Method and apparatus for transmitting or receiving sounding reference signal in wireless communication system
A method for transmitting a sounding reference signal (SRS) by a user equipment (UE) in a wireless communication system supporting Time Division Duplex (TDD) includes: receiving transmission comb (TC) information indicating any one of a total of 4 TCs supported by a 4-TC SRS; mapping the 4-TC SRS to an SRS symbol of an Uplink Pilot Time Slot (UpPTS) of a TDD special subframe based on the TC information; and transmitting the 4-TC SRS through the UpPTS. In the mapping of the 4-TC SRS, the 4-TC SRS is mapped in a unit of 1 resource element (RE) per 4 REs on the SRS symbol based on a TC indicated by the TC information. The transmission of the 4-TC SRS is supported when a plurality of symbols are configured in the UpPTS.
1. A method for transmitting a sounding reference signal (SRS) by a user equipment (UE) in a wireless communication system supporting Time Division Duplex (TDD), the method comprising:
receiving transmission comb (TC) information indicating any one of a total of 4 TCs supported by a 4-TC SRS;
mapping the 4-TC SRS to an SRS symbol of an Uplink Pilot Time Slot (UpPTS) of a TDD special subframe based on the TC information; and
transmitting the 4-TC SRS through the UpPTS,
wherein in the mapping of the 4-TC SRS, the 4-TC SRS is mapped in a unit of 1 resource element (RE) per 4 REs on the SRS symbol based on a TC indicated by the TC information, and
wherein the transmission of the 4-TC SRS is supported when a plurality of symbols are configured in the UpPTS.
2. The method according to claim 1 , wherein
when a single symbol is configured in the UpPTS, the single symbol supports transmission of a 2-TC SRS other than the 4-TC SRS.
3. The method according to claim 1 , wherein an index of the SRS symbol to which the 4-TC SRS mapped is fixed within the UpPTS.
4. The method according to claim 1 , wherein the transmission of the 4-TC SRS is not allowed in an uplink subframe in which a 2-TC SRS is transmitted.
5. The method according to claim 1 , further comprising:
receiving information on an additional symbol available for SRS transmission from a base station (BS) through RRC signaling.
6. The method according to claim 1 , wherein the 4-TC SRS is transmitted through one or two of a plurality of antenna ports of the UE.
7. The method according to claim 6 , wherein:
if the 4-TC SRS is transmitted through a single antenna port, the single antenna port srs p (n) is determined by the following equation A,
srs
p
(
n
)
=
n
mod
M
n
=
⌊
(
10
·
n
f
+
⌊
n
s
2
⌋
)
T
SRS
⌋
[
Equation
A
]
where M is the number of reception (Rx) antennas of the UE, n f is a system frame number (SFN), n s is a slot number, and T SRS is a UE-specific SRS transmission periodicity.
8. The method according to claim 6 , wherein:
if the 4-TC SRS is transmitted through two antenna ports, the two antenna ports srs p (n) and srs p+1 (n) are determined by the following equation B,
srs
p
(
n
)
=
2
·
(
n
mod
M
2
)
srs
p
+
1
(
n
)
=
2
·
(
n
mod
M
2
)
+
1
n
=
⌊
(
10
·
n
f
+
⌊
n
s
2
⌋
)
T
SRS
⌋
[
Equation
B
]
where M is the number of reception (Rx) antennas of the UE, n f is a system frame number (SFN), n s is a slot number, and T SRS is a UE-specific SRS transmission periodicity.
9. A user equipment (UE) for transmitting a sounding reference signal (SRS) in a wireless communication system supporting Time Division Duplex (TDD) comprising:
a receiver to receive transmission comb (TC) information indicating any one of a total of 4 TCs supported by a 4-TC SRS;
a processor to map the 4-TC SRS to an SRS symbol of an Uplink Pilot Time Slot (UpPTS) of a TDD special subframe based on the TC information; and
a transmitter to transmit the 4-TC SRS through the UpPTS,
wherein in mapping the 4-TC SRS the processor maps the 4-TC SRS in a unit of 1 resource element (RE) per 4 REs on the SRS symbol based on a TC indicated by the TC information, and
wherein the 4-TC SRS transmission is supported when a plurality of symbols are configured in the UpPTS.
10. A method for receiving a sounding reference signal (SRS) by a base station (BS) in a wireless communication system supporting Time Division Duplex (TDD) comprising:
transmitting transmission comb (TC) information indicating any one of a total of 4 TCs supported by a 4-TC SRS; and
receiving the 4-TC SRS mapped to an SRS symbol of an Uplink Pilot Time Slot (UpPTS) of a TDD special subframe based on the TC information,
wherein the 4-TC SRS is mapped in a unit of 1 resource element (RE) per 4 REs on the SRS symbol based on a TC indicated by the TC information, and
wherein the reception of the 4-TC SRS is supported when a plurality of symbols are configured in the UpPTS.
11. The method according to claim 10 , wherein
when a single symbol is configured in the UpPTS, the single symbol supports transmission of a 2-TC SRS other than the 4-TC SRS.
12. The method according to claim 10 , wherein an index of the SRS symbol to which the 4-TC SRS mapped is fixed within the UpPTS.
13. The method according to claim 10 , wherein a transmission of the 4-TC SRS is not allowed in an uplink subframe in which a 2-TC SRS is transmitted.
14. The method according to claim 10 , further comprising:
transmitting, to a user equipment (UE) through RRC signaling, information on an additional symbol available for SRS transmission.
15. The method according to claim 10 , wherein the 4-TC SRS is transmitted through one or two of a plurality of antenna ports of a user equipment (UE).