Receiver feedback in wireless systems

Abstract

Systems, methods, and instrumentalities are disclosed for receiver feedback in wireless systems. Receiver feedback format, content, type and/or timing may be determined as a function of, for example, at least one of a type of soft-combining processing to apply in a HARQ process, a HARQ operating point for the HARQ process, one or more reference transmissions for controlling a type of HARQ feedback for the HARQ process, and a feedback suppression parameter for one or more transmissions in a sequence associated with the HARQ process or a transport block (TB). Uniform and non-uniform CB-to-CBG mapping may be provided (e.g., by a WTRU) based on, for example, one or more parameters, interference and channel conditions and/or a probability of or actual pre-empting transmissions. A CB to CBG mapping indication may be provided, for example, in support of selecting a CB to CBG mapping from multiple CB to CBG mappings. Intra- and inter-WTRU interference/preemption indications may be provided.

1 - 15 . (canceled) 
     
     
         16 . A wireless transmit/receive unit (WTRU) comprising:
 a processor and a transceiver which are configured to:   receive configuration information including information indicating a code block group (CBG)-based type of hybrid automatic repeat request (HARQ) feedback should be provided by the WTRU,   receive a first downlink control information (DCI) associated with a first downlink transmission,   receive the first downlink transmission that comprises at least one transport block (TB), wherein the at least one TB comprises a plurality of CBGs, and wherein each of the CBGs comprises one or more code blocks (CBs), and   on condition that the first DCI indicates that a TB-based type of HARQ feedback is to be provided for the first downlink transmission, transmit a first TB-based HARQ feedback associated with the first downlink transmission, wherein the first TB-based HARQ feedback includes a number of bits corresponding to a number of the CBGs of the first downlink transmission.   
     
     
         17 . The WTRU of  claim 16 , wherein the number of bits of the first TB-based HARQ feedback associated with the first downlink transmission each have a first value. 
     
     
         18 . The WTRU of  claim 17 , wherein the first value indicates whether or not the at least one TB of the first downlink transmission was successfully decoded. 
     
     
         19 . The WTRU of  claim 16 , wherein the processor and the transceiver are configured to:
 receive a second DCI associated with a second downlink transmission;   receive the second downlink transmission that comprises at least one TB, wherein the at least one TB comprises a second plurality of CBGs, and wherein each of the CBGs of the second plurality of CBGs comprises one or more second CBs, and   on condition that the second DCI indicates that the CBG-based type of HARQ feedback is to be provided for the second downlink transmission, transmit a second CB-based HARQ feedback associated with the second downlink transmission, wherein the second CBG-based HARQ feedback includes a second number of bits corresponding to the second number of CBGs of the second downlink transmission.   
     
     
         20 . The WTRU of  claim 19 , wherein the bits of the second CBG-based HARQ feedback associated with the second downlink transmission have values indicating whether or not a corresponding one of the CBGs of the second downlink transmission was successfully decoded. 
     
     
         21 . The WTRU of  claim 16 , wherein the processor is further configured to:
 determine a mapping of the CBs into the plurality of CBGs of the first downlink transmission in at least one of a frequency domain or a time domain, and   wherein the first downlink transmission is received using the mapping.   
     
     
         22 . The WTRU of  claim 21 , wherein the mapping is based on one or more of: a number of subcarriers or orthogonal frequency division multiplexing (OFDM) symbols assigned to the plurality of CBGs, a maximum code block length, the number of CBGs of the first downlink transmission, a number of CBs in the first downlink transmission, and/or one or more of a number of time symbols or a number of resource blocks occupied by a potential pre-empting transmission. 
     
     
         23 . The WTRU of  claim 16 , wherein the first downlink transmission is associated with a HARQ process. 
     
     
         24 . The WTRU of  claim 16 , wherein the first DCI comprises a bitmap, and wherein the bitmap indicates which CBGs the first downlink transmission can be combined with previously received CBGs. 
     
     
         25 . The WTRU of  claim 16 , wherein the processor and the transceiver are configured to:
 receive configuration information including information indicating a maximum number of CBGs per TB, and wherein the first TB-based HARQ feedback includes the number of bits equal to the maximum number of CBGs per TB.   
     
     
         26 . A method implemented by a wireless transmit/receive unit (WTRU) comprising,
 receiving configuration information including information indicating a code block group (CBG)-based type of Hybrid Automatic Repeat Request (HARQ) feedback should be provided by the WTRU;   receiving a first downlink control information (DCI) associated with a first downlink transmission;   receiving the first downlink transmission that comprises at least one transport block (TB), wherein the at least one TB comprises a plurality of CBGs, and wherein each of the CBGs comprises one or more code blocks (CBs); and   on condition that the first DCI indicates that a TB-based type of HARQ feedback is to be provided for the first downlink transmission, transmitting a first TB-based HARQ feedback associated with the first downlink transmission, wherein the first TB-based HARQ feedback includes a number of bits corresponding to a number of the CBGs of the first downlink transmission.   
     
     
         27 . The method of  claim 26 , wherein the number of bits of the first TB-based HARQ feedback associated with the first downlink transmission each have a first value. 
     
     
         28 . The method of  claim 27 , wherein the first value indicates whether or not the at least one TB of the first downlink transmission was successfully decoded. 
     
     
         29 . The method of  claim 26 , further comprising:
 receiving a second DCI associated with a second downlink transmission;   receiving the second downlink transmission that comprises at least one TB, wherein the at least one TB comprises a second plurality of CBGs, and wherein each of the second plurality of CBGs comprises one or more second CBs; and   on condition that the second DCI indicates that the CBG-based type of HARQ feedback is to be provided for the second downlink transmission, transmitting a second CB-based HARQ feedback associated with the second downlink transmission, wherein the second CBG-based HARQ feedback includes a number of bits corresponding to the number of CBGs of the second downlink transmission.   
     
     
         30 . The method of  claim 29 , wherein the bits of the second CBG-based HARQ feedback associated with the second downlink transmission have values indicating whether or not a corresponding one of the CBGs of the second downlink transmission was successfully decoded. 
     
     
         31 . The method of  claim 26 , further comprising:
 determining a mapping of the CBs into the plurality of CBGs of the first downlink transmission in at least one of a frequency domain or a time domain, and   wherein the first downlink transmission is received using the mapping.   
     
     
         32 . The method of  claim 31 , wherein the mapping is based on one or more of: a number of subcarriers or orthogonal frequency division multiplexing (OFDM) symbols assigned to the plurality of CBGs, a maximum code block length, the number of CBGs of the first downlink transmission, a number of CBs in the first downlink transmission, and/or one or more of a number of time symbols or a number of resource blocks occupied by a potential pre-empting transmission. 
     
     
         33 . The method of  claim 26 , wherein the first downlink transmission is associated with a HARQ process. 
     
     
         34 . The method of  claim 26 , wherein the first DCI comprises a bitmap, and wherein the bitmap indicates which CBGs the first downlink transmission can be combined with previously received CBGs. 
     
     
         35 . The method of  claim 26 , further comprising:
 receiving configuration information including information indicating a maximum number of CBGs per TB, and wherein the first TB-based HARQ feedback includes the number of bits equal to the maximum number of CBGs per TB.