Method and apparatus for handling device-to-device feedback transmission in a wireless communication system

A method for a first device to perform a sidelink communication, the method comprising:

• receiving a configuration, from a network, for operating in a network scheduling mode for acquiring sidelink resources;
• receiving, by the first device, a sidelink control information with a report request from a second device;
• triggering or being triggered to transmit a report to the second device in response to the report request, wherein a duration time is configured for canceling or discarding not yet transmitted or assembled report, and wherein the report is sidelink (SL) channel state information (CSI) report and the report comprises at least one of a Channel Quality Indicator, a Rank Indicator, or a Precoding Matrix Indicator;
• triggering, by the first device, a scheduling request in response to the SL CSI report for the second device or the report request from the second device if the first device has no available sidelink resource for transmitting the SL CSI report;
• and
• canceling or discarding the SL CSI report if the first device has not yet transmitted or assembled the SL CSI report within the duration time.

A method for a first device to perform a sidelink communication, the method comprising:

• receiving a sidelink control information with a report request from a second device;
• triggering or being triggered to transmit a report to the second device in response to the report request, wherein:
• a duration time starts or restarts counting when the first device receives or detects:
• the triggering or the being triggered;
• or
• the sidelink control information with the report request,
• the duration time is configured for canceling or discarding not yet transmitted or not yet assembled report, and
• the report is sidelink (SL) channel state information (CSI) report and the report comprises at least one of a Channel Quality Indicator, a Rank Indicator, or a Precoding Matrix Indicator;
• and
• canceling or discarding the report if the first device has not yet transmitted or assembled the report within the duration time.