SIDELINK TRANSMISSION METHOD AND APPARATUS
A sidelink transmission apparatus includes: processor circuitry configured to determine a candidate resource set on an unlicensed frequency band; select a transmission resource in the candidate resource set; determine a listen before talk (LBT) class for a sidelink transmission; and determine a second channel occupancy time to share according to one or more first channel occupancy times; a transmitter configured to transmit sidelink information on the transmission resource when listen before talk which is performed according to the listen before talk class is successful; and a receiver configured to receive one or more COT indications indicating the one or more first channel occupancy times
1 . A sidelink transmission apparatus, comprising:
processor circuitry configured to determine a candidate resource set on an unlicensed frequency band; select a transmission resource in the candidate resource set; determine a listen before talk (LBT) class for a sidelink transmission; and determine a second channel occupancy time to share according to one or more first channel occupancy times;
a transmitter configured to transmit sidelink information on the transmission resource when listen before talk which is performed according to the listen before talk class is successful; and
a receiver configured to receive one or more COT indications indicating the one or more first channel occupancy times
2 . The sidelink transmission apparatus according to claim 1 , wherein the second channel occupancy time is indicated by a COT indication transmitted by a first communication apparatus, the sidelink transmission apparatus and the first communication apparatus satisfying at least one of the following conditions:
the transmitter transmits sidelink information to the first communication apparatus,
the receiver receives sidelink information from the first communication apparatus;
the sidelink transmission apparatus and the first communication apparatus have identical cast types; or
a channel access priority class value of the sidelink transmission apparatus is less than a channel access priority class value of the first communication apparatus.
3 . The sidelink transmission apparatus according to claim 2 wherein the channel access priority class value is carried in a 2nd stage SCI.
4 . The sidelink transmission apparatus according to claim 1 , wherein the processor circuitry is configured to determine the listen before talk class according to whether the sidelink transmission is within a channel occupancy time (COT).
5 . The sidelink transmission apparatus according to claim 4 , wherein when the sidelink transmission is within the channel occupancy time, the listen before talk class is determined as a low class or a high class.
6 . The sidelink transmission apparatus according to claim 4 , wherein when the sidelink transmission is outside the channel occupancy time, the listen before talk class is determined as a high class.
7 . The sidelink transmission apparatus according to claim 4 , wherein the channel occupancy time is obtained via a COT indication received by the sidelink transmission apparatus.
8 . The sidelink transmission apparatus according to claim 4 , wherein the channel occupancy time is obtained by performing listen before talk by the sidelink transmission apparatus.
9 . The sidelink transmission apparatus according to claim 8 , wherein the processor circuitry is configured to obtain the channel occupancy time by performing the listen before talk according to a high-class listen before talk.
10 . The sidelink transmission apparatus according to claim 1 , wherein the sidelink transmission is a first transmission within the channel occupancy time, and a listen before talk class is determined for the first transmission according to a second transmission prior to the first transmission.
11 . The sidelink transmission apparatus according to claim 10 , wherein the listen before talk class is determined as a low class when a time interval between the first transmission and the second transmission is less than a threshold.
12 . The sidelink transmission apparatus according to claim 10 , wherein the listen before talk class is determined as a high class when a time interval between the first transmission and the second transmission is greater than or equal to a threshold.
13 . The sidelink transmission apparatus according to claim 10 , wherein the second transmission comprises at least one of the following:
a sidelink transmission of the sidelink transmission apparatus;
a sidelink transmission of a second communication apparatus transmitting a COT indication for indicating the channel occupancy time; or
a sidelink transmission of a third communication apparatus not transmitting a COT indication for indicating the channel occupancy time.
14 . The sidelink transmission apparatus according to claim 13 , wherein the sidelink transmission apparatus and the second communication apparatus satisfy at least one of the following conditions:
reference signal receiving power between the sidelink transmission apparatus and the second cumminication apparatus is greater than a first threshold;
a distance between the sidelink transmission apparatus and the second cumminication apparatus is less than a second threshold;
the sidelink transmission apparatus is a transmitter of sidelink information of the second communication apparatus;
the sidelink transmission apparatus is a receiver of the sidelink information of the second cumminication apparatus;
the sidelink transmission apparatus and the second communication apparatus have identical cast types; or
a channel access priority class value of the sidelink transmission apparatus is less than a channel access priority class value of the second communication apparatus.
15 . The sidelink transmission apparatus according to claim 13 , wherein the sidelink transmission apparatus and the third communication apparatus satisfy at least one of the following conditions:
reference signal receiving power between the sidelink transmission apparatus and the third communication apparatus is greater than a first threshold;
a distance between the sidelink transmission apparatus and the third communication apparatus is less than a second threshold;
the sidelink transmission apparatus is a transmitter of sidelink information of the third communication apparatus;
the sidelink transmission apparatus is a receiver of the sidelink information of the third communication apparatus;
the sidelink transmission apparatus and the third communication apparatus have identical cast types; or
a channel access priority class value of the sidelink transmission apparatus is less than a channel access priority class value of the third communication apparatus.
16 . The sidelink transmission apparatus according to claim 10 , wherein the second transmission and the first transmission are within the same channel occupancy time.
17 . The sidelink transmission apparatus according to claim 1 , wherein a frequency of monitoring a physical sidelink control channel outside the channel occupancy time is greater than a frequency of monitoring a physical sidelink control channel within the channel occupancy time.
18 . A sidelink transmission method, comprising:
determining a candidate resource set on an unlicensed frequency band;
selecting a transmission resource in the candidate resource set;
determining a listen before talk (LBT) class for a sidelink transmission; and
transmitting sidelink information on the transmission resource when listen before talk which is performed according to the listen before talk class is successful;
wherein the method further comprises:
receiving one or more COT indications indicating one or more first channel occupancy times, and
determining a second channel occupancy time to share according to the one or more first channel occupancy times.
19 . A communication system, comprising:
a first communication device; and
a second communication device configured to communicate with the first communication device,
wherein the first communication device is configured to: determine a candidate resource set on an unlicensed frequency band; select a transmission resource in the candidate resource set; determine a listen before talk (LBT) class for a sidelink transmission; and transmit sidelink information on the transmission resource when listen before talk which is performed according to the listen before talk class is successful;
the first communication device is further configured to: receive one or more COT indications indicating one or more first channel occupancy times, and determine a second channel occupancy time to share according to the one or more first channel occupancy times.