The present invention relates to a wireless communication system, and more particularly, to a method including receiving indication information related to a PUCCH resource set of a specific PUCCH format through system information, the PUCCH resource set comprising a first RB offset, receiving a PDCCH including a resource indicator RI through CCE, and transmitting the control information on the PUCCH, wherein an RB index of the PUCCH is determined based on the first RB offset and a second RB offset related to a first bit value of the RI, and wherein a CS index of the PUCCH is determined based on a combination of [a second bit value of the RI, a 1-bit value based on a starting CCE index of the PDCCH (hereinafter, a CCE-based 1-bit value)] in a CS index set, and an apparatus therefor.