Radio data transmissions with low-density parity-check codes
Methods, apparatus, systems, architectures and interfaces for compressing hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback bits performed by a wireless transmit/receive unit (WTRU) receiving a transmit block (TB) including code block group (CBG) data are provided. The method includes receiving, by the WTRU, information associated with transmitting compressed HARQ-ACK feedback information, receiving, by the WTRU, a TB; determining, by the WTRU, a countdown downlink assignment index (CD_DAI) associated with the received TB; generating, by the WTRU, the compressed HARQ-ACK feedback information by compressing HARQ-ACK feedback bits associated with the received TB; and on condition that: (1) the CD_DAI is equal to zero or (2) the WTRU determines to provide feedback information, transmitting the compressed HARQ-ACK feedback information.
1 . A method for compressing hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback associated with code block group (CBG) data performed by a wireless transmit/receive unit (WTRU), the method comprising:
receiving, by the WTRU, configuration information indicating a maximum number of CBGs per transport block (TB);
receiving, by the WTRU, downlink control information (DCI) associated with a plurality of transport blocks (TBs);
receiving, by the WTRU, one or more TBs of the plurality of TBs, wherein each respective TB includes two or more CBGs;
generating, by the WTRU, compressed HARQ-ACK feedback information by compressing HARQ-ACK feedback bits associated with the plurality of TBs based on the maximum number of CBGs per TB and the DCI; and
transmitting the compressed HARQ-ACK feedback information, wherein the compressed HARQ-ACK feedback information includes: (1) a TB HARQ-ACK bitmap that indicates, for each of the plurality of TBs, whether all of the CBGs included in the respective TB are correctly decoded, (2) a TB valid bitmap that indicates, for each of the plurality of TBs, whether the respective TB is valid and includes at least one CBG that is correctly decoded; and (3) a CBG HARQ-ACK bitmap that indicates, for each of the maximum number of CBGs, whether a respective CBG is correctly decoded in each of the valid TBs.
2 . The method of claim 1 , further comprising:
receiving information indicating compressed HARQ-ACK feedback is to be provided for the plurality of TBs.
3 . The method of claim 1 , further comprising:
determining whether each of the two or more CBGs included in a respective TB of the one or more TBs is correctly decoded.
4 . The method of claim 1 , further comprising:
generating the HARQ-ACK feedback bits for the maximum number of CBGs for each of the plurality of TBs.
5 . The method of claim 4 , wherein the generating of the compressed HARQ-ACK feedback information includes generating the TB HARQ-ACK bitmap, the TB valid bitmap, and the CBG HARQ-ACK bitmap.
6 . The method of claim 1 , wherein the receiving of the DCI includes receiving a first DCI including an initial countdown downlink assignment index, and wherein a number of the plurality of TBs associated with the HARQ-ACK feedback bits is set to a value of the initial countdown downlink assignment index.
7 . The method of claim 6 , wherein the receiving of the DCI includes receiving a second DCI, and
wherein the generating of the compressed HARQ-ACK feedback information is based on a determination that a countdown downlink assignment index included in the second DCI is zero.
8 . The method of claim 1 , wherein the generating of the compressed HARQ-ACK feedback information is based on a determination that a HARQ-ACK group index timer exceeds a threshold value.
9 . The method of claim 1 , wherein the compressed HARQ-ACK feedback information includes a number of bits equal to two times a number of the plurality of TBs plus the maximum number of CBGs per TB.
10 . The method of claim 1 , wherein each respective TB includes a number of CBGs which are less than or equal to the maximum number of CBGs per TB.
11 . A wireless transmit/receive unit (WTRU) for receiving a transmit block (TB) including code block group (CBG) data and compressing hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback bits, the WTRU comprising:
a processor, a memory, and a transceiver configured to:
receive configuration information indicating a maximum number of code block groups (CBGs) per transport block (TB),
receive downlink control information (DCI) associated with a plurality of TBs,
receiving, by the WTRU, one or more TBs of the plurality of TBs, wherein each respective TB includes two or more CBGs,
generate compressed hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback information by compressing HARQ-ACK feedback bits associated with the plurality of TBs based on the maximum number of CBGs per TB and the DCI, and
transmit the compressed HARQ-ACK feedback information, wherein the compressed HARQ-ACK feedback information includes: (1) a TB HARQ-ACK bitmap that indicates, for each of the plurality of TBs, whether all of the CBGs included in the respective TB are correctly decoded, (2) a TB valid bitmap that indicates, for each of the plurality of TBs, whether the respective TB is valid and includes at least one CBG that is correctly decoded; and (3) a CBG HARQ-ACK bitmap that indicates, for each of the maximum number of CBGs, whether a respective CBG is correctly decoded in each of the valid TBs.
12 . The WTRU of claim 11 , wherein the processor, the memory, and the transceiver are configured to:
receive information indicating compressed HARQ-ACK feedback is to be provided for the plurality of TBs.
13 . The method of claim 11 , wherein the processor, the memory, and the transceiver are configured to:
determine whether each of the two or more CBGs included in a respective TB of the one or more TBs is correctly decoded.
14 . The method of claim 11 , wherein the processor, the memory, and the transceiver are configured to:
generate the HARQ-ACK feedback bits for the maximum number of CBGs for each of the plurality of TBs.
15 . The method of claim 14 , wherein the processor, the memory, and the transceiver are configured to generate the compressed HARQ-ACK feedback information which includes to generate the TB HARQ-ACK bitmap, the TB valid bitmap, and the CBG HARQ-ACK bitmap.
16 . The method of claim 11 , wherein the processor, the memory, and the transceiver are configured to receive the DCI which includes to receive a first DCI including an initial countdown downlink assignment index, and wherein a number of the plurality of TBs associated with the HARQ-ACK feedback bits is set to a value of the initial countdown downlink assignment index.
17 . The method of claim 16 , wherein the processor, the memory, and the transceiver are configured to receive the DCI which includes to receive a second DCI, and
wherein the processor, the memory, and the transceiver are configured to determine to generate the compressed HARQ-ACK feedback information based on a countdown downlink assignment index included in the second DCI being zero.
18 . The method of claim 11 , wherein the processor, the memory, and the transceiver are configured to determine to generate the compressed HARQ-ACK feedback information based on a HARQ-ACK group index timer exceeding a threshold value.
19 . The method of claim 11 , wherein the compressed HARQ-ACK feedback information includes a number of bits equal to two times a number of the plurality of TBs plus the maximum number of CBGs per TB.
20 . The method of claim 11 , wherein each respective TB includes a number of CBGs which are less than or equal to the maximum number of CBGs per TB.