Abstract: Systems, methods, and instrumentalities are described herein for supporting CBG-based retransmission with variable CBG size using variable length HARQ-ACK. A WTRU may receive a configuration to use a first table. The first table may be associated with a maximum number of code block groups per transport block (maxCBG/TB). The WTRU may determine a number of HARQ-ACK bits to send for code blocks. The determination may depend on whether an indication is received to switch from the first table to a second table. On a condition that the indication to switch from the first table to the second table is received, the WTRU may send a number of HARQ-ACK bits that is equal to two times the maxCBG/TB. The WTRU may receive a retransmission of a number of code blocks, wherein a code block group size depends on a sent number of HARQ-ACK bits.

Abstract: Systems, methods, and instrumentalities are disclosed for priority-based channel coding for control information. A wireless transmit/receive unit (WTRU) may sort control information associated with a first control information type into a first control information group and the control information associated with a second control information type into a second control information group, for example, based on respective priorities associated with the first and second control information types. The WTRU may group one or more bits of the first control information group into a first bit level control information group and a second bit level control information group based on priority. The WTRU may selectively apply a cyclic redundancy check (CRC) to the first control information group, the second control information group, the first bit level control information group, and/or the second bit level control information group.

Abstract: Systems, methods, and instrumentalities are disclosed for interleaving coded bits. A wireless transmit/receive unit (WTRU) may generate a plurality of polar encoded bits using polar encoding. The WTRU may divide the plurality of polar encoded bits into sub-blocks of equal size in a sequential manner. The WTRU may apply sub-block wise interleaving to the sub-blocks using an interleaver pattern. The sub-blocks associated with a subset of the sub-blocks may be interleaved, and sub-blocks associated with another subset of the sub-blocks may not be interleaved. The sub-block wise interleaving may include applying interleaving across the sub-blocks without interleaving bits associated with each of the sub-blocks. The WTRU may concatenate bits from each of the interleaved sub-blocks to generate interleaved bits, and store the interleaved bits associated with the interleaved sub-blocks in a circular buffer. The WTRU may select a plurality of bits for transmission from the interleaved bits.

Abstract: Mechanisms may be used for aggregating acknowledgement (ACK), block ACK (BA) and/or short packets transmissions for multi-user (MU) wireless communication systems. Aggregation mechanisms may be used for uplink (UL) and/or downlink (DL) orthogonal frequency division multiple access (OFDMA), and/or UL/DL multiple-user multiple input multiple output (MU-MIMO) transmissions, for example. Multi-user short packets may be aggregated and/or simultaneously transmitted for DL, UL, or peer-to-peer (P2P) transmissions.

Abstract: A method and apparatus for performing autonomous transmission for performing collision mitigation and complexity reduction for non-orthogonal multiple access (NOMA) transmissions are disclosed. A wireless transmit/receive unit (WTRU) may receive a configuration with multiple SRs and associated preamble subsets, randomly select a preamble subset and select a SR configuration according to the randomly selected preamble subset based on the received configuration. The WTRU may transmit an SR associated with the selected preamble subset. Next the WTRU may select a preamble from the selected preamble subset, and transmit the selected preamble with a data transmission. Each SR associated with preamble subsets may be distinguished by time and frequency resources, sequence index value, or PUCCH index value.

Abstract: Methods, systems, and devices for addressing collisions of possible random access channel (RACH) occasions. A wireless transmit receive unit (WTRU) may receive an indication of semi-static UL/DL information including configuration of RACH occasions in a remaining minimum system information (RMSI) and an indication of one or more actually transmitted synchronization signal (SS) blocks. The WTRU may then assess whether there are RACH occasions based on the configuration information and determine whether any of the RACH occasions are valid, wherein the RACH occasion may be valid based on Based on the RACH occasion is after all actually transmitted SS blocks indicated and/or whether an SS block override is disabled or enabled. The WTRU may transmit a RACH in one or more of the RACH occasions that have been determined to be valid.

Abstract: Method and apparatus for multi-carrier/multi-cell discontinuous reception (DRX)/discontinuous transmission (DTX) operations and activation/deactivation of DRX/DTX are disclosed. A wireless transmit/receive unit (WTRU) may configure at least one state variable for controlling DRX, DTX or both on a group of cells. The WTRU may receive an order for DRX or DTX activation or deactivation. The WTRU may determine a setting for the state variable based on the order. The WTRU may activate or deactivate DRX or DTX based on the setting for the state variable. The group of cells may include all cells within the same frequency band, all cells in a particular frequency or group of frequencies, and all secondary cells associated with a primary cell. The primary cell may be an uplink (UL) or downlink (DL) primary cell. The secondary cells may be UL or DL secondary cells. The WTRU may apply common, group-specific or cell-specific DRX monitoring.

Abstract: A wireless transmit/receive unit (WTRU) may receive, from a base station, a synchronization signal/physical broadcast channel (SS/PBCH) block transmission. The WTRU may transmit using a physical random access channel (PRACH) resource. Further, the PRACH resource may be determined based on an SS/PBCH block index. Also, the SS/PBCH block index may be determined based on information associated with the SS/PBCH block transmission. In a further example, the information associated with the PBCH block may be derived from a demodulation reference signal (DMRS) sequence. In another example, the DMRS sequence may be a PBCH DMRS sequence. Also, the information associated with the PBCH block may be derived from PBCH payload bits. Further, the SS/PBCH block index may be associated with a beam. In addition, SS/PBCH transmissions of different beams may be transmitted at different times. Further, the PRACH resource may include a preamble resource, a time resource and a frequency resource.

Abstract: A WTRU may include a memory and a processor. The processor may be configured to receive beam grouping information from a gNB or transmission and reception point (TRP). The beam grouping information may indicate a group of beams that the WTRU may report using group-based reporting. The group-based reporting may be a reduced level of reporting compared to a beam-based reporting. The group-based report may include measurement information for a representative beam. The representative beam may be one of the beams in the group or represents an average of the beams in the group. Alternatively, the representative beam may be a beam that has a maximum measurement value compared to other beams in the group. The group-based report may include a reference signal received power (RSRP) for the representative beam and a differential RSRP for each additional beam in the beam group.

Abstract: Systems, methods, and instrumentalities are disclosed for priority-based channel coding for control information. A wireless transmit/receive unit (WTRU) may sort control information associated with a first control information type into a first control information group and the control information associated with a second control information type into a second control information group, for example, based on respective priorities associated with the first and second control information types. The WTRU may group one or more bits of the first control information group into a first bit level control information group and a second bit level control information group based on priority. The WTRU may selectively apply a cyclic redundancy check (CRC) to the first control information group, the second control information group, the first bit level control information group, and/or the second bit level control information group.

Abstract: A method for transmitting system information on a PBCH is described herein. A transmission/reception point (TRP) may generate a concatenated master information block (MIB) transport block that includes information bits associated with system bandwidth information, timing information, system frame number (SFN), a beam sweeping configuration, and a control resource set (CORESET). The TRP may then attach at least 16 cyclic redundancy check (CRC) bits to the concatenated MIB and then prioritize the concatenated MIB and the at least 16 CRC bits based on content. The TRP may then perform channel coding of the prioritized concatenated MIB and the at least 16 CRC bits to produce coded bits using at least one polar encoder with a coding rate that is less than ?, perform rate matching via repetition on the coded bits, and then transmit the rate matched, coded bits on the PBCH of a radio frame.

Abstract: A wireless transmit/receive unit (WTRU) may utilize pre-configured rules for scaling power levels. Channels may be grouped based on a type of data to be transmitted. A power level of a channel from a group may be scaled using the pre-configured rules. A power level of a channel of a supplementary carrier may be scaled before another channel of a non-supplementary carrier.

Abstract: Mechanisms may be used for aggregating acknowledgement (ACK), block ACK (BA) and/or short packets transmissions for multi-user (MU) wireless communication systems. Aggregation mechanisms may be used for uplink (UL) and/or downlink (DL) orthogonal frequency division multiple access (OFDMA), and/or UL/DL multiple-user multiple input multiple output (MU-MIMO) transmissions, for example. Multi-user short packets may be aggregated and/or simultaneously transmitted for DL, UL, or peer-to-peer (P2P) transmissions.

Abstract: Methods, systems, and devices for addressing collisions of possible random access channel (RACH) occasions. A wireless transmit receive unit (WTRU) may receive an indication of semi-static UL/DL information including configuration of RACH occasions in a remaining minimum system information (RMSI) and an indication of one or more actually transmitted synchronization signal (SS) blocks. The WTRU may then assess whether there are RACH occasions based on the configuration information and determine whether any of the RACH occasions are valid, wherein the RACH occasion may be valid based on Based on the RACH occasion is after all actually transmitted SS blocks indicated and/or whether an SS block override is disabled or enabled. The WTRU may transmit a RACH in one or more of the RACH occasions that have been determined to be valid.

Abstract: Systems, methods, and instrumentalities are described herein that may be used for NOMA resource selection. Different types of NOMA resources may be configured by a network and selected by a WTRU based on rules, priorities, fairness, overloading factors, multiple access signature sizes, measurement results, payload sizes, and/or the like. Single-NOMA operations may be performed using DFT-invariant codewords. Multiple NOMA schemes may coexist with different codeword types and/or codeword sizes.

Abstract: A method may comprise receiving a first signal comprising first LDPC bits including systematic bits and parity bits and transmitting information indicating that the first signal was incorrectly received. A second signal comprising second LDPC bits may be received in response to the transmitting. The second signal may include LDPC bits according to a lifting size of an LDPC base graph.

Abstract: A WTRU may include a memory and a processor. The processor may be configured to receive beam grouping information from a gNB or transmission and reception point (TRP). The beam grouping information may indicate a group of beams that the WTRU may report using group-based reporting. The group-based reporting may be a reduced level of reporting compared to a beam-based reporting. The group-based report may include measurement information for a representative beam. The representative beam may be one of the beams in the group or represents an average of the beams in the group. Alternatively, the representative beam may be a beam that has a maximum measurement value compared to other beams in the group. The group-based report may include a reference signal received power (RSRP) for the representative beam and a differential RSRP for each additional beam in the beam group.

Abstract: Methods, devices, and systems for physical random access channel (PRACH) access. A WTRU transmits a message to a gNB. The message includes a PRACH preamble from a first set. The method also includes performing a hidden node detection procedure prior to a random access response (RAR) window. The RAR window corresponds to the transmitted message. The method also includes attempting to receive a RAR in response to the transmitted message, during the RAR window. The method also includes retransmitting the message to the gNB, including a PRACH preamble from a second set, if the RAR is not received during the RAR window and a hidden node is detected; and retransmitting the message to the gNB, including a PRACH preamble from the first set, if the RAR is not received during the RAR window and the hidden node is not detected.

Abstract: A method for transmitting system information on a PBCH is described herein. A transmission/reception point (TRP) may generate a concatenated master information block (MIB) transport block that includes information bits associated with system bandwidth information, timing information, system frame number (SFN), a beam sweeping configuration, and a control resource set (CORESET). The TRP may then attach at least 16 cyclic redundancy check (CRC) bits to the concatenated MIB and then prioritize the concatenated MIB and the at least 16 CRC bits based on content. The TRP may then perform channel coding of the prioritized concatenated MIB and the at least 16 CRC bits to produce coded bits using at least one polar encoder with a coding rate that is less than ?, perform rate matching via repetition on the coded bits, and then transmit the rate matched, coded bits on the PBCH of a radio frame.

Abstract: A method and apparatus for use in a wireless transmit receive unit (WTRU) for receiving and transmitting information blocks is disclosed. A WTRU receives transmitted broadcast information, the transmitted broadcast information including a first information block and a second information block. Based on information in the received second information block, the WTRU transmits a random access preamble. After the transmission of the random access preamble, the WTRU may receive a random access response. Based on information in the received random access response, the WTRU may transmit a message including control information indicating additional information blocks that the WTRU is requesting to receive. After transmission of the transmitted message, the WTRU may receive the additional information blocks. In an example, the transmitted broadcast information may be periodically transmitted broadcast information.