A method of transmitting a signal based on Listen-Before-Talk, LBT, by a user equipment , UE, in a wireless communication system supporting an unlicensed band, the method comprising: performing an LBT procedure; and performing an uplink transmission based on a result of the LBT procedure, wherein in a first case where a physical uplink control channel, PUCCH and a physical uplink shared channel, PUSCH, are scheduled in a single subframe: the LBT procedure includes first LBT for the PUCCH, and second LBT for the PUSCH; and if only the first LBT is successful the PUCCH is transmitted without the PUSCH, and if also the second LBT is successful both the PUCCH and the PUSCH are transmitted, in a second case where the PUCCH is scheduled in a subframe #n, and the PUSCH is scheduled in a subframe #n+1: the LBT procedure includes a random backoff-based third LBT for the PUCCH performed based on information received from a base station , if the random backoff-based third LBT for the PUCCH is successful the PUSCH is transmitted in the subframe #n+1 without the second LBT, otherwise the PUSCH is transmitted after performing the second LBT successfully, at least one of a shorter channel sensing time period , a smaller contention window size, and a greater energy detection threshold is used for the first LBT than that of the second LBT, such that a probability of success of the first LBT is higher than a probability of success of the second LBT. performing an LBT procedure; and performing an uplink transmission based on a result of the LBT procedure, wherein in a first case where a physical uplink control channel, PUCCH and a physical uplink shared channel, PUSCH, are scheduled in a single subframe: the LBT procedure includes first LBT for the PUCCH, and second LBT for the PUSCH; and if only the first LBT is successful the PUCCH is transmitted without the PUSCH, and if also the second LBT is successful both the PUCCH and the PUSCH are transmitted, the LBT procedure includes first LBT for the PUCCH, and second LBT for the PUSCH; and if only the first LBT is successful the PUCCH is transmitted without the PUSCH, and if also the second LBT is successful both the PUCCH and the PUSCH are transmitted, in a second case where the PUCCH is scheduled in a subframe #n, and the PUSCH is scheduled in a subframe #n+1: the LBT procedure includes a random backoff-based third LBT for the PUCCH performed based on information received from a base station , if the random backoff-based third LBT for the PUCCH is successful the PUSCH is transmitted in the subframe #n+1 without the second LBT, otherwise the PUSCH is transmitted after performing the second LBT successfully, the LBT procedure includes a random backoff-based third LBT for the PUCCH performed based on information received from a base station , if the random backoff-based third LBT for the PUCCH is successful the PUSCH is transmitted in the subframe #n+1 without the second LBT, otherwise the PUSCH is transmitted after performing the second LBT successfully, at least one of a shorter channel sensing time period , a smaller contention window size, and a greater energy detection threshold is used for the first LBT than that of the second LBT, such that a probability of success of the first LBT is higher than a probability of success of the second LBT. <EOS>