de
c
ompos
it
ion
to
r
e
duc
e
nois
e
while
pr
e
s
e
r
ving
ke
y
s
ignal
f
e
a
tur
e
s
.
T
he
univer
s
a
l
th
r
e
s
hold
f
or
mul
a
,
=
√
2
log
,
whe
r
e
r
e
pr
e
s
e
nts
the
e
s
ti
mate
d
nois
e
leve
l
a
nd
is
the
s
ignal
length,
wa
s
a
ppli
e
d
t
o
s
e
t
thr
e
s
hold
va
lues
a
t
e
a
c
h
de
c
ompos
it
ion
leve
l
.
T
h
is
method
he
lped
maintain
s
ignal
a
c
c
ur
a
c
y
while
e
f
f
e
c
ti
ve
ly
mi
nim
izing
no
is
e
.
I
n
ter
ms
of
c
ompu
tational
c
ompl
e
xit
y
,
the
DW
T
p
r
ove
d
to
be
e
f
f
icie
nt,
with
a
c
ompl
e
xit
y
o
f
(
)
,
making
it
idea
l
f
or
r
e
a
l
-
ti
me
a
ppli
c
a
ti
ons
,
pa
r
ti
c
ular
ly
given
the
high
-
s
pe
e
d
s
a
mpl
ing
r
a
te
of
12
3
mi
ll
ion
s
a
mpl
e
s
pe
r
s
e
c
ond
(
M
S
P
S
)
.
T
he
ha
r
dwa
r
e
im
ple
menta
ti
on
on
the
Z
ynq
7000
S
oC
uti
li
z
e
d
a
bout
30%
of
the
DSP
s
li
c
e
s
a
nd
40
%
of
the
log
ic
blocks
,
highl
ig
hti
ng
the
r
e
s
our
c
e
e
f
f
icie
nc
y
of
the
wa
ve
let
t
r
a
ns
f
or
m
on
F
P
GA
-
ba
s
e
d
platf
or
ms
.
T
his
leve
l
of
r
e
s
our
c
e
uti
li
z
a
ti
on
e
ns
ur
e
d
that
r
e
a
l
-
ti
me
pr
oc
e
s
s
ing
r
e
quir
e
ments
we
r
e
met
without
ove
r
bu
r
de
ning
the
s
ys
tem.
4.
RE
S
UL
T
S
AN
D
AN
AL
YSI
S
T
he
r
e
s
ult
s
f
r
om
the
thr
e
e
plot
s
in
F
igur
e
4
pr
o
vide
us
e
f
ul
ins
ight
s
int
o
the
pe
r
f
or
manc
e
of
the
S
oC
-
ba
s
e
d
GN
S
S
s
of
twa
r
e
r
e
c
e
iver
.
T
he
a
mpl
it
ud
e
vs
.
ti
me
plot
ve
r
if
ies
the
e
xis
tenc
e
of
modul
a
ted
s
ignals
,
de
mons
tr
a
ti
ng
s
uc
c
e
s
s
f
ul
s
ignal
a
c
quis
it
ion.
T
he
plot
of
r
e
lative
ga
in
vs
.
f
r
e
que
nc
y
il
lus
tr
a
tes
the
a
bil
it
y
to
f
inely
a
djus
t
a
nd
s
e
lec
ti
ve
ly
c
hoos
e
f
r
e
que
nc
ies
,
whic
h
is
e
s
s
e
nti
a
l
f
or
a
c
hieving
a
ppr
opr
iate
pr
oc
e
s
s
ing
of
GN
S
S
s
ignals
.
T
he
qua
dr
a
tur
e
p
lot
e
xhibi
ts
tol
e
r
a
ble
a
mount
s
of
nois
e
,
whic
h
e
nha
nc
e
s
the
de
pe
nda
bil
it
y
of
s
ignal
de
modul
a
ti
on
a
nd
de
c
oding.
F
igur
e
4
ini
ti
a
l
plot
s
hows
the
a
mpl
it
ude
of
the
s
ignal's
a
c
tual
a
nd
im
a
ginar
y
c
ons
ti
tuents
a
s
a
f
unc
ti
on
of
ti
me.
T
he
blue
li
ne
c
o
r
r
e
s
ponds
to
the
a
c
tual
c
omponent
of
t
he
s
ignal,
whe
r
e
a
s
the
or
a
nge
li
ne
c
or
r
e
s
ponds
to
the
im
a
gi
na
r
y
c
omponent.
T
he
f
igur
e
e
xhibi
ts
dis
ti
nc
t
va
r
i
a
ti
ons
in
magnitude
a
t
va
r
ious
ti
me
int
e
r
va
ls
.
S
igni
f
ica
ntl
y,
the
r
e
a
l
c
omponent
o
f
the
s
ignal
e
xhibi
ts
a
s
ubs
tantial
magnitude
f
r
om
20
to
80
mi
c
r
os
e
c
onds
a
nd
on
c
e
a
ga
in
f
r
om
100
to
180
mi
c
r
os
e
c
onds
.
T
he
i
magina
r
y
c
omponent
e
xhibi
ts
a
s
igni
f
ica
nt
magnitude
be
twe
e
n
40
a
nd
120
mi
c
r
os
e
c
onds
,
with
a
tr
a
ns
ient
oc
c
ur
r
e
nc
e
a
t
140
to
160
mi
c
r
os
e
c
onds
.
T
he
s
e
tr
a
ns
it
ions
s
igni
f
y
the
e
xis
tenc
e
of
s
ignal
modul
a
ti
ons
,
whic
h
a
r
e
c
r
uc
ial
f
or
de
modul
a
ti
on
a
nd
s
ubs
e
que
nt
s
ignal
pr
oc
e
s
s
ing.
T
he
s
e
c
ond
plo
t
in
F
igur
e
5
de
mons
tr
a
tes
the
pr
opor
ti
ona
l
incr
e
a
s
e
of
the
s
ignal
with
r
e
s
pe
c
t
to
f
r
e
que
nc
y.
T
he
plot
dis
plays
a
pr
o
mi
ne
nt
pe
a
k
a
t
1
,
176
.
4
M
Hz
,
s
igni
f
ying
the
opti
mal
f
r
e
que
nc
y
f
or
the
s
ignal's
r
e
lative
ga
in.
T
his
pe
a
k
s
igni
f
ies
the
f
i
ne
a
djus
tm
e
nt
of
the
s
ys
tem's
R
F
f
r
ont
-
e
nd
a
nd
s
ignal
c
ondit
ioni
ng
to
thi
s
f
r
e
que
nc
y,
e
s
s
e
nti
a
l
f
or
the
s
uc
c
e
s
s
f
ul
c
a
ptur
e
a
nd
pr
oc
e
s
s
ing
of
GN
S
S
s
ign
a
ls
.
T
he
r
e
lative
ga
in
de
c
r
e
a
s
e
s
dr
a
matica
ll
y
a
f
ter
r
e
a
c
hin
g
thi
s
pe
a
k,
e
mphas
izing
the
f
r
e
que
nc
y
s
e
lec
ti
vit
y
of
the
r
e
c
e
iver
s
ys
tem.
T
he
thi
r
d
plo
t
in
F
igu
r
e
4
is
a
s
c
a
tt
e
r
plot
that
il
lus
tr
a
tes
the
in
-
pha
s
e
(
I
)
a
nd
qua
d
r
a
tur
e
(
Q
)
c
omponents
of
the
s
ignal.
T
he
dis
pe
r
s
ion
of
po
int
s
a
r
ound
the
or
igi
n
indi
c
a
tes
the
pr
e
s
e
nc
e
of
nois
e
a
s
we
ll
Evaluation Warning : The document was created with Spire.PDF for Python.
I
nt
J
E
lec
&
C
omp
E
ng
I
S
S
N:
2088
-
8708
E
nhanc
e
d
global
nav
igat
ion
s
atelli
te
s
y
s
tem
s
igna
l
pr
oc
e
s
s
ing
us
ing
.
.
.
(
C
he
tna
De
v
i
K
h)
487
a
s
the
ove
r
a
ll
qua
li
ty
of
the
s
ignal.
T
he
c
los
e
g
r
ouping
ne
a
r
the
s
tar
ti
ng
point
indi
c
a
tes
that
the
leve
l
of
int
e
r
f
e
r
e
nc
e
is
withi
n
a
c
c
e
ptable
bounda
r
ies
,
e
na
b
li
ng
s
uc
c
e
s
s
f
ul
e
xtr
a
c
ti
on
a
nd
int
e
r
pr
e
tation
of
th
e
GN
S
S
s
ignal.
T
he
s
c
a
tt
e
r
plot
is
a
ls
o
us
e
f
ul
f
or
e
va
luating
the
f
luctua
ti
ons
in
the
pha
s
e
a
nd
a
mpl
it
ude
of
th
e
s
ignal,
whic
h
a
r
e
e
s
s
e
nti
a
l
f
or
p
r
e
c
is
e
GN
S
S
pos
it
ioni
ng.
F
igur
e
4
.
C
ompar
ing
the
a
c
quis
it
ion
metr
ics
f
or
P
R
N
F
igur
e
5
.
Ana
lys
is
of
GN
S
S
S
DR
ba
s
e
ba
nd
pr
oc
e
s
s
ing
a
lgor
it
hm
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2088
-
8708
I
nt
J
E
lec
&
C
omp
E
ng
,
Vol
.
15
,
No.
1
,
F
e
br
ua
r
y
20
25
:
480
-
492
488
F
igur
e
4
de
picts
the
a
c
quis
it
ion
met
r
ics
f
or
va
r
io
us
P
R
N
number
s
,
whic
h
s
pa
n
f
r
om
1
to
31.
F
or
e
a
c
h
P
R
N,
the
a
c
quis
it
ion
mea
s
ur
e
qua
nti
f
ies
the
s
ignal
a
c
quis
it
ion's
r
obus
tnes
s
or
de
pe
nda
bil
it
y.
T
he
plot
s
hows
c
lea
r
pe
a
ks
a
t
P
R
Ns
10,
14,
a
nd
25
,
with
a
c
quis
it
ion
metr
ics
e
xc
e
e
ding
1.
5
a
nd
a
pr
omi
n
e
nt
pe
a
k
ne
a
r
ing
2.
5
a
t
P
R
N
25
.
T
he
s
e
pe
a
ks
r
e
pr
e
s
e
nt
the
point
s
a
t
whic
h
the
GN
S
S
r
e
c
e
iver
c
a
n
c
onf
ident
ly
de
tec
t
a
nd
r
e
c
e
ive
s
a
telli
te
s
ignals
.
On
the
other
ha
nd,
P
R
Ns
2,
6
,
a
nd
18
ha
ve
a
c
quis
it
ion
metr
ics
be
low
0.
5,
indi
c
a
ti
ng
inf
e
r
ior
s
ignal
a
c
quis
it
ion
pe
r
f
or
manc
e
f
or
thes
e
s
a
telli
tes
.
Although
ther
e
is
s
ome
va
r
iati
on,
mos
t
P
R
Ns
tend
to
ha
ve
a
c
quis
it
ion
metr
ics
that
f
a
ll
wi
thi
n
the
mi
d
-
r
a
nge
va
lues
of
0
.
5
to
1
.
0,
s
howing
a
ge
ne
r
a
l
c
ons
is
tenc
y.
T
he
c
ons
is
tent
na
tur
e
of
thi
s
phe
nomenon
indi
c
a
tes
that
the
GN
S
S
r
e
c
e
iver
is
c
a
pa
ble
of
c
ons
is
tently
a
nd
de
pe
nda
bly
c
a
ptur
ing
s
ignals
f
r
o
m
mos
t
s
a
telli
tes
,
but
the
leve
l
of
c
onf
idenc
e
may
va
r
y.
T
he
Z
ynq
7000
S
oC
us
e
s
the
AD
F
M
C
O
M
M
S
3
-
E
B
Z
R
F
f
r
ont
e
nd
to
e
s
tablis
h
a
r
obus
t
c
omm
unica
ti
on
c
onne
c
ti
on
us
ing
a
typi
c
a
l
pa
r
a
ll
e
l
I
/O
int
e
r
f
a
c
e
.
T
his
c
on
f
igur
a
ti
on
e
na
bles
high
-
s
pe
e
d
s
a
mpl
e
d
da
ta
tr
a
ns
mi
s
s
ion
a
t
a
r
e
mar
ka
ble
r
a
te
o
f
a
lm
os
t
123
mi
ll
ion
s
a
mpl
e
s
pe
r
s
e
c
ond
(
c
ompl
e
x
M
S
P
S
)
.
R
e
a
l
-
ti
me
GN
S
S
s
ignal
p
r
oc
e
s
s
ing
r
e
quir
e
s
a
high
da
ta
r
a
t
e
to
a
de
qua
tely
ha
ndle
the
int
e
ns
ive
da
ta
thr
oug
hput.
I
n
a
ddit
ion,
the
int
e
gr
a
ti
on
uti
li
z
e
s
the
s
e
r
ial
pe
r
i
phe
r
a
l
int
e
r
f
a
c
e
(
S
P
I
)
f
or
the
pu
r
pos
e
s
of
c
onf
igur
ing,
mana
ging,
a
nd
moni
to
r
ing
p
r
oc
e
s
s
e
s
.
T
he
S
P
I
int
e
r
f
a
c
e
is
a
quick
a
nd
e
a
s
y
wa
y
to
c
ontr
ol
a
nd
mo
nit
or
the
R
F
f
r
on
t
e
nd
a
nd
the
S
oC
's
many
pa
r
a
mete
r
s
a
nd
f
unc
ti
ons
,
making
s
ur
e
that
pe
r
f
or
manc
e
a
nd
f
lexi
bil
it
y
a
r
e
a
t
their
be
s
t.
F
igur
e
6
de
picts
the
int
r
ica
te
c
on
f
i
gur
a
ti
on,
de
mons
tr
a
ti
ng
the
c
onne
c
ti
on
be
twe
e
n
t
he
Z
ynq
7000
S
oC
boa
r
d
a
nd
the
AD
F
M
C
OM
M
S
3
-
E
B
Z
int
e
r
f
a
c
e
.
I
t
e
mphas
ize
s
the
c
r
uc
ial
c
omponents
a
nd
da
ta
r
outes
that
e
na
ble
thi
s
r
a
pid
a
nd
e
f
f
e
c
ti
ve
c
omm
unica
ti
on
s
ys
tem.
P
utt
ing
the
R
F
f
r
ont
e
nd
a
nd
the
S
oC
togethe
r
is
im
por
tant
f
or
ge
tt
ing
the
be
s
t
pe
r
f
or
ma
nc
e
in
GN
S
S
a
ppli
c
a
ti
ons
be
c
a
us
e
it
u
s
e
s
the
be
s
t
pa
r
ts
of
both
to
give
a
c
c
ur
a
te
a
nd
r
e
li
a
ble
na
vigation
da
ta.
Us
i
ng
the
c
o
nve
n
ti
ona
l
a
pp
r
oa
c
h
,
t
he
F
i
gu
r
e
7
di
s
p
la
ys
t
he
a
c
qu
is
it
io
n
m
e
t
r
ics
f
o
r
P
R
N
nu
m
be
r
s
r
a
ng
in
g
f
r
om
1
to
3
1
.
T
he
a
c
qu
is
it
io
n
me
t
r
ic
me
a
s
ur
e
s
t
he
r
o
bus
tn
e
s
s
o
r
de
pe
nda
bi
l
it
y
o
f
t
he
s
i
gna
l
a
c
q
u
is
i
ti
on
f
o
r
e
a
c
h
P
R
N
.
T
h
e
r
e
is
a
n
o
tab
le
va
r
ia
ti
on
in
th
e
a
c
qu
is
it
io
n
m
e
t
r
ics
a
m
on
g
d
i
f
f
e
r
e
n
t
P
R
Ns
.
T
hi
s
i
mpl
i
e
s
t
ha
t
t
he
s
i
gn
a
l
q
ua
li
ty
a
nd
i
nt
e
ns
it
y
f
lu
c
t
ua
te
a
m
on
g
di
f
f
e
r
e
n
t
s
a
t
e
l
li
tes
,
p
os
s
i
b
ly
d
ue
to
f
a
c
to
r
s
s
u
c
h
a
s
s
a
t
e
l
l
it
e
c
on
di
t
io
n
,
t
r
a
ns
m
is
s
i
on
p
owe
r
,
a
nd
e
n
vi
r
on
me
nt
a
l
c
i
r
c
ums
ta
nc
e
s
.
S
e
v
e
r
a
l
P
R
N
,
s
pe
c
i
f
ica
l
ly
2
,
6
,
a
n
d
1
8
,
ha
ve
a
c
q
uis
it
i
on
met
r
ics
th
a
t
a
r
e
c
o
ns
is
te
nt
ly
lo
we
r
t
ha
n
0
.
5
.
T
his
im
p
li
e
s
a
de
c
l
in
e
i
n
s
i
gna
l
r
e
c
e
p
ti
on
c
a
pa
c
i
ty
,
p
o
ten
t
ia
ll
y
d
ue
to
obs
tac
les
,
mu
l
ti
pl
e
s
i
gn
a
l
pa
ths
,
or
a
r
e
du
c
t
io
n
i
n
s
a
te
ll
i
te
tr
a
ns
mi
s
s
i
on
po
we
r
.
T
he
inves
ti
ga
ti
on
h
ighl
ight
s
the
s
igni
f
ica
nc
e
of
s
t
r
ong
a
nd
f
lexible
s
ignal
a
c
quis
it
ion
tec
hniques
in
GN
S
S
r
e
c
e
iver
s
.
B
y
unde
r
s
tanding
the
f
luctua
ti
ons
in
a
c
quis
it
ion
metr
ics
,
de
ve
loper
s
c
a
n
im
pr
ove
the
r
e
c
e
iver
's
pe
r
f
or
manc
e
.
T
h
is
will
gua
r
a
ntee
de
pe
nda
ble
s
ignal
a
c
quis
it
ion
f
or
va
r
ious
s
a
telli
te
s
ig
na
ls
a
nd
im
pr
ove
the
a
c
c
ur
a
c
y
a
nd
r
e
li
a
bil
it
y
of
GN
S
S
-
ba
s
e
d
na
vigation
s
olut
ions
.
Us
ing
the
pr
opos
e
d
method,
F
igu
r
e
8
il
lus
tr
a
tes
t
he
a
c
quis
it
ion
metr
ics
f
o
r
di
f
f
e
r
e
nt
P
R
N
number
s
r
a
nging
f
r
om
1
to
31
.
F
or
e
a
c
h
P
R
N,
the
a
c
quis
it
ion
metr
ic
qua
nt
if
ies
the
s
ignal
a
c
quis
it
ion's
r
obu
s
tnes
s
or
de
pe
nda
bil
it
y.
T
he
p
r
opos
e
d
method
de
mons
tr
a
t
e
s
e
nha
nc
e
d
a
c
quis
it
ion
metr
ics
f
or
numer
ous
P
R
Ns
in
c
ompar
is
on
to
c
onve
nti
ona
l
methods
.
T
his
indi
c
a
tes
that
the
s
ugge
s
ted
a
ppr
oa
c
h
im
pr
ove
s
the
a
bil
it
y
of
the
GN
S
S
r
e
c
e
iver
to
obtain
a
nd
pr
oc
e
s
s
s
ignals
.
Although
c
e
r
tain
P
R
Ns
ha
ve
notably
h
igh
a
c
quis
it
ion
metr
ics
,
the
s
ugge
s
ted
a
ppr
oa
c
h
a
ls
o
de
mon
s
tr
a
tes
e
quit
a
b
le
e
nha
nc
e
ment
a
c
r
os
s
other
P
R
Ns
,
with
mos
t
a
c
quis
it
ion
metr
ics
f
a
ll
ing
withi
n
the
r
a
nge
of
1.
0
to
1
.
5.
T
he
pr
opos
e
d
s
olut
ion
im
pr
ove
s
the
ove
r
a
ll
pe
r
f
or
manc
e
of
the
GN
S
S
r
e
c
e
iver
,
making
i
t
mor
e
de
pe
nda
ble
wit
h
a
wide
va
r
iety
of
s
a
telli
tes
.
T
he
p
r
opos
e
d
method
f
or
a
na
lyzing
a
c
quis
it
ion
metr
ics
o
f
f
e
r
s
us
e
f
ul
ins
ight
s
int
o
the
im
pr
ove
d
pe
r
f
o
r
manc
e
a
nd
de
pe
nda
bil
it
y
of
the
GN
S
S
r
e
c
e
iver
's
s
ignal
a
c
quis
it
ion
pr
oc
e
s
s
.
T
he
highl
ight
e
d
P
R
Ns
with
high
a
c
quis
it
ion
metr
ics
de
m
ons
tr
a
te
the
e
f
f
e
c
ti
ve
ne
s
s
of
the
s
ugge
s
ted
s
tr
a
tegy
in
boo
s
ti
ng
s
ignal
s
tr
e
ngth
a
nd
r
e
li
a
bil
it
y
,
c
r
uc
ial
f
o
r
a
c
hieving
pr
e
c
is
e
GN
S
S
loca
ti
on.
T
he
a
na
lys
is
highl
ight
s
th
e
e
f
f
ica
c
y
of
the
p
r
opos
e
d
s
tr
a
tegy
in
im
pr
oving
t
he
s
ignal
a
c
quis
it
ion
c
a
pa
bil
it
ies
of
the
GN
S
S
r
e
c
e
iver
.
T
o
e
nha
nc
e
the
ove
r
a
ll
a
c
c
ur
a
c
y
a
nd
r
e
li
a
bil
it
y
o
f
GN
S
S
na
vigation
s
ys
tems
,
e
nginee
r
s
c
a
n
opti
mi
z
e
the
r
e
c
e
iver
's
pe
r
f
or
manc
e
by
c
ompr
e
he
nding
the
e
nha
n
c
e
ments
in
a
c
quis
it
ion
metr
ics
.
T
his
will
e
ns
ur
e
de
pe
nda
ble
s
ignal
a
c
quis
it
ion
a
c
r
os
s
dif
f
e
r
e
nt
s
a
telli
te
s
ignals
.
F
igur
e
6.
I
nteg
r
a
ti
on
of
Z
ynq
7000
S
oC
with
AD
F
M
C
OM
M
S
3
-
E
B
Z
R
F
f
r
ont
e
nd
Evaluation Warning : The document was created with Spire.PDF for Python.
I
nt
J
E
lec
&
C
omp
E
ng
I
S
S
N:
2088
-
8708
E
nhanc
e
d
global
nav
igat
ion
s
atelli
te
s
y
s
tem
s
igna
l
pr
oc
e
s
s
ing
us
ing
.
.
.
(
C
he
tna
De
v
i
K
h)
489
F
igur
e
7.
T
he
r
obus
tnes
s
a
nd
r
e
li
a
bil
it
y
of
s
ignal
a
c
quis
it
ion
f
or
e
a
c
h
P
R
N
F
igur
e
8
.
Ac
quis
it
ion
met
r
ics
vs
P
R
N
number
in
p
r
opos
e
d
method
T
he
s
a
telli
te
c
ons
tellation
map
in
F
igur
e
9
d
is
plays
the
loca
ti
ons
of
dif
f
e
r
e
nt
s
a
telli
tes
c
las
s
if
ied
by
va
r
ious
GN
S
S
s
ys
tems
,
dis
ti
nguis
he
d
by
di
f
f
e
r
e
nt
c
olor
s
(
e
.
g
.
,
g
r
e
e
n
f
or
GPS
,
r
e
d
f
or
GL
ON
ASS
,
blue
f
o
r
Ga
li
leo,
a
nd
pu
r
ple
f
o
r
B
e
iDou)
.
E
a
c
h
s
a
telli
te's
a
z
im
uth
a
ngle
indi
c
a
tes
it
s
pos
it
ion
a
nd
the
di
r
e
c
ti
on
f
r
om
whic
h
it
r
e
c
e
ives
the
s
a
telli
te
s
ignal.
T
he
s
a
telli
tes
unif
or
ml
y
dis
pe
r
s
e
th
r
oughout
the
e
nti
r
e
a
z
im
ut
h
a
ngle
r
a
nge
(
0°
to
360°)
,
indi
c
a
ti
ng
c
omp
r
e
he
ns
ive
s
a
telli
te
c
ove
r
a
ge
f
r
om
a
ll
dir
e
c
ti
ons
.
T
he
int
e
gr
a
ti
o
n
of
the
s
a
telli
te
c
ons
tellation
plot
a
nd
the
s
ignal
s
tr
e
ngth
ba
r
plot
pr
ovides
a
c
ompr
e
he
ns
ive
unde
r
s
tanding
of
the
GN
S
S
r
e
c
e
iver
's
ope
r
a
ti
on
a
nd
s
ur
r
ounding
s
igna
l
c
ondit
ions
.
T
he
wide
dis
tr
ibut
ion
of
s
a
telli
tes
a
c
r
os
s
the
a
z
im
uth
r
a
nge
gua
r
a
ntee
s
s
tr
ong
a
nd
de
pe
nda
ble
c
ove
r
a
ge
,
r
e
duc
ing
the
c
ha
nc
e
of
s
ignal
bloc
ka
ge
a
nd
im
pr
oving
pos
it
ioni
ng
pr
e
c
is
ion.
F
i
gu
r
e
10
p
r
e
s
e
nts
a
th
or
ou
gh
c
o
mpa
r
is
o
n
o
f
t
he
b
a
s
e
li
ne
a
pp
r
oa
c
h
a
n
d
t
he
p
r
op
os
e
d
a
p
pr
oa
c
h
f
o
r
G
NS
S
s
ig
na
l
p
r
oc
e
s
s
i
ng
.
I
t
e
x
a
m
in
e
s
the
nu
mbe
r
o
f
r
e
c
e
i
ve
d
s
a
m
pl
e
s
,
d
r
op
pe
d
s
a
mp
les
,
a
nd
d
a
t
a
l
os
s
p
e
r
c
e
nt
a
g
e
.
T
he
c
o
mpa
r
is
o
n
b
e
t
we
e
n
t
he
ba
s
e
l
i
ne
a
nd
p
r
o
pos
e
d
a
pp
r
oa
c
he
s
d
e
m
ons
t
r
a
tes
s
ub
s
ta
n
ti
a
l
e
nh
a
nc
e
m
e
n
ts
i
n
t
he
pe
r
f
o
r
man
c
e
o
f
th
e
GN
S
S
s
i
g
na
l
p
r
o
c
e
s
s
in
g
s
ys
te
m
w
it
h
t
he
pr
op
os
e
d
a
pp
r
oa
c
h
.
T
he
p
r
op
os
e
d
a
pp
r
oa
c
h
c
a
n
c
a
pt
u
r
e
a
l
a
r
ge
r
q
ua
n
t
it
y
of
s
a
mp
les
,
w
hi
c
h
is
e
s
s
e
nt
ia
l
f
o
r
e
n
ha
nc
in
g
t
he
r
e
s
o
lut
i
on
a
n
d
a
c
c
u
r
a
c
y
o
f
G
NS
S
d
a
t
a
p
r
oc
e
s
s
in
g
.
W
it
h
the
p
r
o
po
s
e
d
a
p
p
r
oa
c
h
,
th
e
s
i
gn
i
f
i
c
a
n
t
de
c
r
e
a
s
e
in
d
r
o
ppe
d
s
a
mp
les
s
ug
ge
s
ts
a
mo
r
e
s
t
r
e
a
m
li
ne
d
d
a
t
a
p
r
oc
e
s
s
in
g
pi
pe
li
n
e
,
r
e
s
ul
ti
ng
i
n
f
e
w
e
r
d
is
r
u
pt
io
ns
a
nd
a
mo
r
e
c
o
ns
is
t
e
n
t
f
lo
w
o
f
da
ta
.
T
he
s
i
gn
i
f
i
c
a
n
t
r
e
du
c
t
io
n
in
da
ta
l
os
s
p
e
r
c
e
n
ta
ge
s
e
e
n
wi
t
h
t
he
p
r
o
pos
e
d
a
p
p
r
oa
c
h
de
mo
ns
tr
a
tes
the
s
ys
t
e
m
's
i
mp
r
ove
d
c
a
pa
c
i
ty
to
e
f
f
ic
ien
t
ly
s
to
r
e
a
nd
ut
il
iz
e
t
he
a
c
qu
i
r
e
d
da
ta
.
E
ns
u
r
in
g
t
he
i
nt
e
g
r
i
ty
a
nd
d
e
p
e
n
da
b
i
li
ty
of
GN
S
S
pos
it
i
on
in
g
a
n
d
na
vi
ga
ti
on
s
ol
ut
io
ns
r
e
q
ui
r
e
s
m
in
im
iz
in
g
da
ta
los
s
.
T
he
a
n
a
l
ys
i
s
s
ho
ws
t
ha
t
t
he
pr
op
os
e
d
a
p
p
r
o
a
c
h
p
r
o
vi
de
s
s
u
bs
tan
t
ia
l
i
mp
r
ov
e
m
e
n
ts
c
o
mp
a
r
e
d
to
th
e
ba
s
e
l
in
e
a
p
p
r
oa
c
h
,
mak
i
ng
it
a
s
upe
r
io
r
o
pt
io
n
f
or
G
NS
S
da
ta
p
r
o
c
e
s
s
in
g
.
T
he
i
mpr
o
ve
me
nts
i
n
r
e
c
e
ive
d
s
a
m
pl
e
s
,
dis
c
a
r
d
e
d
s
a
m
p
les
,
a
nd
d
a
ta
l
os
s
pe
r
c
e
n
tag
e
s
a
ll
c
o
nt
r
ib
ut
e
t
o
a
mo
r
e
r
e
s
i
li
e
n
t
,
p
r
e
c
is
e
,
a
n
d
d
e
p
e
n
da
b
le
GN
S
S
s
ys
te
m
.
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