Category-2 listen-before-talk (LBT) options for new radio-unlicensed (NR-U)

1 . A method of wireless communication, comprising:

receiving, at a first wireless communication device, a first communication signal;

performing, by the first wireless communication device, a listen-before-talk (LBT) based at least in part on one or more channel measurements in one or more measurement periods of a gap duration between the first communication signal and a second communication signal, wherein a timing of the one or more measurement periods is associated with a time partitioning of the gap duration into a plurality of gap duration portions, and wherein a quantity of the plurality of gap duration portions is associated with a length of the gap duration; and

transmitting, by the first wireless communication device, the second communication signal based on the LBT.

2 . The method of claim 1 , wherein:

a first portion of the gap duration is adjacent to a start time of the second communication signal;

a total duration of the one or more measurement periods is based on the gap duration;

the one or more channel measurements comprises a first channel measurement and a second channel measurement;

the one or more measurement periods comprises a first measurement period and a second measurement period;

the second measurement period is within a second portion of the gap duration; and

the performing the LBT is based on the first channel measurement obtained in the first measurement period, and the second channel measurement obtained in the second measurement period.

3 . The method of claim 2 , wherein the first portion of the gap duration is longer than the second portion of the gap duration.

4 . The method of claim 2 , wherein the first measurement period is longer than the second measurement period.

5 . The method of claim 2 , wherein the performing the LBT includes:

determining, by the first wireless communication device, a channel status based on a comparison of at least one of the first channel measurement in the first measurement period or the second channel measurement in the second measurement period against a threshold.

6 . The method of claim 2 , wherein the performing the LBT includes:

determining, by the first wireless communication device, a channel status based on a comparison of a single channel measurement in the first measurement period against a threshold, the single channel measurement corresponding to the first channel measurement.

7 . The method of claim 1 , wherein:

a first portion of the gap duration is adjacent to a start time of the second communication signal;

a total duration of the one or more measurement periods is based on the gap duration; and

the first portion of the gap duration includes a slot having a predetermined duration.

8 . The method of claim 7 , wherein the predetermined duration of the slot is 9 microseconds (μs), and wherein the one or more measurement periods comprises a first measurement period having a duration of at least 4 μs within the slot.

9 . The method of claim 1 , wherein the second communication signal

includes one or more symbols and a cyclic extension associated with the gap duration, and wherein a beginning symbol of the one or more symbols is prepended with the cyclic extension.

10 . The method of claim 9 , wherein:

the transmitting includes:

transmitting, by the first wireless communication device to a second wireless communication device, the one or more symbols based on a symbol boundary, and

the method further comprises:

determining, by the first wireless communication device, a length for the cyclic extension to provide the gap duration.

11 . The method of claim 10 , wherein the determining the length for the cyclic extension includes:

determining, by the first wireless communication device, the length for the cyclic extension based on a timing advance associated with a communication between the first wireless communication device and the second wireless communication device.

12 . The method of claim 9 , further comprising:

receiving, by the first wireless communication device from a second wireless communication device, a configuration including at least one of:

a first indicator including at least one of a length of the cyclic extension, a starting offset for the second communication signal, or a switch gap configuration; or

a second indicator including the LBT type.

13 . The method of claim 12 , wherein the receiving the configuration includes:

receiving, by the first wireless communication device from the second wireless communication device, at least one of a radio resource control (RRC) message including the configuration, a group common-physical downlink control channel (GC-PDCCH) message including the configuration, or a scheduling grant including the configuration.

14 . The method of claim 12 , wherein:

the receiving the configuration includes:

receiving, by the first wireless communication device from the second wireless communication device, the second indicator including the LBT type jointly coded with the first indicator; and

the performing the LBT is further based on the LBT type.

15 . The method of claim 14 , wherein the LBT type is a category LBT, a category 2 LBT associated with a first duration, a category 2 LBT associated with a second duration different from the first duration, or a category 4 LBT.

16 . An apparatus comprising:

a transceiver configured to receive a first communication signal; and

a processor configured to:

perform a listen-before-talk (LBT) based at least in part on one or more channel measurements in one or more measurement periods of a gap duration between the first communication signal and a second communication signal, wherein a timing of the one or more measurement periods is associated with a time-partitioning of the gap duration into a plurality of gap duration portions, and wherein a quantity of the plurality of gap duration portions is associated with a length of the gap duration,

wherein the transceiver is further configured to transmit the second communication signal based on the LBT.

17 . The apparatus of claim 16 , wherein the one or more channel measurements comprises a first channel measurement and a second channel measurement;

a first portion of the gap duration is adjacent to a start time of the second communication signal;

a total duration of the one or more measurement periods is based on the gap duration;

the one or more measurement periods comprises a first measurement period and a second measurement period; and

the LBT is based on the first channel measurement obtained in the first measurement period, and the second channel measurement obtained in the second measurement period.

18 . The apparatus of claim 17 , wherein the processor configured to perform the LBT is configured to:

determine a channel status based on a comparison of at least one of the first channel measurement in the first measurement period or the second channel measurement in the second measurement period against a threshold.

19 . The apparatus of claim 16 , wherein:

a first portion of the gap duration is adjacent to a start time of the second communication signal;

a total duration of the one or more measurement periods is based on the gap duration;

the first portion of the gap duration is a slot having a predetermined duration of 9 microseconds (μs); and

the one or more measurement periods comprises a first measurement period having a duration of at least 4 μs within the slot.

20 . The apparatus of claim 16 , wherein the second communication signal includes one or more symbols and a cyclic extension associated with the gap duration, and wherein a beginning symbol of the one or more symbols is prepended with the cyclic extension.