Uplink MIMO STBC communication method in wireless communication system and apparatus for same

1. A method of transmitting a signal by a first user equipment (UE) in a wireless communication system supporting multi-antenna, the method comprising:

mapping, by the first UE, first demodulation reference signals (DMRSs) for a first antenna port to a first Orthogonal Frequency Division Multiplexing (OFDM) symbol having a lowest OFDM symbol index in a subframe, wherein the first OFDM symbol is used for Automatic Gain Control (AGC);

mapping, by the first UE, second DMRSs for a second antenna port to a second OFDM symbol different from the first OFDM symbol;

mapping, by the first UE, data received from a plurality of antenna ports to one or more OFDM symbols of the subframe other than the first and second OFDM symbols according to Drill a Space-Time Block Code (STBC) scheme; and

transmitting, by the first UE to a second UE, the subframe using a resource allocated for uplink,

wherein, when the one or more OFDM symbols is an odd number of symbols, the second DMRSs for the second antenna port are additionally mapped to a third OFDM symbol among the one or more OFDM symbols, and

wherein the first and second antenna ports are included in the plurality of antenna ports.

2. The method of claim 1 , wherein the step of mapping the data received from the plurality of antenna ports comprises the step of alternately mapping data received from the first antenna port and data received from the second antenna port to the one or more OFDM symbols.

3. The method of claim 2 , wherein when an extended cyclic prefix is used, an index of the second OFDM symbol is 3 and an index of the third OFDM symbol is 8.

4. The method of claim 1 , wherein the data received from each of the plurality of the antenna ports is sequentially mapped to the one or more OFDM symbols according to a subcarrier.

5. A method of receiving a signal by a first user equipment (UE) in a wireless communication system supporting multi-antenna, the method comprising:

receiving, by the first UE from a second UE, a subframe using a resource allocated for uplink; and

performing, by the first UE, Automatic Gain Control (AGC) using a first Orthogonal Frequency Division Multiplexing (OFDM) symbol having a lowest OFDM symbol index in the subframe,

wherein first demodulation reference signals (DMRSs) for a first antenna port are mapped to the first OFDM symbol,

wherein second DMRSs for a second antenna port are mapped to a second OFDM symbol different from the first OFDM symbol,

wherein data received from a plurality of antenna ports are mapped to one or more OFDM symbols of the subframe other than the first and second OFDM symbols according to a Space-Time Block Code (STBC) scheme,

wherein, when the one or more OFDM symbols is an odd number of symbols, the second DMRSs for the second antenna port are additionally mapped to a third OFDM symbol among the one or more OFDM symbols, and

wherein the first and second antenna ports are included in the plurality of antenna ports.

6. The method of claim 5 , wherein the data received from the plurality of antenna ports correspond to data received from the first antenna port and data received from the second antenna port, which are alternately mapped to the one or more OFDM symbols.

7. The method of claim 6 , wherein when an extended cyclic prefix is used, an index of the second OFDM symbol is 3 and an index of the third OFDM symbol is 8.

8. The method of claim 5 , wherein the data received from each of the plurality of the antenna ports is sequentially mapped to the one or more OFDM symbols according to a subcarrier.

9. A user equipment (UE) in a wireless communication system supporting multi-antenna, the UE comprising:

a transmitter; and

a processor, operatively coupled to the transmitter,

wherein the processor:

maps first demodulation reference signals (DMRSs) for a first antenna port to a first Orthogonal Frequency Division Multiplexing (OFDM) symbol having a lowest OFDM symbol index in a subframe, wherein the first OFDM symbol is used for Automatic Gain Control (AGC),

maps second DMRSs for a second antenna port to a second OFDM symbol different from the first OFDM symbol,

maps data received from a plurality of antenna ports to one or more OFDM symbols of the subframe other than the first and second OFDM symbols according to a Space-Time Block Code (STBC) scheme,

controls the transmitter to transmit the subframe using a resource allocated for uplink,

wherein, when the one or more OFDM symbols is an odd number of symbols, the second DMRSs for the second antenna port are additionally mapped to a third OFDM symbol among the one or more OFDM symbols, and

wherein the first and second antenna ports are included in the plurality of antenna ports.

10. A user equipment (UE) in a wireless communication system supporting multi-antenna, the UE comprising:

a receiver; and

a processor, operatively coupled to the receiver,

wherein the processor:

receive a subframe using a resource allocated to uplink,

performs Automatic Gain Control (AGC) using a first Orthogonal Frequency Division Multiplexing (OFDM) symbol having a lowest OFDM symbol index in the subframe,

wherein first demodulation reference signals (DMRSs) for a first antenna port are mapped to the first OFDM symbol, and

wherein second DMRSs for a second antenna port are mapped to a second OFDM symbol different from the first OFDM symbol,

wherein data received from a plurality of antenna ports are mapped to one or more OFDM symbols of the subframe other than the first and second OFDM symbols according to a Space-Time Block Code (STBC) scheme,

wherein, when the one or more OFDM symbols is an odd number of symbols, the second DMRSs for the second antenna port are additionally mapped to a third OFDM symbol among the one or more OFDM symbols, and

wherein the first and second antenna ports are included in the plurality of antenna ports.