Method for transmitting sounding reference signal in multiple antenna wireless communication system and apparatus therefor
A method for transmitting sounding reference signals by a user equipment (UE) in a wireless communication system. The method according to one embodiment includes configuring an initial cyclic shift (CS) value and an initial comb value via a higher layer; setting a comb value for at least one antenna port; and transmitting the sounding reference signals using the comb value via at least one antenna port.
1. A method for transmitting sounding reference signals by a user equipment (UE) in a wireless communication system, the method comprising:
configuring an initial cyclic shift (CS) value and an initial comb value via a higher layer;
setting a comb value for at least one antenna port according to a following Equation A:
k
TC
(
p
~
)
=
{
1
-
k
_
TC
if
n
SRS
cs
∈
{
4
,
5
,
6
,
7
}
and
p
~
∈
{
1
,
3
}
and
N
ap
=
4
k
_
TC
otherwise
<
Equation
A
>
where {tilde over (p)} is an antenna port index, k TC ({tilde over (p)}) is the comb value for the antenna port index {tilde over (p)}, n SRS cs is the initial CS value, k TC is the initial comb value, and N ap is a number of the at least one antenna port; and
transmitting the sounding reference signals using the comb value via at least one antenna port.
2. The method of claim 1 , wherein the initial CS value is an integer between 0 and 7.
3. The method of claim 2 , wherein a cyclic shift value for at least one antenna port is determined in accordance with a following Equation B:
n
SRS
cs
,
p
~
=
(
n
SRS
cs
+
8
p
~
N
ap
)
mod
8
,
<
Equation
B
>
where n SRS cs,{tilde over (p)} is the cyclic shift value for the antenna port index {tilde over (p)}.
4. The method of claim 1 , wherein the initial comb value is 0 or 1.
5. The method of claim 1 , wherein the number of the at least one antenna port is 1, 2, or 4.
6. A user equipment (UE) for setting comb values of four antenna ports for transmitting sounding reference signals in a wireless communication system, the UE comprising:
a processor configured to:
configure an initial cyclic shift (CS) value and an initial comb value via a higher layer, and
set a comb value for at least one antenna port according to a following Equation A:
k
TC
(
p
~
)
=
{
1
-
k
_
TC
if
n
SRS
cs
∈
{
4
,
5
,
6
,
7
}
and
p
~
∈
{
1
,
3
}
and
N
ap
=
4
k
_
TC
otherwise
,
<
Equation
A
>
where {tilde over (p)} is an antenna port index, k TC ({tilde over (p)}) is the comb value for the antenna port index {tilde over (p)}, n SRS cs is the initial CS value, k TC is the initial comb value, and N ap is a number of the at least one antenna port; and
a Radio Frequency (RF) module configured to transmit the sounding reference signals using the comb value via at least one antenna port.
7. The UE of claim 6 , wherein the initial CS value is an integer between 0 and 7.
8. The UE of claim 7 , wherein the processor is further configured to determine a cyclic shift value for at least one antenna port in accordance with a following Equation B:
n
SRS
cs
,
p
~
=
(
n
SRS
cs
+
8
p
~
N
ap
)
mod
8
,
<
Equation
B
>
where n SRS cs,{tilde over (p)} is the cyclic shift value for the antenna port index {tilde over (p)}.
9. The UE of claim 6 , wherein the initial comb value is 0 or 1.
10. The UE of claim 6 , wherein the number of the at least one antenna port is 1, 2, or 4.