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).

Abstract: A method of feedback in a wireless transmit receive unit includes providing a precoding matrix index (PMI), error checking the (PMI) to produce an error check (EC) bit, coding the PMI and the EC bit and transmitting the coded PMI and EC bit.

Abstract: Transmit and/or receive beamforming may be applied to the control channel transmission/reception, e.g., in mmW access link system design. Techniques to identify candidate control channel beams and/or their location in the subframe structure may provide for efficient WTRU operation. A framework for beam formed control channel design may support varying capabilities of mBs and/or WTRUs, and/or may support time and/or spatial domain multiplexing of control channel beams. For a multi-beam system, modifications to reference signal design may discover, identify, measure, and/or decode a control channel beam. Techniques may mitigate inter-beam interference. WTRU monitoring may consider beam search space, perhaps in addition to time and/or frequency search space. Enhancements to downlink control channel may support scheduling narrow data beams. Scheduling techniques may achieve high resource utilization, e.g., perhaps when large bandwidths are available and/or WTRUs may be spatially distributed.

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: 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: A wireless transmit/receive unit (WTRU) may receive a unique word-error check (UW-EC) encoded signal. A pre-decoder data check entity may check for errors based on EC bits and systematic and parity bits from the UW-EC encoded signal. If an error is not detected at the pre-decoder data check entity, data without an error may be signaled to a source decoder without channel decoding.

Abstract: Transmit and/or receive beamforming may be applied to the control channel transmission/reception, e.g., in mmW access link system design. Techniques to identify candidate control channel beams and/or their location in the subframe structure may provide for efficient WTRU operation. A framework for beam formed control channel design may support varying capabilities of mBs and/or WTRUs, and/or may support time and/or spatial domain multiplexing of control channel beams. For a multi-beam system, modifications to reference signal design may discover, identify, measure, and/or decode a control channel beam. Techniques may mitigate inter-beam interference. WTRU monitoring may consider beam search space, perhaps in addition to time and/or frequency search space. Enhancements to downlink control channel may support scheduling narrow data beams. Scheduling techniques may achieve high resource utilization, e.g., perhaps when large bandwidths are available and/or WTRUs may be spatially distributed.

Abstract: Systems, procedures, and instrumentalities are disclosed for transmissions with polar codes. A transmitting entity may determine a mother code length. The mother code length may be based on value(s), e.g., a maximum number of transmissions. The transmitting entity may determine a number of information bits to be polar encoded. The number of information bits may be larger than a number of payload bits. The transmitting entity may map the number of information bits to a number of bit channels of a polar code. The transmitting entity may polar encode the information bits in the bit channels using the determined mother code length. The transmitting entity may partition the polar encoded bits into a number of parts. The number of parts may be based on one or more values, e.g., the maximum number of transmissions. The transmitting entity may transmit bits that have been interleaved to a circular buffer.

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: A method and apparatus for transmitting uplink control information (UCI) for Long Term Evolution-Advanced (LTE-A) using carrier aggregation is disclosed. Methods for UCI transmission in the uplink control channel, uplink shared channel or uplink data channel are disclosed. The methods include transmitting channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), hybrid automatic repeat request (HARQ) acknowledgement/non-acknowledgement (ACK/NACK), channel status reports (CQI/PMI/RI), source routing (SR) and sounding reference signals (SRS). In addition, methods for providing flexible configuration in signaling UCI, efficient resource utilization, and support for high volume UCI overhead in LTE-A are disclosed.

Abstract: Embodiments described herein provide systems and methods for reference signal configuration for multiple panels with panel-specific channel state information reference signals (CSI-RS) configurations and quasi-collocation (QCL) indication, including QCL type definition and indication for panel-specific CSI-RS configurations. Exemplary embodiments further provide multi-component precoder structure with panel specific component precoder and panel common precoder. Embodiments include: (semi)-open-loop schemes using random precoding for panel common precoder and/or panel specific precoder; panel selection/restriction with panel common precoder; MU-MIMO operation using different set of panels; and panel-wise CSI reporting.

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: 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, 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: 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: Methods, systems, and apparatus for supporting uplink Transmission Time Interval (TTI) bundling in Long Term Evolution (LTE) are provided. Methods, systems, and apparatus for signaling, activation/deactivation, and wireless transmit/receive unit (WTRU) behavior are also provided.