Sidelink feedback

An apparatus for a wireless communication system,

• wherein the apparatus is configured to be connected to at least one user device (UE) of the wireless communication system via a sidelink for a sidelink communication with the at least one UE,
• wherein, for a unicast transmission to the UE, the apparatus is configured to receive a slot using a slot structure for a sidelink transmission, a first part of the slot comprising a control signaling and a second part of the slot including data signaling, the slot indicating to the UE whether a feedback is to be returned to the UE, the feedback indicating one or more of the following:
• a successful reception of data at apparatus and/or a sidelink channel condition, and
• wherein, in case the feedback to the UE is desired, the apparatus is configured to
• receive from the second part of a current slot an indication that the feedback is to be provided by the apparatus, and
• determine and transmit the feedback for data transmitted in the current slot to the UE, in a subsequent slot, the subsequent slot having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent slot.

A method for transmitting from a transmitting UE to a receiving UE in a wireless communication system via a sidelink, the method comprising:

• transmitting, by the transmitting UE, a slot using a slot structure for a sidelink transmission, a first part of the slot comprising a control signaling and a second part of the slot including data signaling, the slot indicating to the UE whether a feedback is to be returned to the transmitting UE, the feedback indicating one or more of the following:
• a successful reception of data at the UE and a sidelink channel condition, and
• wherein, in case the feedback from the UE is desired,
• transmitting in the first part of a current slot, using the control signaling, an indication that the feedback is to be provided by the UE, and
• receiving, at the transmitting UE, in a subsequent slot, the feedback from the receiving UE for data transmitted in the current slot, the subsequent slot having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent slot.

A non-transitory digital storage medium having stored thereon a computer program for performing, when said computer program is run by a computer, a method for transmitting from a transmitting UE to a receiving UE in a wireless communication system via a sidelink, the method comprising:

• transmitting, by the transmitting UE, a slot using a slot structure for a sidelink transmission, a first part of the slot comprising a control signaling and a second part of the slot including data signaling, the slot indicating to the UE whether a feedback is to be returned to the transmitting UE, the feedback indicating one or more of the following:
• a successful reception of data at the UE and a sidelink channel condition, and
• wherein, in case the feedback from the UE is desired,
• transmitting in the first part of a current slot an indication that the feedback is to be provided by the UE, and
• receiving, at the transmitting UE, in a subsequent slot, the feedback from the receiving UE for data transmitted in the current slot, the subsequent slot having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent slot.