Transmitting uplink control information in a two-step random access procedure

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may generate an uplink random access message, including a random access preamble and an uplink shared channel resource unit, of a two-step random access procedure. The UE may identify configuration information for uplink control information (UCI) multiplexing. The UE may identify a trigger for inclusion of UCI with the uplink random access message. The UE may multiplex the UCI and a reference signal with the uplink shared channel resource unit and map the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. The UE may transmit the uplink random access message comprising the uplink control information and an indication of the used UCI configuration to the base station.

BACKGROUND

The following relates generally to wireless communications, and more specifically to transmitting uplink control information in a two-step random access procedure.

A UE may perform a random access procedure to establish a Radio Resource Control (RRC) connection with a base station. The random access procedure may be a four-step random access procedure or a two-step random access procedure. In a two-step random access procedure, a UE may send a first uplink message (sometimes referred to as a MsgA) to a base station. The base station may then respond with a second downlink message (also referred to as a MsgB). Options relating to MsgA, or the uplink random access message of a two-step random access procedure, may be further improved.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support transmitting uplink control information (UCI) in a two-step random access procedure. Generally, the described techniques provide for a user equipment (UE) to piggyback UCI onto an uplink random access message of a two-step random access procedure. The uplink random access message may include a random access preamble and a physical resource unit (PRU) for an uplink shared channel. Techniques described herein support a UE multiplexing the UCI onto the PRU for the uplink shared channel. The UE may include UCI in the uplink random access message while in any Radio Resource Control (RRC) state. Additionally, the UE may piggyback the UCI onto the uplink random access message for contention-based two-step random access procedures or contention-free two-step random access procedures.

Techniques for identifying a trigger to include the UCI with the uplink random access message are described. For example, different triggers for including UCI in the uplink random access message are described herein and may be based on an RRC state of the UE, parameter selection of the UE, a type of two-step random access procedure (e.g., contention-based or contention-free procedures), among other conditions or configurations. The UCI may carry one or more types of control information. In some cases, the UCI may be separated or categorized into one or more UCI parts, which may have different priorities. The higher priority UCI parts may be mapped to resource elements which are closer to the reference signals in the PRU. This may lead to a higher likelihood that the higher priority UCI part is decoded correctly by a base station. In some examples, the UE may indicate how many UCI parts are included in the UCI. For example, the UE may indicate the number of UCI parts based on a preamble grouping, a reference signal grouping, a PRU puncturing, or a pointer configuration. Similarly, the UE may indicate whether UCI is included in the uplink random access message at all based on preamble grouping, reference signal group, PRU puncturing, or a combination thereof.

A method of wireless communications is described. The method may include identifying a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generating the uplink random access message, the uplink random access message including a random access preamble and associated an uplink shared channel resource unit, identifying a trigger for inclusion of the uplink control information with the uplink random access message, multiplexing the uplink control information and a reference signal with the uplink shared channel resource unit based on the configuration, mapping the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmitting the uplink random access message including the uplink control information to a base station.

An apparatus for wireless communications is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify a trigger for inclusion of the uplink control information with the uplink random access message, multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration, map the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmit the uplink random access message including the uplink control information to a base station.

Another apparatus for wireless communications is described. The apparatus may include means for identifying a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generating the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identifying a trigger for inclusion of the uplink control information with the uplink random access message, multiplexing the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration, mapping the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmitting the uplink random access message including the uplink control information to a base station.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by a processor to identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify a trigger for inclusion of the uplink control information with the uplink random access message, multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration, map the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmit the uplink random access message including the uplink control information to a base station.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a set of uplink control information parts of the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, mapping the uplink control information further may include operations, features, means, or instructions for mapping the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each type of the uplink control information is associated with a priority.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for mapping a first uplink control information part with a higher priority closer to resource elements to which the reference signal may be mapped than a second uplink control information part with a lower priority.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each uplink control information part of the set of uplink control information parts includes a different priority of the uplink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating a number of uplink control information parts in the set of uplink control information parts based on a preamble grouping of the random access preamble.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating a number of uplink control information parts in the set of uplink control information parts based on a demodulation reference signal (DMRS) grouping.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating a number of uplink control information parts in the set of uplink control information parts based on puncturing the uplink shared channel resource unit.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for including, in a first uplink control information part, a pointer to a second uplink control information part, where a number of uplink control information parts in the set of uplink control information parts may be indicated based on a number of pointers including at least the pointer.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying configuration information for mapping the uplink control information, the configuration information including beta offset information, one or more formats for the uplink control information, a payload size, or any combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication of the configuration information from the base station, where the configuration information may be identified based on a Radio Resource Control (RRC) state of the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication may be received in a SIB, a an RRC message, or downlink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the UE may be in an RRC active mode, an RRC idle mode, or an RRC inactive mode.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the two-step random access procedure may be a contention-free two-step random access procedure or a contention-based two-step random access procedure.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for receiving a downlink control channel message from the base station, where the inclusion of uplink control information may be based on receiving the downlink control channel message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for receiving a group common downlink control channel message from the base station, where the inclusion of uplink control information may be based on receiving the group common downlink control channel message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for receiving RRC signaling from the base station, where the inclusion of uplink control information may be based on receiving the RRC signaling.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for determining the uplink random access message may be a retransmission of an initial uplink random access message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes a redundancy version, a HARQ process identifier, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for identifying configured sets of resource unit sizes, modulation and coding schemes (MCS), transport block sizes (TBS), or any combination thereof, selecting a resource unit size, an MCS, and a TBS to use for the uplink random access message, and including an indicator of the selected resource unit size, the selected MCS, and the selected TBS in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for identifying a configured set of random access occasions, selecting a random access occasion for transmitting the uplink random access message from the configured set of random access occasions, where the random access occasion may be associated with a synchronization signal block (SSB) beam index, and including an indicator of the SSB beam index in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for identifying a configured set of random access preambles, selecting the random access preamble from the configured set of random access preambles, where the random access preamble may be associated with a synchronization signal block (SSB) beam index, and including an indicator of the SSB beam index in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the trigger further may include operations, features, means, or instructions for performing a measurement on a downlink reference signal from the base station to obtain a downlink measurement, and including an indicator of the downlink measurement in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes uplink shared channel configuration information, acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a CSI report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink shared channel configuration information includes modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TBS), a new data indicator (NDI), a HARQ process number, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the RSRP measurement information may be from a serving cell, one or more neighboring cells, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the beam management information includes a list of preferred beam indexes.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the beam management information includes transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a CSI report, a scheduling request, or any combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating that the uplink random access message includes the uplink control information based on a preamble grouping for the random access preamble.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating that the uplink random access message includes the uplink control information based on a demodulation reference signal (DMRS) grouping.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for indicating that the uplink random access message includes the uplink control information based on puncturing the uplink shared channel resource unit.

A method of wireless communications at a base station is described. The method may include receiving an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identifying that uplink control information is included in the uplink random access message, identifying a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decoding the uplink control information based on the mapping, and decoding the uplink random access message based on the uplink control information.

An apparatus for wireless communications at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify that uplink control information is included in the uplink random access message, identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decode the uplink control information based on the mapping, and decode the uplink random access message based on the uplink control information.

Another apparatus for wireless communications at a base station is described. The apparatus may include means for receiving an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identifying that uplink control information is included in the uplink random access message, identifying a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decoding the uplink control information based on the mapping, and decoding the uplink random access message based on the uplink control information.

A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify that uplink control information is included in the uplink random access message, identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decode the uplink control information based on the mapping, and decode the uplink random access message based on the uplink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a set of uplink control information parts of the uplink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a mapping of the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying that a first uplink control information part with a higher priority may be mapped closer to resource elements to which the reference signal may be mapped than a second uplink control information part with a lower priority.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for decoding the first uplink control information part with the higher priority based on the first uplink control information part being mapped closer to resource elements to which the reference signal may be mapped.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each uplink control information part of the set of uplink control information parts includes a different type of the uplink control information.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a number of uplink control information parts in the set of uplink control information parts based on a preamble grouping for the random access preamble.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a number of uplink control information parts in the set of uplink control information parts based on a demodulation reference signal (DMRS) grouping.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a number of uplink control information parts in the set of uplink control information parts based on puncturing the uplink shared channel resource unit.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, in a first uplink control information part, a pointer to a second uplink control information part, where a number of uplink control information parts in the set of uplink control information parts may be identified based on a number of pointers including at least the pointer.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining configuration information for mapping the uplink control information, the configuration information including a beta offset, formats for the uplink control information, a payload size, or any combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an indication of the configuration information to the UE based on an RRC state of the UE, where the configuration information may be identified based on receiving the indication.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication may be received in a SIB, a an RRC message, or downlink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the UE may be in an RRC active mode, an RRC idle mode, or an RRC inactive mode.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the two-step random access procedure may be a contention-free two-step random access procedure or a contention-based two-step random access procedure.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for transmitting a downlink control channel message to the UE, where the downlink control channel message triggers the UE to include the uplink control information in the uplink random access message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for transmitting a group common downlink control channel message to the UE, where the group common downlink control channel message triggers the UE to include the uplink control information in the uplink random access message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for transmitting RRC signaling to the UE, where the RRC signaling triggers the UE to include the uplink control information in the uplink random access message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for determining the uplink random access message may be a retransmission of an initial uplink random access message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes a redundancy version, a HARQ process identifier, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for identifying configured sets of resource unit sizes, modulation and coding schemes (MCS), transport block sizes (TBS), or any combination thereof, and identifying, from the UE, an indicator of a selected resource unit size, a selected MCS, and a selected TBS in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for identifying a configured set of random access occasions, where each random access occasion of the configured set of random access occasions may be associated with a synchronization signal block (SSB) beam index, and identifying, from the UE, an indicator of an SSB beam index associated with a random access occasion of the configured set of random access occasions in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for identifying a configured set of random access preambles, where each random access preamble of the configured set of random access preambles may be associated with a synchronization signal block (SSB) beam index, and identifying, from the UE, an indicator of an SSB beam index associated with the random access preamble in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying that uplink control information may be included in the uplink random access message further may include operations, features, means, or instructions for transmitting a downlink reference signal to the UE, and identifying an indicator of a downlink measurement for the downlink reference signal in the uplink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes uplink shared channel configuration information, acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a CSI report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink shared channel configuration information includes modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TB S), a new data indicator (NDI), a HARQ process number, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the RSRP measurement information may be from the base station, one or more neighboring cells of the base station, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the beam management information includes a list of preferred beam indexes.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the beam management information includes transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink control information includes acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a CSI report, a scheduling request, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the identifying that uplink control information may be included in the uplink random access message may be based on a preamble grouping for the random access preamble.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the identifying that uplink control information may be included in the uplink random access message may be based on a demodulation reference signal (DMRS) grouping.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the identifying that uplink control information may be included in the uplink random access message may be based on puncturing the uplink shared channel resource unit.

DETAILED DESCRIPTION

Some wireless communications systems may support two-step random access procedures. Where a four-step random access procedure includes two, separate uplink transmissions and two, separate downlink transmissions for a user equipment (UE) to establish a Radio Resource Control (RRC) connection with a base station, a two-step random access procedure may establish an RRC connection with two transmissions: an uplink random access message and a downlink random access message. Therefore, a two-step random access procedure may provide benefits of reduced signaling overhead and reduced latency when compared to a four-step random access procedure. The uplink random access message may include a random access preamble and a physical resource unit (PRU) to transmit an RRC connection request over an uplink shared channel. In response to the uplink random access message, a base station may transmit a downlink random access message, including a random access response and an acknowledgment for the RRC connection request. Techniques described herein support a UE to piggyback uplink control information (UCI) onto the uplink random access message. The UCI may be multiplexed with reference signals in the PRU of the uplink random access message. A UE may include UCI in an uplink random access message while in any RRC state. For example, the UE may be in RRC connected mode, RRC inactive mode, or RRC idle mode. Additionally, the UE may piggyback the UCI onto the uplink random access message for contention-based two-step random access procedures or contention-free two-step random access procedures.

In some cases, the UE may be triggered to include the UCI with the uplink random access message. In some cases, the UE may identify some configuration, condition, or situation where including the UCI may assist the base station in decoding the uplink random access message. Different triggers for including UCI in the uplink random access message are described herein.

The UCI may carry one or more types of control information. For example, the UCI may include uplink shared channel configuration information, feedback information, a scheduling request, measurements or measurement information, beam management information, or a combination thereof. In some cases, the UCI may be separated or categorized into one or more UCI parts. In some examples, each UCI part may carry different information. In some cases, the different UCI parts may have different priorities. The higher priority UCI parts may be mapped to resource elements which are closer to the reference signals in the PRU. This may lead to a higher likelihood that the higher priority UCI part is decoded correctly by a base station. In some examples, the UE may indicate how many UCI parts are included in the UCI. For example, the UE may indicate the number of UCI parts based on a preamble grouping, a reference signal grouping, a PRU puncturing, or a pointer configuration. Similarly, the UE may indicate whether UCI is included in the uplink random access message at all based on preamble grouping, reference signal group, PRU puncturing, or a combination thereof.

Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to transmitting uplink control information in a two-step random access procedure.

FIG. 1illustrates an example of a wireless communications system100that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The wireless communications system100includes base stations105, UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, wireless communications system100may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

A UE115may piggyback UCI onto an uplink random access message of a two-step random access procedure. The uplink random access message may include a random access preamble and a PRU for an uplink shared channel. Techniques described herein support a UE115to multiplex the UCI onto the PRU for the uplink shared channel. The UE115may include UCI in the uplink random access message while in any RRC state. Additionally, the UE115may piggyback the UCI onto the uplink random access message for contention-based two-step random access procedures or contention-free two-step random access procedures.

There may be different triggers for the UE115to include UCI in the uplink random access message. These triggers may be based on an RRC state of the UE115, parameters selected by the UE115, a type of two-step random access procedure (e.g., contention-based or contention-free procedures), among other conditions or configurations. The UCI may carry one or more types of control information. In some cases, the UCI may be separated or categorized into one or more UCI parts, which may have different priorities. The higher priority UCI parts may be mapped to resource elements which are closer to the reference signals in the PRU. This may lead to a higher likelihood that the higher priority UCI part is decoded correctly by a base station105. In some examples, the UE115may indicate how many UCI parts are included in the UCI. For example, the UE115may indicate the number of UCI parts based on a preamble grouping, a reference signal grouping, a PRU puncturing, or a pointer configuration. Similarly, the UE115may indicate whether UCI is included in the uplink random access message at all based on preamble grouping, reference signal group, PRU puncturing, or a combination thereof.

FIG. 2illustrates an example of a wireless communications system200that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. In some examples, wireless communications system200may implement aspects of wireless communications system100. The wireless communications system200includes UE115-aand base station105-a, which may be respective examples of a UE115and a base station105.

UE115-aand base station105-amay support two-step random access procedures. Where a four-step random access procedure includes two, separate uplink transmissions (e.g., steps1and3) and two, separate downlink transmissions (e.g., steps2and4) for a UE115to establish an RRC connection with a base station105, a two-step random access procedure may establish an RRC connection with an uplink random access message205and a downlink random access message210. Therefore, a two-step random access procedure may provide benefits of reduced signaling overhead and reduced latency when compared to a four-step random access procedure.

The uplink random access message205may include a random access preamble220and resources for an uplink shared channel. For example, the uplink random access message may include a RACH preamble and a PUSCH physical resource unit (PRU)215. In the uplink random access message205of a two-step random access procedure, UE115-amay transmit both a random access preamble220(e.g., step one of a four-step random access procedure) and an RRC connection request in the PRU215(e.g., step three of a four-step random access procedure). In some cases, the uplink random access message205may be referred to as message A, or MsgA.

In response to the uplink random access message205, base station105-amay transmit a downlink random access message210. The downlink random access message210of the two-step random access procedure may include a random access response (e.g., step two of a four-step random access procedure) and an acknowledgment for the RRC connection request (e.g., step four of a four-step random access procedure). The downlink random access message210may be referred to as message B or MsgB.

In some cases, UE115-amay include UCI230in the uplink shared channel transmission of the uplink random access message205. For example, UE115-amay piggyback the UCI230onto the PUSCH resources of the PRU215. The UCI230may be multiplexed with the PUSCH message and demodulation reference signals (DMRS)225in the PRU215. Including the UCI230may be optional. For example, a UE115may transmit an uplink random access message205with or without UCI230. However, including the UCI230may provide a UE115with some additional flexibility for uplink signaling.

Some systems may support a UE115to multiplex uplink control information on PUSCH resources when the UE115is in an RRC connected mode. Multiplexing uplink control information on PUSCH resources may be supported for both grant-based and configured-grant transmission when the UE115is in the RRC connected mode. The techniques described herein may provide for piggybacking the UCI230onto PUSCH resources in the uplink random access message205of a two-step random access procedure. Multiplexing the UCI230onto the PRU215may provide an adjustable tradeoff between flexibility and reduced latency and signaling overhead.

The techniques described herein support UE115-ato include the UCI230in the uplink random access message205when in any RRC state. For example, UE115-amay be capable of multiplexing the UCI230onto the PRU215when in RRC connected mode, RRC inactive mode, or RRC idle mode. Additionally, UE115-amay be able to piggyback the UCI230onto the uplink random access message205for contention-based 2-step random access procedures and contention-free 2-step random access procedures.

In some examples, base station105-a, or another network device, may configure UE115-awith a UCI multiplexing configuration. The UCI multiplexing configuration may include the rules, options, formats, etc., for multiplexing the UCI230onto the uplink random access message205. The UCI multiplexing configuration may be indicated in system information (e.g., a system information block), RRC signaling, or downlink control channel signaling (e.g., via DCI). The type of signaling used to indicate the UCI multiplexing configuration may be based on an RRC state of UE115-a. In some examples, UE115-amay be configured with the UCI multiplexing configuration prior to starting the two-step random access procedure.

In some cases, UE115-amay be triggered to include the UCI230with the uplink random access message205. In some cases, UE115-amay identify some configuration, condition, or situation where including the UCI230may assist base station105-ain decoding the uplink random access message205. In some cases, the different triggers, or indications of the different triggers, may be included in the UCI multiplexing configuration.

In some cases, such as for a contention-free two-step random access procedure, piggybacked UCI may be triggered by a downlink control channel message. For example, base station105-amay transmit downlink control information (DCI) to UE115-a. The DCI may trigger UE115-ato include UCI230in the uplink random access message205. In contention-free communications, UE115-amay have dedicated PDCCH resources and dedicated UCI. Therefore, the PDCCH trigger for contention-free two-step random access procedures may be a unicast transmission. In this example, base station105-amay transmit signaling to trigger UE115-a(e.g., and just UE115-a) to include UCI in a uplink random access message205.

For contention-based two-step random access procedures when UE115-ais in an RRC connected state, the piggybacked UCI may be triggered by a group-common DCI or via RRC signaling. In contention-based two-step random access procedures, base station105-amay not be aware of which UE115is actually transmitting. Therefore, when triggering UCI piggybacking, base station105-amay implement some broadcasting techniques to indicate the trigger. In some cases, the broadcast techniques may be indicating the trigger via a group common PDCCH. UE115-amay receive the group common PDCCH, identify the trigger to include UCI230in the uplink random access message205, then multiplex the UCI230in the PRU215of the uplink random access message205.

For contention-based two-step random access procedures when UE115-ais in an RRC inactive state or an RRC idle state, the trigger to include the UCI230may be identified based on one or more conditions. In a first example, UE115-amay identify that the uplink random access message205is a retransmission of an initial uplink random access message. UE115-amay then indicate that the uplink random access message205is a retransmission to assist base station105-ain determining to perform HARQ combining. In some cases, UE115-amay include a redundancy version, HARQ process ID, or both in the UCI230. Base station105-amay receive the uplink random access message205and identify the UCI230, including the HARQ process ID, redundancy version, or both. Base station105-amay then use the UCI230to perform the HARQ combining.

In a second example, UE115-amay be pre-configured with multiple candidates of PRU size (e.g., for the PRU215), modulation and coding scheme (MCS), transport block size (TBS), or any combination thereof. In some examples, UE115-amay select a PRU size, MCS, TBS, or a combination thereof. UE115-amay then include an indication of the selected values. By including an indication of the chosen PRU size, MCS, TBS, etc., base station105-amay use the indicated information instead of blindly decoding and trying multiple different values. Therefore, this may reduce the decoding complexity at base station105-a, as base station105-amay otherwise not know what values UE115-achose. Therefore, if UE115-aselects a PRU size, MCS, or TBS from a preconfigured set, this may trigger UE115-ato include an indication of the selection in the UCI230.

In a third example, UE115-amay select from multiple random access occasions, from multiple preamble subsets, or both, which may be associated with different synchronization signal block (SSB) beam indexes. In some cases, UE115-amay include an indication of the SSB beam to random access occasion relationship in the UCI230. For example, UE115-amay include an indication of the SSB beam index which corresponds to the selected random access occasion and preamble subset for the uplink random access message205. This may reduce blind decoding complexity at base station105-a. Therefore, if UE115-aselects a random access occasion, a preamble, or a preamble subset, this may trigger UE115-ato include an indication of the selection (e.g., or relationship of a received SSB to the selection) in the UCI230.

In a fourth example, UE115-amay have measurements for downlink signaling, which UE115-ais to report to base station105-a. The measurements may be, for example, reference signal received power (RSRP) measurements, an interference profile, or channel state information (CSI). These downlink measurements may assist base station105-ain scheduling decisions for UE115-a. If UE115-ahas taken downlink measurements, this may trigger UE115-ato include the measurements in the uplink random access message205.

The UCI230may carry one or more types of control information. For example, the UCI230may include uplink shared channel configuration information. In some cases, the uplink shared channel configuration information may include, for example, an MCS, an RV, a TBS, a new data indicator (NDI), a HARQ process number, or any combination thereof. In some cases, the UCI230may include acknowledgement (ACK) or negative acknowledgment (NACK) feedback (e.g., HARQ feedback), a CSI report, or a scheduling request. In some cases, the bit-width for the ACK/NACK feedback, CSI report, or scheduling request may be configurable. In some cases, the UCI230may include interference measurements or positioning-related measurements. In some examples, the UCI230may include RSRP measurements from the serving cell (e.g., base station105-a) or from neighboring cells. The RSRP measurements may be an example of level1RSRP measurements. The RSRP measurements may have a configurable bit-width. In some cases, the UCI230may include beam management information. For example, the beam management information may include a list of preferred SSB or CSI-RS beam indexes. In some cases, the beam management information may include transmit beam switching information between the MsgA preamble and the MsgA PUSCH (e.g., between the random access preamble220and the PRU215). In some examples, the UCI230multiplexed on the PRU215may have its own UCI format.

In some cases, the UCI230may be broken into one or more UCI parts235. Each UCI part235may carry different information. For example, a first UCI part235may carry ACK/NACK feedback, a second UCI part235may carry PUSCH configuration information, and a third UCI part235may carry beam management information.

In some cases, the different UCI parts235may have different priorities. For example, one UCI part235may a higher priority than the other UCI parts235. The higher priority UCI parts235may be mapped to resource elements which are closer to the DMRS225in the PRU215. This may lead to a higher likelihood that the higher priority UCI part235is decoded correctly by base station105-a. Some additional examples of UCI mapping are described with reference toFIG. 3.

In some examples, UE115-amay indicate how many UCI parts235make up the UCI230. For example, the UCI230may include three UCI parts235, and UE115-amay indicate to base station105-athat there are three UCI parts235. In some cases, UE115-amay indicate the number of UCI parts235based on a preamble grouping.

For example, if UE115-auses an odd preamble index, there may be just one UCI part235. If UE115-auses an odd preamble index, this may indicate that there are two UCI parts. Other techniques for indicating the number of UCI parts via preamble grouping may be supported as well (e.g., based on modulo operations, etc.). In some cases, UE115-amay indicate the number of UCI parts235based on DMRS grouping. For example, an odd DMRS port index may be associated with single-part UCI, where an even DMRS port index may be associated with two-port UCI. In some examples, UE115-amay indicate the number of UCI parts based on PUSCH puncturing. For example, UE115-amay puncture one or two resource elements for MsgA PUSCH mapping. The time and frequency locations of the punctured resource elements may be semi-static, which may be indicated in system information or signaled by RRC.

In some cases, UE115-amay indicate the number of UCI parts235based on a pointer configuration. For example, a chain table may be configured between different UCI parts235. A first UCI part235may include a pointer to the next UCI part235. For example, UCI part X may include a pointer to UCI part X+1. Therefore, as long as a UCI part has a pointer, base station105-amay determine that there are at least X+1 pointers. When a UCI part235does not have a pointer, base station105-amay be able to determine how many UCI parts235make up the UCI230.

UE115-amay include an indication of whether the uplink random access message205includes the UCI230at all. For example, inclusion of the UCI230may be optional or configurable, or the UCI230may not always be triggered to be included in the uplink random access message205. Therefore, UE115-amay indicate whether the uplink random access message205includes the UCI230. In some cases, the inclusion of UCI230may be indicated by a preamble grouping, a DMRS grouping, a PUSCH puncturing, or any combination thereof. The preamble grouping, DMRS grouping, and PUSCH puncturing indications may be similar to those above described with reference to indicating a number of UCI parts235.

FIG. 3illustrates an example of a resource mapping configuration300that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. In some examples, the resource mapping configuration300may implement aspects of wireless communications system100.

As described herein, a UE115may be configured for a two-step random access procedure. In a first message of the two-step random access procedure, a UE115may transmit a preamble305and an uplink shared channel message in a shared channel PRU310. UEs115described herein may implement techniques to multiplex UCI315on the PRU310, including, or piggybacking, the UCI315in the uplink random access message.

In some cases, multiple UEs115configured for two-step random access procedures may share the same time, frequency, or beam resources to transmit piggybacked UCI315. The UEs115sharing the same PUSCH time, frequency, and beam resources may be configured with a number of UCI parts (e.g., 0 parts, 1 part, 2 parts, 3 parts, etc.). In some cases, the number of UCI parts for the UEs115sharing the resources may be the same or different. For example, a first UE115may transmit preamble305-aand UCI315-ain PRU310-a. A second UE115may transmit preamble305-band UCI315-bin PRU310-b. UCI315-aand UCI315-bmay at least partially overlap in time, frequency, and beam resources.

When multi-part UCI is supported, the UCI parts may be classified into different priorities. The UCI parts may then be mapped to resource elements based on their respective priorities. For example, higher priority UCI parts may be mapped to resource elements which are to DMRS resource elements. This may increase the likelihood that the high priority UCI parts are successfully decoded by the receiver (e.g., a base station105). In some cases, this may also mitigate possible interference from other UEs115which may share the same resources for two-step random access procedures. In some cases, based on the RRC state of a UE115, the configuration information for UCI piggybacking (e.g., beta offsets, formats, payload size, etc.) may be indicated in system information, signaled by RRC, or signaled by DCI.

FIG. 4illustrates an example of a process flow400that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. In some examples, process flow400may implement aspects of wireless communications system100. Process flow400may include UE115-band base station105-b, which may be respective examples of a UE115and a base station105described herein.

UE115-bmay identify a configuration for multiplexing UCI on an uplink random access message of a two-step random access procedure. In some cases, UE115-bmay receive the configuration for multiplexing UCI from the network, such as from base station105-b. Base station105-bmay transmit the configuration via DCI, RRC signaling, or system information. In some cases, the signaling used to indicate the configuration for multiplexing UCI may be based on an RRC state of UE115-b. For example, if in an RRC connected state, UE115-bmay receive the configuration for multiplexing UCI via DCI.

At405, UE115-bmay generate an uplink random access message of the two-step random access procedure, the uplink random access message including a random access preamble and an uplink shared channel resource unit. The uplink random access message may be an example of a MsgA as described herein. The uplink shared channel resource unit may be an example of a PUSCH PRU.

At410, UE115-bmay identify a trigger for inclusion of UCI with the uplink random access message. Generally, UE115-bmay be triggered to include UCI with the uplink random access message if the inclusion of the UCI decreases decoding complexity for base station105-b. Additionally, or alternatively, UE115-bmay be triggered to include UCI if the inclusion of the UCI improves scheduling decisions of base station105-b. In some cases, identifying the trigger is based on receiving a downlink control channel message from base station105-b, where the inclusion of the UCI is based on receiving the downlink control channel message. In some cases, identifying the trigger is based on receiving a group common downlink control channel message from base station105-b, wherein the inclusion of UCI is based on receiving the group common downlink control channel message. In some examples, UE115-bmay receive RRC signaling from base station105-b, which may trigger the inclusion of UCI in the uplink random access message. In some cases, UE115-bmay identify the trigger based on determining the uplink random access message a retransmission of an initial uplink random access message. In some examples, UE115-bmay select a resource unit size, an MCS, a TBS, or any combination thereof, from preconfigured sets, where the UCI is triggered to be included in the uplink random access message based on UE115-bmaking the selection. Other examples of triggers are described herein and may be described in more detail with respect toFIG. 2.

In some cases, the UCI may include one or more UCI parts. UE115-bmay identify a set of UCI parts of the UCI. In some cases, each of the UCI parts may include different types of UCI. In some examples, each of the different UCI parts may have, or may be assigned, a different priority. For example, a UCI part including high priority control information may be considered a high priority UCI part.

At415, UE115-bmay multiplex the UCI and a reference signal with the uplink shared channel resource unit. A DMRS may be an example of the reference signal. In some cases, UE115-bmay multiplex one or more reference signals in the uplink shared channel resource unit.

At420, UE115-bmay map the UCI to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. For example, higher priority UCI may be mapped closer to resource elements to which the reference signal is mapped. This may lead to a higher likelihood of the higher priority UCI being successfully decoded by base station105-b. In some cases, UE115-bmay map high priority UCI parts closer to resource elements to which the reference signal is mapped.

At425, UE115-bmay transmit the uplink random access message including the uplink control information to base station105-b. Base station105-bmay receive the uplink random access message

At430, base station105-bmay identify that uplink control information is included in the uplink random access message. At435, base station105-bmay identify a mapping of the UCI to resource elements in the uplink shared channel resource unit based on a priority of the UCI and a location of resource elements to which a reference signal is mapped. Base station105-bmay decode the UCI based on the mapping at440. At445, base station105-bmay decode the uplink random access message based on the UCI. In some cases, the UCI may include information which assists base station105-bin decoding the uplink random access message. For example, the UCI may include an RV, HARQ process, or both, if the uplink random access message is a retransmission. In some cases, the UCI may include an MCS, a TBS, a resource unit size, etc., which may improve blind decoding performance at base station105-b.

FIG. 5shows a block diagram500of a device505that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device505may be an example of aspects of a UE115as described herein. The device505may include a receiver510, a communications manager515, and a transmitter520. The device505may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver510may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to transmitting uplink control information in a two-step random access procedure, etc.). Information may be passed on to other components of the device505. The receiver510may be an example of aspects of the transceiver820described with reference toFIG. 8. The receiver510may utilize a single antenna or a set of antennas.

The communications manager515may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify a trigger for inclusion of the uplink control information with the uplink random access message, multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration, map the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmit the uplink random access message including the uplink control information to a base station. The communications manager515may be an example of aspects of the communications manager810described herein.

The actions performed by the UE communications manager515as described herein may be implemented to realize one or more potential advantages. One implementation may allow a UE115to have increased signaling flexibility. These techniques support a UE115to include UCI in a RACH message while operating in any RRC state. In some cases, the UE115may transmit measurement information which may assist a base station105in making scheduling decisions for the UE115. This may lead to improved scheduling and communications quality for the UE115. These techniques may also provide benefits for a base station105. UCI included in the uplink random access message may improve decoding performance at the base station105.

FIG. 6shows a block diagram600of a device605that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device605may be an example of aspects of a device505, or a UE115as described herein. The device605may include a receiver610, a communications manager615, and a transmitter645. The device605may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The communications manager615may be an example of aspects of the communications manager515as described herein. The communications manager615may include an uplink random access message generating component620, a UCI trigger component625, a multiplexing component630, a UCI mapping component635, an uplink random access message transmitting component640, and a UCI multiplexing configuration component650. The communications manager615may be an example of aspects of the communications manager810described herein.

The UCI multiplexing configuration component650may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure. The uplink random access message generating component620may generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The UCI trigger component625may identify a trigger for inclusion of the uplink control information with the uplink random access message. The multiplexing component630may multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration. The UCI mapping component635may map the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped. The uplink random access message transmitting component640may transmit the uplink random access message including the uplink control information to a base station.

Based on piggybacking UCI onto an uplink random access message, a processor of a UE115(e.g., controlling the receiver610, the transmitter645, or the transceiver820as described with reference toFIG. 8) may flexibly transmit UCI to a base station105. The UCI may be received at the base station105, and the base station105may make adjustments based on the UCI. For example, the UCI may include measurement information, scheduling requests, beam management information, etc., which may lead to enhance communications for the UE115.

The transmitter645may transmit signals generated by other components of the device605. In some examples, the transmitter645may be collocated with a receiver610in a transceiver module. For example, the transmitter645may be an example of aspects of the transceiver820described with reference toFIG. 8. The transmitter645may utilize a single antenna or a set of antennas.

FIG. 7shows a block diagram700of a communications manager705that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The communications manager705may be an example of aspects of a communications manager515, a communications manager615, or a communications manager810described herein. The communications manager705may include an uplink random access message generating component710, a UCI trigger component715, a multiplexing component720, a UCI mapping component725, an uplink random access message transmitting component730, a UCI parts component735, a UCI inclusion indication component740and a UCI multiplexing configuration component745. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The UCI multiplexing configuration component745may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure.

The uplink random access message generating component710may generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. In some cases, the UE is in an RRC active mode, an RRC idle mode, or an RRC inactive mode.

In some cases, the two-step random access procedure is a contention-free two-step random access procedure or a contention-based two-step random access procedure.

The UCI trigger component715may identify a trigger for inclusion of the uplink control information with the uplink random access message. In some examples, the UCI trigger component715may receive a downlink control channel message from the base station, where the inclusion of uplink control information is based on receiving the downlink control channel message. In some examples, the UCI trigger component715may receive a group common downlink control channel message from the base station, where the inclusion of uplink control information is based on receiving the group common downlink control channel message.

In some examples, the UCI trigger component715may receive RRC signaling from the base station, where the inclusion of uplink control information is based on receiving the RRC signaling. In some examples, the UCI trigger component715may determine the uplink random access message is a retransmission of an initial uplink random access message. In some examples, the UCI trigger component715may identify configured sets of resource unit sizes, modulation and coding schemes (MCS), transport block sizes (TBS), or any combination thereof. In some examples, the UCI trigger component715may select a resource unit size, an MCS, and a TBS to use for the uplink random access message. In some examples, the UCI trigger component715may include an indicator of the selected resource unit size, the selected MCS, and the selected TBS in the uplink control information.

In some examples, the UCI trigger component715may identify a configured set of random access occasions. In some examples, the UCI trigger component715may select a random access occasion for transmitting the uplink random access message from the configured set of random access occasions, where the random access occasion is associated with a synchronization signal block (SSB) beam index.

In some examples, the UCI trigger component715may identify a configured set of random access preambles. In some examples, the UCI trigger component715may select the random access preamble from the configured set of random access preambles, where the random access preamble is associated with a synchronization signal block (SSB) beam index.

In some examples, the UCI trigger component715may include an indicator of the SSB beam index in the uplink control information. In some examples, the UCI trigger component715may perform a measurement on a downlink reference signal from the base station to obtain a downlink measurement. In some examples, the UCI trigger component715may include an indicator of the downlink measurement in the uplink control information. In some cases, the uplink control information includes a redundancy version, a HARQ process identifier, or both.

In some cases, the uplink control information includes uplink shared channel configuration information, ACK or NACK feedback, a CSI report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof. In some cases, the uplink shared channel configuration information includes modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TB S), a new data indicator (NDI), a HARQ process number, or any combination thereof. In some cases, the RSRP measurement information is from a serving cell, one or more neighboring cells, or any combination thereof. In some cases, the beam management information includes a list of preferred beam indexes.

In some cases, the beam management information includes transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit. In some cases, the uplink control information includes ACK or NACK feedback, a CSI report, a scheduling request, or any combination thereof.

The multiplexing component720may multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration. The UCI mapping component725may map the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. In some examples, the UCI mapping component725may identify configuration information for mapping the uplink control information, the configuration information including a beta offset, formats for the uplink control information, a payload size, or any combination thereof.

In some examples, the UCI mapping component725may receive an indication of the configuration information from the base station based on an RRC state of the UE, where the configuration information is identified based on receiving the indication. In some cases, the indication is received in a SIB, an RRC message, or downlink control information. The uplink random access message transmitting component730may transmit the uplink random access message including the uplink control information to a base station.

The UCI parts component735may identify a set of uplink control information parts of the uplink control information. In some examples, the UCI parts component735may map the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts. In some examples, the UCI parts component735may map a first uplink control information part with a higher priority closer to resource elements to which the reference signal is mapped than a second uplink control information part with a lower priority.

In some examples, the UCI parts component735may indicate a number of uplink control information parts in the set of uplink control information parts based on a preamble grouping for the random access preamble. In some examples, the UCI parts component735may indicate a number of uplink control information parts in the set of uplink control information parts based on a DMRS grouping. In some examples, the UCI parts component735may indicate a number of uplink control information parts in the set of uplink control information parts based on puncturing the uplink shared channel resource unit.

In some examples, the UCI parts component735may include, in a first uplink control information part, a pointer to a second uplink control information part, where a number of uplink control information parts in the set of uplink control information parts is indicated based on a number of pointers including at least the pointer. In some examples, the UCI parts component735may include an indicator of the SSB beam index in the uplink control information. In some cases, each uplink control information part of the set of uplink control information parts includes a different type of the uplink control information.

The UCI inclusion indication component740may indicate that the uplink random access message includes the uplink control information based on a preamble grouping for the random access preamble. In some examples, indicating that the uplink random access message includes the uplink control information based on a DMRS grouping. In some examples, indicating that the uplink random access message includes the uplink control information based on puncturing the uplink shared channel resource unit.

FIG. 8shows a diagram of a system800including a device805that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device805may be an example of or include the components of device505, device605, or a UE115as described herein. The device805may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager810, an I/O controller815, a transceiver820, an antenna825, memory830, and a processor840. These components may be in electronic communication via one or more buses (e.g., bus845).

The communications manager810may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure, generate the uplink random access message, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify a trigger for inclusion of the uplink control information with the uplink random access message, multiplex the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration, map the uplink control information to resource elements in the uplink shared channel resource unit based on a type of the uplink control information and a location of resource elements to which the reference signal is mapped, and transmit the uplink random access message including the uplink control information to a base station. In some examples, the priority of the uplink control information may be based on, or associated with, a type of the uplink control information.

The memory830may include RAM and ROM. The memory830may store computer-readable, computer-executable code835including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory830may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

FIG. 9shows a block diagram900of a device905that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device905may be an example of aspects of a base station105as described herein. The device905may include a receiver910, a communications manager915, and a transmitter920. The device905may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver910may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to transmitting uplink control information in a two-step random access procedure, etc.). Information may be passed on to other components of the device905. The receiver910may be an example of aspects of the transceiver1220described with reference toFIG. 12. The receiver910may utilize a single antenna or a set of antennas.

The communications manager915may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify that uplink control information is included in the uplink random access message, identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decode the uplink control information based on the mapping, and decode the uplink random access message based on the uplink control information. The communications manager915may be an example of aspects of the communications manager1210described herein.

The actions performed by the base station communications manager915as described herein may be implemented to realize one or more potential advantages. One implementation may allow a base station105to efficiently decode an uplink random access message. UCI piggybacked onto the uplink random access message may include information which the base station105can use to efficiently decode the uplink random access message. For example, if the uplink random access message is a retransmission, the UCI may include a redundancy version, a HARQ process ID, or both. The base station105may then perform HARQ combining based on this information. Generally, the UCI may improve blind decoding performance at the base station105.

FIG. 10shows a block diagram1000of a device1005that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device1005may be an example of aspects of a device905, or a base station105as described herein. The device1005may include a receiver1010, a communications manager1015, and a transmitter1045. The device1005may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver1010may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to transmitting uplink control information in a two-step random access procedure, etc.). Information may be passed on to other components of the device1005. The receiver1010may be an example of aspects of the transceiver1220described with reference toFIG. 12. The receiver1010may utilize a single antenna or a set of antennas.

The communications manager1015may be an example of aspects of the communications manager915as described herein. The communications manager1015may include an uplink random access message receiving component1020, a UCI identifying component1025, a mapping identifying component1030, a UCI decoding component1035, and an uplink random access message decoding component1040. The communications manager1015may be an example of aspects of the communications manager1210described herein.

The uplink random access message receiving component1020may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit.

The UCI identifying component1025may identify that uplink control information is included in the uplink random access message. The mapping identifying component1030may identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped. The UCI decoding component1035may decode the uplink control information based on the mapping. The uplink random access message decoding component1040may decode the uplink random access message based on the uplink control information.

The transmitter1045may transmit signals generated by other components of the device1005. In some examples, the transmitter1045may be collocated with a receiver1010in a transceiver module. For example, the transmitter1045may be an example of aspects of the transceiver1220described with reference toFIG. 12. The transmitter1045may utilize a single antenna or a set of antennas.

FIG. 11shows a block diagram1100of a communications manager1105that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The communications manager1105may be an example of aspects of a communications manager915, a communications manager1015, or a communications manager1210described herein. The communications manager1105may include an uplink random access message receiving component1110, a UCI identifying component1115, a mapping identifying component1120, a UCI decoding component1125, an uplink random access message decoding component1130, and a UCI part identifying component1135. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The uplink random access message receiving component1110may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit.

In some cases, the UE is in an RRC active mode, an RRC idle mode, or an RRC inactive mode. In some cases, the two-step random access procedure is a contention-free two-step random access procedure or a contention-based two-step random access procedure.

The UCI identifying component1115may identify that uplink control information is included in the uplink random access message. In some examples, the UCI identifying component1115may transmit a downlink control channel message to the UE, where the downlink control channel message triggers the UE to include the uplink control information in the uplink random access message.

In some examples, the UCI identifying component1115may transmit a group common downlink control channel message to the UE, where the group common downlink control channel message triggers the UE to include the uplink control information in the uplink random access message. In some examples, the UCI identifying component1115may determine the uplink random access message is a retransmission of an initial uplink random access message.

In some examples, the UCI identifying component1115may identify a configured set of random access occasions, where each random access occasion of the configured set of random access occasions is associated with a synchronization signal block (SSB) beam index. In some examples, the UCI identifying component1115may identify, from the UE, an indicator of an SSB beam index associated with a random access occasion of the configured set of random access occasions in the uplink control information.

In some examples, the UCI identifying component1115may identify a configured set of random access preambles, where each random access preamble of the configured set of random access preambles is associated with a synchronization signal block (SSB) beam index. In some examples, the UCI identifying component1115may identify, from the UE, an indicator of an SSB beam index associated with the random access preamble in the uplink control information.

In some examples, the UCI identifying component1115may transmit a downlink reference signal to the UE. In some examples, the UCI identifying component1115may identify an indicator of a downlink measurement for the downlink reference signal in the uplink control information.

In some cases, the uplink control information includes a redundancy version, a HARQ process identifier, or both. In some cases, the uplink control information includes uplink shared channel configuration information, ACK or NACK feedback, a CSI report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof. In some cases, the uplink shared channel configuration information includes modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TBS), a new data indicator (NDI), a HARQ process number, or any combination thereof. In some cases, the RSRP measurement information is from the base station, one or more neighboring cells of the base station, or any combination thereof.

In some cases, the beam management information includes a list of preferred beam indexes. In some cases, the beam management information includes transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit. In some cases, the uplink control information includes ACK or NACK feedback, a CSI report, a scheduling request, or any combination thereof. In some cases, the identifying that uplink control information is included in the uplink random access message is based on a preamble grouping for the random access preamble. In some cases, the identifying that uplink control information is included in the uplink random access message is based on a DMRS grouping. In some cases, the identifying that uplink control information is included in the uplink random access message is based on puncturing the uplink shared channel resource unit.

The mapping identifying component1120may identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped. In some examples, the mapping identifying component1120may determine configuration information for mapping the uplink control information, the configuration information including a beta offset, formats for the uplink control information, a payload size, or any combination thereof.

In some examples, the mapping identifying component1120may transmit an indication of the configuration information to the UE based on an RRC state of the UE, where the configuration information is identified based on receiving the indication. In some cases, the indication is received in a SIB, an RRC message, or downlink control information.

The UCI decoding component1125may decode the uplink control information based on the mapping. The uplink random access message decoding component1130may decode the uplink random access message based on the uplink control information.

The UCI part identifying component1135may identify a set of uplink control information parts of the uplink control information. In some examples, the UCI part identifying component1135may identify a mapping of the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts. In some examples, the UCI part identifying component1135may identify that a first uplink control information part with a higher priority is mapped closer to resource elements to which the reference signal is mapped than a second uplink control information part with a lower priority. In some examples, the UCI part identifying component1135may decode the first uplink control information part with the higher priority based on the first uplink control information part being mapped closer to resource elements to which the reference signal is mapped.

In some examples, the UCI part identifying component1135may identify a number of uplink control information parts in the set of uplink control information parts based on a preamble grouping for the random access preamble. In some examples, the UCI part identifying component1135may identify a number of uplink control information parts in the set of uplink control information parts based on a DMRS grouping. In some examples, the UCI part identifying component1135may identify a number of uplink control information parts in the set of uplink control information parts based on puncturing the uplink shared channel resource unit.

In some examples, the UCI part identifying component1135may identify, in a first uplink control information part, a pointer to a second uplink control information part, where a number of uplink control information parts in the set of uplink control information parts is identified based on a number of pointers including at least the pointer.

In some cases, each uplink control information part of the set of uplink control information parts includes a different type of the uplink control information.

FIG. 12shows a diagram of a system1200including a device1205that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The device1205may be an example of or include the components of device905, device1005, or a base station105as described herein. The device1205may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager1210, a network communications manager1215, a transceiver1220, an antenna1225, memory1230, a processor1240, and an inter-station communications manager1245. These components may be in electronic communication via one or more buses (e.g., bus1250).

The communications manager1210may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit, identify that uplink control information is included in the uplink random access message, identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped, decode the uplink control information based on the mapping, and decode the uplink random access message based on the uplink control information.

The memory1230may include RAM, ROM, or a combination thereof. The memory1230may store computer-readable code1235including instructions that, when executed by a processor (e.g., the processor1240) cause the device to perform various functions described herein. In some cases, the memory1230may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

FIG. 13shows a flowchart illustrating a method1300that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1300may be implemented by a UE115or its components as described herein. For example, the operations of method1300may be performed by a communications manager as described with reference toFIGS. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At1305, the UE may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure. The operations of1305may be performed according to the methods described herein. In some examples, aspects of the operations of1305may be performed by a UCI multiplexing configuration component as described with reference toFIGS. 5 through 8.

At1310, the UE may generate an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1310may be performed according to the methods described herein. In some examples, aspects of the operations of1310may be performed by an uplink random access message generating component as described with reference toFIGS. 5 through 8.

At1315, the UE may identify a trigger for inclusion of uplink control information with the uplink random access message. The operations of1315may be performed according to the methods described herein. In some examples, aspects of the operations of1315may be performed by a UCI trigger component as described with reference toFIGS. 5 through 8.

At1320, the UE may multiplex the uplink control information and a reference signal with the uplink shared channel resource unit. The operations of1320may be performed according to the methods described herein. In some examples, aspects of the operations of1320may be performed by a multiplexing component as described with reference toFIGS. 5 through 8.

At1325, the UE may map the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. The operations of1325may be performed according to the methods described herein. In some examples, aspects of the operations of1325may be performed by a UCI mapping component as described with reference toFIGS. 5 through 8.

At1330, the UE may transmit the uplink random access message including the uplink control information to a base station. The operations of1330may be performed according to the methods described herein. In some examples, aspects of the operations of1330may be performed by an uplink random access message transmitting component as described with reference toFIGS. 5 through 8.

FIG. 14shows a flowchart illustrating a method1400that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1400may be implemented by a UE115or its components as described herein. For example, the operations of method1400may be performed by a communications manager as described with reference toFIGS. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At1405, the UE may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure. The operations of1405may be performed according to the methods described herein. In some examples, aspects of the operations of1405may be performed by a UCI multiplexing configuration component as described with reference toFIGS. 5 through 8.

At1410, the UE may generate an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1410may be performed according to the methods described herein. In some examples, aspects of the operations of1410may be performed by an uplink random access message generating component as described with reference toFIGS. 5 through 8.

At1415, the UE may identify a trigger for inclusion of uplink control information with the uplink random access message. The operations of1415may be performed according to the methods described herein. In some examples, aspects of the operations of1415may be performed by a UCI trigger component as described with reference toFIGS. 5 through 8.

At1420, the UE may identify a set of uplink control information parts of the uplink control information. The operations of1420may be performed according to the methods described herein. In some examples, aspects of the operations of1420may be performed by a UCI parts component as described with reference toFIGS. 5 through 8.

At1425, the UE may multiplex the uplink control information and a reference signal with the uplink shared channel resource unit. The operations of1425may be performed according to the methods described herein. In some examples, aspects of the operations of1425may be performed by a multiplexing component as described with reference toFIGS. 5 through 8.

At1430, the UE may map the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. The operations of1430may be performed according to the methods described herein. In some examples, aspects of the operations of1430may be performed by a UCI mapping component as described with reference toFIGS. 5 through 8.

At1435, the UE may map the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts. The operations of1435may be performed according to the methods described herein. In some examples, aspects of the operations of1435may be performed by a UCI parts component as described with reference toFIGS. 5 through 8.

At1440, the UE may transmit the uplink random access message including the uplink control information to a base station. The operations of1440may be performed according to the methods described herein. In some examples, aspects of the operations of1440may be performed by an uplink random access message transmitting component as described with reference toFIGS. 5 through 8.

FIG. 15shows a flowchart illustrating a method1500that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1500may be implemented by a UE115or its components as described herein. For example, the operations of method1500may be performed by a communications manager as described with reference toFIGS. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

In some cases, the UE may identify a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure. At1505, the UE may generate an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1505may be performed according to the methods described herein. In some examples, aspects of the operations of1505may be performed by an uplink random access message generating component as described with reference toFIGS. 5 through 8.

At1510, the UE may identify a trigger for inclusion of uplink control information with the uplink random access message. The operations of1510may be performed according to the methods described herein. In some examples, aspects of the operations of1510may be performed by a UCI trigger component as described with reference toFIGS. 5 through 8.

At1515, the UE may identify a configured set of random access occasions. The operations of1515may be performed according to the methods described herein. In some examples, aspects of the operations of1515may be performed by a UCI trigger component as described with reference toFIGS. 5 through 8.

At1520, the UE may select a random access occasion for transmitting the uplink random access message from the configured set of random access occasions, where the random access occasion is associated with a synchronization signal block (SSB) beam index. The operations of1520may be performed according to the methods described herein. In some examples, aspects of the operations of1520may be performed by a UCI trigger component as described with reference toFIGS. 5 through 8.

At1525, the UE may include an indicator of the SSB beam index in the uplink control information. The operations of1525may be performed according to the methods described herein. In some examples, aspects of the operations of1525may be performed by a UCI parts component as described with reference toFIGS. 5 through 8.

At1530, the UE may multiplex the uplink control information and a reference signal with the uplink shared channel resource unit. The operations of1530may be performed according to the methods described herein. In some examples, aspects of the operations of1530may be performed by a multiplexing component as described with reference toFIGS. 5 through 8.

At1535, the UE may map the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which the reference signal is mapped. The operations of1535may be performed according to the methods described herein. In some examples, aspects of the operations of1535may be performed by a UCI mapping component as described with reference toFIGS. 5 through 8.

At1540, the UE may transmit the uplink random access message including the uplink control information to a base station. The operations of1540may be performed according to the methods described herein. In some examples, aspects of the operations of1540may be performed by an uplink random access message transmitting component as described with reference toFIGS. 5 through 8.

FIG. 16shows a flowchart illustrating a method1600that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1600may be implemented by a base station105or its components as described herein. For example, the operations of method1600may be performed by a communications manager as described with reference toFIGS. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At1605, the base station may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1605may be performed according to the methods described herein. In some examples, aspects of the operations of1605may be performed by an uplink random access message receiving component as described with reference toFIGS. 9 through 12.

At1610, the base station may identify that uplink control information is included in the uplink random access message. The operations of1610may be performed according to the methods described herein. In some examples, aspects of the operations of1610may be performed by a UCI identifying component as described with reference toFIGS. 9 through 12.

At1615, the base station may identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped. The operations of1615may be performed according to the methods described herein. In some examples, aspects of the operations of1615may be performed by a mapping identifying component as described with reference toFIGS. 9 through 12.

At1620, the base station may decode the uplink control information based on the mapping. The operations of1620may be performed according to the methods described herein. In some examples, aspects of the operations of1620may be performed by a UCI decoding component as described with reference toFIGS. 9 through 12.

At1625, the base station may decode the uplink random access message based on the uplink control information. The operations of1625may be performed according to the methods described herein. In some examples, aspects of the operations of1625may be performed by an uplink random access message decoding component as described with reference toFIGS. 9 through 12.

FIG. 17shows a flowchart illustrating a method1700that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1700may be implemented by a base station105or its components as described herein. For example, the operations of method1700may be performed by a communications manager as described with reference toFIGS. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At1705, the base station may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1705may be performed according to the methods described herein. In some examples, aspects of the operations of1705may be performed by an uplink random access message receiving component as described with reference toFIGS. 9 through 12.

At1710, the base station may identify that uplink control information is included in the uplink random access message. The operations of1710may be performed according to the methods described herein. In some examples, aspects of the operations of1710may be performed by a UCI identifying component as described with reference toFIGS. 9 through 12.

At1715, the base station may identify a set of uplink control information parts of the uplink control information. The operations of1715may be performed according to the methods described herein. In some examples, aspects of the operations of1715may be performed by a UCI part identifying component as described with reference toFIGS. 9 through 12.

At1720, the base station may identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped. The operations of1720may be performed according to the methods described herein. In some examples, aspects of the operations of1720may be performed by a mapping identifying component as described with reference toFIGS. 9 through 12.

At1725, the base station may identify a mapping of the set of uplink control information parts to respective resource elements based on respective priorities of the set of uplink control information parts. The operations of1725may be performed according to the methods described herein. In some examples, aspects of the operations of1725may be performed by a UCI part identifying component as described with reference toFIGS. 9 through 12.

At1730, the base station may decode the uplink control information based on the mapping. The operations of1730may be performed according to the methods described herein. In some examples, aspects of the operations of1730may be performed by a UCI decoding component as described with reference toFIGS. 9 through 12.

At1735, the base station may decode the uplink random access message based on the uplink control information. The operations of1735may be performed according to the methods described herein. In some examples, aspects of the operations of1735may be performed by an uplink random access message decoding component as described with reference toFIGS. 9 through 12.

FIG. 18shows a flowchart illustrating a method1800that supports transmitting uplink control information in a two-step random access procedure in accordance with aspects of the present disclosure. The operations of method1800may be implemented by a base station105or its components as described herein. For example, the operations of method1800may be performed by a communications manager as described with reference toFIGS. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At1805, the base station may receive an uplink random access message of a two-step random access procedure, the uplink random access message including a random access preamble and an associated uplink shared channel resource unit. The operations of1805may be performed according to the methods described herein. In some examples, aspects of the operations of1805may be performed by an uplink random access message receiving component as described with reference toFIGS. 9 through 12.

At1810, the base station may identify that uplink control information is included in the uplink random access message. The operations of1810may be performed according to the methods described herein. In some examples, aspects of the operations of1810may be performed by a UCI identifying component as described with reference toFIGS. 9 through 12.

At1815, the base station may determine configuration information for mapping the uplink control information, the configuration information including a beta offset, formats for the uplink control information, a payload size, or any combination thereof. The operations of1815may be performed according to the methods described herein. In some examples, aspects of the operations of1815may be performed by a mapping identifying component as described with reference toFIGS. 9 through 12.

At1820, the base station may identify a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped. The operations of1820may be performed according to the methods described herein. In some examples, aspects of the operations of1820may be performed by a mapping identifying component as described with reference toFIGS. 9 through 12.

At1825, the base station may decode the uplink control information based on the mapping. The operations of1825may be performed according to the methods described herein. In some examples, aspects of the operations of1825may be performed by a UCI decoding component as described with reference toFIGS. 9 through 12.

At1830, the base station may decode the uplink random access message based on the uplink control information. The operations of1830may be performed according to the methods described herein. In some examples, aspects of the operations of1830may be performed by an uplink random access message decoding component as described with reference toFIGS. 9 through 12.

Example 1. A method for wireless communications, comprising: identifying a configuration for multiplexing uplink control information on an uplink random access message of a two-step random access procedure; generating the uplink random access message, the uplink random access message comprising a random access preamble and an associated uplink shared channel resource unit; identifying a trigger for inclusion of the uplink control information with the uplink random access message; multiplexing the uplink control information and a reference signal in the uplink shared channel resource unit based on the configuration; mapping the uplink control information to resource elements in the uplink shared channel resource unit based at least in part on a type of the uplink control information and a location of resource elements to which the reference signal is mapped; and transmitting the uplink random access message comprising the uplink control information to a base station.

Example 2: The method of example 1, further comprising: identifying a plurality of uplink control information parts of the uplink control information.

Example 3: The method of examples 1 or 2, wherein each type of the uplink control information is associated with a priority and wherein mapping the uplink control information further comprises: mapping the plurality of uplink control information parts to respective resource elements based at least in part on respective priorities of the plurality of uplink control information parts.

Example 4: The method of example 3, further comprising: mapping a first uplink control information part with a higher priority closer to resource elements to which the reference signal is mapped than a second uplink control information part with a lower priority.

Example 5: The method of any of examples 1 to 4, wherein each uplink control information part of the plurality of uplink control information parts comprises a different type of the uplink control information.

Example 6: The method of any of examples 1 to 5, further comprising: indicating a number of uplink control information parts in the plurality of uplink control information parts based at least in part on a preamble grouping for the random access preamble.

Example 7: The method of any of examples 1 to 6, further comprising: indicating a number of uplink control information parts in the plurality of uplink control information parts based at least in part on a demodulation reference signal (DMRS) grouping.

Example 8: The method of any of examples 1 to 7, further comprising: indicating a number of uplink control information parts in the plurality of uplink control information parts based at least in part on puncturing the uplink shared channel resource unit.

Example 9: The method of any of examples 1 to 8, further comprising: including, in a first uplink control information part, a pointer to a second uplink control information part, wherein a number of uplink control information parts in the plurality of uplink control information parts is indicated based at least in part on a number of pointers comprising at least the pointer.

Example 10: The method of any of examples 1 to 9, further comprising: identifying configuration information for mapping the uplink control information, the configuration information comprising a beta offset, formats for the uplink control information, a payload size, or any combination thereof.

Example 11: The method of example 10, further comprising: receiving an indication of the configuration information from the base station based at least in part on a Radio Resource Control (RRC) state of the UE, wherein the configuration information is identified based at least in part on receiving the indication.

Example 12: The method of example 11, wherein the indication is received in a system information block (SIB), an RRC message, or downlink control information.

Example 13: The method of any of examples 1 to 12, wherein the UE is in a Radio Resource Control (RRC) active mode, an RRC idle mode, or an RRC inactive mode.

Example 14: The method of any of examples 1 to 13, wherein the two-step random access procedure is a contention-free two-step random access procedure or a contention-based two-step random access procedure.

Example 15: The method of any of examples 1 to 14, wherein identifying the trigger further comprises: receiving a downlink control channel message from the base station, wherein the inclusion of uplink control information is based at least in part on receiving the downlink control channel message.

Example 16: The method of any of examples 1 to 15, wherein identifying the trigger further comprises: receiving a group common downlink control channel message from the base station, wherein the inclusion of uplink control information is based at least in part on receiving the group common downlink control channel message.

Example 17: The method of any of examples 1 to 16, wherein identifying the trigger further comprises: receiving Radio Resource Control (RRC) signaling from the base station, wherein the inclusion of uplink control information is based at least in part on receiving the RRC signaling.

Example 18: The method of any of examples 1 to 17, wherein identifying the trigger further comprises: determining the uplink random access message is a retransmission of an initial uplink random access message.

Example 19: The method of example 18, wherein the uplink control information comprises a redundancy version, a hybrid automatic repeat request (HARM) process identifier, or both.

Example 20: The method of any of examples 1 to 19, wherein identifying the trigger further comprises: identifying configured sets of resource unit sizes, modulation and coding schemes (MCS), transport block sizes (TBS), or any combination thereof; selecting a resource unit size, an MCS, and a TBS to use for the uplink random access message; and including an indicator of the selected resource unit size, the selected MCS, and the selected TBS in the uplink control information.

Example 21: The method of any of examples 1 to 20, wherein identifying the trigger further comprises: identifying a configured set of random access occasions; selecting a random access occasion for transmitting the uplink random access message from the configured set of random access occasions, wherein the random access occasion is associated with a synchronization signal block (SSB) beam index; and including an indicator of the SSB beam index in the uplink control information.

Example 22: The method of any of examples 1 to 21, wherein identifying the trigger further comprises: identifying a configured set of random access preambles; selecting the random access preamble from the configured set of random access preambles, wherein the random access preamble is associated with a synchronization signal block (SSB) beam index; and including an indicator of the SSB beam index in the uplink control information.

Example 23: The method of any of examples 1 to 22, wherein identifying the trigger further comprises: performing a measurement on a downlink reference signal from the base station to obtain a downlink measurement; and including an indicator of the downlink measurement in the uplink control information.

Example 24: The method of any of examples 1 to 23, wherein the uplink control information comprises uplink shared channel configuration information, acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a channel state information (CSI) report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof.

Example 25: The method of any of examples 1 to 24, wherein the uplink shared channel configuration information comprises modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TBS), a new data indicator (NDI), a hybrid automatic repeat request (HARQ) process number, or any combination thereof.

Example 26: The method of any of examples 1 to 25, wherein the RSRP measurement information is from a serving cell, one or more neighboring cells, or any combination thereof.

Example 27: The method of any of examples 1 to 26, wherein the beam management information comprises a list of preferred beam indexes.

Example 28: The method of any of examples 1 to 27, wherein the beam management information comprises transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit.

Example 29: The method of any of examples 1 to 28, wherein the uplink control information comprises acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a channel state information (CSI) report, a scheduling request, or any combination thereof.

Example 30: The method of any of examples 1 to 29, further comprising: indicating that the uplink random access message comprises the uplink control information based at least in part on a preamble grouping for the random access preamble.

Example 31: The method of any of examples 1 to 30, further comprising: indicating that the uplink random access message comprises the uplink control information based at least in part on a demodulation reference signal (DMRS) grouping.

Example 32: The method of any of examples 1 to 31, further comprising: indicating that the uplink random access message comprises the uplink control information based at least in part on puncturing the uplink shared channel resource unit.

Example 33. A method for wireless communications at a base station, comprising: receiving an uplink random access message of a two-step random access procedure, the uplink random access message comprising a random access preamble and an associated uplink shared channel resource unit; identifying that uplink control information is included in the uplink random access message; identifying a mapping of the uplink control information to resource elements in the uplink shared channel resource unit based at least in part on a priority of the uplink control information and a location of resource elements to which a reference signal is mapped; decoding the uplink control information based at least in part on the mapping; and decoding the uplink random access message based at least in part on the uplink control information.

Example 34: The method of example 33, further comprising: identifying a plurality of uplink control information parts of the uplink control information.

Example 35: The method of example 34, further comprising: identifying a mapping of the plurality of uplink control information parts to respective resource elements based at least in part on respective priorities of the plurality of uplink control information parts.

Example 36: The method of example 35, further comprising: identifying that a first uplink control information part with a higher priority is mapped closer to resource elements to which the reference signal is mapped than a second uplink control information part with a lower priority.

Example 37: The method of example 36, further comprising: decoding the first uplink control information part with the higher priority based at least in part on the first uplink control information part being mapped closer to resource elements to which the reference signal is mapped.

Example 38: The method of example 34, wherein each uplink control information part of the plurality of uplink control information parts comprises a different type of the uplink control information.

Example 39: The method of example 34, further comprising: identifying a number of uplink control information parts in the plurality of uplink control information parts based at least in part on a preamble grouping for the random access preamble.

Example 40: The method of example 34, further comprising: identifying a number of uplink control information parts in the plurality of uplink control information parts based at least in part on a demodulation reference signal (DMRS) grouping.

Example 41: The method of example 34, further comprising: identifying a number of uplink control information parts in the plurality of uplink control information parts based at least in part on puncturing the uplink shared channel resource unit.

Example 42: The method of example 34, further comprising: identifying, in a first uplink control information part, a pointer to a second uplink control information part, wherein a number of uplink control information parts in the plurality of uplink control information parts is identified based at least in part on a number of pointers comprising at least the pointer.

Example 43: The method of any of examples 33, further comprising: determining configuration information for mapping the uplink control information, the configuration information comprising a beta offset, formats for the uplink control information, a payload size, or any combination thereof.

Example 44: The method of example 43, further comprising: transmitting an indication of the configuration information to the UE based at least in part on a Radio Resource Control (RRC) state of the UE, wherein the configuration information is identified based at least in part on receiving the indication.

Example 45: The method of example 44, wherein the indication is received in a system information block (SIB), an RRC message, or downlink control information.

Example 46: The method of any of examples 33, wherein the UE is in a Radio Resource Control (RRC) active mode, an RRC idle mode, or an RRC inactive mode.

Example 47: The method of any of examples 33, wherein the two-step random access procedure is a contention-free two-step random access procedure or a contention-based two-step random access procedure.

Example 48: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: transmitting a downlink control channel message to the UE, wherein the downlink control channel message triggers the UE to include the uplink control information in the uplink random access message.

Example 49: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: transmitting a group common downlink control channel message to the UE, wherein the group common downlink control channel message triggers the UE to include the uplink control information in the uplink random access message.

Example 50: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: transmitting Radio Resource Control (RRC) signaling to the UE, wherein the RRC signaling triggers the UE to include the uplink control information in the uplink random access message.

Example 51: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: determining the uplink random access message is a retransmission of an initial uplink random access message.

Example 52: The method of example 51, wherein the uplink control information comprises a redundancy version, a hybrid automatic repeat request (HARQ) process identifier, or both.

Example 53: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: identifying configured sets of resource unit sizes, modulation and coding schemes (MCS), transport block sizes (TBS), or any combination thereof; and identifying, from the UE, an indicator of a selected resource unit size, a selected MCS, and a selected TBS in the uplink control information.

Example 54: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: identifying a configured set of random access occasions, wherein each random access occasion of the configured set of random access occasions is associated with a synchronization signal block (SSB) beam index; and identifying, from the UE, an indicator of an SSB beam index associated with a random access occasion of the configured set of random access occasions in the uplink control information.

Example 55: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: identifying a configured set of random access preambles, wherein each random access preamble of the configured set of random access preambles is associated with a synchronization signal block (SSB) beam index; and identifying, from the UE, an indicator of an SSB beam index associated with the random access preamble in the uplink control information.

Example 56: The method of any of examples 33, wherein identifying that uplink control information is included in the uplink random access message further comprises: transmitting a downlink reference signal to the UE; and identifying an indicator of a downlink measurement for the downlink reference signal in the uplink control information.

Example 57: The method of any of examples 33, wherein the uplink control information comprises uplink shared channel configuration information, acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a channel state information (CSI) report, a scheduling request, interference measurement information, positioning measurement information, reference signal received power (RSRP) measurement information, beam management information, or any combination thereof.

Example 58: The method of example 57, wherein the uplink shared channel configuration information comprises modulation and coding scheme (MCS) information, a redundancy version, a transport block size (TBS), a new data indicator (NDI), a hybrid automatic repeat request (HARD) process number, or any combination thereof.

Example 59: The method of example 57, wherein the RSRP measurement information is from the base station, one or more neighboring cells of the base station, or any combination thereof.

Example 60: The method of example 57, wherein the beam management information comprises a list of preferred beam indexes.

Example 61: The method of example 57, wherein the beam management information comprises transmit beam switching information indicating a first transmit beam for the random access preamble and a second transmit beam for the uplink shared channel resource unit.

Example 62: The method of any of examples 33, wherein the uplink control information comprises acknowledgment (ACK) or negative acknowledgment (NACK) feedback, a channel state information (CSI) report, a scheduling request, or any combination thereof.

Example 63: The method of any of examples 33, wherein the identifying that uplink control information is included in the uplink random access message is based at least in part on a preamble grouping for the random access preamble.

Example 64: The method of any of examples 33, wherein the identifying that uplink control information is included in the uplink random access message is based at least in part on a demodulation reference signal (DMRS) grouping.

Example 65: The method of any of examples 33, wherein the identifying that uplink control information is included in the uplink random access message is based at least in part on puncturing the uplink shared channel resource unit.

Example 66: An apparatus comprising at least one means for performing a method of any of examples 1 to 32.

Example 67: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 1 to 32.

Example 69: An apparatus comprising at least one means for performing a method of any of examples 33 to 65.

Example 70: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 33 to 65.