Method for uplink channel access to unlicensed band in wireless communication system, and device therefor

1. A method for operating a user equipment in a wireless communication system, the method comprising:

receiving, from a base station, an uplink grant that schedules an uplink transmission to the base station in at least one subframe through an unlicensed cell;

determining a channel access type for performing the uplink transmission among a first type channel access and a second type channel access according to a predetermined interval determined based on a downlink transmission through the unlicensed cell from the base station, wherein the first type channel access is based on a channel sensing with a random backoff before data transmission, wherein the second type channel access is based on a channel sensing with a single interval before data transmission; and

performing the uplink transmission in the at least one subframe using the determined channel access type,

wherein the uplink transmission is performed using the second type channel access when all of the uplink transmission in the at least one subframe is included in the predetermined interval.

2. The method of claim 1 , wherein the uplink grant indicates a channel access type to be used among the first type channel access or the second type channel access in the uplink transmission.

3. The method of claim 1 , wherein when the uplink transmission is not included in the predetermined interval or only a part of the uplink transmission is included in the predetermined interval, the uplink transmission is performed using a channel access type indicated in the uplink grant.

4. The method of claim 1 , wherein the predetermined interval is determined based on a maximum channel occupation time set by the downlink transmission.

5. The method of claim 1 , wherein information on whether the at least one subframe is a last subframe for the uplink transmission is received through a common control channel.

6. The method of claim 1 , wherein when the uplink transmission is performed in the next subframe of the downlink transmission through the unlicensed cell, the uplink transmission is performed using the second type channel access.

7. A user equipment of a wireless communication system, the user equipment comprising:

a wireless communication module; and

a processor configured to:

receive, from a base station, an uplink grant that schedules an uplink transmission to the base station in at least one subframe through an unlicensed cell,

determine a channel access type for performing the uplink transmission among a first type channel access and a second type channel access according to a predetermined interval determined based on a downlink transmission through the unlicensed cell from the base station, and

perform, through the wireless communication module, the uplink transmission using the determined channel access type,

wherein the first type channel access is based on a channel sensing with a random backoff before data transmission, wherein the second type channel access is based on a channel sensing with a single interval before data transmission,

wherein the processor is configured to perform the uplink transmission using the second type channel access when all of the uplink transmission is included in a predetermined interval determined based on a downlink transmission through the unlicensed cell from the base station.

8. The user equipment of claim 7 , wherein the uplink grant indicates a channel access type to be used among the first type channel access or the second type channel access in the uplink transmission.

9. The user equipment of claim 7 , wherein when the uplink transmission is not included in the predetermined interval or only a part of the uplink transmission is included in the predetermined interval, the processor is configured to perform the uplink transmission using a channel access type indicated in the uplink grant.

10. The user equipment of claim 7 , wherein the predetermined interval is determined based on a maximum channel occupation time set by the downlink transmission.

11. The user equipment of claim 7 , wherein information on whether the at least one subframe is the last subframe for the uplink transmission is received through a common control channel.

12. The user equipment of claim 7 , wherein when the uplink transmission is performed in the next subframe of the downlink transmission through the unlicensed cell, the processor is configured to perform the uplink transmission using the second type channel access.

13. A base station in a wireless communication system, the base station comprising:

a wireless communication module; and

a processor configured to:

transmit, through the wireless communication module, an uplink grant scheduling transmission of an uplink transmission through an unlicensed cell in at least one subframe and indicating a channel access type to be used when the user equipment transmits the uplink transmission among the first type channel access or the second type channel access to a user equipment, wherein the first type channel access is based on a channel sensing with a random backoff before data transmission, wherein the second type channel access is based on a channel sensing with a single interval before data transmission,

receive, through the wireless communication module, the uplink transmission from the user equipment in the at least one subframe, and

determine a channel access type to be used by the user equipment among the first type channel access and the second type channel access based on a predetermined interval determined based on downlink transmission from the base station to the user equipment through the unlicensed cell,

wherein when all of the uplink transmission in the at least one subframe is included in the predetermined interval, the processor is configured to transmit common downlink control information indicating to perform the second type channel access in the uplink transmission.

14. The base station of claim 13 , wherein when the uplink transmission in the at least one subframe is not included in the predetermined interval or only a part of the uplink transmission in the at least one subframe is included in the predetermined interval, the processor is configured to transmit the uplink grant indicating to perform the first type channel access in the uplink transmission.

15. The base station of claim 13 , wherein the predetermined interval is determined based on a maximum channel occupation time set by the downlink transmission.

16. The base station of claim 13 , wherein the common downlink control information comprises information on whether the at least one subframe is the last subframe for the uplink transmission.

17. A wireless communication network comprising:

a user equipment,

a base station

wherein the user equipment configured to:

receive, from the base station, an uplink grant that schedules an uplink transmission to the base station in at least one subframe through an unlicensed cell,

determine a channel access type for performing the uplink transmission among a first type channel access and a second type channel access according to a predetermined interval determined based on a downlink transmission through the unlicensed cell from the base station, and

perform the uplink transmission using the determined channel access type, wherein the first type channel access is based on a channel sensing with a random backoff before data transmission, wherein the second type channel access is based on a channel sensing with a single interval before data transmission,

wherein the processor is configured to perform the uplink transmission using the second type channel access when all of the uplink transmission is included in a predetermined interval determined based on a downlink transmission through the unlicensed cell from the base station.