Method and apparatus for channel state reporting in wireless communication system

1. A method performed by a first wireless device in a wireless communication system, the method comprising:

establishing a sidelink connection between the first wireless device and a second wireless device;

receiving, from the second wireless device, sidelink control information (SCI) for triggering a sidelink (SL)-channel state information (CSI) reporting;

triggering the SL-CSI reporting based on the SCI; and

based on i) triggering the SL-CSI reporting and ii) a sidelink resource for a transmission of a media access control (MAC) control element (CE) for the SL-CSI reporting being unavailable, transmitting a signal for requesting the sidelink resource to a network.

2. The method of claim 1 , wherein the sidelink resource comprises a SL grant.

3. The method of claim 1 , wherein the transmitting the signal comprises:

triggering a SL-buffer status report (BSR);

creating the SL-BSR comprising information informing that the SL-CSI reporting is triggered for a destination identity (ID); and

transmitting the SL-BSR to the network.

4. The method of claim 3 , wherein the information comprises at least one of the destination ID, a logical channel group ID, or a buffer size.

5. The method of claim 3 , further comprising:

receiving, from the network, downlink control information (DCI) comprising scheduling information for the SL resource after transmitting the SL-BSR to the network; and

transmitting, to the second wireless device via the SL resource, the MAC CE for the SL-CSI reporting including SL-CSI.

6. The method of claim 3 , wherein the transmitting the signal comprises:

upon determining that the sidelink resource for a transmission of the MAC CE for the SL-CSI reporting is unavailable and the first wireless device is configured with a sidelink resource allocation mode 1 , triggering a scheduling request (SR); and

transmitting the SR to the network via a physical resource uplink channel (PUCCH),

wherein the sidelink resource allocation mode 1 is the mode in which sidelink resource are scheduled by the network.

7. The method of claim 6 , further comprising:

receiving, from the network, downlink control information (DCI) comprising scheduling information for an uplink resource after transmitting the SR to the network,

wherein the transmitting the SL-BSR comprises transmitting the SL-BSR to the network via the uplink resource.

8. The method of claim 1 , wherein the first wireless device is in communication with at least one of a user equipment, a network, or autonomous vehicles other than the wireless device.

9. A wireless device in a wireless communication system comprising:

a transceiver;

a memory; and

at least one processor operatively coupled to the transceiver and the memory, and configured to:

establish a sidelink connection between the first wireless device and a second wireless device;

control the transceiver to receive, from the second wireless device, sidelink control information (SCI) for triggering a sidelink (SL)-channel state information (CSI) reporting;

trigger the SL-CSI reporting based on the SCI; and

based on i) triggering the SL-CSI reporting and ii) a sidelink resource for a transmission of a media access control (MAC) control element (CE) for the SL-CSI reporting being unavailable, control the transceiver to transmit a signal for requesting the sidelink resource to a network.

10. The wireless device of claim 9 , wherein the sidelink resource comprises a SL grant.

11. The wireless device of claim 9 , wherein the at least one processor is further configured to:

trigger a SL-buffer status report (BSR);

create the SL-BSR comprising information informing that the SL-CSI reporting is triggered for a destination identity (ID); and

control the transceiver to transmit the SL-BSR to the network.

12. The wireless device of claim 11 , wherein the information comprises at least one of the destination ID, a logical channel group ID, or a buffer size.

13. The wireless device of claim 11 , wherein the at least one processor is further configured to control the transceiver to:

receive, from the network, downlink control information (DCI) comprising scheduling information for the SL resource after transmitting the SL-BSR to the network; and

transmit, to the second wireless device via the SL resource, the MAC CE for the SL-CSI reporting including SL-CSI.

14. The wireless device of claim 11 , wherein the at least one processor is further configured to:

upon determining that the sidelink resource for a transmission of the MAC CE for the SL-CSI reporting is unavailable and the first wireless device is configured with a sidelink resource allocation mode 1 , trigger a scheduling request (SR), wherein the sidelink resource allocation mode 1 is the mode in which sidelink resource are scheduled by the network;

control the transceiver to transmit the SR to the network via a physical resource uplink channel (PUCCH);

control the transceiver to receive, from the network, downlink control information (DCI) comprising scheduling information for an uplink resource after transmitting the SR to the network; and

control the transceiver to transmit the SL-BSR to the network via the uplink resource.

15. A computer-readable medium having recorded thereon a program for performing each step of a method on a computer, the method comprising:

establishing a sidelink connection between the first wireless device and a second wireless device;

receiving, from the second wireless device, sidelink control information (SCI) for triggering a sidelink (SL)-channel state information (CSI) reporting;

triggering the SL-CSI reporting based on the SCI; and

based on i) triggering the SL-CSI reporting and ii) a sidelink resource for a transmission of a media access control (MAC) control element (CE) for the SL-CSI reporting being unavailable, transmitting a signal for requesting the sidelink resource to a network.