Method and apparatus for listen-before-talk (LBT) related operation in a wireless communication system using unlicensed band
The present disclosure relates to a communication method and system for converging a 5 th -Generation (5G) communication system for supporting higher data rates beyond a 4 th -Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure provides a method for monitoring a carrier and transmitting a signal over an unlicensed band.
1. A method performed by a terminal in a wireless communication system, the method comprising:
receiving configuration information associated with configured resources, the configuration information including information on a periodicity of an uplink transmission using the configured resources;
identifying listen before talk (LBT) related information including information on at least one LBT priority class;
transmitting at least one physical uplink shared channel (PUSCH) on a cell associated with an unlicensed band using the configured resources according to the periodicity, based on the LBT related information;
receiving downlink control information (DCI) including downlink feedback information for the at least one PUSCH transmitted using the configured resources;
identifying at least one hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback corresponding to the at least one PUSCH in a reference subframe based on the downlink feedback information; and
adjusting a contention window value for the uplink transmission, based on the LBT related information and the at least one HARQ-ACK feedback.
2. The method of claim 1 , wherein the at least one PUSCH is transmitted according to the periodicity without an uplink scheduling signaling.
3. The method of claim 1 , wherein in case that the at least one HARQ-ACK feedback includes at least one ACK corresponding to the at least one PUSCH in the reference subframe, the contention window value for every LBT priority class is set to a minimum value, based on the LBT related information.
4. The method of claim 1 , wherein in case that the at least one HARQ-ACK feedback does not include any ACK corresponding to the at least one PUSCH in the reference subframe, the contention window value for every LBT priority class is increased to a next higher allowed value, based on the LBT related information.
5. The method of claim 1 , further comprising performing an LBT operation based on the LBT related information and the adjusted contention window value.
6. The method of claim 5 , further comprising transmitting an uplink signal on the cell associated with the unlicensed band, based on the performed LBT operation.
7. A terminal in a wireless communication system, the terminal comprising:
a transceiver; and
at least one processor configured to:
receive, via the transceiver, configuration information associated with configured resources, the configuration information including information on a periodicity of an uplink transmission using the configured resources,
identify listen before talk (LBT) related information including information on at least one LBT priority class,
transmit, via the transceiver, at least one physical uplink shared channel (PUSCH) on a cell associated with an unlicensed band using the configured resources according to the periodicity, based on the LBT related information,
receive, via the transceiver, downlink control information (DCI) including downlink feedback information for the at least one PUSCH transmitted using the configured resources,
identify at least one hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback corresponding to the at least one PUSCH in a reference subframe based on the downlink feedback information, and
adjust a contention window value for the uplink transmission, based on the LBT related information and the at least one HARQ-ACK feedback.
8. The terminal of claim 7 , wherein the at least one PUSCH is transmitted according to the periodicity without an uplink scheduling signaling.
9. The terminal of claim 7 , wherein in case that the at least one HARQ-ACK feedback includes at least one ACK corresponding to the at least one PUSCH in the reference subframe, the contention window value for every LBT priority class is set to a minimum value, based on the LBT related information.
10. The terminal of claim 7 , wherein in case that the at least one HARQ-ACK feedback does not include any ACK corresponding to the at least one PUSCH in the reference subframe, the contention window value for every LBT priority class is increased to a next higher allowed value, based on the LBT related information.
11. The terminal of claim 7 , wherein the at least one processor is further configured to perform an LBT operation based on the LBT related information and the adjusted contention window value.
12. The terminal of claim 11 , wherein the at least one processor is further configured to transmit, via the transceiver, an uplink signal on the cell associated with the unlicensed band, based on the performed LBT operation.