<s>
In	O
signal	O
processing	O
,	O
direction	B-Algorithm
of	I-Algorithm
arrival	I-Algorithm
(	O
DOA	O
)	O
denotes	O
the	O
direction	O
from	O
which	O
usually	O
a	O
propagating	O
wave	O
arrives	O
at	O
a	O
point	O
,	O
where	O
usually	O
a	O
set	O
of	O
sensors	O
are	O
located	O
.	O
</s>
<s>
Often	O
there	O
is	O
the	O
associated	O
technique	O
of	O
beamforming	B-Algorithm
which	O
is	O
estimating	O
the	O
signal	O
from	O
a	O
given	O
direction	O
.	O
</s>
<s>
Recently	O
beamforming	B-Algorithm
has	O
also	O
been	O
used	O
in	O
radio	O
frequency	O
(	O
RF	O
)	O
applications	O
such	O
as	O
wireless	O
communication	O
.	O
</s>
<s>
Compared	O
with	O
the	O
spatial	O
diversity	O
techniques	O
,	O
beamforming	B-Algorithm
is	O
preferred	O
in	O
terms	O
of	O
complexity	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
beamforming	B-Algorithm
in	O
general	O
has	O
much	O
lower	O
data	O
rates	O
.	O
</s>
<s>
Various	O
techniques	O
for	O
calculating	O
the	O
direction	B-Algorithm
of	I-Algorithm
arrival	I-Algorithm
,	O
such	O
as	O
angle	B-Algorithm
of	I-Algorithm
arrival	I-Algorithm
(	O
AoA	O
)	O
,	O
time	O
difference	O
of	O
arrival	O
(	O
TDOA	O
)	O
,	O
frequency	O
difference	O
of	O
arrival	O
(	O
FDOA	O
)	O
,	O
or	O
other	O
similar	O
associated	O
techniques	O
.	O
</s>
<s>
Limitations	O
on	O
the	O
accuracy	O
of	O
estimation	O
of	O
direction	B-Algorithm
of	I-Algorithm
arrival	I-Algorithm
signals	O
in	O
digital	B-Algorithm
antenna	I-Algorithm
arrays	I-Algorithm
are	O
associated	O
with	O
jitter	O
ADC	O
and	O
DAC	O
.	O
</s>
