Abstract: Methods, devices and systems are provided for performing a random access (RA) procedure. A wireless transmit/receive unit (WTRU) may be configured to receive RA resource sets, where each of the RA resource sets is associated with a node-B directional beam, select an RA resource set from among the RA resource sets, and initiate an RA procedure based on the selected RA resource set. The RA procedure may include selecting multiple preambles which include a preamble for each resource of a plurality of resources corresponding to the selected RA resource set. The WTRU may be configured to sequentially transmit the selected multiple preambles in sequential RA transmissions, and may be configured to receive, from a node-B, in response to the RA transmissions, at least one RA response (RAR), where each of the received at least one RAR corresponds to one of the transmitted multiple preambles.

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 disclosed for error check-based synchronization. Physical Broadcast Channel (PBCH) data may be determined. A scrambling (e.g., a first scrambling) of the PBCH data may be scrambled via a sequence (e.g., a first sequence). The first sequence may be based on a cell ID and/or timing information. Error check bits may be attached to the scrambled PBCH data and to the timing information. The error check bits may include one or more cyclic redundancy check (CRC) bits. The scrambled PBCH data, the timing information (e.g., the unscrambled timing information), and/or the attached error check bits may be polar encoded. The polar encoding may result in polar encoded bits. A scrambling (e.g., a second scrambling) of the polar encoded bits may be scrambled via a sequence (e.g., a second sequence). The first sequence and the second sequence may be different. The polar encoded bits may be transmitted.

Abstract: Methods and apparatus for sounding reference signal (SRS) power control for a wireless transmitter/receiver unit (WTRU) are disclosed. These methods and apparatus include methods and apparatus for carrier-specific and carrier-common SRS power control in WTRUs that utilize carrier aggregation techniques. These methods and apparatus also include methods and apparatus for SRS power control in WTRUs utilizing both carrier aggregation and time division multiplexing (TDM) techniques. Additionally, these methods and apparatus include methods and apparatus for SRS power control for WTRUs utilizing multiple input multiple output MIMO operation. Methods and apparatus for SRS overhead reduction and power management in a WTRU are also disclosed.

Abstract: 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.

Abstract: A wireless transmit/receive unit (WTRU) may receive a first downlink control information (DCI) in a first slot. The first DCI may include an indication of a first quasi co-location (QCL) reference. The WTRU may receive a second DCI in a second slot. The second DCI may include scheduling information for a first physical downlink shared channel (PDSCH) transmission. The WTRU may receive the first PDSCH transmission in accordance with the first QCL reference indicated by the first DCI received in the first slot and in accordance with the scheduling information for the first PDSCH transmission included in the second DCI received in the second slot.

Abstract: Methods and systems for transmitting uplink control information and feedback are disclosed for carrier aggregation systems. A user equipment device may be configured to transmit uplink control information and other feedback for several downlink component carriers using one or more uplink component carriers. The user equipment device may be configured to transmit such data using a physical uplink control channel rather than a physical uplink shared channel. The user equipment device may be configured to determine the uplink control information and feedback data that is to be transmitted, the physical uplink control channel resources to be used to transmit the uplink control information and feedback data, and how the uplink control information and feedback data may be transmitted over the physical uplink control channel.

Abstract: Methods and apparatus for beam management are disclosed. A WTRU may include a plurality of antenna panels, each antenna panel comprising a plurality of antennas configured to transmit on directional transmit (TX) beams. The WTRU may send, to a transmission reception point (TRP), antenna panel capability information for the plurality of antenna panels and receive a reference signal (RS) configuration for configuring RS resource sets. The WTRU may send an RS transmission trigger frame identifying triggered RS resource sets from the configured RS resource sets. The WTRU may identify a set of antenna panels to be used with the triggered RS resource sets. The WTRU may determine an UL TX beam sweeping mode and an association between the triggered RS resources sets and the set of antenna panels. The WTRU may perform UL beam sweeping using the triggered RS resource sets and associated set of antenna panels.

Abstract: Systems, methods and instrumentalities are disclosed for WTRU-initiated beam recovery including beam switching and/or beam sweeping. A WTRU may be configured to detect a beam failure condition, identify a candidate beam for resolving the beam failure condition, and send a beam failure recovery request to a network entity. The WTRU may include the candidate beam in the beam failure recovery request and may receive a response from the network entity regarding the request and/or a solution for the beam failure condition. WTRU-initiated beam recovery may be used to resolve radio link failures and improve system performance by avoiding the necessity to perform an acquisition procedure. Additionally, beam sweeping may be performed at a sub-time unit level to provide a fast sweeping mechanism.

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.

Abstract: Systems, methods, and instrumentalities are disclosed for error check-based synchronization. Physical Broadcast Channel (PBCH) data may be determined. A scrambling (e.g., a first scrambling) of the PBCH data may be scrambled via a sequence (e.g., a first sequence). The first sequence may be based on a cell ID and/or timing information. Error check bits may be attached to the scrambled PBCH data and to the timing information. The error check bits may include one or more cyclic redundancy check (CRC) bits. The scrambled PBCH data, the timing information (e.g., the unscrambled timing information), and/or the attached error check bits may be polar encoded. The polar encoding may result in polar encoded bits. A scrambling (e.g., a second scrambling) of the polar encoded bits may be scrambled via a sequence (e.g., a second sequence). The first sequence and the second sequence may be different. The polar encoded bits may be transmitted.

Abstract: A device capable of operating in a wireless communication environment. The device may be configured to determine a plurality of control signaling bits. The device may determine a plurality of cyclic redundancy check (CRC) bits based on the plurality of control signaling bits. The device may apply a channel coding scheme to the plurality of control signaling bits and the plurality of CRC bits. The plurality of CRC bits may be distributed among the plurality of control signaling bits prior to applying the channel coding scheme. The device may transmit the channel coded plurality of control signaling bits and CRC bits.

Abstract: Systems and methods are disclosed for performing random access (RA) in 5G New Radio (NR) systems, including New Radio in unlicensed spectrum (NR-U) systems. A wireless transmit/receive unit (WTRU) may receive a configuration for physical random access channel (PRACH) resources. The WTRU may determine whether to use a first type of PRACH transmission or a second type of PRACH transmission. For the first type of PRACH transmission, the WTRU may select a PRACH resource, without performing listen-before-talk (LBT), immediately following reception of an synchronization signal block (SSB). For the second type of PRACH transmission, the WTRU may randomly select the PRACH resource associated with the SSB, and perform a first LBT on the selected PRACH resource. The WTRU may transmit a PRACH preamble in the selected PRACH resource. The WTRU may perform a second LBT for random access response (RAR) reception for hidden node detection.

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: A wireless transmit/receive unit (WTRU) may low-density parity-check (LDPC) encode data into LDPC blocks. Further, the WTRU may produce and append a cyclic redundancy check (CRC) to each of the LDPC blocks. Also, the WTRU may concatenate the plurality of LDPC blocks and appended CRCs. Additionally, the WTRU may produce information associated with error checks. Moreover, the WTRU may produce a codeword using a codebook. The codeword may be based on the information associated with the error checks. In addition, the WTRU may produce an orthogonal frequency-division multiplex (OFDM) signal by mapping the codeword and the concatenated plurality of LDPC blocks and appended CRCs onto resource elements of the OFDM signal. Further, the WTRU may transmit the produced OFDM signal. In a further example, the WTRU may produce an additional CRC in addition to the appended CRCs, and the produced OFDM signal may include the additional CRC.

Abstract: Methods and systems for transmitting uplink control information and feedback are disclosed for carrier aggregation systems. A user equipment device may be configured to transmit uplink control information and other feedback for several downlink component carriers using one or more uplink component carriers. The user equipment device may be configured to transmit such data using a physical uplink control channel rather than a physical uplink shared channel. The user equipment device may be configured to determine the uplink control information and feedback data that is to be transmitted, the physical uplink control channel resources to be used to transmit the uplink control information and feedback data, and how the uplink control information and feedback data may be transmitted over the physical uplink control channel.

Abstract: A wireless transmit/receive unit (WTRU) may monitor control resource sets (CORESETs) to receive a physical downlink control channel (PDCCH) having downlink control information (DCI) that includes a scheduling offset and an indicated beam for a scheduled physical downlink shared channel (PDSCH) reception. When the scheduling offset of the scheduled PDSCH is less than a threshold, a default beam of a transmission configuration indication (TCI) state may be utilized to receive the scheduled PDSCH. When the scheduling offset of the scheduled PDSCH is more than a threshold, the indicated beam is utilized to receive the scheduled PDSCH on a condition that a measured quality is above a measurement threshold or the default beam may be utilized when the measured quality is below the measurement threshold.

Abstract: Systems, methods and instrumentalities are disclosed for WTRU-initiated beam recovery including beam switching and/or beam sweeping. A WTRU may be configured to detect a beam failure condition, identify a candidate beam for resolving the beam failure condition, and send a beam failure recovery request to a network entity. The WTRU may include the candidate beam in the beam failure recovery request and may receive a response from the network entity regarding the request and/or a solution for the beam failure condition. WTRU-initiated beam recovery may be used to resolve radio link failures and improve system performance by avoiding the necessity to perform an acquisition procedure. Additionally, beam sweeping may be performed at a sub-time unit level to provide a fast sweeping mechanism.

Abstract: Access, collision handling, and resolution for non-orthogonal multiple-access (NOMA) may be used. Fixed or dynamic group demodulation reference signal (DMRS) and multiple-access (MA) signature for NOMA retransmission may be used. A wireless transmit/receive unit (WTRU) may receive MAS information or DMRS information from a network entity. A WTRU may receive indication of the MAS information or DMRS information via a subgrouping-based scheme, a bitmap indication, or a binary threshold. A WTRU may receive an indication of a resource group size from the network entity. Based on the resource group size, the WTRU may determine whether the MAS information or the DMRS information is indicated via the subgrouping-based scheme or via the binary threshold scheme. The WTRU, based on how the MAS information or the DMRS information is indicated, may determine a resource to be used for a NOMA transmission. The WTRU may send the NOMA transmission using the determined resource.

Abstract: Systems, methods, and instrumentalities are disclosed herein associated with physical random access, e.g., for new radio (NR) implementations such as NR-unlicensed (NR-U). A wireless transmit/receive unit (WTRU) may switch a position of a PRACH occasion (RO) with another RO to reduce latency (e.g., so that a WTRU can transmit a preamble without performing a LBT operation). Systems, methods, and instrumentalities are disclosed for reserving a listen-before-talk (LBT) procedure gap at the beginning of a random access channel (RACH) occasion (RO) in New Radio (NR) unlicensed (NR-U) systems. The present systems, methods, and instrumentalities may (e.g., may also) be applied to consecutive ROs. This may include reserving a LBT gap for example, for a RO transmission (e.g., for each of the consecutive ROs). Low latency RACH for NR-U systems may be supported (e.g., mapping rules for the RO may be implemented).