The present disclosure relates to a first radio node configured for orthogonal frequency division multiplexing (OFDM), comprising a receiver, a transmitter, a processor and a memory storing instructions executable by the processor for causing the transmitter in a first mode of operation with a first subcarrier spacing f1: to transmit a sequence of prefixed OFDM symbols, and in a second mode of operation with a second subcarrier spacing f2: to transmit a sequence of prefixed OFDM symbols, wherein the sequence of transmitted OFDM symbols is aligned with a predefined repeating radio frame, which is common to both the first and second modes of operation, or with an integer multiple of the predefined repeating radio frame; and the first and second subcarrier spacings are related by an integer factor, f1/f2=p or f1/f2=1/p, with p≠1 integer.