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.