Method and apparatus for NTN coverage extension for PUCCH and PUSCH

Abstract

A method and apparatus for non-terrestrial network (NTN) coverage extension is provided. A user equipment (UE) transmits an indication of UE capability for physical uplink control channel (PUCCH) repetitions of a fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission in a random access channel (RACH) procedure to a network node of the NTN. The UE determines a trigger for PUCCH repetitions of the Msg4 HARQ-ACK transmission during the RACH procedure. In response to the trigger, the UE transmits one or more Msg4 HARQ-ACK repetitions from the UE to the network node.

Description

[Technical Field]

[0001] TECHNICAL FIELD This application relates generally to wireless communication systems, including Non-Terrestrial Network (NTN) communications. [Background technology]

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G), the 3GPP new radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs) (commonly known to industry groups as Wi-Fi®).

[0003] As contemplated by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to communicate between base stations of the RAN (sometimes commonly referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices known as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, a GERAN implements a GSM and / or EDGE RAT, a UTRAN implements a universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, an E-UTRAN implements an LTE RAT (sometimes simply referred to as LTE), and an NG-RAN implements an NR RAT (sometimes referred to herein as a 5G RAT, a 5G NR RAT, or simply NR). In certain deployments, an E-UTRAN can also implement an NR RAT. In certain deployments, an NG-RAN can also implement an LTE RAT.

[0005] A base station used by a RAN may correspond to that RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as an evolved Node B, enhanced Node B, eNode B, or eNB). An example of an NG-RAN base station is a next-generation Node B (sometimes referred to as a Node B or gNB).

[0006] The RAN provides communication services with external entities via a connection to a core network (CN). For example, the E-UTRAN can utilize the evolved packet core (EPC), and the NG-RAN can utilize the 5G core network (5GC).

[0007] To easily identify the discussion of any particular element or act, the most significant digit(s) of a reference number refers to the number of the figure in which that element is first introduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a signaling diagram of a four-step RACH procedure according to some embodiments.

[0009] [Figure 2] FIG. 1 is a signaling diagram of a two-step RACH procedure according to some embodiments.

[0010] [Figure 3] 1 is a flowchart illustrating a UE procedure for determining a preamble and / or RACH occasion based on the UE capability of physical uplink control channel (PUCCH) repetition of a fourth message (Msg4) Hybrid Automatic Repeat Request Acknowledge (HARQ-ACK) transmission in a random-access channel (RACH) procedure, according to one embodiment.

[0011] [Figure 4] FIG. 2 is a block diagram illustrating measurement timing during communication between a satellite and a UE, in accordance with certain embodiments.

[0012] [Figure 5] 1 is a flowchart of a method for a UE according to one embodiment.

[0013] [Figure 6] 1 is a flowchart of a UE procedure according to one embodiment.

[0014] [Figure 7] 1 is a flowchart of a method for a network node in an NTN for joint channel estimation of a PUSCH according to one embodiment;

[0015] [Figure 8] 1 is a flowchart of a method for UEs for joint channel estimation of PUSCH according to one embodiment.

[0016] [Figure 9]10 is a flowchart of a method for a network node in an NTN to perform joint channel estimation for a PUSCH according to another embodiment.

[0017] [Figure 10] 10 is a flowchart of a method for UEs for joint channel estimation of PUSCH according to another embodiment;

[0018] [Figure 11] 1 is a method for a network node of an NTN, according to one embodiment.

[0019] [Figure 12] 1 illustrates an example architecture of a wireless communication system according to embodiments disclosed herein.

[0020] [Figure 13] FIG. 1 illustrates a system for performing signaling between a wireless device and a network device according to embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0021] Various embodiments are described in terms of a UE. However, reference to a UE is provided merely for purposes of illustration. The illustrative embodiments may be used with any electronic component, configured with hardware, software, and / or firmware, capable of establishing a connection to a network and exchanging information and data with the network. Accordingly, a UE as described herein is used to represent any suitable electronic component.

[0022] Certain efforts for non-terrestrial network (NTN) enhancements attempt to improve coverage and / or efficiency while taking into account NTN characteristics, including large propagation delays and satellite movement. For example, certain efforts are directed to specifying physical uplink control channel (PUCCH) enhancements for fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmissions (e.g., repetitions) in random access channel (RACH) procedures. Other efforts include, for example, considering demodulation reference signal (DMRS) bundling for the physical uplink shared channel (PUSCH) while taking into account NTN specifications (e.g., time-frequency pre-compensation).

[0023] For PUCCH repetition for Msg4 HARQ-ACK, the options, if configured in a cell-specific manner, may include details on how the UE performs the repetition, the UE requests the repetition and is dynamically instructed to perform the repetition, the UE indicates the repetition capability and is dynamically instructed to perform the repetition, and / or the UE indicates the repetition capability before Msg4. In a particular system, the supported number of PUCCH transmissions for Msg4 HARQ-ACK includes 1 transmission, 2 transmissions, 4 transmissions, and 8 transmissions (i.e., {1, 2, 4, 8} transmissions). A single PUCCH transmission may be performed according to configuration / instruction from a network node in the NTN (e.g., in signaling regarding the number of transmissions) if single PUCCH transmission is supported.

[0024] For NTN-specific PUSCH DMRS bundling, the enhancements may cover handling phase differences across slots due to timing drift and / or Doppler shift (e.g., whether or how long a UE can meet the phase continuity requirements in Table 6.4.2.5-1 of 3 GPP Technical Specification (TS) 38.101-1, given a frequency error within ±0.1 parts per million (PPM) specified in Section 6.4.1 of 3 GPP Technical Specification (TS) 38.101-5 and a timing error specified in Table 7.1C.2-1 of 3 GPP TS 38.133), whether the network can be enhanced to meet the requirements, or whether the UE can pre-compensate for the phase difference.

[0025] A four-step random access channel (RACH) procedure may include at least a first message (Msg1), a second message (Msg2), a third message (Msg3), and a fourth message (Msg4) between a UE and a network node. The four-step RACH procedure may also be referred to as a Type 1 RACH. For example, FIG. 1 is a signaling diagram illustrating a RACH procedure 100 by a UE 102 and a network node 104 that may be used in certain embodiments. As shown, the UE 102 may send a Msg1 transmission 106 to the network node 104. The Msg1 transmission 106 may include a physical random access channel (PRACH) preamble that includes timing information for the uplink transmission.

[0026] In response to receiving the Msg1 transmission 106, the network node 104 may transmit an Msg2 transmission 108 on a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). The Msg2 transmission 108 may also be referred to as a random access response (RAR) message. The Msg2 transmission 108 may include timing parameters or information, an uplink grant for the Msg3 transmission 110, a temporary cell radio network temporary identifier (TC-RNTI), etc.

[0027] In response to the Msg3 transmission 110, the network node 104 may transmit a Msg4 PDSCH transmission 112, which may include a contention resolution message. After the UE 102 transmits the Msg3 transmission 110, a contention resolution timer starts. The network node 104 assists the UE 102 in contention resolution using a cell radio network temporary identifier (C-RNTI) on the PDCCH or a contention resolution identification information element (IE) on the PDSCH. The UE 102 continues to monitor the PDCCH before the timer expires, and if the UE 102 acquires a C-RNTI on the PDCCH, or if the UE acquires a temporary C-RNTI on the PDCCH and a media access control (MAC) protocol data unit (PDU) is successfully decoded, the UE 102 considers contention resolution successful and stops the timer. If the contention resolution timer expires, the UE 102 considers contention resolution to have failed.

[0028] To extend the coverage of the Msg4 PDSCH transmission 112, the network node 104 may apply repetition to the Msg4 PDSCH transmission 112. For example, the network node 104 may transmit one or more Msg4 PDSCH repetitions 114. The Msg4 PDSCH repetitions 114 allow the network node 104 to retransmit the contention resolution information transmitted via the Msg4 PDSCH transmission 112 at different times. In that way, if the UE 102 fails to receive the Msg4 PDSCH transmission 112 due to interference, the UE 102 will have an additional opportunity to receive the Msg4 information.

[0029] After the UE 102 receives the Msg4 PDSCH transmission 112 and any repetitions, the UE 102 may transmit a Msg4 HARQ-ACK 116 to the network node 104 on a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The HARQ-ACK timing may be adjusted for the Msg4 PDSCH repetition. The Msg4 HARQ-ACK 116 allows the UE 102 to provide feedback regarding the Msg4 PDSCH transmission 112. To extend the Msg4 HARQ-ACK 116, the wireless communication system may support the UE transmitting one or more Msg4 HARQ-ACK repetitions 118. The Msg4 HARQ-ACK repetition 118 includes the UE repeatedly transmitting the Msg4 HARQ-ACK on the PUCCH. In this way, if the network node 104 misses receiving the Msg4 HARQ-ACK 116 due to interference, the network node 104 will have an additional opportunity to receive the HARQ-ACK information.

[0030] In some embodiments, Msg4 HARQ-ACK repetition with DMRS bundling may be used to extend Msg4. For DMRS, a time domain window (TDW) may be specified. During the TDW, the UE is expected to maintain power consistency and phase continuity between PUCCH repetitions as HARQ-ACK for Msg4.

[0031] A two-step RACH procedure can reduce the latency of a four-step RACH procedure and may include at least a first message (MsgA) and a second message (MsgB). The two-step RACH procedure is sometimes referred to as a Type 2 RACH. For example, FIG. 2 is a signaling diagram illustrating a two-step RACH procedure 200 by a UE 202 and a network node 204 that may be used in certain embodiments. As shown, the UE 202 may transmit an MsgA transmission 206 to the network node 204. The MsgA transmission 206 may include the Msg1 and Msg3 transmissions shown in FIG. 1. In response to receiving the MsgA transmission 206, the network node 204 may transmit an MsgB transmission 208 on a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH). The MsgB transmission 208 may include the Msg2 and Msg4 transmissions shown in FIG. 1.

[0032] After the UE 202 receives the MsgB transmission 208 (and any repetitions of the MsgB transmission 208), the UE 202 may transmit a PUCCH HARQ-ACK 210 to the network node 204. The PUCCH HARQ-ACK 210 allows the UE 202 to provide feedback regarding the MsgB transmission 208 (i.e., the Msg2+Msg4 transmission). To enhance the PUCCH HARQ-ACK 210, the wireless communication system may support the UE sending one or more PUCCH HARQ-ACK repetitions 212. A PUCCH HARQ-ACK repetition 212 involves the UE 202 repeatedly transmitting the PUCCH HARQ-ACK to the network node 204. In this way, if the network node 204 fails to receive the PUCCH HARQ-ACK 210 due to interference, the network node 204 will have an additional opportunity to receive the HARQ-ACK information. As used herein, for simplicity, references to Msg4 HARQ-ACK repetitions may refer to PUCCH HARQ-ACK repetitions for Type 2 RACH.

[0033] Certain embodiments disclosed herein provide for indicating the UE's capability for PUCCH repetition before an Msg4 PDSCH transmission (or MsgB transmission) in the RACH procedure. The UE may further indicate the number of Msg4 HARQ-ACK repetitions for each PUCCH resource set. In other embodiments, a procedure is provided to ensure that requests for PUCCH repetition for Mg4 are valid when the satellite may move relative to the UE. Furthermore, certain embodiments efficiently use RACH resources for UEs that do not have the capability for PUCCH repetition for Mg4. Other embodiments distinguish between UEs that have or do not have the capability for phase difference pre-compensation.

[0034] Msg4 UE indication of PUCCH repetition capability for HARQ-ACK

[0035] In a particular embodiment, the UE transmits an indication of the UE capability for PUCCH repetitions of Msg4 HARQ-ACK transmissions in the RACH procedure. In one such embodiment, the UE uses capability-related signaling to indicate whether the UE supports PUCCH repetitions of Msg4 HARQ-ACK transmissions. The UE may, for example, indicate that it supports PUCCH repetitions regardless of how many repetitions are supported. Alternatively, the UE may indicate a specific number of transmissions it supports for PUCCH repetitions. For example, if the supported number of transmissions is {1, 2, 4, 8} transmissions, the UE may indicate that it supports one transmission and four transmissions (i.e., {1, 4} transmissions) for PUCCH repetitions. This may be signaled in a bitmap of length 4 to indicate the supported transmission numbers. Alternatively, the UE may indicate an upper limit (i.e., maximum number) of transmissions it supports for PUCCH repetitions. For example, a UE may indicate that it can support up to four PUCCH transmissions, which implies that the UE supports {1,2,4} PUCCH transmissions. The UE may use a 2-bit field (e.g., "00" to indicate {1} PUCCH transmissions, "01" to indicate {1,2} PUCCH transmissions, "10" to indicate {1,2,4} PUCCH transmissions, and "11" to indicate {1,2,4,8} PUCCH transmissions) to indicate its maximum supported number of transmissions.

[0036] In another embodiment, the UE indicates its capabilities via the PRACH. For example, the UE 102 shown in Figure 1 may include an indication of UE capabilities in the Msg1 transmission 106. As another example, the UE 202 shown in Figure 2 may include an indication of UE capabilities in the MsgB transmission 208.

[0037] A UE may use different PRACH preambles to indicate its different capabilities on PUCCH repetition for Msg4 HARQ-ACK. For example, preambles 0 through 15 may indicate that the UE supports up to one PUCCH transmission, preambles 16 through 31 may indicate that the UE supports up to two PUCCH transmissions, preambles 32 through 47 may indicate that the UE supports up to four PUCCH transmissions, and preambles 48 through 63 may indicate that the UE supports up to eight PUCCH transmissions. In another example, preambles 0 through 31 may indicate that the UE does not support PUCCH repetition (i.e., only legacy PUCCH for Msg4 HARQ-ACK), and preambles 32 through 63 may indicate that the UE supports PUCCH repetition for Msg4 HARQ-ACK.

[0038] In another embodiment, the UE can use different RACH occasions to indicate its different capabilities on PUCCH repetition for Msg4 HARQ-ACK. The RACH occasions correspond to the time and frequency resources available for reception of the PRACH. For example, the UE can transmit a PRACH on a first RACH occasion to indicate that the UE does not support PUCCH repetition (i.e., only legacy PUCCH for Msg4 HARQ-ACK), and the UE can transmit a PRACH on a second RACH occasion to indicate that the UE supports PUCCH repetition for Msg4 HARQ-ACK.

[0039] In another embodiment, the UE uses both different PRACH preambles and different RACH occasions to indicate its different capabilities on PUCCH repetition for Msg4 HARQ-ACK. For example, preambles 0-31 on RACH occasions 0-31 may indicate that the UE supports up to one PUCCH transmission, preambles 0-31 on RACH occasions 32-63 may indicate that the UE supports up to two PUCCH transmissions, preambles 32-63 on RACH occasions 0-31 may indicate that the UE supports up to four PUCCHs, and preambles 32-63 on RACH occasions 32-63 may indicate that the UE supports up to eight PUCCHs. The mapping between the UE's PUCCH repetition capabilities and PRACH preambles / RACH occasions may be broadcast in a system information block (SIB). For example, System Information Block Type 1 (SIB1), System Information Block Type 19 (SIB19), or a new SIB type associated with NTN communication may be used to indicate the mapping. The UE may first read the SIB and then, based on its capabilities, determine which set of preambles and RACH occasions to use for PRACH transmission.

[0040] 3 is a flowchart of an example UE method 300 for determining a preamble and / or RACH occasion based on UE capabilities, according to one embodiment. In block 302, the UE receives a signaling information base (SIB) for an indication of a mapping rule between a set of preambles and RACH occasions and a PUCCH repetition capability for Msg4 HARQ-ACK transmissions in a RACH procedure. In block 304, the UE determines a set of preambles and RACH occasions based on the PUCCH repetition capability for Msg4. In block 306, the UE selects a preamble and RACH occasion from the determined set and transmits the corresponding PRACH.

[0041] In another embodiment, the UE indicates its PUCCH repetition capability for Msg4 HARQ-ACK via the Msg3 PUSCH (see FIG. 1) or the MsgA PUSCH (see FIG. 2) in the RACH procedure. Different sets of UE contention resolution identifiers (IDs) can be used to indicate different UE capabilities of PUCCH repetition.

[0042] In another embodiment, UE capability and triggering of PUCCH repetition for Msg4 HARQ-ACK are jointly indicated. The UE may transmit a dedicated preamble and / or a dedicated RACH occasion only when the UE has PUCCH repetition capability and when the UE determines that PUCCH repetition is needed. This may be based, for example, on whether a measured synchronization signal block (SSB) reference signal received power (RSRP) is below a threshold. Otherwise, if the UE is not capable of PUCCH repetition or if the UE determines that PUCCH repetition is not needed, the UE does not transmit a dedicated preamble and / or a dedicated RACH occasion to trigger PUCCH repetition for Msg4 HARQ-ACK.

[0043] In another embodiment, the UE indicates the capability of PUCCH repetition for Msg4 via a Medium Access Control (MAC) Control Element (CE). In one such embodiment, a new MAC CE associated with NTN communication is introduced for capability indication, and a bitmap can be used to indicate the number of supported repetitions. In another embodiment, the existing MAC CE is used, and the reserved bits are reused to indicate this capability. The MAC CE can be carried, for example, in the Msg3 PUSCH or the MsgA PUSCH.

[0044] Msg4 Repetition number indication for PUCCH for HARQ-ACK

[0045] When the network node receives a UE's request for PUCCH repetitions for Msg4 HARQ-ACK, the network node determines whether to schedule PUCCH repetitions for Msg4 HARQ-ACK and how many PUCCH repetitions to apply. Certain embodiments disclosed herein support this dynamic indication of PUCCH repetitions for Msg4 HARQ-ACK.

[0046] In one embodiment, the network node provides the UE with an indication of the number of repetitions of the PUCCH Msg4 HARQ-ACK. Such an embodiment reuses a predefined cell-specific PUCCH resource set. For example, referring to Table 9.2.1-1 in 3GPP TS 38.213, DCI 1_0 for the Msg4 PDSCH may indicate the number of PUCCH repetitions for the Msg4 HARQ-ACK. The IE PUCCH-ConfigCommon may be reused such that a single parameter pucch-ResourceCommon is used to indicate the PUCCH resource set for both the NTN and the terrestrial network (TN). Alternatively, the IE PUCCH-ConfigCommon may be modified with a new parameter pucch-ResourceCommonNTN to indicate the PUCCH resource set for the NTN, and the existing parameter pucch-ResourceCommon may be used to indicate the PUCCH resource set for the TN.

[0047] Another embodiment modifies existing predefined cell-specific PUCCH resource sets, such as Table 9.2.1-1 in 3GPP TS 38.213. For example, a new column can be added to the table to indicate the number of repetitions for each PUCCH resource set. The IE PUCCH-ConfigCommon can be reused or modified as discussed above. Alternatively, several new rows can be added to the table for NTN to indicate that the number of repetitions is greater than 1 (which is a modification of the IE PUCCH-ConfigCommon).

[0048] Another embodiment adds new predefined cell-specific PUCCH resource sets, for example, a new table may include the number of repetitions for each PUCCH resource set (which is a modification of the IE PUCCH-ConfigCommon).

[0049] SSB measurement timeline

[0050] In certain embodiments, SSB-RSRP measurements may be considered a triggering condition for PUCCH repetitions for Msg4 HARQ-ACK. For example, when the SSB-RSRP measurement falls below a threshold, the UE may determine that channel conditions between the UE and a network node are deteriorating, such that PUCCH repetitions for Msg4 HARQ-ACK may be required to increase the likelihood of sufficient feedback. However, in the case of NTN, movement of network nodes relative to the UE may reduce the usefulness of SSB-RSRP measurements as a triggering condition.

[0051] 4 is a block diagram illustrating measurement timing during communication between a satellite 402 and a UE 404, according to a particular embodiment. At a first time when the satellite 402 is at a first location relative to the UE 404, the UE 404 may receive and perform RSRP measurements of the SSB from the satellite 402. At a second time when the satellite 402 is at a second location relative to the UE 404, the UE 404 may initiate the RACH process by sending a PRACH to the satellite 402. However, because the mobile satellite 402 has changed from the first location to the second location relative to the UE 404, channel conditions may have improved or deteriorated from the first time when the SSB was received to the second time when the PRACH was transmitted.

[0052] Thus, in certain embodiments, the UE 404 is not expected to use SSB-RSRP measurements that are X milliseconds prior to the transmission of the PRACH, where the value of X may be configured by the network, for example, via SIB1 or SIB19, or a new SIB associated with NTN communication.

[0053] 5 is a flowchart of a method 500 for a UE according to one embodiment. At block 502, the method 500 includes transmitting an indication of the UE's capability for a physical uplink control channel (PUCCH) repetition of a fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission in a random access channel (RACH) procedure from the UE to a network node of a non-terrestrial network (NTN). At block 504, the method 500 includes determining a trigger for a PUCCH repetition of the Msg4 HARQ-ACK transmission during the RACH procedure. At block 506, in response to the trigger, the method 500 includes transmitting one or more Msg4 HARQ-ACK repetitions from the UE to the network node.

[0054] In a particular embodiment of method 500, sending the indication includes sending a capability signal from the UE to the network node. For example, the capability signal may indicate whether the UE supports PUCCH repetitions for Msg4 HARQ-ACK transmissions. Alternatively, the capability signal may indicate the number of transmissions supported by the UE for PUCCH repetitions for Msg4 HARQ-ACK transmissions, and the capability signal may include a 4-bit bitmap for indicating the number of transmissions. In another embodiment, the capability signal may indicate an upper limit on the number of transmissions supported by the UE for PUCCH repetitions for Msg4 HARQ-ACK transmissions, and the capability signal may include a 2-bit bitmap indicating the upper limit on the number of transmissions.

[0055] In certain embodiments of method 500, sending the indication includes sending a Physical Random Access Channel (PRACH) message from the UE to the network node in a RACH procedure. For example, method 500 may further include using a PRACH preamble to indicate different UE capabilities for PUCCH repetitions of the Msg4 HARQ-ACK transmission. Additionally, or in other embodiments, method 500 may further include using a RACH occasion to indicate different UE capabilities for PUCCH repetitions of the Msg4 HARQ-ACK transmission.

[0056] In a particular embodiment, the method 500 further includes receiving, at the UE, a system information block (SIB) including a mapping rule between different UE capabilities for PUCCH repetitions of Msg4 HARQ-ACK transmissions and multiple sets of PRACH preambles and RACH occasions, determining a specific set of the multiple sets of PRACH preambles and RACH occasions based on the UE capabilities for PUCCH repetitions of Msg4 HARQ-ACK transmissions, selecting a specific PRACH preamble and a specific RACH occasion from the specific set, and transmitting a PRACH message from the UE to a network node using the specific PRACH preamble and the specific RACH occasion for the RACH procedure. In such a particular embodiment, the PRACH message is one of a first message (Msg1) transmission from the UE to the network node in a Type 1 random access procedure or a message A (MsgA) transmission from the UE to the network node in a Type 2 random access procedure. In a particular embodiment, the SIB is selected from a group including System Information Block Type 1 (SIB1), System Information Block Type 19 (SIB19), and system information block types related to NTN communications.

[0057] In certain embodiments of the method 500, transmitting the indication includes transmitting the indication in a third message (Msg3) physical uplink shared channel (PUSCH) transmission in a Type 1 random access channel procedure or a message A (MsgA) PUSCH transmission in a Type 2 random access channel procedure. Different sets of UE contention resolution identifiers (IDs) may indicate different UE capabilities for PUCCH repetitions of Msg4 HARQ-ACK transmissions.

[0058] In a particular embodiment of method 500, the indication includes a joint indication of UE capability for PUCCH repetition of Msg4 HARQ-ACK transmission and triggering of PUCCH repetition of Msg4 HARQ-ACK transmission. Method 500 may further include transmitting at least one of a dedicated preamble and a dedicated RACH occasion corresponding to the joint indication only if the UE has UE capability for PUCCH repetition of Msg4 HARQ-ACK transmission and the UE determines the triggering.

[0059] In a particular embodiment of the method 500, transmitting the indication includes transmitting, via a Medium Access Control (MAC) Control Element (CE), an indication including a bitmap configured to indicate a supported number of repetitions or reserved bits to indicate the UE capability for PUCCH repetitions of the Msg4 HARQ-ACK transmission.

[0060] In certain embodiments of the method 500, transmitting the indication includes transmitting the indication via a Medium Access Control (MAC) Control Element (CE) carried in a third message (Msg3) physical uplink shared channel (PUSCH) transmission in a Type 1 random access procedure or a message A (MsgA) PUSCH transmission in a Type 2 random access procedure.

[0061] In certain embodiments, the method 500 further includes receiving, at the UE, from a network node, a repetition number for PUCCH repetitions of the Msg4 HARQ-ACK transmission.

[0062] In a particular embodiment of method 500, the UE determines the number of repetitions by reusing a predefined cell-specific PUCCH resource set, and a downlink control information (DCI) format for an Msg4 physical downlink shared channel (PDSCH) transmission indicates the number of repetitions for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

[0063] In a particular embodiment of method 500, the UE determines the number of repetitions from the modified existing predefined cell-specific PUCCH resource set, and a new column in the table corresponding to the existing predefined cell-specific PUCCH resource set indicates the number of repetitions of each PUCCH resource in the existing predefined cell-specific PUCCH resource set.

[0064] In a particular embodiment of the method 500, the UE determines the number of repetitions from the modified existing predefined cell-specific PUCCH resource sets, and multiple new rows in the table corresponding to the existing predefined cell-specific PUCCH resource sets for the NTN indicate that the number of repetitions of each PUCCH resource set in the existing predefined cell-specific PUCCH resource sets is greater than 1.

[0065] In a particular embodiment of the method 500, the UE determines the number of repetitions from the new predefined cell-specific PUCCH resource sets, and the new table indicates the number of repetitions for each PUCCH resource set in the new predefined cell-specific PUCCH resource sets.

[0066] In a particular embodiment of the method 500, the PUCCH-ConfigCommon information element (IE) is reused to include a single parameter of pucch-ResourceCommon that indicates the PUCCH resource set for both the NTN and the terrestrial network (TN).

[0067] In a particular embodiment of method 500, the PUCCH-ConfigCommon information element (IE) is modified with a first parameter of pucch-ResourceCommon to indicate a first PUCCH resource set for the terrestrial network (TN), and a second parameter of pucch-ResourceCommonNTN is used to indicate a second PUCCH resource set for the NTN.

[0068] In a particular embodiment of method 500, determining the trigger includes measuring, at the UE, a synchronization signal block (SSB) from a network node to obtain an SSB reference signal received power (RSRP) measurement at a first time; and, in response to the SSB RSRP measurement being below a threshold, using the SSB RSRP measurement as the trigger when a physical random access channel (PRACH) message in a RACH procedure from the UE to the network node at a second time is within a predetermined elapsed time from the first time; and not using the SSB RSRP measurement as the trigger when the PRACH message at the second time is not within the predetermined elapsed time from the first time. The predetermined elapsed time may be configured by the network node using a system information block (SIB) selected from a group including system information block type 1 (SIB1), system information block type 19 (SIB19), and system information block types associated with NTN communications.

[0069] UE not capable of PUCCH repetition for Msg4 HARQ-ACK

[0070] Certain embodiments provide a solution for UEs that do not have the capability for PUCCH repetition for Msg4 HARQ-ACK. If the UE does not have the capability for PUCCH repetition for Msg4 HARQ-ACK, the UE is unlikely to have a successful RACH procedure when the channel conditions between the satellite and the UE are poor. Therefore, using transmission resources for initial access may be a waste of resources and power. Instead, the UE may wait until the channel conditions improve before initiating the RACH procedure. In one embodiment, the UE may determine whether to transmit a PRACH based on an SSB-RSRP measurement value. If the SSB-RSRP measurement value is above a threshold, the UE may transmit a PRACH, assuming that the PUCCH for Msg4 HARQ-ACK can be successfully delivered. If the SSB-RSRP measurement value is below the threshold, the UE may determine not to transmit a PRACH. Alternatively, the UE may continue to monitor the SSB.

[0071] For example, Figure 6 is a flowchart of a UE method 600 according to one embodiment. In block 602, the UE measures the RSRP of an SSB from a network node in the NTN. In block 604, if the UE does not have PUCCH repetition capability for Msg4 and the measured SSB-RSRP may be below a threshold, the UE may not transmit a PRACH. Alternatively, the UE may continue to monitor the SSB. In block 606, if the UE does not have PUCCH repetition capability for Msg4 but the measured SSB-RSRP is above a threshold, the UE transmits a PRACH.

[0072] Another example method for a UE includes configuring the UE to perform a random access channel (RACH) procedure without capability for a physical uplink control channel (PUCCH) repetition of a fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission; measuring, at the UE, a reference signal received power (RSRP) of a synchronization signal block (SSB) signal from a network node to obtain an SSB-RSRP measurement value; continuing to monitor the SSB signal from the network node without sending a physical random access channel (PRACH) message from the UE to the network node in the RACH procedure when the SSB-RSRP measurement value is less than a threshold; and sending a PRACH message from the UE to the network node in the RACH procedure when the SSB-RSRP measurement value is greater than or equal to the threshold.

[0073] PUSCH DMRS bundling for UEs with different capabilities

[0074] In a particular embodiment, the UE reports its capability of phase difference pre-compensation in the NTN under timing drift and / or Doppler shift. This capability may be reported together with or independently from the capability report for demodulation reference signal (DMRS) bundling. The reported capability may further describe the maximum value of the phase difference that the UE can pre-compensate. The capability report may be in either radio resource control (RRC) signaling or MAC CE. For example, a new MAC CE may be introduced for capability indication, or an existing MAC CE may include a reserved bit that is reused to indicate this capability.

[0075] In one embodiment, the network schedules a configured granted PUSCH for the UE, which may indicate a DMRS bundling (i.e., TDW) size based on the UE's capabilities for maximum TDW duration and phase difference pre-compensation, and the uplink segmented transmission duration. The network performs joint channel estimation based on the indicated TDW for the PUSCH DMRS bundling.

[0076] In another embodiment, the network schedules a configured granted PUSCH for the UE, which may indicate a DMRS bundling (i.e., TDW) size based on the UE's capability for maximum TDW duration and uplink segmented transmission duration. The network performs joint channel estimation based on the indicated TDW for the PUSCH DMRS bundling and the reported UE's capability for phase difference pre-compensation.

[0077] 7 is a flowchart of a method 700 for a network node in an NTN for joint channel estimation of a PUSCH, according to one embodiment. At block 702, the method 700 includes transmitting an indication of an uplink segmentation duration for DMRS bundling from the network node to a user equipment (UE). At block 704, the method 700 includes receiving, at the network node, a UE capability report from the UE in response to the indication, the UE's maximum time domain window (TDW) duration capability and the UE's phase difference pre-compensation capability. At block 706, the method 700 includes scheduling a configured granted PUSCH for the UE, indicating a PUSCH DMRS bundling size based on the UE's maximum TDW duration capability, the UE's phase difference pre-compensation capability, and the uplink segmentation duration. At block 708, the method 700 includes performing joint channel estimation based on the PUSCH DMRS bundling size.

[0078] In one embodiment of the method 700, the UE capability report further indicates the UE's capability for DMRS bundling.

[0079] In one embodiment, the method 700 further includes receiving an independent report of the UE's capability for DMRS bundling.

[0080] In one embodiment of the method 700, the UE capability report further includes a maximum value corresponding to the phase difference pre-compensation capability of the UE.

[0081] In one embodiment of the method 700, the UE capability report is received in RRC signaling.

[0082] In one embodiment of the method 700, a UE capability report is received at a MAC CE configured to report a capability of phase difference pre-compensation in the NTN under at least one of timing drift and Doppler shift.

[0083] In one embodiment of the method 700, the UE capability report is received in a MAC CE that includes a reserved bit to indicate the phase difference pre-compensation capability of the UE.

[0084] 8 is a flowchart of a method 800 for a UE for joint channel estimation of a PUSCH according to one embodiment. At block 802, the method 800 includes receiving an uplink segmentation duration for DMRS bundling from a network node in an NTN. At block 804, the method 800 includes reporting from the UE to the network node a UE capability for a maximum time domain window (TDW) duration and phase difference pre-compensation. At block 806, the method 800 includes receiving, from the network node, scheduling information for a configured granted PUSCH indicating a PUSCH DMRS bundling size. At block 808, the method 800 includes transmitting the configured granted PUSCH from the UE to the network node based on the PUSCH DMRS bundling size indicated by the network node.

[0085] In one embodiment of the method 800, reporting the UE capabilities further includes jointly reporting the UE's capabilities for DMRS bundling.

[0086] In one embodiment, the method 800 further includes transmitting an independent report of the UE's capability for DMRS bundling from the UE to a network node.

[0087] In one embodiment of the method 800, the UE capabilities reported by the UE to the network node further include a maximum value for phase difference pre-compensation.

[0088] In one embodiment of the method 800, reporting the UE capabilities includes transmitting the UE capabilities in RRC signaling from the UE to a network node.

[0089] In one embodiment of the method 800, reporting the UE capabilities includes transmitting a MAC CE from the UE to a network node configured to report a capability of phase difference pre-compensation in the NTN under at least one of timing drift and Doppler shift.

[0090] In one embodiment of the method 800, reporting the UE capabilities includes transmitting a MAC CE from the UE to a network node that includes a reserved bit to indicate the UE's ability to perform phase difference pre-compensation.

[0091] 9 is a flowchart of a method 900 for a network node in an NTN to perform joint channel estimation for a PUSCH according to another embodiment. At block 902, the method 900 includes transmitting an indication of an uplink segmentation duration for DMRS bundling from the network node to a UE. At block 904, the method 900 includes receiving, at the network node, a UE capability report from the UE in response to the indication, the UE's maximum time domain window (TDW) duration capability and the UE's phase difference pre-compensation capability. At block 906, the method 900 includes scheduling a configured granted PUSCH for the UE, the PUSCH DMRS bundling size being based on the UE's maximum TDW duration capability and the uplink segmentation duration. At block 908, the method 900 includes performing joint channel estimation based on the PUSCH DMRS bundling size and phase difference pre-compensation capability reported by the UE.

[0092] In one embodiment of the method 900, the UE capability report further indicates the UE's capability for DMRS bundling.

[0093] In one embodiment, the method 900 further includes receiving an independent report of the UE's capability for DMRS bundling.

[0094] In one embodiment of the method 900, the UE capability report further includes a maximum value corresponding to a phase difference pre-compensation capability of the UE.

[0095] In one embodiment of the method 900, the UE capability report is received in RRC signaling.

[0096] In one embodiment of the method 900, a UE capability report is received at a MAC CE configured to report a capability of phase difference pre-compensation in the NTN under at least one of timing drift and Doppler shift.

[0097] In one embodiment of the method 900, the UE capability report is received in a MAC CE that includes a reserved bit to indicate the phase difference pre-compensation capability of the UE.

[0098] 10 is a flowchart of a method 1000 for a UE for joint channel estimation of a PUSCH according to another embodiment. At block 1002, the method 1000 includes, at the UE, receiving an uplink segmentation duration for demodulation reference signal (DMRS) bundling from a network node in the NTN. At block 1004, the method 1000 includes reporting from the UE to the network node a maximum time domain window (TDW) duration and UE capabilities for phase difference pre-compensation. At block 1006, the method 1000 includes, at the UE, receiving from the network node scheduling information for a configured granted PUSCH indicating a PUSCH DMRS bundling size. At block 1008, the method 1000 includes transmitting the configured granted PUSCH from the UE to the network node based on the PUSCH DMRS bundling size indicated by the network node and the UE capabilities for phase difference pre-compensation.

[0099] In one embodiment of the method 1000, reporting the UE capabilities further includes jointly reporting the UE's capabilities for DMRS bundling.

[0100] In one embodiment, the method 1000 further includes sending, from the UE to a network node, an independent report of the UE's capability for DMRS bundling.

[0101] In one embodiment of the method 1000, the UE capabilities reported by the UE to the network node further include a maximum value for phase difference pre-compensation.

[0102] In one embodiment of the method 1000, reporting the UE capabilities includes transmitting the UE capabilities in RRC signaling from the UE to a network node.

[0103] In one embodiment of the method 1000, reporting the UE capabilities includes transmitting a MAC CE from the UE to a network node configured to report the capability of phase difference pre-compensation in the NTN under at least one of timing drift and Doppler shift.

[0104] In one embodiment of the method 1000, reporting the UE capabilities includes transmitting a MAC CE from the UE to a network node that includes a reserved bit to indicate the UE's ability to perform phase difference pre-compensation.

[0105] 11 is a method 1100 for a network node of an NTN according to one embodiment. At block 1102, the method 1100 includes receiving, at the network node, from the UE an indication of UE capability for PUCCH repetitions of Msg4 HARQ-ACK transmissions in a RACH procedure. At block 1104, the method 1100 includes indicating, from the network node to the UE, a repetition number for PUCCH repetitions of the Msg4 HARQ-ACK transmission. At block 1106, the method 1100 includes receiving, at the network node, from the UE during the RACH procedure, one or more Msg4 HARQ-ACK repetitions according to the repetition number.

[0106] In one embodiment of the method 1100, indicating the number of repetitions includes reusing a predefined cell-specific PUCCH resource set, and a downlink control information (DCI) format for an Msg4 physical downlink shared channel (PDSCH) transmission indicates the number of repetitions for PUCCH repetitions of the Msg4 HARQ-ACK transmission.

[0107] In one embodiment of the method 1100, indicating the number of repetitions includes modifying existing predefined cell-specific PUCCH resource sets, and new columns in the table corresponding to the existing predefined cell-specific PUCCH resource sets indicate the number of repetitions of each PUCCH resource in the existing predefined cell-specific PUCCH resource sets.

[0108] In one embodiment of the method 1100, indicating the number of repetitions includes modifying an existing predefined cell-specific PUCCH resource set, and multiple new rows in the table corresponding to the existing predefined cell-specific PUCCH resource set for the NTN indicate that the number of repetitions of each PUCCH resource in the existing predefined cell-specific PUCCH resource set is greater than one.

[0109] In one embodiment of the method 1100, indicating the number of repetitions includes using a new predefined cell-specific PUCCH resource set, and the new table indicates the number of repetitions of each PUCCH resource in the new predefined cell-specific PUCCH resource set.

[0110] In a particular embodiment of the method 1100, the PUCCH-ConfigCommon information element (IE) is reused to include a single parameter of pucch-ResourceCommon that indicates the PUCCH resource set for both the NTN and the terrestrial network (TN).

[0111] In a particular embodiment of method 1100, the PUCCH-ConfigCommon information element (IE) is modified using a first parameter of pucch-ResourceCommon to indicate a first PUCCH resource set for the terrestrial network (TN), and a second parameter of pucch-ResourceCommonNTN is used to indicate a second PUCCH resource set for the NTN.

[0112] 12 illustrates an example architecture of a wireless communication system 1200 according to embodiments disclosed herein. The following description is provided for the example wireless communication system 1200 operating in conjunction with LTE system standards and / or 5G or NR system standards, as provided by the 3GPP technical specifications.

[0113] 12, wireless communication system 1200 includes UE 1202 and UE 1204 (although any number of UEs may be used). In this example, UE 1202 and UE 1204 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may comprise any mobile or non-mobile computing devices configured for wireless communication.

[0114] The UEs 1202 and 1204 may be configured to be communicatively coupled to a RAN 1206. In an embodiment, the RAN 1206 may be an NG-RAN, an E-UTRAN, etc. The UEs 1202 and 1204 utilize connections (or channels) with the RAN 1206 (shown as connection 1208 and connection 1210, respectively), each of which comprises a physical communication interface. The RAN 1206 may include one or more base stations, such as base station 1212 and base station 1214, that facilitate the connections 1208 and 1210.

[0115] In this example, connection 1208 and connection 1210 are air interfaces for enabling such communication coupling and may correspond to the RAT(s) used by RAN 1206, such as, for example, LTE and / or NR.

[0116] In some embodiments, the UE 1202 and the UE 1204 can also directly exchange communication data via the sidelink interface 1216. The UE 1204 is configured to access an access point (shown as AP 1218) via a connection 1220, as shown. By way of example, the connection 1220 can include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, and the AP 1218 can include a Wi-Fi router. In this example, the AP 1218 can be connected to other networks (e.g., the Internet) without going through the CN 1224.

[0117] In an embodiment, the UEs 1202 and 1204 may be configured to communicate with each other or with the base stations 1212 and / or 1214 using orthogonal frequency division multiplexing (OFDM) communication signals over multi-carrier communication channels according to various communication technologies, such as, but not limited to, an orthogonal frequency division multiple access (OFDMA) communication technology (e.g., for downlink communication) or a single-carrier frequency division multiple access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink communication), and the scope of the embodiments is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0118] In some embodiments, all or a portion of the base station 1212 or the base station 1214 may be implemented as one or more software entities executing on a server computer as part of a virtual network. Additionally or in other embodiments, the base station 1212 or the base station 1214 may be configured to communicate with each other via the interface 1222. In embodiments where the wireless communication system 1200 is an LTE system (e.g., where the CN 1224 is the EPC), the interface 1222 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs) connecting to the EPC and / or between two eNBs connecting to the EPC. In embodiments where the wireless communication system 1200 is an NR system (e.g., where the CN 1224 is the 5GC), the interface 1222 may be an Xn interface. The Xn interface may be defined between two or more base stations (e.g., two or more gNBs) connecting to the 5GC, between the base station 1212 (e.g., a gNB) and an eNB connecting to the 5GC, and / or between two eNBs connecting to the 5GC (e.g., the CN 1224).

[0119] The RAN 1206 is shown communicatively coupled to the CN 1224. The CN 1224 may comprise one or more network elements 1226 configured to provide various data and telecommunication services to customers / subscribers (e.g., users of UEs 1202 and 1204) connected to the CN 1224 via the RAN 1206. The components of the CN 1224 may be implemented in a single physical device or separate physical devices, including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0120] In an embodiment, the CN 1224 may be an EPC, and the RAN 1206 may be connected to the CN 1224 via an S1 interface 1228. In an embodiment, the S1 interface 1228 may be divided into two parts: an S1 user plane (S1-U) interface that carries traffic data between the base station 1212 or the base station 1214 and a serving gateway (S-GW), and an S1-MME interface that is a signaling interface between the base station 1212 or the base station 1214 and a mobility management entity (MME).

[0121] In an embodiment, the CN 1224 may be a 5GC, and the RAN 1206 may be connected to the CN 1224 via an NG interface 1228. In an embodiment, the NG interface 1228 may be divided into two parts: an NG-User Plane (NG-U) interface that carries traffic data between the base station 1212 or 1214 and a User Plane Function (UPF), and an S1 Control Plane (NG-C) interface that is a signaling interface between the base station 1212 or 1214 and an Access and Mobility Management Function (AMF).

[0122] In general, the application server 1230 may be an element that provides applications that use Internet Protocol (IP) bearer resources (e.g., packet-switched data services) with the CN 1224. The application server 1230 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 1202 and the UE 1204 via the CN 1224. The application server 1230 may communicate with the CN 1224 via an IP communication interface 1232.

[0123] 13 illustrates a system 1300 for performing signaling 1334 between a wireless device 1302 and a network device 1318 according to embodiments disclosed herein. The system 1300 may be part of a wireless communication system as described herein. The wireless device 1302 may be, for example, a UE of the wireless communication system. The network device 1318 may be, for example, a base station (e.g., eNB or gNB) of the wireless communication system.

[0124] The wireless device 1302 may include one or more processor(s) 1304. The processor(s) 1304 may execute instructions to cause various operations of the wireless device 1302 to be performed, as described herein. The processor(s) 1304 may include, for example, one or more baseband processors implemented using a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0125] The wireless device 1302 may include a memory 1306. The memory 1306 may be a non-transitory computer-readable storage medium that stores instructions 1308 (e.g., may include instructions being executed by the processor(s) 1304). The instructions 1308 may also be referred to as program code or computer programs. The memory 1306 may also store data used by, and results computed by, the processor(s) 1304.

[0126] The wireless device 1302 may include one or more transceiver(s) 1310, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses antenna(s) 1312 of the wireless device 1302 to facilitate signaling (e.g., signaling 1334) to and / or from the wireless device 1302 with other devices (e.g., network devices 1318) according to a corresponding RAT.

[0127] The wireless device 1302 may include one or more antenna(s) 1312 (e.g., one, two, four, or more). In embodiments with multiple antenna(s) 1312, the wireless device 1302 may exploit the spatial diversity of such multiple antenna(s) 1312 to transmit and / or receive multiple different data streams over the same time and frequency resources. This behavior is sometimes referred to, for example, as multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting and receiving devices that enable this aspect). MIMO transmission by the wireless device 1302 may be achieved in accordance with precoding (or digital beamforming) applied at the wireless device 1302 that multiplexes data streams across the antenna(s) 1312 according to known or assumed channel characteristics such that each data stream is received at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream) with an appropriate signal strength relative to the other streams. Particular embodiments may use Single-User MIMO (SU-MIMO) methods (in which data streams are all directed to a single receiver) and / or Multi-User MIMO (MU-MIMO) methods (in which individual data streams may be directed to individual (different) receivers in different locations in the spatial domain).

[0128] In particular embodiments having multiple antennas, the wireless device 1302 may implement analog beamforming techniques whereby the phases of the signals transmitted by the antenna(s) 1312 are adjusted relative to one another so that the (joint) transmissions of the antenna(s) 1312 can be directed (this may be referred to as beam steering).

[0129] The wireless device 1302 may include one or more interface(s) 1314. The interface(s) 1314 may be used to provide input to or output from the wireless device 1302. For example, a wireless device 1302 that is a UE may include interface(s) 1314 such as a microphone, speaker, touchscreen, buttons, etc. to enable a user of the UE to provide input and / or output to the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 1310 / antenna(s) 1312 already described) that enable communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi, Bluetooth, etc.).

[0130] The wireless device 1302 may include an NTN coverage expansion module 1316. The NTN coverage expansion module 1316 may be implemented via hardware, software, or a combination thereof. For example, the NTN coverage expansion module 1316 may be implemented as a processor, circuitry, and / or instructions 1308 stored in memory 1306 and executed by processor(s) 1304. In some examples, the NTN coverage expansion module 1316 may be integrated within the processor(s) 1304 and / or transceiver(s) 1310. For example, the NTN coverage expansion module 1316 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor(s) 1304 or transceiver(s) 1310.

[0131] The NTN coverage extension module 1316 can be used in various embodiments of the present disclosure, for example, the embodiments of FIGS.

[0132] The network device 1318 may include one or more processor(s) 1320. The processor(s) 1320 may execute instructions to cause various operations of the network device 1318 to be performed, as described herein. The processor(s) 1320 may include, for example, one or more baseband processors implemented using a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0133] The network device 1318 may include a memory 1322. The memory 1322 may be a non-transitory computer-readable storage medium that stores instructions 1324 (e.g., may include instructions being executed by the processor(s) 1320). The instructions 1324 may also be referred to as program code or a computer program. The memory 1322 may also store data used by the processor(s) 1320 and results computed by the processor(s) 1320.

[0134] The network device 1318 may include one or more transceiver(s) 1326, which may include RF transmitter and / or receiver circuitry using antenna(s) 1328 of the network device 1318 to facilitate signaling (e.g., signaling 1334) to and / or from the network device 1318 with other devices (e.g., the wireless device 1302) according to a corresponding RAT.

[0135] The network device 1318 may include one or more antenna(s) 1328 (e.g., one, two, four, or more). In embodiments with multiple antenna(s) 1328, the network device 1318 may perform MIMO, digital beamforming, analog beamforming, beamsteering, etc., as described.

[0136] The network device 1318 may include one or more interface(s) 1330. The interface(s) 1330 may be used to provide input to or output from the network device 1318. For example, a network device 1318 that is a base station may include interface(s) 1330 consisting of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 1326 / antenna(s) 1328 already described) that enables the base station to communicate with other equipment in the core network and / or to communicate with external networks, computers, databases, etc., for purposes of operation, management, and maintenance of the base station or other equipment operatively connected thereto.

[0137] The network device 1318 may include an NTN coverage expansion module 1332. The NTN coverage expansion module 1332 may be implemented via hardware, software, or a combination thereof. For example, the NTN coverage expansion module 1332 may be implemented as a processor, circuitry, and / or instructions 1324 stored in memory 1322 and executed by the processor(s) 1320. In some examples, the NTN coverage expansion module 1332 may be integrated within the processor(s) 1320 and / or transceiver(s) 1326. For example, the NTN coverage expansion module 1332 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor(s) 1320 or transceiver(s) 1326.

[0138] The NTN coverage extension module 1332 can be used in various aspects of the present disclosure, for example, the aspects of Figures 1, 2, 4, 7, 9, and 11.

[0139] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of methods 300, 500, 600, and 800. The apparatus may be, for example, an apparatus of a UE (such as wireless device 1302, which is a UE as described herein).

[0140] Embodiments contemplated herein may include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of methods 300, 500, 600, and 800. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 1306 of wireless device 1302 that is a UE, as described herein).

[0141] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry that performs one or more elements of methods 300, 500, 600, and 800. The apparatus may be, for example, an apparatus of a UE (such as wireless device 1302, which is a UE as described herein).

[0142] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of methods 300, 500, 600, and 800. The apparatus may be, for example, an apparatus of a UE (such as wireless device 1302, which is a UE as described herein).

[0143] Embodiments contemplated herein include signals described in or associated with one or more elements of methods 300, 500, 600 and 800.

[0144] Embodiments contemplated herein include computer programs or computer program products including instructions, where execution of the program by a processor causes the processor to perform one or more elements of methods 300, 500, 600, and 800. The processor may be a processor of a UE (such as processor(s) 1304 of a wireless device 1302 that is a UE, as described herein). These instructions may be located, for example, within the processor and / or on a memory of the UE (such as memory 1306 of a wireless device 1302 that is a UE, as described herein).

[0145] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of methods 700, 900, 1000, and 1100. The apparatus may be, for example, a base station apparatus (such as base station network device 1318 described herein).

[0146] Embodiments contemplated herein may include one or more non-transitory computer-readable media containing instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of methods 700, 900, 1000, and 1100. This non-transitory computer-readable medium may be, for example, memory of a base station (e.g., memory 1322 of network device 1318 that is a base station as described herein).

[0147] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry that performs one or more elements of methods 700, 900, 1000, and 1100. The apparatus may be, for example, a base station apparatus (such as base station network device 1318 described herein).

[0148] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of methods 700, 900, 1000, and 1100. The apparatus may be, for example, that of a base station (such as base station network device 1318 described herein).

[0149] Embodiments contemplated herein include signals described in or associated with one or more elements of methods 700, 900, 1000, and 1100.

[0150] Embodiments contemplated herein include a computer program or computer program product including instructions, where execution of the program by a processing element causes the processing element to perform one or more elements of methods 700, 900, 1000, and 1100. The processor may be a processor of a base station (such as processor(s) 1320 of network device 1318 that is a base station, as described herein). These instructions may be located, for example, within the processor and / or on a memory of the base station (such as memory 1322 of network device 1318 that is a base station, as described herein).

[0151] For one or more embodiments, at least one of the components depicted in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor described above in connection with one or more of the figures herein may be configured to operate according to one or more of the examples described herein. As another example, circuitry associated with a UE, a base station, a network element, etc., as described above in connection with one or more of the foregoing figures, may be configured to operate according to one or more of the examples described herein.

[0152] Any of the above embodiments can be combined with any other embodiment (or combination of embodiments) unless otherwise stated. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0153] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that contain specific logic for performing the operations, or may include a combination of hardware, software, and / or firmware.

[0154] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, divided into multiple systems, or otherwise divided or combined. Additionally, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in another embodiment. It is recognized that parameters, attributes, aspects, etc. are described in one or more embodiments for clarity only, and that parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, etc. of other embodiments, unless specifically disclaimed herein.

[0155] It is well understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of authorized uses should be clearly indicated to users.

[0156] While the foregoing has been described in some detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatus described herein. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope of the appended claims and their equivalents.

Claims

1. 1. A method for a user equipment (UE), comprising: sending, from the UE to a network node of a non-terrestrial network (NTN), an indication of UE capability for a Physical Uplink Control Channel (PUCCH) repetition of a fourth message (Msg 4) Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) transmission in a Random Access Channel (RACH) procedure; determining a trigger for the PUCCH repetition of the Msg4 HARQ-ACK transmission during the RACH procedure; and transmitting one or more Msg4 HARQ-ACK repetitions from the UE to the network node in response to the trigger.

2. The method of claim 1 , wherein the sending of the indication comprises sending a capability signal from the UE to the network node.

3. The method of claim 2 , wherein the capability signal indicates whether the UE supports the PUCCH repetition of the Msg4 HARQ-ACK transmission.

4. The method of claim 2 , wherein the capability signal indicates a number of transmissions supported by the UE for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

5. The method of claim 4 , wherein the capability signal includes a 4-bit bitmap for indicating the number of transmissions.

6. The method of claim 2 , wherein the capability signal indicates an upper limit on the number of transmissions supported by the UE for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

7. The method of claim 6 , wherein the capability signal includes a two-bit bitmap for indicating the upper limit of the number of transmissions.

8. 2. The method of claim 1, wherein sending the indication comprises sending a Physical Random Access Channel (PRACH) message from the UE to the network node in the RACH procedure.

9. The method of claim 8 , further comprising: using a PRACH preamble to indicate different UE capabilities for the PUCCH repetition of the Msg4 HARQ-ACK transmission.

10. The method of claim 8 or claim 9, further comprising using a RACH occasion to indicate the different UE capabilities for the PUCCH repetition of the Msg4 HARQ-ACK transmission.

11. receiving, at the UE, a system information block (SIB) including mapping rules between the different UE capabilities for the PUCCH repetitions of the Msg4 HARQ-ACK transmission and multiple sets of the PRACH preamble and the RACH occasions; determining a particular set of the plurality of sets of the PRACH preamble and the RACH occasion based on the UE capability for the PUCCH repetition of the Msg4 HARQ-ACK transmission; selecting a particular PRACH preamble and a particular RACH occasion from the particular set; transmitting the PRACH message from the UE to the network node using the specific PRACH preamble and the specific RACH occasion for the RACH procedure; The method of claim 10 further comprising:

12. 12. The method of claim 11 , wherein the PRACH message is one of a first message (Msg1) transmission from the UE to the network node in a Type 1 random access procedure or a message A (MsgA) transmission from the UE to the network node in a Type 2 random access procedure.

13. 12. The method of claim 11, wherein the SIB is selected from the group consisting of System Information Block Type 1 (SIB1), System Information Block Type 19 (SIB19), and system information block types related to NTN communications.

14. 2. The method of claim 1, wherein transmitting the indication comprises transmitting the indication in a third message (Msg3) physical uplink shared channel (PUSCH) transmission in a Type 1 random access channel procedure or a message A (MsgA) PUSCH transmission in a Type 2 random access channel procedure.

15. The method of claim 14, wherein different sets of UE contention resolution identifiers (IDs) indicate different UE capabilities for the PUCCH repetition of the Msg4 HARQ-ACK transmission.

16. The method of claim 1 , wherein the indication comprises a joint indication of the UE capability for the PUCCH repetition of the Msg4 HARQ-ACK transmission and the trigger of the PUCCH repetition of the Msg4 HARQ-ACK transmission.

17. 17. The method of claim 16, further comprising: transmitting at least one of a dedicated preamble and a dedicated RACH occasion corresponding to the joint indication only when the UE has the UE capability for the PUCCH repetition of the Msg4 HARQ-ACK transmission and the UE determines the trigger.

18. 2. The method of claim 1, wherein transmitting the indication comprises transmitting the indication via a medium access control (MAC) control element (CE) including a bitmap configured to indicate a supported number of repetitions or reserved bits to indicate the UE capability for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

19. 2. The method of claim 1, wherein transmitting the indication comprises transmitting the indication via a Medium Access Control (MAC) Control Element (CE) carried in a third message (Msg3) Physical Uplink Shared Channel (PUSCH) transmission in a Type 1 random access procedure or a Message A (MsgA) PUSCH transmission in a Type 2 random access procedure.

20. The method of claim 1 , further comprising receiving, at the UE from the network node, a repetition number for the PUCCH repetition of the Msg4 HARQ-ACK transmission.

21. 21. The method of claim 20, wherein the UE determines the number of repetitions by reusing a predefined cell-specific PUCCH resource set, and a downlink control information (DCI) format for an Msg4 Physical Downlink Shared Channel (PDSCH) transmission indicates the number of repetitions for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

22. 21. The method of claim 20, wherein the UE determines the number of repetitions from a modified existing predefined cell-specific PUCCH resource set, and a new column in a table corresponding to the existing predefined cell-specific PUCCH resource set indicates the number of repetitions for each PUCCH resource in the existing predefined cell-specific PUCCH resource set.

23. 21. The method of claim 20, wherein the UE determines the number of repetitions from a modified existing pre-defined cell-specific PUCCH resource set, and wherein new rows in a table corresponding to the existing pre-defined cell-specific PUCCH resource sets for the NTN indicate that the number of repetitions for each PUCCH resource set in the existing pre-defined cell-specific PUCCH resource set is greater than one.

24. 21. The method of claim 20, wherein the UE determines the number of repetitions from new predefined cell-specific PUCCH resource sets, and a new table indicates the number of repetitions for each PUCCH resource set in the new predefined cell-specific PUCCH resource sets.

25. 23. The method of claim 21 or 22, wherein the PUCCH-ConfigCommon information element (IE) is reused to include a single parameter of pucch-ResourceCommon indicating a PUCCH resource set for both the NTN and the terrestrial network (TN).

26. 25. The method according to claim 21, wherein a PUCCH-ConfigCommon information element (IE) is modified with a first parameter of pucch-ResourceCommon to indicate a first PUCCH resource set for a terrestrial network (TN), and a second parameter of pucch-ResourceCommonNTN is used to indicate a second PUCCH resource set for the NTN.

27. determining the trigger measuring, at the UE, a synchronization signal block (SSB) from the network node to obtain an SSB reference signal received power (RSRP) measurement at a first time; In response to the SSB RSRP measurement being less than a threshold, using the SSB RSRP measurement value as the trigger when a Physical Random Access Channel (PRACH) message from the UE to the network node in the RACH procedure at a second time is within a predetermined time elapsed from the first time; 2. The method of claim 1, further comprising: not using the SSB RSRP measurement as the trigger when the PRACH message at the second time is not within the predetermined elapsed time from the first time.

28. 28. The method of claim 27, wherein the predetermined elapsed time is configured by the network node using a system information block (SIB) selected from the group consisting of system information block type 1 (SIB1), system information block type 19 (SIB19), and system information block types associated with NTN communications.

29. 1. A method for a user equipment (UE), comprising: configuring the UE to perform a random access channel (RACH) procedure without capability for physical uplink control channel (PUCCH) repetition of a fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission; measuring, at the UE, a reference signal received power (RSRP) of a synchronization signal block (SSB) signal from a network node to obtain an SSB-RSRP measurement value; When the SSB-RSRP measurement value is less than a threshold, continuously monitoring the SSB signal from the network node without transmitting a Physical Random Access Channel (PRACH) message from the UE to the network node in the RACH procedure; transmitting the PRACH message from the UE to the network node in the RACH procedure when the SSB-RSRP measurement value is greater than or equal to the threshold.

30. 1. A method for a network node of a non-terrestrial network (NTN), comprising: receiving, at the network node, from a user equipment (UE) an indication of UE capability for a physical uplink control channel (PUCCH) repetition of a fourth message (Msg4) hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission in a random access channel (RACH) procedure; indicating a repetition number for the PUCCH repetition of the Msg4 HARQ-ACK transmission from the network node to the UE; and receiving, at the network node, one or more Msg4 HARQ-ACK repetitions from the UE during the RACH procedure according to the repetition number.

31. 31. The method of claim 30, wherein the indicating the number of repetitions includes reusing a predefined cell-specific PUCCH resource set, and wherein a downlink control information (DCI) format for an Msg4 Physical Downlink Shared Channel (PDSCH) transmission indicates the number of repetitions for the PUCCH repetitions of the Msg4 HARQ-ACK transmission.

32. 31. The method of claim 30, wherein indicating the number of repetitions includes modifying an existing pre-defined cell-specific PUCCH resource set, wherein a new column in a table corresponding to the existing pre-defined cell-specific PUCCH resource set indicates the number of repetitions for each PUCCH resource in the existing pre-defined cell-specific PUCCH resource set.

33. 31. The method of claim 30, wherein indicating the number of repetitions includes modifying an existing pre-defined cell-specific PUCCH resource set, wherein new rows in a table corresponding to the existing pre-defined cell-specific PUCCH resource sets for the NTN indicate that the number of repetitions for each PUCCH resource in the existing pre-defined cell-specific PUCCH resource set is greater than one.

34. 31. The method of claim 30, wherein the indicating the number of repetitions includes using a new predefined cell-specific PUCCH resource set, and a new table indicates the number of repetitions for each PUCCH resource in the new predefined cell-specific PUCCH resource set.

35. 33. The method of claim 31 or 32, wherein the PUCCH-ConfigCommon information element (IE) is reused to include a single parameter of pucch-ResourceCommon indicating a PUCCH resource set for both the NTN and the terrestrial network (TN).

36. 35. The method according to claim 31, wherein a PUCCH-ConfigCommon information element (IE) is modified with a first parameter of pucch-ResourceCommon to indicate a first PUCCH resource set for a terrestrial network (TN), and a second parameter of pucch-ResourceCommonNTN is used to indicate a second PUCCH resource set for the NTN.

37. Apparatus comprising means for carrying out the method of any of claims 1 to 36.

38. 37. A computer readable medium containing instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method of any of claims 1 to 36.

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