The invention relates to a transmitting device for performing an initial and one or more retransmissions of data via a sidelink interface. A receiver and processor perform a resource sensing procedure to acquire information about radio resources usable for the device to transmit data at a later point in time. The processor performs an autonomous radio resource allocation to select time frequency radio resources within a transmission window to be used for performing a first transmission of the data, based on information acquired by the resource sensing procedure. The processor determines a data transmission timing pattern, that indicates a transmission timing for performing one or more transmissions of data. A transmitter performs the first data transmission using the selected time-frequency radio resources and performs the data retransmissions at the transmission timing defined by the determined data transmission timing pattern with respect to the first data transmission.