Method and apparatus for controlling transmit power in wireless communication system
A method and apparatus of controlling transmit power in a wireless communication system is provided. A wireless apparatus selects one transmit mode among a plurality of transmit modes, and determines the transmit power on the basis of the selected transmit mode. The wireless apparatus transmits an uplink channel by using the transmit power.
1. A method for transmitting a control signal in a wireless communication system, the method comprising:
determining, by a user equipment (UE), a first physical uplink control channel (PUCCH) resource for a first antenna port and a second PUCCH resource for a second antenna port; and
transmitting, by the UE, a PUCCH via the first antenna port and the second antenna port by using the first PUCCH resource and the second PUCCH resource based on an uplink transmit power,
wherein the uplink transmit power P PUCCH (i) at subframe i is determined by:
P PUCCH ( i )=min{ P CMAX(i) , P 0 — PUCCH PL+h ( n CQI , n HARQ )+Δ F — PUCCH ( F )+Δ( M )+ g ( i )}
where P CMAX(i) is a configured UE transmit power in subframe i,
P 0 — PUCCH is a parameter composed based on provisions by a higher layer,
Δ F 13 PUCCH (F) is a parameter provided by the higher layer,
h(n COI , n HARQ ) is a PUCCH format dependent value,
PL is a downlink pathloss estimate calculated in the UE,
g(i) is a value related to a UE specific value, and
Δ(M) is an offset value when the PUCCH is transmitted via the first antenna port and the second antenna port.
2. The method of claim 1 , wherein Δ(M)=0 when the PUCCH is transmitted via one antenna port.
3. The method of claim 1 , wherein a list of values of Δ(M) is provided by a base station in accordance with PUCCH formats.
4. The method of claim 3 , wherein the PUCCH formats are defined by:
PUCCH Format
Modulation Scheme
Number of Bits per subframe
1
N/A
N/A
1a
BPSK
1
1b
QPSK
2
2
QPSK
20
2a
QPSK + BPSK
21
2b
QPSK + BPSK
22
5. The method of claim 1 , wherein the PUCCH carries at least one of a scheduling request, an ACK/NACK for hybrid automatic repeat request (HARQ) and a channel quality indicator (CQI).
6. The method of claim 1 , further comprising:
receiving information about a transmission mode from a base station, the transmission mode indicating that the PUCCH is transmitted via one antenna port or two antenna ports.
7. A user equipment (UE) in a wireless communication system, the UE comprising:
a first antenna port;
a second antenna port;
a transceiver configured to:
determine a first physical uplink control channel (PUCCH) resource for a first antenna port and a second PUCCH resource for a second antenna port, and
transmit a PUCCH via the first antenna port and the second antenna port by using the first PUCCH resource and the second PUCCH resource based on an uplink transmit power; and
a transmit power controller configured to determine the uplink transmit power P PUCCH (i) at subframe i by:
P PUCCH ( i )=min{ P CMAX(i) , P 0 — PUCCH +PL+h ( n CQI , n HARQ )+Δ F — PUCCH ( F )+Δ( M )+ g ( i )}
where P CMAX(i) is a configured UE transmit power in subframe i,
P 0 — PUCCH is a parameter composed based on provisions by a higher layer,
Δ F — PUCCH (F) is a parameter provided by the higher layer,
h(n COI , n HARQ ) is a PUCCH format dependent value,
PL is a downlink pathloss estimate calculated in the UE,
g(i) is a value related to a UE specific value, and
Δ(M) is an offset value when the PUCCH is transmitted via the first antenna port and the second antenna port.
8. The UE of claim 7 , wherein Δ(M)=0 when the uplink control channel is transmitted via one antenna port.
9. The UE of claim 7 , wherein a list of values of Δ(M) is provided by a base station in accordance with PUCCH formats.
10. The UE of claim 9 , wherein the PUCCH formats are defined by:
PUCCH Format
Modulation Scheme
Number of Bits per subframe
1
N/A
N/A
1a
BPSK
1
1b
QPSK
2
2
QPSK
20
2a
QPSK + BPSK
21
2b
QPSK + BPSK
22
11. The UE of claim 7 , wherein the PUCCH carries at least one of a scheduling request, an ACK/NACK for hybrid automatic repeat request (HARQ) and a channel quality indicator (CQI).
12. The UE of claim 7 , wherein the transceiver is configured to receive information about a transmission mode from a base station, the transmission mode indicating that the uplink control channel is transmitted via one antenna port or two antenna ports.