Multiple timing advances supporting multiple transmission and reception points

Abstract

There is provided an apparatus configured to receive downlink control information (DCI) with a PDCCH command on a physical downlink control channel (PDCCH), the PDCCH command initiating a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, where the DCI includes an identification of a first transmit and receive point (TRP) or a second TRP to which the PRACH transmission is to point; and configuring a transceiver circuit to transmit the PRACH transmission to the first TRP or the second TRP based at least in part on the DCI.

Description

Background Art

[0001] A user equipment (UE) may be connected to the network via a base station. A base station may control multiple transmit and receive points (TRPs). In New Radio, it has been decided that for multi-TRP operation based on multi-downlink control information (multi-DCI) with two timing advance (TA) enhancements, contention-free random access (CFRA) triggered by a physical downlink control channel (PDCCH) command should be supported for both intra-cell and inter-cell cases. However, it needs to be determined how the PDCCH command CFRA procedure can be enhanced so that the physical random access channel (PRACH) is triggered towards the second TRP. Summary of the Invention

[0002] Some example embodiments relate to an apparatus having processing circuitry configured to: receive downlink control information (DCI) having a PDCCH command on a physical downlink control channel (PDCCH) that initiates a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, wherein the DCI includes an identification of a first transmit and receive point (TRP) or a second TRP to which the PRACH transmission is to be directed; and configure transceiver circuitry to transmit the PRACH transmission to the first TRP or the second TRP based at least in part on the DCI.

[0003] Other example embodiments relate to a method for: receiving downlink control information (DCI) with a physical downlink control channel (PDCCH) having a PDCCH command that initiates a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, wherein the DCI includes an identifier of a first transmit and receive point (TRP) or a second TRP to which the PRACH transmission is to be directed; and configuring the PRACH transmission to the first TRP or the second TRP based at least in part on the DCI. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 Example network arrangements are shown according to various example embodiments.

[0005] Figure 2 An example user equipment (UE) is shown according to various example embodiments.

[0006] Figure 3 An example base station is shown according to various example embodiments.

[0007] Figure 4 An example arrangement including two TRPs transmitted to a UE is shown according to various example embodiments.

[0008] Figure 5 Example DCI formats including a new target cell index field are shown according to various example embodiments.

[0009] Figure 6 A random access response (RAR) medium access control (MAC) protocol data unit (PDU) is shown, including a reserved bit for indicating reuse of a timing advance group identity (TAG-ID) according to various example embodiments.

[0010] Figure 7 A diagram of a RACH preamble is shown, illustrating CFRA PRACH resources associated with a given synchronization signal block (SSB) divided into two subgroups, according to various example embodiments.

[0011] Figure 8 A diagram illustrating an SSB of a serving cell divided into two subgroups according to various example embodiments.

[0012] Figure 9 A signaling diagram illustrating a first example of UL beam determination for PRACH transmission of a PDCCH command according to various example embodiments is shown.

[0013] Figure 10 A signaling diagram illustrating a second example of UL beam determination for PRACH transmission of PDCCH commands according to various example embodiments is shown.

[0014] Figure 11 An example timing diagram illustrating an example RAR window according to various example embodiments is shown.

[0015] Figure 12 Example timing diagrams for determining DL reference timing based on DL-RSs associated with different CORESET pool index values ​​for a first TRP and a second TRP according to various example embodiments are provided. DETAILED DESCRIPTION

[0016] The example embodiments may be further understood with reference to the following description and associated drawings, wherein like elements have the same reference numerals. The example embodiments relate to multi-TRP operation based on multi-DCI with two TA enhancements to support the following scenarios: at least for inter-cell multi-DCI, a PDCCH command transmitted by one TRP triggers a RACH procedure toward the same TRP or a different TRP.

[0017] The example embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, the term UE as described herein is used to represent any electronic component.

[0018] Example embodiments are also described with reference to fifth-generation (5G) New Radio (NR) networks and next-generation Node Bs (gNBs). However, reference to 5G NR networks or gNBs is provided for illustrative purposes only. Example embodiments may be utilized with any suitable type of network and base station.

[0019] A gNB may be configured with multiple transmit and receive points (TRPs). Throughout this specification, a TRP generally refers to a set of components configured to transmit and / or receive beams. In some embodiments, multiple TRPs may be deployed locally at the gNB. For example, the gNB may include multiple antenna arrays / panels, each configured to generate a different beam. In other embodiments, multiple TRPs may be deployed at various locations and connected to the gNB via backhaul connections. For example, multiple small cells may be deployed at different locations and connected to the gNB. However, these examples are provided for illustrative purposes only. Those skilled in the art will understand that TRPs are configured to adapt to a variety of different conditions and deployment scenarios. Therefore, any reference to a TRP as a specific network component or to multiple TRPs deployed in a specific arrangement is for illustrative purposes only. The TRPs described herein may represent any type of network component configured to transmit and / or receive beams.

[0020] The network may support multi-TRP (mTRP) based transmissions. From the UE's perspective, mTRP operation may include establishing and maintaining connections with multiple TRPs simultaneously. To receive mTRP transmissions, the UE may be equipped with multiple receive (RX) panels (e.g., antenna panels and receive chains), where each RX panel can receive signals from a separate TRP.

[0021] According to an example embodiment, techniques for implementing multi-DCI based multi-TRP operations are introduced, including but not limited to: distinguishing between intra-cell and inter-cell CFRA processes; determining an uplink (UL) beam for sending a preamble code of a PDCCH command toward a second TRP; determining beam information for receiving a random access response (RAR), including type 1 common search space (CSS) monitoring and physical downlink shared channel (PDSCH) reception; and sending a timing advance group identifier (TAG-ID) to the TRP.

[0022] Figure 1An example network arrangement 100 according to various example embodiments is shown. The example network arrangement 100 includes a UE 110. Those skilled in the art will appreciate that the UE 110 can be any type of electronic component configured to communicate via a network, such as a mobile phone, tablet computer, desktop computer, smartphone, phablet, embedded device, wearable device, Internet of Things (IoT) device, etc. A practical network arrangement can include any number of UEs used by any number of users. Therefore, the example of a single UE 110 is provided for illustrative purposes only.

[0023] UE 110 can be configured to communicate with one or more networks. In the example of network arrangement 100, the network with which UE 110 can wirelessly communicate is a 5G NR radio access network (RAN) 120. However, UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, next generation RAN (NG-RAN), long term evolution (LTE) RAN, traditional cellular networks, wireless local area networks (WLAN), etc.), and UE 110 can also communicate with the network via a wired connection. Referring to the exemplary embodiment, UE 110 can establish a connection with 5G NR RAN 120. Therefore, UE 110 may have at least a 5G NR chipset to communicate with 5G NR RAN 120.

[0024] The 5G NR RAN 120 may be part of a cellular network that may be deployed by a network operator, such as Verizon, AT&T, T-Mobile, etc. The 5G NR RAN 120 may include, for example, base stations or access nodes (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell, microcell, small cell, femtocell, etc.) configured to transmit and receive communication traffic from UEs equipped with appropriate cellular chipsets.

[0025] In network arrangement 100, 5G NR RAN 120 deploys gNB 120A. gNB 120A may be configured with multiple Transmission Relay Protocols (TRPs). Each TRP may represent one or more components configured to transmit and / or receive signals. In some embodiments, multiple TRPs may be deployed locally on gNB 120A. In other embodiments, multiple TRPs may be distributed at different locations and connected to gNB 120A via backhaul connections. For example, multiple small cells may be deployed at different locations and connected to gNB 120A. However, these examples are provided for illustrative purposes only. TRPs are configured to adapt to a variety of different conditions and deployment scenarios. Therefore, any reference to a TRP as a specific network component or to multiple TRPs deployed in a specific arrangement is for illustrative purposes only. A TRP, as described herein, may represent any type of network component configured to transmit and / or receive beams. As indicated above, in some examples, the terms "TRP" and "cell" may be used interchangeably to generally refer to the same connection and / or node.

[0026] Any association procedure may be performed to connect the UE 110 to the 5G NR RAN 120. For example, as discussed above, the 5G NR RAN 120 may be associated with a particular cellular provider where the UE 110 and / or its user has protocol and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR RAN 120, the UE 110 may send corresponding credential information in order to associate with the 5G NR RAN 120. More specifically, the UE 110 may associate with a particular base station (e.g., gNB 120A).

[0027] The network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 may refer to an interconnected collection of components that manage the operation and traffic of the cellular network. It may include an evolved packet core (EPC) and / or a 5G core (5GC). The cellular core network 130 also manages traffic flowing between the cellular network and the Internet 140. The IMS 150 may generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 may communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 may communicate directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 may generally be described as a collection of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 to communicate with various networks.

[0028] Figure 2An example UE 110 is shown according to various example embodiments. The UE 110 will refer to Figure 1 1. The UE 110 may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a power supply, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, and the like.

[0029] The processor 205 may be configured to execute multiple engines of the UE 110. For example, the engine may include a PDCCH commanded CFRA engine 235. The PDCCH commanded CFRA engine 235 may perform various operations related to multi-TRP operation based on multiple DCIs. These various operations will be described in more detail below.

[0030] The engine 235 described above is provided as an application (e.g., a program) executed by the processor 205 for illustrative purposes only. The functionality associated with the engine 235 may also be represented as a separate integrated component of the UE 110, or may be a modular component coupled to the UE 110, such as an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engine may also be embodied as one application or multiple independent applications. In addition, in some UEs, the functionality described for the processor 205 is split between two or more processors, such as a baseband processor and an application processor. The example embodiments may be implemented in any of these or other configurations of the UE.

[0031] Memory arrangement 210 may be a hardware component configured to store data related to operations performed by UE 110. Display device 215 may be a hardware component configured to display data to a user, and I / O device 220 may be a hardware component that enables a user to enter input. Display device 215 and I / O device 220 may be separate components or may be integrated together (such as a touch screen).

[0032] The transceiver 225 may be a hardware component configured to establish a connection with the 5G NR-RAN 120, LTE-RAN (not shown in the figure), traditional RAN (not shown in the figure), WLAN (not shown in the figure), etc. Thus, the transceiver 225 may operate on a variety of different frequencies or channels (e.g., a set of contiguous frequencies). The transceiver 225 includes circuitry configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information for implementing any of the methods described herein. The processor 205 may be operably coupled to the transceiver 225 and configured to receive signals from and / or send signals to the transceiver 225. The processor 205 may be configured to encode and / or decode signals (e.g., signaling from a base station of the network) for implementing any of the methods described herein.

[0033] Figure 3 An example base station 300 is shown according to various example embodiments. Base station 300 may represent a gNB 120A or any other type of access node through which UE 110 may establish a connection and manage network operations.

[0034] The base station 300 may include a processor 305, a memory arrangement 310, an input / output (I / O) device 315, a transceiver 320, a plurality of TRPs 325, and other components 330. The other components 3330 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports for electrically connecting the base station 300 to other electronic devices and / or a power source, a TxRU, a transceiver chain, an antenna element, an antenna panel, and the like.

[0035] As described above, in some scenarios, multiple TRPs 325 may be deployed locally at the base station 300. In other scenarios, one or more of the multiple TRPs may be deployed at a physical location remote from the base station 300 and connected to the base station via a backhaul connection. The base station 300 may be configured to control the multiple TRPs 325 and perform operations such as, but not limited to, assigning resources, configuring reference signals, implementing beam management techniques, and the like.

[0036] The processor 305 may be configured to execute multiple engines of the base station 300. For example, the engine may include a PDCCH command CFRA engine 335, which may perform various operations related to multi-TRP operation based on multiple DCIs. These operations will be described in detail below.

[0037] The engine 335 described above as an application (e.g., a program) executed by the processor 305 is merely an example. The functionality associated with the engine 335 may also be represented as a separate, integrated component of the base station 300, or may be a modular component coupled to the base station 300, such as an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. Furthermore, in some base stations, the functionality described for the processor 305 is split between multiple processors (e.g., a baseband processor, an application processor, etc.). The example embodiments may be implemented in any of these or other configurations of the base station.

[0038] The memory arrangement 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I / O device 315 may be a hardware component or port that enables a user to interact with the base station 300.

[0039] The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UEs in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., a set of contiguous frequencies). Thus, the transceiver 320 may include one or more components (e.g., radios) to enable data exchange with various networks and UEs. The transceiver 320 includes circuitry configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information for implementing any of the methods described herein. The processor 305 may be operably coupled to the transceiver 320 and configured to receive signals from and / or send signals to the transceiver 320. The processor 305 may be configured to encode and / or decode signals (e.g., signaling from a UE) for implementing any of the methods described herein.

[0040] Figure 4 An example arrangement 400 is shown including two TRPs 410 and 420 transmitting to a UE 110 according to various example embodiments. Figure 4 An example is illustrated in which UE 110 has activated two panels and is exchanging signals with a first TRP 410 via a first panel and with a second TRP 420 via a second panel. In this example, TRP 410 can be considered a serving cell and TRP 420 a non-serving cell.

[0041] As described above, in NR, it has been decided that for multi-DCI based multi-TRP operation with two TA enhancements, CFRA triggered by PDCCH commands should be supported for both intra-cell and inter-cell cases. The example embodiment provides enhancements to the PDCCH command CFRA process so that PRACH can be triggered towards the second TRP (e.g., the TRP where no DCI is sent). These enhancements of the example embodiment solve the problems associated with multi-DCI based multi-TRP operation, including but not limited to: distinguishing between intra-cell and inter-cell CFRA processes; determining the uplink (UL) beam for the preamble transmission of the PDCCH command towards the second TRP; determining the beam information for receiving random access response (RAR), including type 1 common search space (CSS) monitoring and physical downlink shared channel (PDSCH) reception.

[0042] In addition, if Figure 4 As shown, UE 110 will send a timing advance group identity (TAG-ID) to the TRP. Example embodiments provide a way to indicate the TAG-ID associated with two TRPs. These example embodiments address issues such as determining the exact downlink (DL) reference timing on a per-mTRP basis.

[0043] In some example implementations, a 3-bit target cell index field may be introduced for the legacy PDCCH order DCI format by reusing the reserved bits of fallback DCI format 1_0 or adding a new field to DCI format 1_1. In some designs, an additional PCI index associated with a non-serving cell (e.g., TRP 420) via radio resource control (RRC) signaling may be indicated by the new field. The code point "000" value may be reserved for intra-cell PDCCH order RACH procedures.

[0044] Figure 5 An example DCI format 500 including a new target cell index field is shown according to various example embodiments. Figure 5 The example of shows the fallback DCI format 1_0 with the new target cell index field. However, based on the principles described herein, those skilled in the art will understand how to modify other existing DCI formats to include the new target cell index field.

[0045] DCI format 500 includes traditional other Rel-17 fields related to the PDCCH command of DCI 510. DCI format 500 also shows the current reserved bit 520. The reserved bit 520 is used to introduce a new target cell index field 530. As described above, the new target cell index field 530 can be a 3-bit field for indicating the target cell. However, the new target cell index field 530 is not limited to 3 bits and can be another size based on the number of potential target cells. As described above, UE 110 may have received RRC signaling including a PCI index associated with a non-serving cell (e.g., TRP 420). If the non-serving cell is a target cell, the PCI index can be indicated by the new target cell index field 530. As also described above, the value "000" in the new target cell index field 530 can be reserved for the intra-cell PDCCH command RACH process.

[0046] The DCI format 500 with the new target cell index field 530 remains the same size as the legacy (eg, Rel-17 DCI) because some of the available reserved bits 520 are reused to implement the new target cell index field 530 .

[0047] As described above, the example embodiment also introduces a way to indicate the TAG-IDs associated with two TRPs. Figure 5 The example of FIG5 shows one way to indicate the TAG-ID corresponding to the identified target cell (e.g., via the target cell index field 530). In this example embodiment, the DCI format 500 also includes an additional 3-bit field (TAG-ID field 540), which also includes the reused reserved bit 520. The value of the TAG-ID corresponding to the identified target cell is one TAG candidate from up to 8 TAG candidates (e.g., a 3-bit combination).

[0048] Likewise, the DCI format 500 with the TAG-ID field 540 remains the same size as legacy (e.g., Rel-17 DCI) because some of the available reserved bits 520 are reused to implement the TAG-ID field 540. The DCI format 500 may not include the TAG-ID field 540 because, as will be described in more detail below, there may be other ways to indicate a TAG-ID.

[0049] In other example embodiments, the associated TAG-ID is provided by a legacy RAR medium access control (MAC) protocol data unit (PDU) by reusing a reserved bit.

[0050] Figure 66 shows a RAR MAC PDU 600 including a reserved bit for indicating reuse of a TAG-ID according to various example embodiments. Figure 6 In the example of , it can be considered that the reserved bit 610 can be reused to indicate the TAG-ID corresponding to the target cell. The 1-bit field can only carry the value "0" or "1", so the exact TAG-ID cannot be directly indicated in the reserved bit 610. Instead, the TAG-ID can be inferred from the value of the reserved bit 610 and the context in which it is sent. An example of how to infer the TAG-ID is provided below.

[0051] In these example embodiments, the TAG-ID of the second TRP may be considered to be pre-configured or implicitly determined based on the TAG-ID of the first TRP. Then, the reused reserved bit 610 of 1 bit with a value of "0" indicates that the TA is applied to the TAG-ID associated with the first TRP, and a value of "1" indicates that the TA is applied to the TAG-ID associated with the second TRP.

[0052] According to these example embodiments, a TAG-ID may be associated with different UL signals / channels. A coresetPoolIndex value of "0" or "1" for each TAG-ID may be provided to the UE 110 via RRC signaling. Thus, in one example, for a physical uplink shared channel (PUSCH) transmission scheduled by a dynamic grant PUSCH (DG-PUSCH) or activated by a DCI associated with a CORESET having a CORESETpoolIndex value i (i=0,1) (e.g., a type 2 configured grant PUSCH (CG-PUSCH)), the TAG-ID associated with the CORESETpoolIndex value i is applied to the PUSCH transmission, e.g., the value of i is the value included in the reserved bits 610. Depending on the value in the reserved bits 610, the TAG-ID will correspond to the TAG-ID of the TRP having the corresponding CORESETpoolIndex value.

[0053] In another example, for Type 1 CG-PUSCH, Sounding Reference Signal (SRS) transmission (including P / SP / AP SRS) and Physical Uplink Control Channel (PUCCH) resources, the TAG-ID is provided as part of the configuration through RRC signaling.

[0054] In other example embodiments, an associated TAG-ID is provided for intra-cell mTRP operation. For example, the CFRA PRACH resources associated with a given SSB can be divided into two subgroups. If the corresponding preamble belongs to the nth group (n=1, 2), the TA obtained via the RACH process corresponds to the nth TAG.

[0055] Figure 7 A diagram of a RACH preamble 700 is shown, illustrating CFRA PRACH resources associated with a given SSB divided into two subgroups, according to various example embodiments. As shown in the example, there is a contention-based preamble 710, which may be ignored for the purposes of these example embodiments. There is also a contention-free preamble 720. As described above, the contention-free preamble 720 is divided into two subgroups, subgroup #1 730 and subgroup #2 740. RACH resources are provided by PDCCH orders. Therefore, UE 110 can derive a TAG-ID based on which subgroup triggered the RACH procedure.

[0056] In an example embodiment, a subgroup with a lower ID (eg, subgroup #1 730) may be associated with a TAG-ID with a lower ID. However, this is not a requirement of the example embodiment, and any other association between subgroups and TAG-IDs may be used.

[0057] In yet another example embodiment, an associated TAG-ID is also provided for intra-cell mTRP operation. In these example embodiments, the SSBs are also divided into two subgroups, but through system information block (SIB) information or RRC signaling. If the corresponding SSB indicated in the PDCCH command DCI belongs to the nth group (n=1, 2), the TA obtained via the RACH process corresponds to the nth TAG-ID.

[0058] Figure 8 A diagram illustrates an SSB 800 of a serving cell divided into two subgroups according to various example embodiments. In this example, serving cell SSB 810 is divided into SSB subgroup #1 820 and SSB subgroup #2 830. As described above, this division can be signaled via SIB or RRC signaling. When the PDCCH command DCI indicates an SSB belonging to one of these groups, the RACH procedure corresponds to the TAG-ID associated with that group.

[0059] As described above, example embodiments also relate to UL beam determination for PRACH transmissions of PDCCH commands. As will be described in more detail below, in some example embodiments, the PRACH transmission is aligned with the TRP at which the PDCCH command is being transmitted, while in other example embodiments, the PRACH transmission is not aligned with the TRP at which the PDCCH command is being transmitted. These example embodiments are described in more detail below.

[0060] According to some example embodiments, UE 110 uses a reference signal (RS) configured with quasi co-location (QCL) type D (e.g., an SSB or channel state information (CSI)-RS associated with a serving cell) of a PDCCH (in which a PDCCH command triggering CFRA is detected) for UL beam determination. These example embodiments may be suitable for handover, but may also be applicable to other scenarios.

[0061] Figure 9 A signaling diagram 900 is shown of a first example of UL beam determination for PRACH transmission of a PDCCH command according to various example embodiments. The signaling diagram 900 shows the example described directly above. As will be described in more detail below, Figure 9 In the example, the TRP 420 that is sending the PDCCH command is also the TRP pointed to by the PRACH.

[0062] In 910, a PDCCH command is sent from non-serving cell TRP 420 to UE 110. This PDCCH command, sent by non-serving cell TRP 420 from a CORESET associated with the target TRP / non-serving cell 420 (i.e., CORESETpoolIndex=1), can still trigger a PRACH towards non-serving cell TRP 420. Thus, the CORESET identified in the PDCCH command allows UE 110 to select an appropriate TRP and beam for PRACH transmission. Thus, in 920, UE 110 sends a PRACH to non-serving cell TRP 420, and in 930, non-serving cell TRP 420 sends a PDCCH for RAR and a RARPDSCH to UE 110.

[0063] Figure 9 The general principle of selecting the UL beam for PRACH transmission shown is that UE 110 selects the UL beam based on where (e.g., TRP 410 or TRP 420) the DCI including the PDDCH order is received. Figure 9 The example may also show that a PDCCH command is received from TRP 410, and UE 110 will select an UL beam for PRACH transmission based on the DCI received from TRP 410.

[0064] According to other example embodiments, UE 110 uses the SSB identified by the SSB index value provided in the PDCCH order for UL beam determination.

[0065] Figure 10Signaling diagram 1000 shows a second example of UL beam determination for PRACH transmission for PDCCH commands according to various example embodiments. Signaling diagram 1000 shows the example described directly above. As will be described in more detail below, in Figure 10 , the TRP 410 transmitting the PDCCH command is not the TRP (e.g., TRP 420) that the PRACH is directed to.

[0066] In 1010, the PDCCH command is sent from the serving cell TRP 410 to the UE 110. The PDCCH command includes an SSB identified by an SSB index value. In this example, the SSB index value included in the PDCCH command can be considered to be the SSB index value of the non-serving cell TRP420. Although Figure 10 is not shown, the UE 110 will receive and measure the SSB from the non-serving cell TRP 420. Therefore, when the SSB index value corresponding to the non-serving cell TRP 420 is received in the PDCCH command, the UE 110 can determine the UL beam for PRACH transmission based on the information derived from the SSB received from the non-serving cell TRP 420. Thus, in 1020, the UE 110 sends a PRACH to the non-serving cell TRP 420, and in in 1030, the serving cell TRP 410 sends a PDCCH for the RAR and an RAR PDSCH to the UE110.

[0067] According to other example embodiments, the UE 110 can use the "cell indicator" field included in the PDCCH command DCI to perform UL beam determination. In one example, the cell indicator field can be added to the PDCCH command DCI as a single-bit field that indicates whether the CFRA triggered by the PDCCH command is for the serving cell or a non-serving cell. For example, the value "0" indicates the serving cell, while the value "1" indicates the non-serving cell.

[0068] In a second example, the cell indicator field can be added to the PDCCH command DCI as a three-bit field that indicates whether the CFRA triggered by the PDCCH command is for the serving cell or a non-serving cell. For non-serving cells, the value of the cell indicator field indicates the associated "additional PCI index" preconfigured for each non-serving cell / TRP by RRC signaling. The value "k" (0 < k < 8 (e.g., 3 bits allow values 0 to 7)) is the corresponding additional PCI index for the non-serving cell / TRP. The additional PCI index is described above. The value "0" indicates the serving cell.

[0069] In these example embodiments, if the value "0" is provided in the PDCCH command DCI in the first example or the second example, the UE 110 can use the information about Figure 9 The described operations may be used to select an UL beam for RACH, for example, where UE 110 detects that PDCCH is used to select an UL beam. Otherwise, UE 110 may use the Figure 10 The described operations are used to select the UL beam for RACH, for example, based on the SSB value indicated in the PDCCH order.

[0070] According to other example embodiments, UE 110 may use Figure 9 or Figure 10 The described operations are used to perform UL beam determination. The selection of these alternative operations can be explicitly configured through RRC signaling.

[0071] In some of the example embodiments, a PRACH transmission (e.g., PRACH transmission 920) may be transmitted using a single instance without repetition. These example embodiments may be more advantageous for handover scenarios. However, example embodiments of transmitting without repetition are not limited to handover scenarios.

[0072] According to some example embodiments, operations related to UL beam determination for PRACH transmission may also be applied to DL Transmission Configuration Indicator (TCI) status determination to monitor PDCCH for corresponding Msg2 reception. Figure 9 and 10 As described in the example of , there may be some scenarios in which the RAR is sent by the serving cell TRP 410 and other scenarios in which the RAR is sent by the non-serving cell TRP 420.

[0073] For example, Figure 10 As shown, using the non-serving cell TRP 420 to send the RAR may cause some DL interruption due to various reasons. Therefore, in some example embodiments, regardless of the TRP that sends the PDCCH order, the RAR is always sent from the serving cell TRP 410 to avoid interruption of DL reception. Figure 9 The only change will be that the PDCCH and RAR PDSCH transmission 930 for RAR will be performed by the serving cell TRP 410.

[0074] In other example embodiments, RAR transmission may follow the reference Figure 10 The same rules as described for PRACH transmission are used, e.g., RAR is based on the SSB index included in the PDCCH order.

[0075] As described above, example embodiments also involve a method for PDCCH monitoring for RAR reception that depends on whether the associated non-serving cell is an active additional PCI with at least one DL TCI state activated by a TCI activation MAC-CE (which may be referred to as an "active non-serving cell"). UE 110 may not send any UL signals to an inactive non-serving cell. However, a PDCCH command for CFRA may still be useful so that the network can obtain a TA value even before the PCI is activated to reduce latency.

[0076] There may be multiple scenarios for these example implementations. In the first scenario, if a PDCCH command triggers a PRACH transmission towards an active non-serving cell, and the associated RAR is received from a serving cell, including both PDCCH and PDSCH, such as for Figure 10 As shown. The TA value indicated by the received RAR is immediately applied to the associated TAG-ID. In some designs, an offset value Δ (e.g., in symbols) may be configured via SIB or dedicated RRC signaling to compensate for the RAR forwarding delay from the target non-serving cell to the serving cell. Accordingly, the RAR window starts at the first symbol of the earliest CORESET for the type 1-PDCCH CSS set on which the UE is configured to receive PDCCH, and the RAR window is at least N=1+Δ symbols, followed by the last symbol of the PRACH opportunity corresponding to the PRACH. In a carrier aggregation (CA) scenario, the RAR is received from a special cell (SpCell) where a type 1 CSS is configured for the serving cell.

[0077] Figure 11 An example timing diagram 1100 is shown illustrating an example RAR window according to various example embodiments. The timing diagram 1100 illustrates an example of the first case described above. Figure 11 , a plurality of Type 1 CSS monitoring opportunities 1110 to 1170 may be considered to be illustrated on a timeline. Each consecutive monitoring opportunity 1110 to 1170 may be considered to be separated by a time slot, as shown between monitoring opportunities 1120 and 1130. The use of Type 1 CSS monitoring opportunities is merely an example, and any other monitoring opportunity configured to include RAR transmissions may be represented by monitoring opportunities 1110 to 1170.

[0078] At 1105, UE 110 sends a PRACH transmission. In a conventional system, UE 110 would start monitoring the RAR at the beginning of the timeslot including monitoring opportunity 1120. However, as described above, there may be a delay due to the RAR forwarding delay from the target non-serving cell to the serving cell (e.g., on the backhaul link). As described above, the delay (Δ) may be signaled to UE 110 using SIB or dedicated RRC signaling. In this example, Δ = 28 symbols (e.g., 2 timeslots) may be considered. Therefore, instead of starting monitoring at the beginning of the timeslot including monitoring opportunity 1120, UE 110 will apply a delay of Δ = 28 symbols and start the RAR monitoring window 1180 at the beginning of the timeslot including monitoring opportunity 1140. The length of the RAR monitoring window 1180 may be configured to have any length, and Figure 11 The lengths shown are examples only.

[0079] In the second case, if the PRACH transmission triggered by the PDCCH command is towards an inactive non-serving cell, there may be different options that can be considered for monitoring RAR messages. In the first option, RAR is not expected for the UE that sends CFRA PRACH. In the second option, RAR is received in the same manner as described above for the first case. However, the TA value provided by the RAR is stored at the UE and is not applied until one of the following conditions is met. The first condition may be that at least one TCI state associated with the inactive non-serving cell is activated by MAC-CE signaling through code point linking with the TCI field of the DCI format. The second condition may be that a TAG-ID associated with the TA value is provided in L1 / L2 Triggered Mobility (LTM) MAC-CE signaling. When the second condition is a triggering condition for applying the TA value, the application time of the TA value may be defined relative to the last symbol of the corresponding MAC-CE.

[0080] Example embodiments also relate to DL reference timing for applying UL TA values. As described above, each TAG-ID may be associated with a CORESET pool index value of "0" or "1" on a reference component carrier (CC). The DL reference timing for applying the UL TA value of the TAG-ID may be determined as follows. The DL reference timing for a TAG-ID associated with a CORESET pool index value "i" (i=0,1) is based on the first detected path (in time) in the reference CC of the DL RS in the active TCI state associated with the same CORESET pool index value "i" (i=0,1).

[0081] Figure 12An example timing diagram 1200 is provided for determining DL reference timing based on DL-RS associated with different CORESET pool index values ​​of a first TRP 1210 and a second TRP 1220 according to various example embodiments. In this example, each TRP may be considered to be activated with three DL TCI states associated with three different reference signals (RS), e.g., TRP 1210 has a CORESET pool index = 0 and a DL RS with an active TCI state: RS 0,0 、RS 0,1 、RS 0,2 ; and TRP 1220 has DL RS with CORESET pool index = 1 and active TCI state: RS 1,0 、RS 1,1 、RS 1,2 .

[0082] The first detected DL RS path in time for TRP 1210 is RS 0,2 , for TRP 1220 is RS 1,0 In this example, RS is selected for TRP 1210 with CORESET pool index = 0 and TRP 1220 with CORESET pool index = 1. 0,2 and RS 1,0 , to derive the DL reference timing to apply TA to UL transmission.

[0083] Example

[0084] In a first embodiment, a method performed by a user equipment (UE) communicating with a first transmit and receive point (TRP) and a second TRP of a base station, the method comprising: receiving downlink control information (DCI) having a PDCCH command on a physical downlink control channel (PDCCH), the PDCCH command initiating a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, wherein the DCI includes an identifier of the first TRP or the second TRP to which the PRACH transmission is to be directed; and sending the PRACH transmission to the first TRP or the second TRP based at least in part on the DCI.

[0085] In a second embodiment, the method according to the first embodiment is used, wherein the identifier includes a 3-bit target cell index field in the DCI, wherein the value of the 3-bit target cell index field identifies the first TRP or the second TRP.

[0086] In a third embodiment, the method according to the second embodiment is provided, wherein the DCI comprises fallback DCI format 1_0.

[0087] In a fourth embodiment, the method according to the second embodiment is described, wherein the second TRP is a non-serving cell, and the value of the 3-bit target cell index field corresponding to the second TRP is received by the UE via radio resource control (RRC) signaling before receiving the DCI.

[0088] In a fifth embodiment, the method according to the first embodiment is described, wherein the DCI also includes a 3-bit timing advance group identifier (TAG-ID) field, wherein the value of the 3-bit TAG-ID field identifies the TAG-ID corresponding to the first TRP or the second TRP.

[0089] In a sixth embodiment, according to the method described in the first embodiment, the method also includes: receiving a random access response (RAR) medium access control (MAC) protocol data unit (PDU), and the random access response (RAR) medium access control (MAC) protocol data unit (PDU) includes information corresponding to the timing advance group identifier (TAG-ID) corresponding to the first TRP or the second TRP.

[0090] In a seventh embodiment, the method according to the sixth embodiment is used, wherein determining the TAG-ID from the information includes: receiving the value of the coresetPoolIndex of each TAG-ID constituting a TAG-ID candidate pool via RRC signaling, wherein the TAG-ID is a member of the TAG-ID candidate pool; determining whether a physical uplink shared channel (PUSCH) is scheduled using dynamic grant or activated by a second DCI received on a CORESET having a first coresetPoolIndex value; and sending the PUSCH based on the TA value of the TAG-ID corresponding to the first CORESETpoolIndex value.

[0091] In an eighth embodiment, the method according to the sixth embodiment, wherein determining the TAG-ID from the information includes: determining that the transmission is one of the configured authorized PUSCH transmission, the sounding reference signal (SRS) transmission, or the PUCCH transmission; and receiving a radio resource control (RRC) message, the radio resource control (RRC) message indicating the TAG-ID of the first TRP or the second TRP used for one of the configured authorized PUSCH transmission, the SRS transmission, or the PUCCH transmission.

[0092] In a ninth embodiment, the method according to the first embodiment, wherein the CFRA PRACH resources associated with the synchronization signal block (SSB) are divided into a first preamble subgroup and a second preamble subgroup, wherein each subgroup corresponds to a timing advance group identifier (TAG-ID) corresponding to a first TRP or a second TRP, the method further comprising performing a random access channel (RACH) procedure to determine a preamble belonging to the first preamble subgroup or the second preamble subgroup, wherein a timing advance (TA) obtained via the RACH procedure corresponds to the TAG-ID of the first TRP or the second TRP.

[0093] In a tenth embodiment, the method according to the ninth embodiment is used, wherein the first preamble code subgroup has a first identifier (ID), the first identifier (ID) has a value lower than the value of the second ID of the second preamble code subgroup, and the first preamble code subgroup is associated with a first TAG-ID having a value lower than the value of the second TAG-ID.

[0094] In an eleventh embodiment, the method according to the first embodiment is used, wherein a synchronization signal block (SSB) is divided into a first subgroup and a second subgroup through a system information block (SIB) or a dedicated radio resource control (RRC) signal, wherein each subgroup corresponds to a timing advance group identifier (TAG-ID) corresponding to the first TRP or the second TRP, and the method further includes: performing a random access channel (RACH) process on the SSB indicated by the PDCCH command to determine whether the indicated SSB belongs to the first subgroup or the second subgroup, wherein the timing advance (TA) obtained via the RACH process corresponds to the TAG-ID of the first TRP when the indicated SSB belongs to the first subgroup, or corresponds to the TAG-ID of the second TRP when the indicated SSB belongs to the second subgroup.

[0095] In a twelfth embodiment, according to the method of the first embodiment, the method further comprises: determining an uplink (UL) beam on which to transmit the PRACH indicated by the PDCCH order.

[0096] In a thirteenth embodiment, the method according to the twelfth embodiment, wherein determining the UL beam includes: determining a reference signal (RS) configured with a quasi co-location (QCL) type D for the PDCCH including the PDCCH command, wherein the RS corresponds to the beam of the first TRP or the second TRP.

[0097] In a fourteenth embodiment, the method according to the twelfth embodiment, wherein determining the UL beam includes: determining an SSB identified by an SSB index value provided in the PDCCH command, wherein the SSB corresponds to a beam of the first TRP or the second TRP.

[0098] In a fifteenth embodiment, the method according to the twelfth embodiment, wherein determining the UL beam comprises: determining a value of a cell indicator field of the PDCCH command, wherein the value corresponds to the first TRP or the second TRP.

[0099] In a sixteenth embodiment, the method according to the fifteenth embodiment is provided, wherein the cell indicator field includes 1 bit or 3 bits, wherein a value of 0 in the cell indicator field indicates the first TRP, and a non-zero value in the cell indicator field indicates the second TRP, wherein the first TRP is a serving cell and the second TRP is a non-serving cell.

[0100] In a seventeenth embodiment, the method according to the sixteenth embodiment, wherein the non-zero value of the 3-bit cell indicator field corresponding to the second TRP is received by the UE via radio resource control (RRC) signaling before receiving the DCI.

[0101] In an eighteenth embodiment, the method according to the sixteenth embodiment, wherein when the value is 0, determining the UL beam includes: determining a reference signal (RS) configured with a quasi co-location (QCL) type D for the PDCCH including the PDCCH command, wherein the RS corresponds to the beam of the first TRP.

[0102] In a nineteenth embodiment, the method according to the sixteenth embodiment, wherein when the value is non-zero, determining the UL beam includes: determining the SSB identified by the SSB index value provided in the PDCCH command, wherein the SSB corresponds to the beam of the second TRP.

[0103] In a twentieth embodiment, a method according to the twelfth embodiment, wherein determining the UL beam includes one of: determining a reference signal (RS) configured with a quasi-co-location (QCL) type D for the PDCCH including the PDCCH command, wherein the RS corresponds to the beam of the first TRP or the second TRP; or determining an SSB identified by an SSB index value provided in the PDCCH command, wherein the SSB corresponds to the beam of the first TRP or the second TRP, wherein the one of the determinations performed by the UE is configured through RRC signaling.

[0104] In a twenty-first embodiment, the method according to the first embodiment, wherein the PRACH transmission is sent without repetition.

[0105] In a twenty-second embodiment, the method according to the first embodiment, wherein the PRACH transmission is sent to the second TRP, the second TRP is a non-serving cell having at least one downlink (DL) transmission configuration indicator (TCI) state activated, the method further comprising: monitoring a random access response (RAR) corresponding to the PRACH transmission in a monitoring opportunity associated with the CFRA; receiving the RAR including a timing advance (TA) value; and applying the TA value to communication with the second TRP.

[0106] In a twenty-third embodiment, according to the method described in the twenty-second embodiment, the method further includes: receiving a delay value indicating the delay of RAR forwarding between the first TRP and the second TRP; and determining the start time of starting to monitor the scheduling DCI for the RAR based at least on the delay value.

[0107] In a twenty-fourth embodiment, a method according to the twenty-third embodiment, wherein determining the time includes: determining a first time to send the PRACH; determining a second time including the start of a first time slot of a monitoring opportunity; and determining the start time to start monitoring the scheduling DCI for the RAR by adding a third time associated with the delay value to the second time.

[0108] In a twenty-fifth embodiment, the method according to the first embodiment is performed, wherein the PRACH transmission is sent to the second TRP, and the second TRP is a non-serving cell that does not have an activated downlink (DL) transmission configuration indicator (TCI) state.

[0109] In a twenty-sixth embodiment, according to the method of the twenty-fifth embodiment, the UE omits monitoring a random access response (RAR) corresponding to the PRACH transmission.

[0110] In a twenty-seventh embodiment, according to the method described in the twenty-fifth embodiment, the method further includes: monitoring a random access response (RAR) corresponding to the PRACH transmission in a monitoring opportunity associated with the CFRA; receiving the RAR including a timing advance (TA) value; and storing the TA value at the UE.

[0111] In a twenty-eighth embodiment, according to the method of the twenty-seventh embodiment, the method further includes: applying the TA value to communications with the second TRP when at least one DL TCI state associated with the second TRP is activated.

[0112] In a twenty-ninth embodiment, according to the method described in the twenty-seventh embodiment, the method further includes: when the TAG-ID associated with the TA value of the second TRP is provided in the L1 / L2 triggered mobility (LTM) MAC-CE signaling, applying the TA value to the communication with the second TRP.

[0113] In a thirtieth embodiment, according to the method described in the first embodiment, the method further includes: receiving a random access response (RAR), the random access response (RAR) including a timing advance (TA) value for UL transmission having the TRP associated with a coresetPoolIndex value of "0" or a second TRP associated with a coresetPoolIndex value of "1"; and determining a DL reference timing for the UL transmission pointing to the first TRP or the second TRP by applying the corresponding UL TA value.

[0114] In a thirty-first embodiment, a method according to the thirtieth embodiment, wherein determining the DL reference timing for the first TRP or the second TRP includes: for a TAG-ID associated with a coresetPoolIndex value "i", i=0,1, determining a first detected path in a timely manner based on a DL RS of an active TCI state associated with the corresponding coresetPoolIndex value "i".

[0115] In a thirty-second embodiment, a processor is provided, wherein the processor is configured to perform any of the methods according to the first to thirty-first embodiments.

[0116] In a fortieth embodiment, a user equipment comprises a transceiver configured to communicate with a base station and a processor, the processor being communicatively coupled to the transceiver and configured to perform any of the methods according to the first to thirty-first embodiments.

[0117] Those skilled in the art will appreciate that the example embodiments described above can be implemented with any suitable software configuration or hardware configuration or combination thereof. Example hardware platforms for implementing the example embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. The example embodiments of the above methods may be embodied as a program comprising lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, can be executed on a processor or microprocessor.

[0118] Although this application describes various embodiments, each having different features in various combinations, those skilled in the art will understand that any feature of one embodiment may be combined with features of other embodiments in any manner that is not expressly disavowed or that is not functionally or logically inconsistent with the operation of the device or the stated function of the disclosed embodiment.

[0119] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0120] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, it is intended that the present disclosure covers modifications and variations of the present disclosure as long as they come within the scope of the appended claims and their equivalents.

Claims

1. A method comprising: receiving, on a physical downlink control channel (PDCCH), downlink control information (DCI) with a PDCCH order initiating a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, wherein the DCI includes an identification of a first transmit and receive point (TRP) or a second TRP to which the PRACH transmission is to be directed; and The PRACH transmission is configured to the first TRP or the second TRP based at least in part on the DCI.

2. The method of claim 1, wherein the identifier comprises a 3-bit target cell index field in the DCI, wherein a value of the 3-bit target cell index field identifies the first TRP or the second TRP.

3. The method of claim 2, wherein the DCI comprises fallback DCI format 1_0.

4. The method according to claim 1, further comprising: A random access response (RAR) medium access control (MAC) protocol data unit (PDU) is received, wherein the random access response (RAR) medium access control (MAC) protocol data unit (PDU) includes information corresponding to a timing advance group identifier (TAG-ID) corresponding to the first TRP or the second TRP.

5. The method of claim 4, wherein determining the TAG-ID from the information comprises: Receiving, via RRC signaling, a value of coresetPoolIndex for each TAG-ID constituting a TAG-ID candidate pool, wherein the TAG-ID is a member of the TAG-ID candidate pool; determining whether a physical uplink shared channel (PUSCH) is scheduled using a dynamic grant or activated by a second DCI received on a CORESET having a first coresetPoolIndex value; as well as The PUSCH is configured based on a timing advance (TA) value of the TAG-ID corresponding to the first CORESETpoolIndex value.

6. The method of claim 4, wherein determining the TAG-ID from the information comprises: determining whether the transmission is one of a configured authorized PUSCH transmission, a sounding reference signal (SRS) transmission, or a PUCCH transmission; as well as A radio resource control (RRC) message is received, the radio resource control (RRC) message indicating the TAG-ID of the first TRP or the second TRP used for one of the configured authorized PUSCH transmission, the SRS transmission, or the PUCCH transmission.

7. The method according to claim 1, further comprising: An uplink (UL) beam is determined on which to transmit the PRACH indicated by the PDCCH order.

8. The method of claim 7, wherein determining the UL beam comprises: Determine an SSB identified by an SSB index value provided in the PDCCH command, wherein the SSB corresponds to a beam of the first TRP or the second TRP.

9. The method according to claim 1, further comprising: receiving a random access response (RAR) including a timing advance (TA) value for an UL transmission having the TRP associated with a coresetPoolIndex value of '0' or the TRP associated with a coresetPoolIndex value of '1'; The DL reference timing for the UL transmission pointing to the first TRP or the second TRP is determined by applying the corresponding TA value for the UL transmission.

10. The method of claim 9, wherein determining the DL reference timing for the first TRP or the second TRP comprises: For TAG-IDs associated with coresetPoolIndex values ​​"i", i=0, 1, the first detected path in time is determined based on the DL RS of the active TCI state associated with the corresponding coresetPoolIndex value "i".

11. An apparatus comprising a processing circuit configured to: receiving, on a physical downlink control channel (PDCCH), downlink control information (DCI) with a PDCCH order initiating a contention-free random access (CFRA) procedure including a physical random access channel (PRACH) transmission, wherein the DCI includes an identification of a first transmit and receive point (TRP) or a second TRP to which the PRACH transmission is to be directed; and The transceiver circuit is configured to transmit the PRACH to the first TRP or the second TRP based at least in part on the DCI.

12. The apparatus of claim 11, wherein the identifier comprises a 3-bit target cell index field in the DCI, wherein a value of the 3-bit target cell index field identifies the first TRP or the second TRP.

13. The apparatus of claim 12, wherein the DCI comprises fallback DCI format 1_0.

14. The apparatus of claim 11 , wherein the processing circuit is further configured to: A random access response (RAR) medium access control (MAC) protocol data unit (PDU) is received, wherein the random access response (RAR) medium access control (MAC) protocol data unit (PDU) includes information corresponding to a timing advance group identifier (TAG-ID) corresponding to the first TRP or the second TRP.

15. The apparatus of claim 14, wherein the processing circuit determines the TAG-ID from the information by being configured to: Receiving, via RRC signaling, a value of coresetPoolIndex for each TAG-ID constituting a TAG-ID candidate pool, wherein the TAG-ID is a member of the TAG-ID candidate pool; determining whether a physical uplink shared channel (PUSCH) is scheduled using a dynamic grant or activated by a second DCI received on a CORESET having a first coresetPoolIndex value; as well as The PUSCH is configured based on a timing advance (TA) value of the TAG-ID corresponding to the first CORESETpoolIndex value.

16. The apparatus of claim 14, wherein the processing circuit determines the TAG-ID from the information by being configured to: determining whether the transmission is one of a configured granted PUSCH transmission, a sounding reference signal (SRS) transmission, or a PUCCH transmission; and A radio resource control (RRC) message is received, the radio resource control (RRC) message indicating the TAG-ID of the first TRP or the second TRP used for one of the configured authorized PUSCH transmission, the SRS transmission, or the PUCCH transmission.

17. The apparatus of claim 11 , wherein the processing circuit is further configured to: An uplink (UL) beam is determined on which to transmit the PRACH indicated by the PDCCH order.

18. The apparatus of claim 17, wherein the processing circuit determines the UL beam by being configured to: Determine an SSB identified by an SSB index value provided in the PDCCH command, wherein the SSB corresponds to a beam of the first TRP or the second TRP.

19. The apparatus of claim 11 , wherein the processing circuit is further configured to: receiving a random access response (RAR) including a timing advance (TA) value for an UL transmission having the TRP associated with a coresetPoolIndex value of '0' or the TRP associated with a coresetPoolIndex value of '1'; The DL reference timing for the UL transmission pointing to the first TRP or the second TRP is determined by applying the corresponding TA value for the UL transmission.

20. The apparatus of claim 19, wherein the processing circuit determines the DL reference timing for the first TRP or the second TRP by being configured to: For TAG-IDs associated with coresetPoolIndex values ​​"i", i=0, 1, the first detected path in time is determined based on the DL RS of the active TCI state associated with the corresponding coresetPoolIndex value "i".

Images