Method and apparatus for transmitting and receiving sidelink data

1. A method for performing a sidelink data transmission, carried out by a transmitter user equipment (UE), the method comprising:

transmitting a radio resource allocation request message for requesting an allocation of a radio resource used for the sidelink data transmission;

receiving first radio resource information for the sidelink data transmission and second radio resource information for a sidelink data retransmission;

performing the sidelink data transmission based on the first radio resource information; and

performing the sidelink data retransmission based on the second radio resource information upon a triggering of retransmission, which associates with a reception of hybrid automatic repeat request (HARQ) feedback information for sidelink data,

wherein a first radio resource allocated by the first radio resource information is a resource pool for an initial transmission of the sidelink data, and a second radio resource allocated by the second radio resource information is a resource pool for retransmitting the sidelink data,

wherein the first radio resource and the second radio resource included in N resource pools correspond to the initial transmission and N−1 retransmissions, respectively, where N is an integer number equal to or greater than 1.

2. The method according to claim 1 , wherein the first radio resource information and the second radio resource information are received through sidelink control information (SCI).

3. The method according to claim 1 , wherein the number of second radio resources included in the second radio resource information is set based on channel information for transmission of the sidelink data.

4. The method according to claim 3 , wherein the channel information includes at least one of a wideband channel quality indicator (CQI), a subband CQI, a precoding matrix indicator (PMI), a Rank Indicator (RI), or a modulation coding scheme (MCS).

5. A method for monitoring a sidelink data transmission, carried out by a receiver user equipment (UE), the method comprising:

receiving first radio resource information for the sidelink data transmission and second radio resource information for a sidelink data retransmission from a transmitter UE;

monitoring the sidelink data transmission over a first radio resource;

transmitting hybrid automatic repeat request (HARQ) feedback information to the transmitter UE based on that the sidelink data is not received; and

monitoring the sidelink data retransmission that the transmitter UE has retransmitted over a second radio resource according to the HARQ feedback information,

wherein the first radio resource allocated by the first radio resource information is a resource pool for an initial transmission of sidelink data, and the second radio resource included in the second radio resource information is a resource pool for retransmitting the sidelink data,

wherein the first radio resource and the second radio resource included in N resource pools correspond to the initial transmission and N−1 retransmissions, respectively, where N is an integer number equal to or greater than 1.

6. The method according to claim 5 , wherein the first radio resource information and the second radio resource information are received through sidelink control information (SCI).

7. The method according to claim 5 , wherein the number of second radio resources is set based on channel information for reception of the sidelink data.

8. The method according to claim 7 , wherein the channel information includes at least one of a wideband channel quality indicator (CQI), a subband CQI, a precoding matrix indicator (PMI), a Rank Indicator (RI), or a modulation coding scheme (MCS).

9. A transmitter user equipment (UE) for performing a sidelink data transmission, the transmitter UE comprising:

a transmitter that transmitting a radio resource allocation request message for requesting allocation of a radio resource used for the sidelink data transmission; and

a receiver that receiving first radio resource information for the sidelink data transmission and second radio resource information for a sidelink data retransmission,

wherein the transmitter performs the sidelink data transmission based on the first radio resource information, and upon a triggering of retransmission, which associates with a reception of hybrid automatic repeat request (HARQ) feedback information for sidelink data, the transmitter further performs the sidelink data retransmission based on the second radio resource information,

wherein a first radio resource allocated by the first radio resource information is a resource pool for an initial transmission of the sidelink data, and a second radio resource allocated by the second radio resource information is a resource pool for retransmitting the sidelink data,

wherein the first radio resource and the second radio resource included in N resource pools correspond to the initial transmission and N−1 retransmissions, respectively, where N is an integer number equal to or greater than 1.

10. The transmitter UE according to claim 9 , wherein the first radio resource information and the second radio resource information are received through sidelink control information (SCI).

11. The transmitter UE according to claim 9 , wherein the number of second radio resources included in the second radio resource information is set based on channel information for transmission of the sidelink data.

12. The transmitter UE according to claim 11 , wherein the channel information includes at least one of a wideband channel quality indicator (CQI), a subband CQI, a matrix indicator (PMI), a Rank Indicator (RI), or a modulation coding scheme (MCS).