<s>
In	O
the	O
field	O
of	O
wireless	O
communication	O
,	O
macrodiversity	B-Protocol
is	O
a	O
kind	O
of	O
space	O
diversity	B-Protocol
scheme	I-Protocol
using	O
several	O
receiver	O
or	O
transmitter	O
antennas	O
for	O
transferring	O
the	O
same	O
signal	O
.	O
</s>
<s>
In	O
a	O
cellular	O
network	O
or	O
a	O
wireless	B-Architecture
LAN	I-Architecture
,	O
macro-diversity	B-Protocol
implies	O
that	O
the	O
antennas	O
are	O
typically	O
situated	O
in	O
different	O
base	O
station	O
sites	O
or	O
access	B-Device
points	I-Device
.	O
</s>
<s>
Receiver	O
macro-diversity	B-Protocol
is	O
a	O
form	O
of	O
antenna	B-Protocol
combining	I-Protocol
,	O
and	O
requires	O
an	O
infrastructure	O
that	O
mediates	O
the	O
signals	O
from	O
the	O
local	O
antennas	O
or	O
receivers	O
to	O
a	O
central	O
receiver	O
or	O
decoder	O
.	O
</s>
<s>
Transmitter	O
macro-diversity	B-Protocol
may	O
be	O
a	O
form	O
of	O
simulcasting	O
,	O
where	O
the	O
same	O
signal	O
is	O
sent	O
from	O
several	O
nodes	O
.	O
</s>
<s>
the	O
channel	O
frequency	O
and	O
the	O
spreading	O
sequence	O
)	O
,	O
the	O
transmitters	O
are	O
said	O
to	O
form	O
a	O
single-frequency	B-Device
network	I-Device
—	O
a	O
term	O
used	O
especially	O
in	O
the	O
broadcasting	O
world	O
.	O
</s>
<s>
The	O
aim	O
is	O
to	O
combat	O
fading	O
and	O
to	O
increase	O
the	O
received	O
signal	O
strength	O
and	O
signal	O
quality	O
in	O
exposed	O
positions	O
in	O
between	O
the	O
base	O
stations	O
or	O
access	B-Device
points	I-Device
.	O
</s>
<s>
Macro	B-Protocol
diversity	I-Protocol
may	O
also	O
facilitate	O
efficient	O
multicast	O
services	O
,	O
where	O
the	O
same	O
frequency	O
channel	O
can	O
be	O
used	O
for	O
all	O
transmitters	O
sending	O
the	O
same	O
information	O
.	O
</s>
<s>
The	O
diversity	B-Protocol
scheme	I-Protocol
may	O
be	O
based	O
on	O
transmitter	O
(	O
downlink	O
)	O
macro-diversity	B-Protocol
and/or	O
receiver	O
(	O
uplink	O
)	O
macro-diversity	B-Protocol
.	O
</s>
<s>
CDMA	B-Protocol
soft	B-Protocol
handoff	I-Protocol
:	O
</s>
<s>
UMTS	B-Protocol
softer	B-Protocol
handoff	I-Protocol
.	O
</s>
<s>
3GPP	O
long-term	O
evolution	O
(	O
LTE	O
)	O
multicast-broadcast	O
single-frequency	B-Device
network	I-Device
(	O
MBSFN	O
)	O
,	O
making	O
it	O
possible	O
to	O
efficiently	O
send	O
the	O
same	O
data	O
to	O
many	O
mobiles	O
in	O
adjacent	O
cells	O
.	O
</s>
<s>
Cooperative	B-Protocol
diversity	I-Protocol
,	O
for	O
example	O
3GPP	O
long	O
term	O
evolution	O
(	O
LTE	O
)	O
coordinated	O
multipoint	O
transmission/reception	O
(	O
CoMP	O
)	O
,	O
making	O
it	O
possible	O
to	O
increase	O
the	O
data	O
rate	O
to	O
a	O
mobile	O
situated	O
in	O
the	O
overlap	O
of	O
several	O
base	O
station	O
transmission	O
ranges	O
.	O
</s>
<s>
The	O
baseline	O
form	O
of	O
macrodiversity	B-Protocol
is	O
called	O
single-user	O
macrodiversity	B-Protocol
.	O
</s>
<s>
In	O
next	O
more	O
advanced	O
form	O
of	O
macrodiversity	B-Protocol
,	O
multiple	O
distributed	O
users	O
communicate	O
with	O
multiple	O
distributed	O
base	O
stations	O
in	O
the	O
same	O
time	O
and	O
frequency	O
resource	O
.	O
</s>
<s>
In	O
macrodiversity	B-Protocol
scenario	O
,	O
</s>
<s>
It	O
has	O
been	O
shown	O
that	O
there	O
exists	O
a	O
functional	O
link	O
between	O
the	O
permanent	O
of	O
macrodiversity	B-Protocol
power	O
profile	O
matrix	O
,	O
and	O
the	O
performance	O
of	O
multi-user	O
macrodiversity	B-Protocol
systems	O
in	O
fading	O
.	O
</s>
<s>
Although	O
it	O
appears	O
as	O
if	O
the	O
macrodiversity	B-Protocol
only	O
manifests	O
itself	O
in	O
the	O
power	O
profile	O
,	O
systems	O
that	O
rely	O
on	O
macrodiversity	B-Protocol
will	O
typically	O
have	O
other	O
types	O
of	O
transmit	O
power	O
constraints	O
(	O
e.g.	O
,	O
each	O
element	O
of	O
has	O
a	O
limited	O
average	O
power	O
)	O
and	O
different	O
sets	O
of	O
coordinating	O
transmitters/receivers	O
when	O
communicating	O
with	O
different	O
users	O
.	O
</s>
