The present invention relates to a wireless communication system. Specifically, the present invention relates to a method comprising: configuring a first cell group consisting of a PCell and zero or more SCells, and a second cell group consisting of SCell(s); determining transmit power of a first PUCCH to be transmitted through the PCell; and determining transmit power of a second PUCCH to be transmitted through a predetermined SCell in the second cell group, wherein the transmit powers of the first PUCCH and the second PUCCH are adjusted so that the total sum of transmit power of a terminal is not greater than the maximum transmit power of the terminal, considering a minimum guaranteed power which is assigned to each cell group according to protection priorities between cell groups, and the minimum guaranteed power assigned to each cell group is selectively applied to a specific UCI among a plurality of UCIs.