Transmission with restrictions in unlicensed spectrum
Systems, devices, and methods for operating in an unlicensed band are disclosed herein. In one example, a device may receive configuration information that includes a maximum channel occupancy time (MCOT) and a plurality of parameters including a plurality of transmission opportunity windows (TOWs). Based on the configuration information, the device may split a transmission into a plurality of bursts that may be grouped into sets of bursts based on how many bursts fit within a TOW. The number of bursts in a set of bursts may be less than or equal to the MCOT. The device may perform a clear channel assessment (CCA) to determine if the channel is busy and to determine a start time within the TOW for the bursts. The device may then transmit the set of bursts for that TOW, where each burst may have a burst indicator (BI).
1 . A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:
receiving resource allocation information for a set of transmissions, wherein each transmission of the set of transmissions is allocated for transmission of at least one repetition of a transport block, and the resource allocation information indicates a number of time resources allocated for each of the set of transmissions;
transmitting the transport block using a first transmission of the set of transmissions, wherein the transport block is transmitted in the first transmission using the number of time resources indicated by the resource allocation information;
determining that at least one time resource associated with a second transmission of the set of transmissions is not available for transmission by the WTRU; and
transmitting the transport block using the second transmission of the set of transmissions, wherein the transport block is transmitted in the second transmission using less than the number of time resources indicated by the resource allocation information based on the determination that the at least one time resource associated with the second transmission was not available for transmission by the WTRU.
2 . The method of claim 1 , wherein the number of time resources allocated for each of the set of transmissions corresponds to a number of orthogonal frequency division multiplexing (OFDM) symbols.
3 . The method of claim 1 , wherein the resource allocation information is received in downlink control information (DCI).
4 . The method of claim 1 , wherein the resource allocation information indicates a number of the set of transmissions that are used for repetition of the transport block.
5 . The method of claim 1 , wherein determining that the at least one time resource associated with the second transmission of the set of transmissions is not available for transmission comprises determining that the at least one time resource associated with the second transmission of the set of transmissions is outside a channel occupancy time (COT).
6 . The method of claim 1 , wherein determining that the at least one time resource associated with the second transmission of the set of transmissions is not available is based on a listen before talk (LBT) operation.
7 . The method of claim 1 , where each transmission of the set of transmissions is contiguous in time.
8 . A wireless transmit/receive unit (WTRU) comprising:
a processor, the processor configured to:
receive resource allocation information for a set of transmissions, wherein each transmission of the set of transmissions is allocated for transmission of at least one repetition of a transport block, and the resource allocation information indicates a number of time resources allocated for each of the set of transmissions;
transmit the transport block using a first transmission of the set of transmissions, wherein the transport block is transmitted in the first transmission using the number of time resources indicated by the resource allocation information;
determine that at least one time resource associated with a second transmission of the set of transmissions is not available for transmission by the WTRU; and
transmit the transport block using the second transmission of the set of transmissions, wherein the transport block is transmitted in the second transmission using less than the number of time resources indicated by the resource allocation information based on the determination that the at least one time resource associated with the second transmission was not available for transmission by the WTRU.
9 . The WTRU of claim 8 , wherein the number of time resources allocated for each of the set of transmissions corresponds to a number of orthogonal frequency division multiplexing (OFDM) symbols.
10 . The WTRU of claim 8 , wherein the resource allocation information is received in downlink control information (DCI).
11 . The WTRU of claim 8 , wherein the processor is further configured to:
determine that the at least one time resource associated with the second transmission of the set of transmissions is not available for transmission based on the at least one time resource associated with the second transmission of the set of transmissions being outside a channel occupancy time (COT).
12 . The WTRU of claim 8 , wherein each transmission of the set of transmissions is associated with a respective redundancy version of the transport block.
13 . The WTRU of claim 8 , wherein at least one transmission of the set of transmissions is used for transmission of multiple repetitions of the transport block.
14 . The WTRU of claim 8 , the processor further configured to:
perform a listen before talk (LBT) operation prior to transmitting the transport block using the first transmission of the set of transmissions, and wherein the at least one time resource associated with the second transmission of the set of transmissions is determined to be unavailable based on the LBT operation.
15 . The WTRU of claim 8 , wherein each transmission of the set of transmissions is contiguous in time.
16 . The WTRU of claim 8 , wherein the first transmission of the set of transmissions is a repetition.
17 . A method implemented by a base station, the method comprising:
transmitting resource allocation information for a set of transmissions, wherein each transmission of the set of transmissions is allocated for transmission of at least one repetition of a transport block, and the resource allocation information indicates a number of time resources allocated for each of the set of transmissions;
receiving the transport block using a first transmission of the set of transmissions, wherein the transport block is received in the first transmission using the number of time resources indicated by the resource allocation information; and
receiving the transport block using a second transmission of the set of transmissions, wherein the transport block is received in the second transmission using less than the number of time resources indicated by the resource allocation information.
18 . The method of claim 17 , wherein the number of time resources allocated for each of the set of transmissions corresponds to a number of orthogonal frequency division multiplexing (OFDM) symbols.
19 . The method of claim 17 , wherein the resource allocation information is transmitted in downlink control information (DCI).
20 . The method of claim 17 , wherein at least one time resource associated with the second transmission of the set of transmissions is outside a channel occupancy time (COT).