A method and an apparatus for transmitting/receiving signals in a wireless communication system, according to one embodiment of the present invention, perform a 2- or 4-step random access process in a shared spectrum. In a method for interpreting an FDRA field for PUSCH transmissions corresponding to an RAR in a 4-step random access process or a fallback RAR in a 2-step random access process, the FDRA field is truncated to its X LSB, or the FDRA field is padded with Y MSB, on the basis of whether interlace allocation for a PUSCH for access to a shared spectrum channel is provided, and the FDRA field is interpreted as the FDRA field of downlink control information (DCI) format 0_0.