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 sidelink frame comprising a certain frame duration, a first part of the sidelink frame comprising a control signaling and a second part of the sidelink frame including data signaling, the sidelink frame 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 a sidelink channel condition, and
• wherein, in case the feedback to the UE is desired, the apparatus is configured to
• receive from the second first part of a current sidelink frame, and
• determine and transmit the feedback for data transmitted in the current sidelink frame to the UE, in a subsequent sidelink frame, the subsequent sidelink frame having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent sidelink frame.

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 sidelink frame comprising a certain frame duration, a first part of the sidelink frame comprising a control signaling and a second part of the sidelink frame including data signaling, the sidelink frame indicating to the UE whether a feedback is to be returned to the apparatus, 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 second part of a current sidelink frame an indication that the feedback is to be provided by the UE, and
• receiving, at the transmitting UE, in a subsequent sidelink frame, the feedback from the receiving UE for data transmitted in the current sidelink frame, the subsequent sidelink frame having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent sidelink frame.

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 sidelink frame comprising a certain frame duration, a first part of the sidelink frame comprising a control signaling and a second part of the sidelink frame including data signaling, the sidelink frame indicating to the UE whether a feedback is to be returned to the apparatus, 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 second first part of a current sidelink frame an indication that the feedback is to be provided by the UE, and
• receiving, at the transmitting UE, in a subsequent sidelink frame, the feedback from the receiving UE for data transmitted in the current sidelink frame, the subsequent sidelink frame having a data signaling shortened by a certain duration, and the feedback being transmitted during the certain duration in the subsequent sidelink frame.