Method for configuring transmission opportunity section in wireless access system supporting unlicensed band, and device for supporting same
The present invention relates to a wireless access system supporting an unlicensed band, and provides a method for configuring a transmission opportunity (TxOP) section, and devices for supporting the same. The method for configuring a transmission opportunity (TxOP) section in a wireless access system supporting carrier aggregation (CA) with an unlicensed band, in one embodiment of the present invention, comprises the steps of: receiving, by a terminal, TxOP start information for indicating the start of the TxOP section; receiving orthogonal frequency division multiplexing (OFDM) symbol position information for indicating an OFDM symbol starting data transmission and reception in the TxOP section; and transmitting and receiving the data in a subframe (SF) of an S cell indicated by the TxOP start information on the basis of the OFDM symbol position information.
1. A method of receiving data from a base station via an unlicensed band by a user equipment (UE) in a wireless access system supporting carrier aggregation (CA) with the unlicensed band, the method comprising:
receiving transmission opportunity (TxOP) configuration information from the base station, wherein the TxOP configuration information indicates a first TxOP duration and a second TxOP duration, the second TxOP duration is after the first TXOP duration, the first TxOP duration comprising at least one partial subframe shorter than 1 ms;
receiving orthogonal frequency division multiplexing (OFDM) start symbol position information for a start position of a data transmission within the first and second TxOP durations, wherein the start position of the data transmission is determined based on a channel state of the unlicensed band; and
receiving the data via the unlicensed band during one or more subframes based on the OFDM start symbol position information and the TxOP configuration information,
wherein the channel state of the unlicensed band is related with whether an idle state starts at a subframe before the one or more subframes or not, and
wherein an end of the first TxOP duration equals to an end of a subframe of a primary cell (PCell) of the CA, wherein the PCell is a serving cell configured on a licensed band, and wherein a secondary cell (SCell) of the CA is a serving cell configured on the unlicensed band.
2. The method of claim 1 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted via the PCell of the CA.
3. The method of claim 2 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted through a different physical downlink control channel (PDCCH).
4. The method of claim 3 , wherein the TxOP configuration information or the OFDM start symbol position information is transmitted through a resource allocation field of a downlink control information (DCI) format contained in the PDCCH.
5. The method of claim 2 , wherein the TxOP configuration information is transmitted via a higher layer signal and wherein the OFDM start symbol position information is transmitted via a physical downlink control channel (PDCCH).
6. The method of claim 1 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted via the SCell of the CA and wherein the SCell is scheduled by a self-carrier scheduling scheme.
7. The method of claim 6 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted through a different physical downlink control channel (PDCCH).
8. The method of claim 6 , wherein the TxOP configuration information is transmitted via a higher layer signal and wherein the OFDM start symbol position information is transmitted via a physical downlink control channel (PDCCH).
9. A user equipment (UE) for receiving data from a base station via an unlicensed band in a wireless access system supporting carrier aggregation (CA) with the unlicensed band, the UE comprising:
a transceiver; and
a processor configured to:
control the transceiver to support a configuration of a first transmission opportunity (TxOP) duration and a second TxOP duration, the second TxOP duration is after the first TXOP duration, the first TxOP duration comprising at least one partial subframe shorter than 1 ms,
control the transceiver to receive TxOP configuration information from the base station, wherein the TxOP configuration information indicates the first TxOP duration and the second TxOP duration,
control the transceiver to receive orthogonal frequency division multiplexing (OFDM) start symbol position information for a start position of a data transmission within the first and second TxOP durations, wherein the start position of the data transmission is determined based on a channel state of the unlicensed band, and
control the transceiver to receive the data via the unlicensed band during one or more subframes based on the OFDM start symbol position information and the TxOP configuration information,
wherein the channel state of the unlicensed band is related with whether an idle state starts at a subframe before the one or more subframes or not, and
wherein an end of the first TxOP duration equals to an end of a subframe of a primary cell (PCell) of the CA, wherein the PCell is a serving cell configured on a licensed band, and wherein a secondary cell (SCell) of the CA is a serving cell configured on the unlicensed band.
10. The UE of claim 9 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted via the PCell of the CA.
11. The UE of claim 10 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted through a different physical downlink control channel (PDCCH).
12. The UE of claim 11 , wherein the TxOP configuration information or the OFDM start symbol position information is transmitted through a resource allocation field of a downlink control information (DCI) format contained in the PDCCH.
13. The UE of claim 10 , wherein the TxOP configuration information is transmitted via a higher layer signal and wherein the OFDM start symbol position information is transmitted via a physical downlink control channel (PDCCH).
14. The UE of claim 9 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted via the SCell of the CA and wherein the SCell is scheduled by a self-carrier scheduling scheme.
15. The UE of claim 14 , wherein the TxOP configuration information and the OFDM start symbol position information are transmitted through a different physical downlink control channel (PDCCH).
16. The UE of claim 14 , wherein the TxOP configuration information is transmitted via a higher layer signal and wherein the OFDM start symbol position information is transmitted via a physical downlink control channel (PDCCH).