<s>
Transmit	B-Protocol
diversity	I-Protocol
is	O
radio	O
communication	O
using	O
signals	O
that	O
originate	O
from	O
two	O
or	O
more	O
independent	O
sources	O
that	O
have	O
been	O
modulated	B-Application
with	O
identical	O
information-bearing	O
signals	O
and	O
that	O
may	O
vary	O
in	O
their	O
transmission	B-Algorithm
characteristics	I-Algorithm
at	O
any	O
given	O
instant	O
.	O
</s>
<s>
When	O
using	O
diversity	B-Protocol
transmission	I-Protocol
and	O
reception	O
,	O
the	O
amount	O
of	O
received	O
signal	O
improvement	O
depends	O
on	O
the	O
independence	O
of	O
the	O
fading	O
characteristics	O
of	O
the	O
signal	O
as	O
well	O
as	O
circuit	O
outages	O
and	O
failures	O
.	O
</s>
<s>
In	O
these	O
cases	O
,	O
transmit	B-Protocol
diversity	I-Protocol
can	O
be	O
used	O
to	O
provide	O
diversity	O
benefit	O
at	O
a	O
receiver	O
with	O
multiple	O
transmit	O
antennas	O
only	O
.	O
</s>
<s>
With	O
transmit	B-Protocol
diversity	I-Protocol
,	O
multiple	O
antennas	O
transmit	O
delayed	O
versions	O
of	O
a	O
signal	O
,	O
creating	O
frequency-selective	O
fading	O
,	O
which	O
is	O
equalized	O
at	O
the	O
receiver	O
to	O
provide	O
diversity	B-Protocol
gain	I-Protocol
.	O
</s>
<s>
Since	O
transmit	B-Protocol
diversity	I-Protocol
with	O
N	O
antennas	O
results	O
in	O
N	O
sources	O
of	O
interference	O
to	O
other	O
users	O
,	O
the	O
interference	O
environment	O
will	O
be	O
different	O
from	O
conventional	O
systems	O
with	O
one	O
transmit	O
antenna	O
.	O
</s>
<s>
Thus	O
even	O
if	O
transmit	B-Protocol
diversity	I-Protocol
has	O
almost	O
the	O
same	O
performance	O
as	O
receive	O
diversity	O
in	O
noise-limited	O
environments	O
,	O
the	O
performance	O
in	O
interference-limited	O
environments	O
will	O
differ	O
.	O
</s>
