The embodiments of the present invention relate to a wireless access system supporting an unlicensed band and to methods for generating a discovery signal (DRS), methods for generating and transmitting a channel state information reference signal included in the DRS, and devices for supporting same. The method for transmitting a discovery signal (DRS) including a channel state information reference signal (CSI-RS) in a wireless access system supporting an unlicensed band, according to one embodiment of the present invention, may comprise the steps of: initiating, in subframe n (SF #n), a listen-before-talk (LBT) procedure for checking whether the unlicensed band is idle or not; if an LBT procedure succeeds in SF #n+k, generating a sequence for transmitting the CSI-RS on the basis of the subframe index j indicating SF #j; and transmitting the DRS, including the CSI-RS, in SF #n+k. Herein n, k, and j are preferably integers greater than or equal to 0 and less than or equal to 9.