<s>
Spectral	B-Protocol
efficiency	I-Protocol
,	O
spectrum	B-Protocol
efficiency	I-Protocol
or	O
bandwidth	B-Protocol
efficiency	I-Protocol
refers	O
to	O
the	O
information	O
rate	O
that	O
can	O
be	O
transmitted	O
over	O
a	O
given	O
bandwidth	B-Algorithm
in	O
a	O
specific	O
communication	O
system	O
.	O
</s>
<s>
It	O
is	O
a	O
measure	O
of	O
how	O
efficiently	O
a	O
limited	O
frequency	O
spectrum	O
is	O
utilized	O
by	O
the	O
physical	B-Application
layer	I-Application
protocol	O
,	O
and	O
sometimes	O
by	O
the	O
medium	B-Protocol
access	I-Protocol
control	I-Protocol
(	O
the	O
channel	O
access	O
protocol	O
)	O
.	O
</s>
<s>
The	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
of	O
a	O
digital	O
communication	O
system	O
is	O
measured	O
in	O
bit/s/Hz	B-Protocol
,	O
or	O
,	O
less	O
frequently	O
but	O
unambiguously	O
,	O
in	O
(	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
It	O
is	O
the	O
net	O
bit	O
rate	O
(	O
useful	O
information	O
rate	O
excluding	O
error-correcting	B-Error_Name
codes	I-Error_Name
)	O
or	O
maximum	O
throughput	O
divided	O
by	O
the	O
bandwidth	B-Algorithm
in	O
hertz	O
of	O
a	O
communication	O
channel	O
or	O
a	O
data	O
link	O
.	O
</s>
<s>
Alternatively	O
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
may	O
be	O
measured	O
in	O
bit/symbol	O
,	O
which	O
is	O
equivalent	O
to	O
bits	O
per	O
channel	O
use	O
(	O
bpcu	O
)	O
,	O
implying	O
that	O
the	O
net	O
bit	O
rate	O
is	O
divided	O
by	O
the	O
symbol	O
rate	O
(	O
modulation	O
rate	O
)	O
or	O
line	B-Protocol
code	I-Protocol
pulse	O
rate	O
.	O
</s>
<s>
Link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
is	O
typically	O
used	O
to	O
analyze	O
the	O
efficiency	O
of	O
a	O
digital	O
modulation	O
method	O
or	O
line	B-Protocol
code	I-Protocol
,	O
sometimes	O
in	O
combination	O
with	O
a	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
(	O
FEC	B-Error_Name
)	O
code	O
and	O
other	O
physical	B-Application
layer	I-Application
overhead	O
.	O
</s>
<s>
In	O
the	O
latter	O
case	O
,	O
a	O
"	O
bit	O
"	O
refers	O
to	O
a	O
user	O
data	O
bit	O
;	O
FEC	B-Error_Name
overhead	O
is	O
always	O
excluded	O
.	O
</s>
<s>
The	O
modulation	B-Protocol
efficiency	I-Protocol
in	O
bit/s	O
is	O
the	O
gross	O
bit	O
rate	O
(	O
including	O
any	O
error-correcting	B-Error_Name
code	I-Error_Name
)	O
divided	O
by	O
the	O
bandwidth	B-Algorithm
.	O
</s>
<s>
Example	O
1	O
:	O
A	O
transmission	O
technique	O
using	O
one	O
kilohertz	O
of	O
bandwidth	B-Algorithm
to	O
transmit	O
1,000	O
bits	O
per	O
second	O
has	O
a	O
modulation	B-Protocol
efficiency	I-Protocol
of	O
1	O
(	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
Example	O
2	O
:	O
A	O
V.92	O
modem	B-Application
for	O
the	O
telephone	O
network	O
can	O
transfer	O
56,000	O
bit/s	O
downstream	O
and	O
48,000	O
bit/s	O
upstream	O
over	O
an	O
analog	O
telephone	O
network	O
.	O
</s>
<s>
Due	O
to	O
filtering	O
in	O
the	O
telephone	O
exchange	O
,	O
the	O
frequency	O
range	O
is	O
limited	O
to	O
between	O
300	O
hertz	O
and	O
3,400	O
hertz	O
,	O
corresponding	O
to	O
a	O
bandwidth	B-Algorithm
of	O
3,400	O
−	O
300	O
=	O
3,100	O
hertz	O
.	O
</s>
<s>
The	O
spectral	B-Protocol
efficiency	I-Protocol
or	O
modulation	B-Protocol
efficiency	I-Protocol
is	O
56,000	O
/3	O
,	O
100	O
=	O
18.1	O
(	O
bit/s	O
)	O
/Hz	O
downstream	O
,	O
and	O
48,000	O
/3	O
,	O
100	O
=	O
15.5	O
(	O
bit/s	O
)	O
/Hz	O
upstream	O
.	O
</s>
<s>
An	O
upper	O
bound	O
for	O
the	O
attainable	O
modulation	B-Protocol
efficiency	I-Protocol
is	O
given	O
by	O
the	O
Nyquist	O
rate	O
or	O
Hartley	O
's	O
law	O
as	O
follows	O
:	O
For	O
a	O
signaling	O
alphabet	O
with	O
M	O
alternative	O
symbols	O
,	O
each	O
symbol	O
represents	O
N	O
=	O
log2	O
M	O
bits	O
.	O
</s>
<s>
N	O
is	O
the	O
modulation	B-Protocol
efficiency	I-Protocol
measured	O
in	O
bit/symbol	O
or	O
bpcu	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
baseband	B-Algorithm
transmission	I-Algorithm
(	O
line	B-Protocol
coding	I-Protocol
or	O
pulse-amplitude	B-Device
modulation	I-Device
)	O
with	O
a	O
baseband	B-Algorithm
bandwidth	B-Algorithm
(	O
or	O
upper	O
cut-off	O
frequency	O
)	O
B	O
,	O
the	O
symbol	O
rate	O
can	O
not	O
exceed	O
2B	O
symbols/s	O
in	O
view	O
to	O
avoid	O
intersymbol	O
interference	O
.	O
</s>
<s>
Thus	O
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
can	O
not	O
exceed	O
2N	O
(	O
bit/s	O
)	O
/Hz	O
in	O
the	O
baseband	B-Algorithm
transmission	I-Algorithm
case	O
.	O
</s>
<s>
In	O
the	O
passband	B-Algorithm
transmission	O
case	O
,	O
a	O
signal	O
with	O
passband	B-Algorithm
bandwidth	B-Algorithm
W	O
can	O
be	O
converted	O
to	O
an	O
equivalent	B-Algorithm
baseband	I-Algorithm
signal	I-Algorithm
(	O
using	O
undersampling	B-Algorithm
or	O
a	O
superheterodyne	O
receiver	O
)	O
,	O
with	O
upper	O
cut-off	O
frequency	O
W/2	O
.	O
</s>
<s>
If	O
double-sideband	O
modulation	O
schemes	O
such	O
as	O
QAM	B-Device
,	O
ASK	O
,	O
PSK	O
or	O
OFDM	B-Protocol
are	O
used	O
,	O
this	O
results	O
in	O
a	O
maximum	O
symbol	O
rate	O
of	O
W	O
symbols/s	O
,	O
and	O
in	O
that	O
the	O
modulation	B-Protocol
efficiency	I-Protocol
can	O
not	O
exceed	O
N	O
(	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
If	O
digital	O
single-sideband	B-Device
modulation	I-Device
is	O
used	O
,	O
the	O
passband	B-Algorithm
signal	I-Algorithm
with	O
bandwidth	B-Algorithm
W	O
corresponds	O
to	O
a	O
baseband	B-Algorithm
message	O
signal	O
with	O
baseband	B-Algorithm
bandwidth	B-Algorithm
W	O
,	O
resulting	O
in	O
a	O
maximum	O
symbol	O
rate	O
of	O
2W	O
and	O
an	O
attainable	O
modulation	B-Protocol
efficiency	I-Protocol
of	O
2N	O
(	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
Example	O
3	O
:	O
A	O
16QAM	B-Device
modem	B-Application
has	O
an	O
alphabet	O
size	O
of	O
M	O
=	O
16	O
alternative	O
symbols	O
,	O
with	O
N	O
=	O
4	O
bit/symbol	O
or	O
bpcu	O
.	O
</s>
<s>
Since	O
QAM	B-Device
is	O
a	O
form	O
of	O
double	O
sideband	O
passband	B-Algorithm
transmission	O
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
cannot	O
exceed	O
N	O
=	O
4( 	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
Example	O
4	O
:	O
The	O
8VSB	B-Device
(	O
8-level	O
vestigial	O
sideband	O
)	O
modulation	O
scheme	O
used	O
in	O
the	O
ATSC	B-Device
digital	I-Device
television	I-Device
standard	I-Device
gives	O
N	O
=3	O
bit/symbol	O
or	O
bpcu	O
.	O
</s>
<s>
Since	O
it	O
can	O
be	O
described	O
as	O
nearly	O
single-side	O
band	O
,	O
the	O
modulation	B-Protocol
efficiency	I-Protocol
is	O
close	O
to	O
2N	O
=	O
6( 	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
In	O
practice	O
,	O
ATSC	B-Device
transfers	O
a	O
gross	O
bit	O
rate	O
of	O
32Mbit/s	O
over	O
a	O
6MHz	O
wide	O
channel	O
,	O
resulting	O
in	O
a	O
modulation	B-Protocol
efficiency	I-Protocol
of	O
32/6	O
=	O
5.3	O
(	O
bit/s	O
)	O
/Hz	O
.	O
</s>
<s>
Example	O
5	O
:	O
The	O
downlink	O
of	O
a	O
V.92	O
modem	B-Application
uses	O
a	O
pulse-amplitude	B-Device
modulation	I-Device
with	O
128	O
signal	O
levels	O
,	O
resulting	O
in	O
N	O
=	O
7	O
bit/symbol	O
.	O
</s>
<s>
Since	O
the	O
transmitted	O
signal	O
before	O
passband	B-Algorithm
filtering	O
can	O
be	O
considered	O
as	O
baseband	B-Algorithm
transmission	I-Algorithm
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
cannot	O
exceed	O
2N	O
=	O
14( 	O
bit/s	O
)	O
/Hz	O
over	O
the	O
full	O
baseband	B-Algorithm
channel	I-Algorithm
(	O
0	O
to	O
4kHz	O
)	O
.	O
</s>
<s>
As	O
seen	O
above	O
,	O
a	O
higher	O
spectral	B-Protocol
efficiency	I-Protocol
is	O
achieved	O
if	O
we	O
consider	O
the	O
smaller	O
passband	B-Algorithm
bandwidth	B-Algorithm
.	O
</s>
<s>
If	O
a	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
code	O
is	O
used	O
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
is	O
reduced	O
from	O
the	O
uncoded	O
modulation	B-Protocol
efficiency	I-Protocol
figure	O
.	O
</s>
<s>
Example	O
6	O
:	O
If	O
a	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
(	O
FEC	B-Error_Name
)	O
code	O
with	O
code	O
rate	O
1/2	O
is	O
added	O
,	O
meaning	O
that	O
the	O
encoder	O
input	O
bit	O
rate	O
is	O
one	O
half	O
the	O
encoder	O
output	O
rate	O
,	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
is	O
50%	O
of	O
the	O
modulation	B-Protocol
efficiency	I-Protocol
.	O
</s>
<s>
In	O
exchange	O
for	O
this	O
reduction	O
in	O
spectral	B-Protocol
efficiency	I-Protocol
,	O
FEC	B-Error_Name
usually	O
reduces	O
the	O
bit-error	O
rate	O
,	O
and	O
typically	O
enables	O
operation	O
at	O
a	O
lower	O
signal-to-noise	O
ratio	O
(	O
SNR	O
)	O
.	O
</s>
<s>
An	O
upper	O
bound	O
for	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
possible	O
without	O
bit	O
errors	O
in	O
a	O
channel	O
with	O
a	O
certain	O
SNR	O
,	O
if	O
ideal	O
error	O
coding	O
and	O
modulation	O
is	O
assumed	O
,	O
is	O
given	O
by	O
the	O
Shannon	O
–	O
Hartley	O
theorem	O
.	O
</s>
<s>
Example	O
7	O
:	O
If	O
the	O
SNR	O
is	O
1	O
,	O
corresponding	O
to	O
0	O
decibel	O
,	O
the	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
can	O
not	O
exceed	O
1( 	O
bit/s	O
)	O
/Hz	O
for	O
error-free	O
detection	O
(	O
assuming	O
an	O
ideal	O
error-correcting	B-Error_Name
code	I-Error_Name
)	O
according	O
to	O
Shannon	O
–	O
Hartley	O
regardless	O
of	O
the	O
modulation	O
and	O
coding	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
a	O
data	O
compression	O
scheme	O
,	O
such	O
as	O
the	O
V.44	O
or	O
V.42bis	O
compression	O
used	O
in	O
telephone	B-Application
modems	I-Application
,	O
may	O
however	O
give	O
higher	O
goodput	O
if	O
the	O
transferred	O
data	O
is	O
not	O
already	O
efficiently	O
compressed	O
.	O
</s>
<s>
The	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
of	O
a	O
wireless	O
telephony	O
link	O
may	O
also	O
be	O
expressed	O
as	O
the	O
maximum	O
number	O
of	O
simultaneous	O
calls	O
over	O
1MHz	O
frequency	O
spectrum	O
in	O
erlangs	O
per	O
megahertz	O
,	O
or	O
E/MHz	O
.	O
</s>
<s>
In	O
wireless	B-General_Concept
networks	I-General_Concept
,	O
the	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
can	O
be	O
somewhat	O
misleading	O
,	O
as	O
larger	O
values	O
are	O
not	O
necessarily	O
more	O
efficient	O
in	O
their	O
overall	O
use	O
of	O
radio	O
spectrum	O
.	O
</s>
<s>
In	O
a	O
wireless	B-General_Concept
network	I-General_Concept
,	O
high	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
may	O
result	O
in	O
high	O
sensitivity	O
to	O
co-channel	O
interference	O
(	O
crosstalk	O
)	O
,	O
which	O
affects	O
the	O
capacity	O
.	O
</s>
<s>
For	O
example	O
,	O
in	O
a	O
cellular	O
telephone	O
network	O
with	O
frequency	O
reuse	O
,	O
spectrum	B-Architecture
spreading	I-Architecture
and	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
reduce	O
the	O
spectral	B-Protocol
efficiency	I-Protocol
in	O
(	O
bit/s	O
)	O
/Hz	O
but	O
substantially	O
lower	O
the	O
required	O
signal-to-noise	O
ratio	O
in	O
comparison	O
to	O
non-spread	O
spectrum	O
techniques	O
.	O
</s>
<s>
This	O
can	O
allow	O
for	O
much	O
denser	O
geographical	O
frequency	O
reuse	O
that	O
compensates	O
for	O
the	O
lower	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
,	O
resulting	O
in	O
approximately	O
the	O
same	O
capacity	O
(	O
the	O
same	O
number	O
of	O
simultaneous	O
phone	O
calls	O
)	O
over	O
the	O
same	O
bandwidth	B-Algorithm
,	O
using	O
the	O
same	O
number	O
of	O
base	O
station	O
transmitters	O
.	O
</s>
<s>
As	O
discussed	O
below	O
,	O
a	O
more	O
relevant	O
measure	O
for	O
wireless	B-General_Concept
networks	I-General_Concept
would	O
be	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
in	O
bit/s/Hz	B-Protocol
per	O
unit	O
area	O
.	O
</s>
<s>
However	O
,	O
in	O
closed	O
communication	O
links	O
such	O
as	O
telephone	O
lines	O
and	O
cable	O
TV	O
networks	O
,	O
and	O
in	O
noise-limited	O
wireless	O
communication	O
system	O
where	O
co-channel	O
interference	O
is	O
not	O
a	O
factor	O
,	O
the	O
largest	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
that	O
can	O
be	O
supported	O
by	O
the	O
available	O
SNR	O
is	O
generally	O
used	O
.	O
</s>
<s>
In	O
digital	O
wireless	B-General_Concept
networks	I-General_Concept
,	O
the	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
or	O
area	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
is	O
typically	O
measured	O
in	O
(	O
bit/s	O
)	O
/Hz	O
per	O
unit	O
area	O
,	O
in	O
(	O
bit/s	O
)	O
/Hz	O
per	O
cell	O
,	O
or	O
in	O
(	O
bit/s	O
)	O
/Hz	O
per	O
site	O
.	O
</s>
<s>
It	O
is	O
a	O
measure	O
of	O
the	O
quantity	O
of	O
users	O
or	O
services	O
that	O
can	O
be	O
simultaneously	O
supported	O
by	O
a	O
limited	O
radio	B-Algorithm
frequency	I-Algorithm
bandwidth	I-Algorithm
in	O
a	O
defined	O
geographic	O
area	O
.	O
</s>
<s>
summed	O
over	O
all	O
users	O
in	O
the	O
system	O
,	O
divided	O
by	O
the	O
channel	O
bandwidth	B-Algorithm
and	O
by	O
the	O
covered	O
area	O
or	O
number	O
of	O
base	O
station	O
sites	O
.	O
</s>
<s>
This	O
measure	O
is	O
affected	O
not	O
only	O
by	O
the	O
single-user	O
transmission	O
technique	O
,	O
but	O
also	O
by	O
multiple	O
access	O
schemes	O
and	O
radio	B-Protocol
resource	I-Protocol
management	I-Protocol
techniques	O
utilized	O
.	O
</s>
<s>
It	O
can	O
be	O
substantially	O
improved	O
by	O
dynamic	O
radio	B-Protocol
resource	I-Protocol
management	I-Protocol
.	O
</s>
<s>
Higher-layer	O
protocol	O
overhead	O
(	O
above	O
the	O
media	B-Protocol
access	I-Protocol
control	I-Protocol
sublayer	I-Protocol
)	O
is	O
normally	O
neglected	O
.	O
</s>
<s>
Example	O
8	O
:	O
In	O
a	O
cellular	O
system	O
based	O
on	O
frequency-division	O
multiple	O
access	O
(	O
FDMA	O
)	O
with	O
a	O
fixed	B-Protocol
channel	I-Protocol
allocation	I-Protocol
(	O
FCA	O
)	O
cellplan	O
using	O
a	O
frequency	O
reuse	O
factor	O
of	O
1/4	O
,	O
each	O
base	O
station	O
has	O
access	O
to	O
1/4	O
of	O
the	O
total	O
available	O
frequency	O
spectrum	O
.	O
</s>
<s>
Thus	O
,	O
the	O
maximum	O
possible	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
in	O
(	O
bit/s	O
)	O
/Hz	O
per	O
site	O
is	O
1/4	O
of	O
the	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
.	O
</s>
<s>
Then	O
each	O
cell	O
has	O
access	O
to	O
1/12	O
of	O
the	O
available	O
spectrum	O
,	O
and	O
the	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
in	O
(	O
bit/s	O
)	O
/Hz	O
per	O
cell	O
or	O
(	O
bit/s	O
)	O
/Hz	O
per	O
sector	O
is	O
1/12	O
of	O
the	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
.	O
</s>
<s>
The	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
of	O
a	O
cellular	O
network	O
may	O
also	O
be	O
expressed	O
as	O
the	O
maximum	O
number	O
of	O
simultaneous	O
phone	O
calls	O
per	O
area	O
unit	O
over	O
1MHz	O
frequency	O
spectrum	O
in	O
E/MHz	O
per	O
cell	O
,	O
E/MHz	O
per	O
sector	O
,	O
E/MHz	O
per	O
site	O
,	O
or	O
(	O
E/MHz	O
)	O
/m2	O
.	O
</s>
<s>
Low	O
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
in	O
(	O
bit/s	O
)	O
/Hz	O
does	O
not	O
necessarily	O
mean	O
that	O
an	O
encoding	B-Protocol
scheme	I-Protocol
is	O
inefficient	O
from	O
a	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
point	O
of	O
view	O
.	O
</s>
<s>
As	O
an	O
example	O
,	O
consider	O
Code	B-Protocol
Division	I-Protocol
Multiplexed	O
Access	O
(	O
CDMA	B-Protocol
)	O
spread	B-Architecture
spectrum	I-Architecture
,	O
which	O
is	O
not	O
a	O
particularly	O
spectral-efficient	O
encoding	B-Protocol
scheme	I-Protocol
when	O
considering	O
a	O
single	O
channel	O
or	O
single	O
user	O
.	O
</s>
<s>
However	O
,	O
the	O
fact	O
that	O
one	O
can	O
"	O
layer	O
"	O
multiple	O
channels	O
on	O
the	O
same	O
frequency	O
band	O
means	O
that	O
the	O
system	O
spectrum	O
utilization	O
for	O
a	O
multi-channel	O
CDMA	B-Protocol
system	O
can	O
be	O
very	O
good	O
.	O
</s>
<s>
Example	O
9	O
:	O
In	O
the	O
W-CDMA	O
3G	B-Architecture
cellular	I-Architecture
system	O
,	O
every	O
phone	O
call	O
is	O
compressed	O
to	O
a	O
maximum	O
of	O
8,500	O
bit/s	O
(	O
the	O
useful	O
bitrate	O
)	O
,	O
and	O
spread	O
out	O
over	O
a	O
5MHz	O
wide	O
frequency	O
channel	O
.	O
</s>
<s>
Spread	B-Architecture
spectrum	I-Architecture
makes	O
it	O
possible	O
to	O
have	O
as	O
low	O
a	O
frequency	O
reuse	O
factor	O
as	O
1	O
,	O
if	O
each	O
base	O
station	O
is	O
divided	O
into	O
3	O
cells	O
by	O
means	O
of	O
3	O
directional	O
sector	O
antennas	O
.	O
</s>
<s>
This	O
corresponds	O
to	O
a	O
system	B-Protocol
spectrum	I-Protocol
efficiency	I-Protocol
of	O
over	O
1	O
×	O
100	O
×	O
0.0017	O
=	O
0.17	O
(	O
bit/s	O
)	O
/Hz	O
per	O
site	O
,	O
and	O
0.17/3	O
=	O
0.06	O
(	O
bit/s	O
)	O
/Hz	O
per	O
cell	O
or	O
sector	O
.	O
</s>
<s>
The	O
spectral	B-Protocol
efficiency	I-Protocol
can	O
be	O
improved	O
by	O
radio	B-Protocol
resource	I-Protocol
management	I-Protocol
techniques	O
such	O
as	O
efficient	O
fixed	O
or	O
dynamic	O
channel	B-Protocol
allocation	I-Protocol
,	O
power	O
control	O
,	O
link	B-Protocol
adaptation	I-Protocol
and	O
diversity	B-Protocol
schemes	I-Protocol
.	O
</s>
<s>
A	O
combined	O
fairness	B-Protocol
measure	I-Protocol
and	O
system	O
spectral	B-Protocol
efficiency	I-Protocol
measure	O
is	O
the	O
fairly	O
shared	O
spectral	B-Protocol
efficiency	I-Protocol
.	O
</s>
<s>
Examples	O
of	O
predicted	O
numerical	O
spectral	B-Protocol
efficiency	I-Protocol
values	O
of	O
some	O
common	O
communication	O
systems	O
can	O
be	O
found	O
in	O
the	O
table	O
below	O
.	O
</s>
<s>
Spectral	B-Protocol
efficiency	I-Protocol
of	O
common	O
communication	O
systems	O
Service	O
Standard	O
Launched	O
,	O
year	O
Max	O
.	O
</s>
<s>
link	B-Protocol
spectral	I-Protocol
efficiency	I-Protocol
,	O
R/B	O
(	O
bit/	O
( s⋅Hz	O
)	O
)	O
Typical	O
reuse	O
factor	O
,	O
1/K	O
System	O
spectral	B-Protocol
efficiency	I-Protocol
,	O
R/B	O
⋅K	O
(	O
bit/	O
( s⋅Hz	O
)	O
)	O
per	O
site	O
)	O
SISO	O
MIMO	O
1G	O
cellular	O
NMT	O
450	O
modem	B-Application
1981	O
0.0012	O
0.025	O
0.45	O
0.142857	O
0.064	O
1G	O
cellular	O
AMPS	O
modem	B-Application
1983	O
0.0003C	O
.	O
</s>
<s>
1.35	O
)	O
0.33333	O
0.45	O
3G	B-Architecture
cellular	I-Architecture
WCDMA	O
FDD	O
2001	O
0.384	O
5	O
0.077	O
1	O
0.51	O
3G	B-Architecture
cellular	I-Architecture
CDMA2000	O
1×	O
PD	O
2002	O
0.153	O
1.2288	O
0.125	O
1	O
0.1720	O
(	O
fully	O
loaded	O
)	O
3G	B-Architecture
cellular	I-Architecture
CDMA2000	O
1×	O
EV-DO	O
Rev.A	O
2002	O
3.072	O
1.2288	O
2.5	O
1	O
1.3	O
Fixed	O
WiMAX	O
IEEE	O
802.16d	O
2004	O
96	O
20	O
4.8	O
0.25	O
1.2	O
3.5G	O
cellular	O
HSDPA	O
2007	O
21.1	O
5	O
4.22	O
1	O
4.22	O
4G	B-Architecture
MBWA	O
iBurst	O
HC-SDMA	O
2005	O
3.9	O
0.625	O
7.3	O
1	O
7.3	O
4G	B-Architecture
cellular	O
LTE	O
2009	O
81.6	O
20	O
4.08	O
16.32	O
(	O
4×4	O
)	O
1	O
(	O
0.33333	O
at	O
the	O
perimeters	O
)	O
16.32	O
4G	B-Architecture
cellular	O
LTE-Advanced	O
2013	O
75	O
20	O
3.75	O
30.00	O
(	O
8×8	O
)	O
1	O
(	O
0.33333	O
at	O
the	O
perimeters	O
)	O
30	O
Wi-Fi	O
IEEE	O
802.11a/g	O
2003	O
54	O
20	O
2.7	O
0.33333	O
0.900	O
Wi-Fi	O
IEEE	O
802.11n	O
(	O
Wi-Fi	O
4	O
)	O
2007	O
72.2	O
(	O
up	O
to	O
150	O
)	O
20	O
(	O
up	O
to	O
40	O
)	O
3.61	O
(	O
up	O
to	O
3.75	O
)	O
Up	O
to	O
15.0	O
(	O
4×4	O
,	O
40MHz	O
)	O
0.33333	O
5.0	O
(	O
4×4	O
,	O
40MHz	O
)	O
Wi-Fi	O
IEEE	O
802.11ac	O
(	O
Wi-Fi	O
5	O
)	O
2012	O
433.3	O
(	O
up	O
to	O
866.7	O
)	O
80	O
(	O
up	O
to	O
160	O
)	O
5.42	O
Up	O
to	O
43.3	O
(	O
8×8	O
,	O
160MHz	O
)	O
0.33333	O
14.4	O
(	O
8×8	O
,	O
160MHz	O
)	O
Wi-Fi	O
IEEE	O
802.11ax	O
(	O
Wi-Fi	O
6	O
)	O
2019	O
600.5	O
(	O
up	O
to	O
1201	O
)	O
80	O
(	O
up	O
to	O
160	O
)	O
7.5	O
Up	O
to	O
60	O
(	O
8×8	O
,	O
160MHz	O
)	O
0.33333	O
20	O
(	O
8×8	O
,	O
160MHz	O
)	O
WiGig	O
IEEE	B-General_Concept
802.11ad	I-General_Concept
2013	O
6756	O
2160	O
3	O
1	O
3	O
Trunked	O
radio	O
system	O
TETRA	O
,	O
low	O
FEC	B-Error_Name
1998	O
0.019	O
4	O
timeslots	O
=	O
0.019	O
(	O
0.029	O
without	O
FEC	B-Error_Name
)	O
0.025	O
0.8	O
0.142857	O
0.1	O
Trunked	O
radio	O
system	O
TETRA	O
II	O
with	O
TEDS	O
,	O
64-QAM	B-Device
,	O
150	O
kHz	O
,	O
low	O
FEC	B-Error_Name
2011	O
0.538	O
4	O
timeslots	O
=	O
0.538	O
0.150	O
(	O
scalable	O
to	O
0.025	O
)	O
3.6	O
Digital	O
radio	O
DAB	O
1995	O
0.576	O
to	O
1.152	O
1.712	O
0.34	O
to	O
0.67	O
0.200	O
0.07	O
to	O
0.13	O
Digital	O
radio	O
DAB	O
with	O
SFN	B-Device
1995	O
0.576	O
to	O
1.152	O
1.712	O
0.34	O
to	O
0.67	O
1	O
0.34	O
to	O
0.67	O
Digital	B-Application
TV	I-Application
DVB-T	O
1997	O
31.67	O
(	O
typ	O
.	O
</s>
<s>
3.0	O
)	O
0.143	O
0.57	O
Digital	B-Application
TV	I-Application
DVB-T	O
with	O
SFN	B-Device
1996	O
31.67	O
(	O
typ	O
.	O
</s>
<s>
3.0	O
)	O
Digital	B-Application
TV	I-Application
DVB-T2	B-Protocol
2009	O
45.5	O
(	O
typ	O
.	O
</s>
<s>
5.0	O
)	O
0.143	O
0.81	O
Digital	B-Application
TV	I-Application
DVB-T2	B-Protocol
with	O
SFN	B-Device
2009	O
45.5	O
(	O
typ	O
.	O
</s>
<s>
5.0	O
)	O
Digital	B-Application
TV	I-Application
DVB-S	O
1995	O
33.8	O
for	O
5.1	O
C/N	O
(	O
44.4	O
for	O
7.8	O
C/N	O
)	O
27.5	O
1.2	O
(	O
1.6	O
)	O
0.250	O
0.3	O
(	O
0.4	O
)	O
Digital	B-Application
TV	I-Application
DVB-S2	O
2005	O
46	O
for	O
5.1	O
C/N	O
(	O
58.8	O
for	O
7.8	O
C/N	O
)	O
30	O
(	O
typ	O
.	O
)	O
</s>
