Patent Description:
<CIT> discloses devices and methods related to physical uplink shared channel repetitions.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE receives a system information block (SIB) from a base station. The UE determines whether the SIB includes a set of candidate repetition factors for physical uplink control channel (PUCCH) transmissions. The UE transmits, to the base station in a message of a random access procedure, an indication of a capability of the UE for PUCCH repetition in response to determining that the SIB includes the set of candidate repetition factors. When the UE has the capability, the UE determines a particular repetition factor based on at least one of the set of candidate repetition factors and a dynamic indication of a repetition factor. When the UE has the capability, the UE further transmits an acknowledgement (ACK) or negative acknowledgement (NACK) of a message <NUM> of the random access procedure in a PUCCH in accordance with the particular repetition factor.

In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided, which do not fall within the subject matter for which protection is sought. The apparatus may be a UE. The UE performs at least one of: a first determination of (a) whether a Bandwidth Part (BWP) selected for a random access procedure is configured with a set of random access (RA) resources indicating Msg3 repetition and Msg4 Hybrid Automatic Repeat Request (HARQ) acknowledgement (ACK) repetition as well as other RA resources not indicating Msg3 repetition or Msg4 HARQ ACK repetition; and (b) whether a reference signal received power (RSRP) of a downlink reference signal is less than a threshold; and a second determination of whether the BWP is configured with the set of RA resources indicating the Msg3 repetition and the Msg4 HARQ ACK repetition and configured with no other RA resources. In response to one of the first determination and the second determination being true, the UE determines that Msg3 repetition and Msg4 HARQ-ACK repetition are applicable for the random access procedure.

Several aspects of telecommunications systems will now be presented with reference to various apparatus and methods.

Accordingly, in one or more example aspects, the functions described may be implemented in hardware, software, or any combination thereof.

The base stations <NUM> configured for <NUM> LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC <NUM> through backhaul links <NUM> (e.g., SI interface). The base stations <NUM> configured for <NUM> NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network <NUM> through backhaul links <NUM>. In addition to other functions, the base stations <NUM> may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter cell interference coordination, connection setup and release, load balancing, distribution for nonaccess stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations <NUM> may communicate directly or indirectly (e.g., through the EPC <NUM> or core network <NUM>) with each other over backhaul links <NUM> (e.g., X2 interface).

The base stations <NUM>/UEs <NUM> may use spectrum up to <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction.

When communicating in an unlicensed frequency spectrum, the STAs <NUM>/AP <NUM> may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

Communications using the mmW/near mmW radio frequency band (e.g., <NUM> - <NUM>) has extremely high path loss and a short range.

The base station <NUM> may transmit a beamformed signal to the UE <NUM> in one or more transmit directions 108a. The UE <NUM> may receive the beamformed signal from the base station <NUM> in one or more receive directions 108b. The base station <NUM>/UE <NUM> may perform beam training to determine the best receive and transmit directions for each of the base station <NUM>/UE <NUM>.

The core network <NUM> may include a Access and Mobility Management Function (AMF) <NUM>, other AMFs <NUM>, a location management function (LMF) <NUM>, a Session Management Function (SMF) <NUM>, and a User Plane Function (UPF) <NUM>. Generally, the SMF <NUM> provides QoS flow and session management.

Although the present disclosure may reference <NUM> New Radio (NR), the present disclosure may be applicable to other similar areas, such as LTE, LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Global System for Mobile communications (GSM), or other wireless/radio access technologies.

Each spatial stream may then be provided to a different antenna <NUM> via a separate transmitter 218TX. Each transmitter 218TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE <NUM>, each receiver 254RX receives a signal through its respective antenna <NUM>. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor <NUM>. The RX processor <NUM> then converts the OFDM symbol stream from the timedomain to the frequency domain using a Fast Fourier Transform (FFT).

The memory <NUM> may be referred to as a computer- readable medium.

The spatial streams generated by the TX processor <NUM> may be provided to different antenna <NUM> via separate transmitters 254TX. Each transmitter 254TX may modulate an RF carrier with a respective spatial stream for transmission. Each receiver 218RX receives a signal through its respective antenna <NUM>. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to a RX processor <NUM>.

The memory <NUM> may be referred to as a computer- readable medium.

NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD). NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g. <NUM> beyond), millimeter wave (mmW) targeting high carrier frequency (e.g. <NUM>), massive MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low latency communications (URLLC) service.

A single component carrier bandwidth of <NUM> may be supported. In one example, NR resource blocks (RBs) may span <NUM> sub-carriers with a sub-carrier bandwidth of <NUM> over a <NUM> duration or a bandwidth of <NUM> over a <NUM> duration (similarly, <NUM> BW for <NUM> SCS over a <NUM> duration). Each radio frame may consist of <NUM> subframes (<NUM>, <NUM>, <NUM> or <NUM> NR slots) with a length of <NUM>. Each slot may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each slot may be dynamically switched. UL and DL slots for NR may be as described in more detail below with respect to <FIG> and <FIG>.

The NR RAN may include a central unit (CU) and distributed units (DUs). A NR BS (e.g., gNB, <NUM> Node B, Node B, transmission reception point (TRP), access point (AP)) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells). For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection, or handover. In some cases DCells may not transmit synchronization signals (SS) in some cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and/or measurement based on the indicated cell type.

The ANC may be a central unit (CU) of the distributed RAN. The backhaul interface to the next generation core network (NG- CN) <NUM> may terminate at the ANC. The backhaul interface to neighboring next generation access nodes (NG-ANs) <NUM> may terminate at the ANC.

For example, for RAN sharing, radio as a service (RaaS), and service specific ANC deployments, the TRP may be connected to more than one ANC.

The local architecture of the distributed RAN <NUM> may be used to illustrate fronthaul definition.

According to aspects, a dynamic configuration of split logical functions may be present within the architecture of the distributed RAN <NUM>. The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP.

<FIG> is a diagram <NUM> showing an example of a DL-centric slot. The DL-centric slot may include a control portion <NUM>. The control portion <NUM> may exist in the initial or beginning portion of the DL-centric slot. The control portion <NUM> may include various scheduling information and/or control information corresponding to various portions of the DL-centric slot. The DL-centric slot may also include a DL data portion <NUM>. The DL data portion <NUM> may sometimes be referred to as the payload of the DL-centric slot.

The DL-centric slot may also include a common UL portion <NUM>. The common UL portion <NUM> may sometimes be referred to as an UL burst, a common UL burst, and/or various other suitable terms. The common UL portion <NUM> may include feedback information corresponding to various other portions of the DL-centric slot. For example, the common UL portion <NUM> may include feedback information corresponding to the control portion <NUM>. Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion <NUM> may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs), and various other suitable types of information.

As illustrated in <FIG>, the end of the DL data portion <NUM> may be separated in time from the beginning of the common UL portion <NUM>. One of ordinary skill in the art will understand that the foregoing is merely one example of a DL-centric slot and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram <NUM> showing an example of an UL-centric slot. The UL-centric slot may include a control portion <NUM>. The control portion <NUM> may exist in the initial or beginning portion of the UL-centric slot. The control portion <NUM> in <FIG> may be similar to the control portion <NUM> described above with reference to <FIG>. The UL-centric slot may also include an UL data portion <NUM>. The UL data portion <NUM> may sometimes be referred to as the pay load of the UL-centric slot. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, the control portion <NUM> may be a physical DL control channel (PDCCH).

As illustrated in <FIG>, the end of the control portion <NUM> may be separated in time from the beginning of the UL data portion <NUM>. The UL-centric slot may also include a common UL portion <NUM>. The common UL portion <NUM> in <FIG> may be similar to the common UL portion <NUM> described above with reference to <FIG>. The common UL portion <NUM> may additionally or alternatively include information pertaining to channel quality indicator (CQI), sounding reference signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will understand that the foregoing is merely one example of an UL-centric slot and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

<FIG> is a diagram <NUM> illustrating a contention-based random access procedure. The random access procedure is the process of establishing a radio link connection between a UE and a base station. In this example, at step S701, the UE <NUM> sends a Message <NUM> (Msg1), which is a preamble, to the base station <NUM> through a Physical Random Access Channel (PRACH). The Message <NUM> is used to notify the base station <NUM> that there is a random access request.

At step S702, after detecting the Message <NUM>, the base station <NUM> responds to the UE <NUM> by sending a Message <NUM> (Msg2). The Message <NUM> is a Random Access Response (RAR), which contains scheduling information, e.g., uplink (UL) grant information, for a Physical Uplink Shared Channel (PUSCH) that carries a Message <NUM> (described infra). The Message <NUM> may also contain Timing Alignment information for synchronization, Temporary C-RNTI (TC-RNTI), and RA preamble identifier.

At step S703, the UE <NUM> sends the Message <NUM> (Msg3) to the base station <NUM> based on the scheduling information carried in the Message <NUM>. The Message <NUM> may contain UE Identity (ID). This is the identity of the UE <NUM>, which allows the base station <NUM> to distinguish between different UEs. The UE ID could be a temporary ID such as the TC-RNTI or C-RNTI. The Message <NUM> may contain Establishment Cause, which indicates the reason for the UE initiating the random access procedure, such as initial access, handover, scheduling request, etc. The Message may contain a Radio Resource Control (RRC) Connection Request. This message is included if the random access is initiated for an RRC connection establishment. It includes parameters needed for the RRC connection setup. In other words, the Message <NUM> carries the UE identity, establishment cause, and other control/data information needed to establish the RRC connection and assist with uplink scheduling. The exact contents depend on the random access procedure trigger and RRC state. Message <NUM> provides the base station with key information prior to contention resolution.

At step S704, after the base station <NUM> receives Message <NUM> from the UE <NUM>, the base station <NUM> sends a Message <NUM> (Msg4), which is a Contention Resolution message. The Message <NUM> is transmitted on the PDSCH and addressed to the C-RNTI of the UE <NUM>. The purpose is to confirm that the base station <NUM> has received Message <NUM> and successfully identified the UE <NUM>. This resolves any potential collisions/contention. It echoes back the UE Identity sent in the Message <NUM> to confirm the UE <NUM> was successfully identified.

At step S705, the UE send a HARQ acknowledgment / negative acknowledgment (HARQ-ACK/NACK) to confirm successful/unsuccessful reception of the Message <NUM>. This HARQ-ACK/NACK information is transmitted on the Physical Uplink Control Channel (PUCCH). The resources used on PUCCH for the HARQ-ACK/NACK may be indicated to the UE in the downlink control information (DCI) that scheduled Message <NUM> with CRC scrambled by TC-RNTI. The HARQ-ACK acts as a normal acknowledgement for a PDSCH transmission. However, in some scenarios (e.g., NR NTN with large coverage requirements), a single HARQ-ACK transmission repetition may not be reliable enough.

To meet the coverage requirements in such scenarios, PUCCH repetition may be used for HARQ-ACK/NACK for Message <NUM> to improve the reliability. With repetition, the UE can transmit the HARQ-ACK/NACK multiple times, which increases the probability that the network successfully receives it.

The network needs to be able to indicate the repetition factor, for example through a common configuration or a combination of a common configuration and/or a UE-specific configuration, to the UE dynamically based on the channel conditions and coverage requirements. This allows the network to control how many repetitions the UE does, for balancing reliability and overhead as needed.

<FIG> is a diagram <NUM> illustrating that a base station configures the number of PUCCH repetition for a UE. In this example, the base station <NUM> send a PUCCH repetition RRC parameter <NUM> to the UE <NUM>. For example, the PUCCH repetition RRC parameter <NUM> may be pucch-AggregationFactor. The PUCCH repetition RRC parameter <NUM> indicates one or more repetition patterns for PUCCH transmissions. The PUCCH repetition RRC parameter <NUM> can be used to configure the repetition factor specifically for Message <NUM> HARQ-ACK/NACK PUCCH. The PUCCH repetition RRC parameter <NUM> can also apply to other PUCCH transmissions using the common PUCCH configuration, or apply to the other PUCCH when a specific PUCCH resource configuration is not provided.

In certain configurations, the PUCCH repetition RRC parameter <NUM> may be added to PUCCH-ConfigCommon information element (IE), which is carried in the System Information Block (SIB) broadcast from the base station <NUM>. The UE <NUM> and other UEs detects the SIB and determines the PUCCH repetition RRC parameter <NUM>.

The PUCCH repetition RRC parameter <NUM> indicates a set of candidate repetition factors for PUCCH transmissions. The set of candidate repetition factors may be, for example, {<NUM>}, {<NUM>}, {<NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, or {<NUM>, <NUM>}, etc. For example, the set of candidate repetition factors {<NUM>} indicates the repetition factor for PUCCH transmission of the PUCCH HARQ-ACK/NACK for Msg4 is <NUM> for all receiving UEs (e.g., the UE <NUM>). The set of candidate repetition factors {<NUM>, <NUM>, <NUM>} indicates the repetition factor for PUCCH transmission of the PUCCH HARQ-ACK/NACK for Msg4 may be <NUM>, <NUM> or <NUM> for all receiving UEs.

The PUCCH-ConfigCommon information element contains configuration parameters for the common resources and repetition factors used for PUCCH transmissions. By including the PUCCH repetition RRC parameter <NUM> in this information element, in certain configurations, the base station can indicate candidate repetition factors that apply not only to the PUCCH transmission containing the HARQ ACK/NACK for the contention resolution message (Msg4), but also to other PUCCH transmissions using the common PUCCH configuration, or apply to the other PUCCH when a specific PUCCH resource configuration is not provided.

For example, the PUCCH repetition RRC parameter <NUM> may configure a set of candidate repetition factors such as {<NUM>, <NUM>, <NUM>}. Other PUCCH transmissions by the UE that use the common PUCCH configuration can also be repeated with a factor selected from the set of candidate repetition factors such as {<NUM>, <NUM>, <NUM>}.

When the PUCCH repetition RRC parameter <NUM> (e.g., the pucch-AggregationFactor) does not exist in the PUCCH-ConfigCommon information element, the UE <NUM> may determine that the default repetition factor is <NUM>. Therefore, the base station <NUM> may not need to configure the PUCCH repetition RRC parameter <NUM> to indicate {<NUM>}.

Subsequently, the base station <NUM> may select a particular repetition factor from the set of candidate repetition factors or a set of default candidate repetition factors indicated in the PUCCH repetition RRC parameter <NUM> for the UE <NUM> (or other particular UEs using the common PUCCH configuration) to use. In certain configurations, the UE <NUM> may determine a particular repetition factor from the set of candidate repetition factors or the set of default candidate repetition factors based on certain rules without additional signaling from the base station <NUM>. In certain configurations, the base station <NUM> sends a UE specific configuration <NUM> to the UE <NUM> to indicate the particular repetition factor that the UE <NUM> uses when transmitting PUCCH HARQ-ACK/NACK for Msg4 or other PUCCH transmissions by the UE that use the common PUCCH configuration. In certain configurations, the set of candidate repetition factors is the common configuration received from the base station, and the set of default candidate repetition factors is predefined configuration.

In a first technique, the UE specific configuration <NUM> is carried in the PDCCH scheduling the RAR of the procedure described referring to <FIG>. For example, a new DCI field, e.g., pucch-AggregationFactor, may be added in the DCI format 1_0 with CRC scrambled by RA-RNTI or MsgB-RNTI to carry the UE specific configuration <NUM>. The pucch-AggregationFactor may be <NUM> or <NUM> bits.

The reserved bits (<NUM> - A) in DCI format 1_0 are used for operation in a cell without shared spectrum access, and the reserved bits (<NUM> - A) are used for operation in a cell with shared spectrum access. A is the number of bits for the field of the least significant bit (LSB) of the system frame number (SFN).

In certain configurations, the values of the pucch-AggregationFactor field (i.e., the UE specific configuration <NUM>) are <NUM> to <NUM>. In one example, the set of candidate repetition factors or the set of default candidate repetition factors for PUCCH transmissions is {<NUM>, <NUM>, <NUM>, <NUM>}. The values of the pucch-AggregationFactor field and the corresponding repetition factors are shown in Table <NUM>. '<NUM>' indicates the first number in the set of candidate repetition factors (i.e., <NUM>), '<NUM>' indicates the second number in the set of candidate repetition factors (i.e., <NUM>), and so on.

<FIG> is a diagram <NUM> illustrating a MAC payload for a Random Access Response (RAR). In a second technique, the UE specific configuration <NUM> may be carried in the MAC payload for the RAR. For example, a new field such as pucch-AggregationFactor can be added in the MAC payload to carry the UE specific configuration <NUM>. In certain configurations, the size of the pucch-AggregationFactor field is <NUM> bit. The MAC payload includes a R field, which includes reserved bits typically set to <NUM>. The MAC payload includes a Timing Advance Command field, which indicates the index value TA used to control the amount of timing adjustment that the MAC entity has to apply. The size of the Timing Advance Command field is <NUM> bits. The MAC payload includes a UL Grant field, which indicates the resources to be used on the uplink. The size of the UL Grant field is <NUM> bits. The MAC payload includes a Temporary C-RNTI field, which indicates the temporary identity used by the MAC entity during the Random Access procedure. The size of the Temporary C-RNTI field is <NUM> bits. The R field may be replaced with a pucch-AggregationFactor field, which indicate the mumber of repetitions for PUCCH. The size of the pucch-AggregationFactor field is <NUM> bit.

In certain configurations, the values of the pucch-AggregationFactor field (i.e., the UE specific configuration <NUM>) are <NUM> and <NUM>. In one example, the set of candidate repetition factors or the set of default candidate repetition factors for PUCCH transmissions is {<NUM>, <NUM>}. The values of the pucch-AggregationFactor field and the corresponding repetition factors are shown in Table <NUM>. '<NUM>' indicates the first number in the set of candidate repetition factors (i.e., <NUM>), and '<NUM>' indicates the second number in the set of candidate repetition factors (i.e., <NUM>).

In a third technique, the UE specific configuration <NUM> may be carried in PDCCH scheduling Msg4. In particular, a new or a re-interpreted DCI field in the DCI format 1_0 with CRC scrambled by TC-RNTI may be used to carry the UE specific configuration <NUM>. In a first approach of the third technique, the <NUM> or <NUM> bits of the Downlink Assignment Index (DAI) field in DCI format 1_0 are reinterpreted to indicate the repetition factor for PUCCH transmission of the HARQ-ACK/NACK for Msg4.

In certain configurations, the values of the DAI field (i.e., the UE specific configuration <NUM>) are <NUM> to <NUM>. For example, <NUM> or <NUM> bits of the DAI field can be reinterpreted to carry the PUCCH repetition factor for Msg4 instead of their original purpose according to mapping rules or mapping equations. The mapping rule maps a value of the DAI field to a corresponding number of the set of candidate repetition factors or the set of default candidate repetition factors. For example, if the DAI field is <NUM> bits, it can indicate a repetition factor of <NUM>, <NUM>, <NUM>, or <NUM> based on the bit values <NUM>, <NUM>, <NUM> and <NUM> respectively. If the DAI field is <NUM> bit, it can indicate a repetition factor of <NUM> or <NUM> based on the bit values <NUM> and <NUM> respectively. The mapping rule may also involve a simple equation like N = <NUM>DAI_value. Alternatively, default values or the set of default candidate repetition factors can be used. For example, if the DAI field is not present or the UE does not support this feature, the default repetition factor is <NUM>. For example, if the set of candidate repetition factors does not exist in the PUCCH repetition RRC parameter <NUM>, the set of default candidate repetition factors may be used, for example, if the DAI field is <NUM> bits, it may indicate a repetition factor of <NUM>, <NUM>, <NUM>, or <NUM> based on the bit values <NUM>, <NUM>, <NUM> and <NUM> respectively.

In certain configurations, when multiple candidate repetition factors (e.g. <NUM>, <NUM>, <NUM>) are configured for the UE through higher layer signaling, the DAI field can be reinterpreted to signal which the repetition factor the UE should use. Specifically, the DAI field is <NUM> bits and has <NUM> possible bit combinations: <NUM>, <NUM>, <NUM>, <NUM>. Thus, the DAI field can represent <NUM> different states. These <NUM> states can be mapped to the 1st, 2nd, 3rd and 4th configured repetition factors.

For example, if the configured candidate repetition factors are {<NUM>, <NUM>, <NUM>}, then '<NUM>' maps to the 1st configured factor <NUM>, '<NUM>' maps to the 2nd configured factor <NUM>, and '<NUM>' maps to the 3rd configured factor <NUM>. The '<NUM>' codepoint is not used since there are only <NUM> configured factors.

Similarly, if the configured factors are {<NUM>, <NUM>}, then '<NUM>' maps to <NUM> and '<NUM>' maps to <NUM>. The codepoints '<NUM>' and '<NUM>' are not used since there are only <NUM> configured factors.

As such, the <NUM> bits of DAI field are used to select among the configured candidate repetition factors for the PUCCH transmission containing the HARQ ACK/NACK for Msg4. The number of usable codepoints depends on how many candidate factors are configured through higher layer signaling. Any excessive codepoints are not used if there are fewer configured factors than the number of possible codepoint states.

In one example, the set of candidate repetition factors for PUCCH transmissions is {<NUM>, <NUM>, <NUM>, <NUM>}. The values of the DAI field and the corresponding repetition factors are shown in Table <NUM>. '<NUM>' indicates the first number in the set of candidate repetition factors (i.e., <NUM>), '<NUM>' indicates the second number in the set of candidate repetition factors (i.e., <NUM>), and so on.

In certain configurations, the values of the DAI field (i.e., the UE specific configuration <NUM>) are <NUM> and <NUM>. In one example, the set of candidate repetition factors for PUCCH transmissions is {<NUM>, <NUM>}. The values of the DAI field and the corresponding repetition factors are shown in Table <NUM>. '<NUM>' indicates the first number in the set of candidate repetition factors (i.e., <NUM>), and '<NUM>' indicates the second number in the set of candidate repetition factors (i.e., <NUM>).

In a second approach of the third technique, the <NUM> bits of the HARQ processes number field in DCI format 1_0 are reinterpreted to indicate the repetition factor for PUCCH transmission of the HARQ-ACK for Msg4. In certain configurations, two bits (e.g., the two leftmost bits) of the HARQ processes number field are used to indicate carry the UE specific configuration <NUM>.

In one example, the set of candidate repetition factors or the set of default candidate repetition factors for PUCCH transmissions is {<NUM>, <NUM>, <NUM>, <NUM>}. As shown in Table <NUM>, When the value range of the "HARQ processes number" field includes <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM> and <NUM> to <NUM>, it indicates the repetition factor for PUCCH transmissions is <NUM>, <NUM>, <NUM> and <NUM>, respectively.

As described supra, for PUCCH repetition for Msg4 HARQ-ACK, the base station <NUM> can configure a cell-specific repetition factor (e.g., the PUCCH repetition RRC parameter <NUM>) via the System Information Block (SIB). The UE <NUM> may report its repetition capability using Msg1 or Msg3. If the UE <NUM> does not report the repetition capability using Msg1 or Msg3, it means that the UE <NUM> is incapable of the configured repetition factors. Further, after receiving a report that the UE <NUM> has the repetition capability, the base station <NUM> can dynamically indicate a UE-specific repetition factor (e.g., the UE specific configuration <NUM>) by using Msg2/Msg4 or DCI scheduling Msg4.

For example, in the System Information Block (SIB), the "PUCCH-ConfigCommon information element" can indicate a 'repetition factor', which specifies the number of repetitions for PUCCH HARQ-ACK for Msg4 transmissions and/or the number of repetitions for other PUCCH transmissions using the PUCCH-ConfigCommon information element. Therefore, SIB can be used to configure one or more parameters to indicate the number of repetitions.

A set of candidate repetition factors including one or more repetition factors can be carried by the PUCCH repetition RRC parameter <NUM> in the SIB. The set of candidate repetition factors may be, for example, {<NUM>}, {<NUM>}, {<NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>}, {<NUM>, <NUM>, <NUM>}, or {<NUM>, <NUM>}, etc..

<FIG> is a flow chart <NUM> illustrating a procedure for transmitting PUCCH in repetition. In operation <NUM>, the UE <NUM> determines if a set of candidate repetition factors is configured in the SIB information element. If not configured, the UE <NUM> proceeds to operation <NUM>; otherwise, the UE <NUM> proceeds to operation <NUM>.

In operation <NUM>, the UE <NUM> determines the number of repetition factors in the set of candidate repetition factors is one or more than one.

Subsequently, the UE <NUM> proceeds to operation <NUM>. In a first configuration, the UE <NUM> proceeds operation <NUM>. Alternatively, in a second configuration, the UE <NUM> proceeds directly to operation <NUM> after operation <NUM> without entering operation <NUM>.

In operation <NUM>, the UE <NUM> further determines if a RSRP threshold is also configured in the SIB. The RSRP threshold is used to determine whether the UE <NUM> should report its capability of PUCCH repetition for Msg4 HARQ-ACK to the network. If an RSRP threshold is configured by the network via SIB, the UE will compare its measured RSRP to this threshold. If the measured RSRP is lower than the configured threshold, it implies the UE is in a coverage limited scenario. In this case, the UE will report its capability of PUCCH repetition for Msg4 HARQ-ACK to the network. If the measured RSRP is not lower than the threshold, the UE will not report the capability. If no RSRP threshold is configured by the network via SIB, the UE will by default report its capability regardless of the measured RSRP. PUCCH repetition is beneficial in coverage limited scenarios to improve reliability. By using the RSRP threshold, the network can control whether the UE reports the repetition capability based on the channel conditions. If the capability is reported, the network can choose to configure PUCCH repetition for Msg4 HARQ-ACK dynamically for that UE. If the capability is not reported, repetition may not be used.

If an RSRP threshold is configured, in operation <NUM>, the UE <NUM> measures an RSRP of a downlink reference signal such as an SSB and determines if the measured RSRP is lower than the RSRP threshold. If the measured RSRP is not lower than the RSRP threshold, the UE <NUM> proceeds to operation <NUM>.

If the measured RSRP is lower than the RSRP threshold, the UE <NUM> proceeds to operation <NUM>. If no RSRP threshold is configured, the UE <NUM> proceeds to operation <NUM>.

In operation <NUM>, the UE <NUM> reports its repetition capability using Msg1 or Msg3 to indicate whether the UE <NUM> has the capability to perform PUCCH repetition. If the UE <NUM> does not report a capability, it implies that the UE <NUM> does not have the capability.

In one example, in Msg3 transmission, the RRC message includes a field, for example, "pucch-AggregationCapability-r18" to indicate whether the UE <NUM> supports PUCCH repetition for Msg4 HARQ-ACK or not. The Msg3 RRC message can be RRCSetupRequest, RRCResumeRequest, RRCReestablishmentRequest, etc. based on the trigger for the random access procedure.

The "pucch-AggregationCapability-r18" field is an optional field taking values of two states such as true/false. If the value is the first state (e.g., true), the UE <NUM> has capability to do repetition for Msg4 HARQ-ACK PUCCH. If the value is the second state (e.g., false), the UE <NUM> does not have capability to do repetition for Msg4 HARQ-ACK PUCCH. Further, the absence of field indicates that the UE does not have capability for PUCCH repetition. As such, the optional field "pucch-AggregationCapability-r18" in the Msg3 RRC message is used by the UE <NUM> to explicitly signal to the base station <NUM> whether it can support PUCCH repetition for Msg4 HARQ-ACK or not. Based on this capability report, the base station <NUM> can determine whether to configure PUCCH repetition for the UE.

If the UE <NUM> does not have the repetition capability, the UE <NUM> proceeds to operation <NUM>. If the UE <NUM> has repetition capability and the number of repetition factors in the set of candidate repetition factors determined in operation <NUM> is <NUM>, the UE <NUM> proceeds to operation <NUM>.

In operation <NUM>, the UE <NUM> determines if a repetition factor is dynamically indicated in Msg2, Msg4, or DCI scheduling Msg <NUM>. In particular, as described supra, the repetition factor for PUCCH transmission of Msg4 HARQ-ACK feedback can be indicated dynamically using the DAI field in the DCI scheduling Msg4. The DCI format 1_0 is used that schedules the PDSCH carrying Msg4, with CRC scrambled by the TC-RNTI allocated to the UE. The DAI field in this DCI is then repurposed to indicate the PUCCH repetition factor that the UE should use for transmitting Msg4 HARQ-ACK. The DAI field bits can be mapped to candidate repetition factor values based on the configured candidates.

If a repetition factor is not dynamically indicated, in operation <NUM>, the UE <NUM> uses the one repetition factor included in the set of candidate repetition factors to perform the repetition. If a repetition factor is dynamically indicated and the UE <NUM> proceeds to operation <NUM> to receive dynamic indication, the UE <NUM> then proceeds to operation <NUM>. In operation <NUM>, the UE uses the indicated repetition factor to perform the repetition.

If the UE <NUM> has repetition capability and the number of repetition factors in the set of candidate repetition factors determined in operation <NUM> is greater than <NUM>, in operation <NUM>, the UE detects a repetition factor dynamically indicated in Msg2, Msg4, or DCI scheduling Msg <NUM>. Then, the UE <NUM> proceeds to operation <NUM>, which is described supra.

When the UE <NUM> enters operation <NUM>, the UE <NUM> transmits PUCCH for Msg4 once without repetition.

In another aspect, which does not fall within the subject matter for which protection is sought, the PUCCH-ConfigCommon information element (IE) in the SIB may include a field pucch-FH-r18 to provide more configuration flexibility for frequency hopping for PUCCH carrying Msg4 HARQ feedback and for other PUCCH transmissions using the PUCCH-ConfigCommon information element, especially when PUCCH repetition is used.

If the pucch-FH-r18 field itself is absent in the PUCCH-ConfigCommon IE, the UE <NUM> accordingly does not use frequency hopping for PUCCH transmissions. The PUCCH will stay on the same frequency resource across all repetitions.

If pucch-FH-r18 is present in the IE and is set to "intra-slot", it enables intra-slot frequency hopping for PUCCH. This means the PUCCH will hop to a different frequency resource within the same slot for each repetition. If pucch-FH-r18 is present and is set to "inter-slot", it enables inter-slot frequency hopping for PUCCH. This means the PUCCH repeats on different frequency resources across slots.

<FIG> is a diagram <NUM>, not falling within the subject matter for which protection is sought, illustrating techniques of determine whether Msg3 repetition and Msg4 HARQ-ACK repetition are applicable for a random access procedure. The base station <NUM> may have configured RA resources <NUM>. Further, the RA resources <NUM> are divided into multiple sets, including set(s) of RA resources <NUM> indicating Msg3 repetition and set(s) of RA resources <NUM> indicating Msg4 HARQ-ACK repetition. Further, the set(s) of RA resources <NUM> indicating Msg3 repetition and the set(s) of RA resources <NUM> indicating Msg4 HARQ-ACK repetition have a subset <NUM> of RA resources indicating both Msg3 repetition and Msg4 HARQ-ACK repetition.

In a first operation, the UE <NUM> determines whether a BWP selected for a random access procedure (e.g., the RA procedure in <FIG>) is configured with the set(s) of RA resources <NUM> indicating Msg3 repetition and Msg4 HARQ-ACK repetition as well as other set(s) of random access resources without indicating Msg3 repetition or Msg4 HARQ-ACK repetition. The UE <NUM> also determines whether the RSRP of a downlink pathloss reference signal is less than thresholds rsrp-ThresholdMsg3 and rsrp-ThresholdMsg4HARQ-ACK. Thresholds rsrp-ThresholdMsg3 and rsrp-ThresholdMsg4HARQ-ACK can be configured in SIB.

Alternatively, in the first operation, the UE <NUM> determines whether only the set(s) of RA resources <NUM> indicating Msg3 repetition and indicating Msg4 HARQ-ACK repetition are configured for the BWP selected for the random access procedure.

If one of the above conditions of the first operation is true, the base station <NUM> and/or the UE <NUM> assume both Msg3 repetition and Msg4 HARQ-ACK repetition are applicable for the current random access procedure.

If none of the conditions of the first operation is true, in a second operation, the UE <NUM> determines whether the BWP selected for the random access procedure is configured with the set(s) of RA resources <NUM> indicating Msg3 repetition and other set(s) of random access resources without indicating Msg3 repetition. The UE <NUM> further determines if the RSRP of the downlink pathloss reference signal is less than threshold rsrp-ThresholdMsg3. Threshold rsrp-ThresholdMsg3 can be configured in SIB.

Alternatively, in the second operation, the UE <NUM> determines whether only the set(s) of RA resources <NUM> indicating Msg3 repetition are configured for the BWP selected for the random access procedure.

If one of the above conditions of the second operation is true, the base station <NUM> and/or the UE <NUM> assume Msg3 repetition is applicable for the current random access procedure.

If none of the conditions of the first operation and the second operation is true, in a third operation, the UE <NUM> determines whether the BWP selected for the random access procedure is configured with the set(s) of RA resources <NUM> indicating Msg4 HARQ-ACK repetition and other set(s) of random access resources without indicating Msg4 HARQ-ACK repetition. Further, the UE <NUM> determines whether the RSRP of the downlink pathloss reference signal is less than threshold rsrp-ThresholdMsg4HARQ-ACK. Threshold rsrp-ThresholdMsg4HARQ-ACK can be configured in SIB.

Alternatively, in the third operation, the UE <NUM> determines that only the set(s) of RA resources <NUM> indicating Msg4 HARQ-ACK repetition are configured for the BWP selected for the random access procedure.

If one of the above conditions of the third operation is true, the base station <NUM> and/or the UE <NUM> assume Msg4 HARQ-ACK repetition is applicable for the current random access procedure.

If none of the above conditions of the first operation, the second operation, and the third operation is true, the base station <NUM> and/or the UE <NUM> assume that neither Msg3 repetition nor Msg4 HARQ-ACK repetition is applicable for the current random access procedure.

Claim 1:
A method (<NUM>) of wireless communication of a user equipment (<NUM>, <NUM>), UE, comprising:
receiving, from a base station (<NUM>, <NUM>), a system information block, SIB;
determining (<NUM>) whether the SIB includes a set of candidate repetition factors for physical uplink control channel, PUCCH, transmissions;
in response to determining that the SIB includes the set of candidate repetition factors:
transmitting (<NUM>), to the base station (<NUM>, <NUM>) in a message of a random access procedure, an indication of a capability of the UE (<NUM>, <NUM>) for PUCCH repetition;
when the UE (<NUM>, <NUM>) has the capability:
determining a particular repetition factor based on at least one of the set of candidate repetition factors and a dynamic indication of a repetition factor; and
transmitting (<NUM>, <NUM>) an acknowledgement, ACK, or negative acknowledgement, NACK, of a message <NUM> of the random access procedure in a PUCCH in accordance with the particular repetition factor.