A transmitting UE schedules radio frequency resources for use in a data transmission. The transmitting UE determines the transmission bandwidth, subject to certain restrictions, such as allowed DFT sizes for the UE for a data transmission. The determination may be performed through autonomous resource selection operations and/or may be performed using information received through signaling received from the network node as part of a scheduling grant. The UE further determines the ALLOCATED BANDWIDTH. The ALLOCATED BANDWIDTH can be determined based on the TRANSMISSION BANDWIDTH, which has been determined, using a defined rule. Furthermore, the UE generates and transmits toward a receiving UE a scheduling assignment (SA) that indicates the number or the set of subchannels that are within, and conform to, the ALLOCATED BANDWIDTH which was determined. The UE can then perform the data transmission using the SA indicated number or set of subchannels.