EP4674193A1

EP4674193A1 - Timing advance (ta) for uplink transmission in a wireless communication system

Info

Publication number: EP4674193A1
Application number: EP23726841.2A
Authority: EP
Inventors: Jia-Hong Liou; Yushu Zhang
Original assignee: Google LLC
Current assignee: Google LLC
Priority date: 2023-04-05
Filing date: 2023-04-05
Publication date: 2026-01-07
Also published as: CN121195567A; WO2024207271A1

Abstract

This disclosure provides systems, methods and apparatuses for timing adjustment of uplink (UL) transmissions from a user equipment (UE) to a network entity (such as a base station). A UE (102) uses a timing advance (TA) value to adjust the transmission time of an UL transmission that uses Multiple-Input Multiple-Output (MIMO). In some aspects of this disclosure, a network entity (104, 106) can use multiple transmit/receive points (TRPs) to communicate with a UE. To maintain physical layer synchronization, a UE can determine a timing advance (TA) value that adjusts the output timing of UL transmissions to a particular TRP (107, 108). In some aspects, a UE can determine a TA value following a beam failure recovery (BFR). In some aspects, a UE can determine a TA value when the network entity fails to provide spatial relation information or transmission configuration indication (TCI) associated with the UL transmission.

Description

TIMING ADVANCE (TA) FOR UPLINK TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication and, more particularly, to timing advance (TA) for uplink transmission in a wireless communication system.

BACKGROUND

Some wireless communication systems use multiple antennas and/or multiple data signals to transmit or receive data via one or more wireless channels. Multiple-Input Multiple-Output (MIMO) refers to a technology for multiplying the capacity of a wireless channel using multiple transmission and receiving antennas. In some instances, MIMO enables a network entity (such as a base station) and user equipment (UE) to communicate using more than one data signal simultaneously over the same radio channel. In some scenarios, the distance between the UE and a network entity can change over time and the timing in which uplink signals arrive at a network element can depend on movement, distance, or spatial relationship. Furthermore, there may be multiple UEs and network entities utilizing a wireless channel. To prevent interference and achieve synchronization of uplink (UL) transmission, a UE might perform a timing adjustment of UL transmissions for various spatial streams of a MIMO UL transmission.
A timing advance (TA) value can be used to control UL transmission timing for UL transmissions (such as a physical uplink shared channel (PUSCH) , physical uplink control channel, or a sounding reference signal (SRS) . The TA value enables the UE to output UL transmissions with a timing adjustment so that the UL transmissions are received by the network entity at a proper time (such as aligned with subframe timing at the network entity) . The 3rd Generation Partnership Project (3GPP) technical specification 38.300 describes timing advance. For example, a network entity (such as the base station) may manage timing advance to keep the physical layer (L1) synchronized. Serving cells having ULs to which the same timing advance applies and using the same timing reference cell are grouped in a timing advance group (TAG) . Each TAG contains or is associated with at least one serving cell with configured uplink, and the mapping of each serving cell to a TAG is configured by control signaling (such as radio resource control (RRC) messaging) from the network entity. A UE may be configured to use the primary cell (PCell) or a secondary cell (SCell) as a timing reference for a first TAG. For a second TAG, the UE may use any of the activated SCells of this TAG as a timing reference cell. Timing advance updates are signaled by the network entity to the UE via media access control (MAC) control element (MAC-CE) commands. Thus, in some deployments, the network entity determines the TA value and sends a timing advance command to the UE. In some deployments, the network entity determines and sends the spatial relation information to the UE so that the UE can then use the spatial relation information to determine a TA value.
BRIEF SUMMARY
The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.
One innovative aspect of the subject matter described in this disclosure can be implemented as a method of wireless communication at a user equipment (UE) . The method includes receiving, from a network entity, a configuration for multiple timing advance (TA) operation mode. The method includes transmitting, to the network entity, an uplink transmission based on a TA parameter associated with the multiple TA operation mode. The uplink transmission including at least one of a first uplink transmission following reception of a beam failure recovery (BFR) response, a second uplink transmission following failure to receive spatial relation information from the network entity, or a third uplink transmission without a joint or uplink transmission configuration indication (TCI) associated with the third uplink transmission.
Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Note that the relative dimensions of the following figures may not be drawn to scale. Like reference numbers and designations in the various drawings indicate like elements. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.
Figure 1A is a diagram illustrating an example wireless communication system including a user equipment (UE) and network entity.
Figure 1B is a diagram illustrating an expanded view of the wireless communication system of Figure 1A.
Figure 1C is a block diagram illustrating an example distributed base station including a central unit (CU) and a distributed unit (DU) .
Figure 2A is a block diagram illustrating an example protocol stack according to which a UE can communicate with network entities.
Figure 2B is a block diagram illustrating an example protocol stack according to which a UE can communicate with a DU and a CU of a distributed network entity.
Figure 3A is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA when spatial relation information is unavailable to the UE.
Figure 3B is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA when an UL channel/RS is not configured to share indicated joint/UL TCI.
Figure 3C is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA after a beam failure recovery.
Figure 3D is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA after a beam failure recovery and an UL channel/RS is not configured to share indicated joint/UL TCI.
Figure 4 is a flow chart illustrating operations of a method performed by a UE for transmitting an uplink transmission in a multiple TA operation mode.
Figure 5 shows a block diagram of an example device that supports determination of a TA value according to some aspects of this disclosure.

DETAILED DESCRIPTION

The following description is directed to certain implementations for the purpose of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless communication according to the 3^rd Generation Partnership Project (3GPP) wireless standards, such as the 4th generation (4G) Long Term Evolution (LTE) and 5th generation (5G) New Radio (NR) standards. However, the described implementations can be implemented in any device, system, or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.15, or 802.16 wireless standards, or other known signals that are used to communicate within a wireless, cellular, or internet of things (IOT) network, such as a system utilizing 3G, 4G, 5G, WiFi or future radio technology.
Various aspects of this disclosure relate to timing adjustment for uplink (UL) transmissions from a user equipment (UE) to a network entity (such as a base station) . In a wireless communication system that uses Multiple-Input Multiple-Output (MIMO) , the UE, the network entity, or both, can use multiple antennas and/or multiple data signals to transmit or receive data via one or more wireless channels. Furthermore, some deployments of a network entity can use multiple transmit/receive points (TRPs) . Multiple TRP (also referred to as M-TRP or Multi-TRP) refers to a feature in which a base station can use more than one TRP to communicate with a UE. In some implementations, the network entity can use different TRPs that are not co-located. The distance between the UE and one or more TRPs can change over time and the timing in which uplink signals arrive at a network element can depend on movement, distance, or spatial relationship. Furthermore, there may be multiple UEs and network entities utilizing a wireless channel. To prevent interference and achieve physical layer synchronization of an uplink (UL) transmission, a UE may perform a timing adjustment of UL transmissions.
A timing advance (TA) value can be used to control timing for UL transmissions (such as a physical uplink shared channel (PUSCH) , physical uplink control channel (PUCCH) , or a sounding reference signal (SRS) ) . The TA value enables the UE to output UL transmissions with a timing adjustment so that the UL transmissions are received by the network entity at a proper time (such as aligned with subframe timing at the network entity) to maintain physical layer synchronization. In some aspects, a TA value may be associated with a TA group (TAG) . A TA group may contain a TAG ID and/or a TA timer, which can be associated with a set of cells. The set of cells associated with the same TAG or TAG ID utilize the same timing advance value. When a UE is served by a cell in a particular TA group, the device uses the TA value associated with that group to adjust its transmission timing. A network entity may provide information to the UE to indicate the TA value. For example, the network entity can provide control signaling (such as a radio resource control (RRC) message, media access control (MAC) control element (MAC-CE) , or downlink control information (DCI) ) that includes information for the UE to derive the TA value. The control signaling might indicate spatial relation information or a joint or UL (joint/UL) transmission configuration indication (TCI) from the network entity. In some aspects, a TAG can be associated with a joint/UL TCI state. Hence, the UE can determine which TAG or TA value to apply for a UL transmission by referring to the indicated joint/UL TCI state for the UL transmission. Furthermore, a spatial relation can be associated with TAG as well within a beam indication framework. Thus, the network entity can maintain the TA value and provide information for the UE to derive the TA value.
As noted above, a UE and a network entity can utilize MIMO techniques, including downlink (DL) MIMO and UL MIMO. In some aspects involving MIMO and M-TRP, the UE and network entity can use multiple TA values in a “multiple TA” mode of operation. For instance, in the multiple TA mode, the UE can maintain two TA values in at least one serving cell (or component carrier (CC) ) . As an example, the multiple TA mode may be used in multiple-DCI (M-DCI) mode in a M-TRP scenario. In M-DCI mode, the UE and network entity may configure a set of resource blocks for transmitting control information. In some aspects, this set of resource blocks is a control resource set (CORESET) and can be configured or associated with a RRC parameter CORESETPoolIndex. However, in some deployments, the network entity might not provide explicit information from which the UE can derive a TA value or TAG to apply for an UL transmission in a multiple TA operation mode. For example, the network entity may not provide spatial relation information or joint/UL TCI state in control signaling. In some other cases, the network entity may fail to provide a reference signal that can be used to obtain spatial relation information or joint/UL TCI state. If the UE relies on such information to determine a TA value or TAG, the UE will be unable to determine an appropriate TA value or TAG. As another example, the network entity might not signal the joint/UL TCI state from which the UE would derive the TA value or TAG. As a further example, either the UE or the network entity may initiate beam failure recovery (BFR) operations in the event that a serving beam has failed. As an example, BFR operations may be performed when the quality of the serving beam is below a threshold. After a successful BFR, the UE may no longer have sufficient information to determine an appropriate TA value or TAG for UL transmission on the new beam.
This disclosure provides systems, methods, and apparatuses for timing adjustment of UL transmissions from a UE using a TA value or TAG that the UE determines. Using various techniques of this disclosure, a UE can derive a TA value or TAG for an UL transmission in cases where the network entity does not explicitly provide enough information to determine a TA value or TAG. These cases include operation after a beam failure recovery, operation following a failure of the network entity to provide spatial relation information, or when the UE is unable to follow or share a joint/UL TCI. In some aspects, the UE can utilize an index that identifies a set of control resource sets currently in use by the UE to determine a TA value or TAG. In some aspects, the UE can determine the TA value according to a fixed or predetermined value. In some aspects, the UE can determine a TA value or TAG based on an RRC signal, a MAC-CE signal, or DCI signal received from the network entity. In some aspects, the UE can utilize channel state information reference signal (CSI-RS) to determine a TA value or TAG. In some aspects, the UE may determine a TA value or TAG after a successful BFR. For example, the UE might revert to single TA operation or determine a TA using random access (RA) procedures.
Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. By maintaining synchronization of physical layer signals using multiple TA operation, the UE can reduce interference to other signals that share the radio frequency spectrum, including those from other UEs or network entities. The multiple TA operation enables the UE to maintain synchronization of the communication channel while also utilizing M-TRP and MIMO capabilities to improve communication, throughput, and signal coverage. Multiple TA operation can improve efficiency of the UL transmissions and reduce the occurrence of synchronization errors. A UE can communicate UL transmission with proper timing adjustments so that signals are received by the network entity at the proper time, improving reception and processing of the UL transmissions. A UE can determine a TA value or TAG to apply for an UL transmission under several scenarios where the UL beam indication is not clear for the UL transmission. The UE can determine the TA value or TAG using an explicit or implicit indication for the network entity, or a rule based method.
The discussion herein is provided in the general context of multiple TA operation in a M-TRP scenario that may include multiple DCI (M-DCI) M-TRP. However, the techniques and concepts discussed herein can be readily applied in other contexts, including LTE/NR/6G or other radio access technologies (RATs) .
Figure 1A is a conceptual diagram illustrating an example wireless communication system. In the example shown in Figure 1A, wireless communication system 100 includes a UE 102 that wirelessly communicates with a network entity 106 via TRPs 108-1 and 108-2 in an M-TRP mode of operation. In some aspects, the network entity 106 can be a base station. Different types of base stations might be referred to as a NodeB, an LTE evolved NodeB (eNB) , a next generation NodeB (gNB) , an access point, a radio head, a transmit/receive point (TRP) , among other examples, depending on the wireless communication standard that the base station supports. In some aspects, the functionality, and thus the hardware components, of the network entity 106 may be distributed across multiple network nodes or devices and may be distributed in a manner to perform the functions described herein. As one example, the functionality of network entity 106 may be distributed across a radio unit (RU) , distributed unit (DU) , or central unit (CU) . The network entity 106 can be configured to use MIMO communication in which multiple TRPs (such as TRP 108-1 and 108-2) associated with the network entity 106 are used to receive wireless communication signals from the UE 102.
As shown in Figure 1A, UE 102 is positioned closer to TRP 108-2 than it is to TRP 108-1 Wireless communications signals transmitted from UE 102 will take less time to travel to TRP 108-2 than signals transmitted from UE 102 to TRP 108-1. However, it is desirable for signals transmitted from UE 102 to network entity 106 via TRPs 108-1 and 108-2 to arrive at approximately the same time and synchronized with a time slot scheduled for communications between network entity 106 and UE 102. In some deployments, network entity 106 may communicate spatial relation information or a reference signal to UE 102 via TRPs 108-1 and 108-2. The UE 102 can use the spatial relation information or reference signal to derive a TA value for each of TRP 108-1 and 108-2. The TA value is a timing adjustment that the UE uses to adjust the output timing of signals from UE 102 so that the signals arrive at network entity 106 at approximately the same time and maintain physical layer synchronization.
In some implementations, the UE 102 can maintain a plurality of TA values for a serving cell. In some cases, the UE 102 can maintain a plurality of TA values, where all of the plurality of TA values are indicated or signaled. In some cases, the UE 102 can maintain a plurality of TA values, where all of the plurality of TA values are derived by the UE 102. In some cases, the UE 102 can maintain a plurality of TA values, where at least one of some TA values are indicated or signaled and at least one of the remaining TA values are derived by the UE.
In some implementations, the UE 102 can maintain a first TA value, which is among the plurality of TA values. In some cases, the UE 102 can maintain a second TA value, which is among the plurality of TA values. In some cases, the first TA value can be associated with a first TRP (such as one of TRPs 107-1, 107-2, 107-3, 108-1 or 108-2) . In some cases, the second TA value can be associated with a second TRP (such as a different one of TRPS 107-1, 107-2, 107-3, 108-1 or 108-2 from the TRP associate with the first TA value) .
The first TA value can:
· apply for or be associated with the first TRP or the first TRP identifier (value) , and/or
· apply for or be associated with UL channel/RS transmission transmitted to the first TRP, and/or
· apply for or be associated with UL channel/RS transmission related to the first TRP identifier (value) .
The second TA value can
· apply for or be associated with the second TRP or the second TRP identifier (value) , and/or
· apply for or be associated with UL channel/RS transmission transmitted to the second TRP, and/or
· apply for or be associated with UL channel/RS transmission related to the second TRP identifier (value) .
In some implementations, the network entity 104, 106 can configure an ID of the first TA value and indicate the ID to the UE 102. In some implementations, the UE 102 can derive the ID of the first TA value based on control signaling from the network entity 104, 106. In some implementations, the network entity 104, 106 can configure an ID of the second TA value and indicate the ID to the UE 102. In some implementations, the UE 102 can derive the ID of the second TA value. Thus, each TA value might be associated with its own ID.
In some implementations, the network entity 104, 106 can configure one or more TA group (s) . A TA group (TAG) can include or be associated with one or more serving cells (such as service cell indices) . Each serving cell included in or associated with the same TAG can use the one or more TA values for the TAG. Each TAG can include or be associated with one or more TA values. In some implementations, the network entity 104, 106 can configure the respective IDs for the one or more TA group (s) . In some implementations, the UE 102 can derive respective IDs for the one or more TA group (s) . Thus, each TAG can have its own ID.
In some implementations, the network entity 104, 106 can configure a first TAG (for example, TA1) and at least one TA value can be associated with the first TAG. In some cases, the first TAG can be among one or more TA group (s) . In some cases, the first TA value or the ID of the first TA value can be associated with the first TAG.
In some implementations, the network entity 104, 106 can configure a second TAG (for example, TA2) and at least one TA value can be associated with the second TAG. In some cases, the second TAG can be among the one or more TA group (s) . In some cases, the second TA value or the ID of the second TA value can be associated with the second TAG.
In some implementations, the first TA value and second TA value can be associated with the same TAG.
In some implementations, the first TAG can include one or more TA values, where the one or more TA values can:
· apply for, or be associated with, the first TRP or the first TRP identifier (value) , and/or
· apply for, or be associated with, an UL channel/RS transmission related to the first TRP or the first TRP identifier (value) .
In some implementations, the second TAG can include, or be associated with, one or more TA values, where the one or more TA values can:
· apply for or be associated with the second TRP or the second TRP identifier (value) , and/or
· apply for or be associated with UL channel/RS transmission related to the second TRP or the second TRP identifier (value) .
In the example shown in Figure 1A, the UE 102 uses a TA₁ value for signals transmitted to network entity 106 via at least TRP 108-1, and uses a TA₂ value for signals transmitted to network entity 106 via at least TRP 108-2. In this example, because UE 102 is closer to TRP 108-2 than it is to TRP 108-1, signals transmitted by UE 102 to TRP 108-2 take less time to arrive at TRP 108-2 than TRP 108-1. Therefore, in order to ensure that signals transmitted by UE 102 to TRPs 108-1 and 108-2 arrive at approximately the same time, UE 102 can delay transmission of signals to TRP 108-2 by using a TA₂ value that is larger than the TA₁ value. For example, UE 102 may set a TA₂ value that is larger than the TA₁ value by an amount needed to ensure nearly simultaneous arrival of signals from UE 102 to TRPs 108-1 and 108-2.
In some implementations, the network entity 106 can assist UE 102 in determining an appropriate TA₁ value and TA₂ value. For example, network entity 106 can provide spatial relation information in a message (such as an RRC message) transmitted to UE 102. The RRC messages that include spatial relation information regarding TRP 108-1 and TRP 108-2. In some aspects, network entity 106 can provide a reference signal from which UE 102 can derive spatial relation information. UE 102 can use the spatial relation information along with other information to determine an appropriate TA₁ value for TRP 108-1 and TA₂ value for TRP 108-2.
However, as noted above, there are cases were UE 102 may not be able to determine which TA value or TAG to apply for an UL transmission. As one example case, a UE may receive an RRC message from the network entity 106. The RRC can indicate scheduling an UL transmission. However, the RRC might not include spatial relation information. For example, a beam indication structure may omit or may not indicate a spatial relation indication or configuration. A further example case is a UL transmission without a joint/UL TCI indicated or configured. For instance, a beam indication structure may not indicate or configure a joint/UL TCI. A further example case is a UL transmission occurring after a beam failure recovery (BFR) procedure is completed or a BFR response is received from network entity 104, 106.
Figure 1B is a conceptual diagram illustrating an expanded view of the wireless communication system of Figure 1A. In the expanded view illustrated in Figure 1B, wireless communication system 100 includes UE 102 network entity 104. Like network entity 106, network entity 104 can be a base station. As noted above, different types of base stations might be referred to as a NodeB, an LTE evolved NodeB (eNB) , a next generation NodeB (gNB) , an access point, a radio head, a transmit/receive point (TRP) , among other examples, depending on the wireless communication standard that the base station supports. The network entity 104 is configured to use MIMO communication in which multiple TRPs associated with the network entity 104 are used to receive signals from the UE 102.
In some implementations, a TRP (such as TRP 107-1, TRP 107-2, TRP 107-3, TRP 108-1 and/or TRP 108-2) can be associated with, or identified by, a TRP identifier. In some implementations, a network entity (such as the network entity 104 or 106) includes or configures a TRP identifier in UL configuration (s) that the network entity transmits to a UE (such as the UE 102) for UL transmission (s) via a TRP identified by the TRP identifier. In some implementation, the UL configuration (s) include downlink control information (DCI) transmitted on a physical downlink control channel (PDCCH) , and/or physical uplink shared channel (PUSCH) configuration, physical uplink control channel (PUCCH) configuration and/or sounding reference signal (SRS) configuration included in a RRC message (such as RRC reconfiguration message or a RRC resume message) that the network entity transmits to the UE. In some implementations, the UL transmission (s) include PUSCH transmission (s) , PUCCH transmission (s) and/or SRS transmission (s) . In some implementations, the network entity includes a TRP identifier in DL configuration (s) that the network entity transmits to the UE 102 for DL transmission (s) via a TRP identified by the TRP identifier. In one implementation, the DL configuration (s) include DCI transmitted on a PDCCH, and/or channel state information (CSI) resource configuration, physical downlink shared channel (PDSCH) configuration (s) and/or physical downlink control channel (PDCCH) configuration (s) included in a RRC message (such as a RRC reconfiguration message or a RRC resume message) that the network entity transmits to the UE. In some implementations, the DL transmission (s) include CSI reference signal (CSI-RS) transmission (s) , synchronization signal block (SSB) transmission (s) , PDSCH transmission (s) and/or PDCCH transmission (s) .
In some implementations, the network entity does not transmit/configure a TRP identifier to the UE and uses an implicit indication indicating a TRP to the UE. In one implementation, the implicit indication can be one of the following 5G configuration parameters: a CORESETPoolIndex, a value (candidate) of a CORESETPoolIndex, dataScramblingIdentityPDSCH, dataScramblingIdentityPDSCH2-r16, or PUCCH-ResourceGroup-r16. In such implementations, the UE derives a TRP (identifier) from the implicit indication. In some implementations, the network entity transmits an RRC message (such as a RRC reconfiguration message or a RRC resume message) including the configuration parameters to the UE.
In some implementations, the network entity 104, 106 configures with, or indicates to, the UE 102 a first TRP identifier. In some implementations, the UE 102 derives a first TRP identifier (value) . In some implementations, the network entity configures with, or indicates to, the UE a second TRP identifier (value) . In some implementations, the UE derives a second TRP identifier (value) . In some implementations, the first TRP identifier can be associated with the first TRP. In some implementations, the second TRP identifier can be associated with the second TRP.
In some implementations, the network entity 104, 106 configures the UE 102 to indicate that a serving cell is associated with the first TRP or the first TRP identifier (value) . In some implementations, the network entity 104, 106 configures the UE 102 to indicate a first control resource set (CORESET) associated with the serving cell or first TRP. The network entity can configure CORESETPoolIndex #0 to identify the first CORESET. In one implementation, the network entity 104, 106 can transmit to the UE a RRC message (such as an RRC setup message, a RRC reconfiguration message or a RRC resume message) configuring the first CORESET and/or including the CORESETPoolIndex #0. The UE 102 can monitor a PDCCH on the first CORESET to receive DCIs from the network entity. For example, the UE 102 can monitor a PDCCH or receive DCIs via the first TRP from the network entity (for example, from the first TRP) . In such a case, the UE 102 determines that CORESETPoolIndex #0 indicates a TRP (for example, the first TRP) of the network entity.
In some implementations, the network entity 104, 106 configures the UE 102 to indicate the serving cell associated with the second TRP or the second TRP identifier (value) . In other implementations, the second TAG is associated with a non-serving cell, and the network entity indicates or configures the association in a second RRC message. In some implementations, the network entity configures the non-serving cell associated with the second TRP or the second TRP identifier (value) . In some implementations, the network entity configures the UE to indicate a second CORESET is associated with the serving cell, non-serving cell or second TRP. The network entity can configure CORESETPoolIndex #1 to identify the second CORESET. In some implementations, the network entity can transmit to the UE a RRC message (such as an RRC setup message, a RRC reconfiguration message or a RRC resume message) configuring the second CORESET and/or including the CORESETPoolIndex #1. Thus, the UE can monitor a PDCCH on the second CORESET to receive DCIs from the network entity. For example, the UE can monitor a PDCCH or receive DCIs via the second TRP from the network entity (for example, from the second TRP) . In such a case, the UE determines that CORESETPoolIndex #1 indicates a TRP (for example, the second TRP) .
As discussed above, in some aspects, network entity 104, 106 can configure UE 102 using RRC messages. In some implementations, the network entity 103, 104 can configure the UE 102 with one or more TCI state lists for a component carrier (CC) of a serving cell, where the CC can be PCell or SCell. For example, the network entity 104, 106 can configure the UE 102 with a joint TCI state list for a CC of a serving cell. For example, the network entity can configure a DL TCI state list and/or a UL TCI state list for a CC of a serving cell. One joint TCI state list can comprise one or more joint TCI states. One DL TCI state list can comprise one or more DL TCI states. One UL TCI state list can comprise one or more UL TCI states.
In some implementations, the network entity 104, 106 can configure the UE 102 with a RRC parameter unifiedTCI-StateType. The RRC parameter unifiedTCI-StateType can be a per-serving-cell configuration. The RRC parameter unifiedTCI-StateType can indicate which type of TCI state list (s) for a serving cell. For example, the RRC parameter unifiedTCI-StateType can indicate “joint” or “separate” . The RRC parameter unifiedTCI-StateType can provide one or more the following indications:
· If the first RRC parameter for a CC of serving cell indicates “joint” , the network entity can explicitly or implicitly configure the UE with one or more joint TCI state list (s) for the CC of serving cell or the UE ;
· If the first RRC parameter for a CC of serving cell indicates “separate” , the network entity can explicitly or implicitly configure the UE with one or more DL TCI state list (s) for the CC of serving cell;
· If the first RRC parameter for a CC of serving cell indicates “separate” , the network entity can explicitly or implicitly configure the UE with one or more UL TCI state list (s) for the CC of serving cell.
In some implementations, if the network entity explicitly configures the UE with one or more TCI state list (s) for a CC of a serving cell, it can imply that the network entity configures the one or more TCI state list (s) (explicitly) under RRC configuration (for example, ServingCellConfig) for a CC of the serving cell.
In some implementations, if the network entity implicitly configures the UE with one or more TCI state list (s) for a CC of serving cell, it can imply at least one of the following:
· the network entity configures the one or more TCI state list (s) under RRC configuration (for example, ServingCellConfig) for other serving cell (s) /CCs or a reference serving cell/CC;
· the UE refers the one or more TCI state list (s) for other serving cell (s) /CCs or a reference serving cell/CC;
· the UE determines that the one or more TCI state list (s) , which is for other serving cell/CCs or a reference serving cell/CC, is also for the CC of the serving cell.
In some aspects, a network entity 104, 106 can provide MAC-CE control signaling for TCI activation and configuration on the UE 102. In some implementations, the network entity 104, 106 can transmit a first MAC-CE to the UE 102 when or after the network entity 104, 106 configures the UE one or more TCI state list (s) for the CC of serving cell; and/or the when the UE 102 refers or determines one or more TCI state list (s) for the CC of serving cell.
In some implementations, the first MAC-CE can activate or indicate one or more TCI states from the one or more TCI state list (s) . The one or more TCI states activated/indicated by the first MAC-CE can map to one or more TCI codepoints in a TCI field. In some cases, the UE 102 can (directly) apply or use the one or more TCI states activated/indicated by the first MAC-CE for performing DL and/or UL transmission (subsequently) .
In some implementations, if the number of TCI states activated/indicated by the first MAC-CE is larger than one, those TCI states activated/indicated by the first MAC-CE can map to one or more TCI codepoints in a TCI field in downlink control information (DCI) . In some implementations, if the number of TCI states activated/indicated by the first MAC-CE is one, the UE 102 can apply or use the TCI state activated/indicated by the first MAC-CE for performing DL and/or UL transmission. In some implementations, if the number of TCI states activated/indicated by the first MAC-CE is two, and/or if the two TCI states activated/indicated by the first MAC-CE are associated with different TRP identifier or applicable for different TRP, the UE 102 can apply or use the two TCI states activated/indicated by the first MAC-CE for performing corresponding DL and/or UL transmission.
In some implementations, one TCI state can be mapped to one TCI codepoint, based on the first MAC-CE. In some cases, more than one TCI state can be mapped to one TCI codepoint, based on the first MAC-CE. In some cases, the TCI codepoint can indicate one or more of the following:
· one or more joint TCI states: one or more of the joint TCI states can be TCI states associated with the UL and/or DL for the first TRP, one or more other joint TCI states can be TCI states associated with UL and/or DL for the second TRP.
· one or more DL TCI states: one or more DL TCI states can be TCI states associated with the DL for the first TRP, one or more other DL TCI states can be TCI states associated with DL for the second TRP.
· one or more UL TCI states: one or more UL TCI states can be TCI states associated with the UL for the first TRP, one or more other UL TCI states can be TCI states associated with the UL for the second TRP.
· one or more DL TCI states and one or more UL TCI states: one or more TCI states can be TCI states associated with the UL for the first TRP, one or more other TCI states can be TCI states associated with the DL for the second TRP, or vice versa.
In some cases, the number of joint TCI states indicated in a TCI codepoint by the network entity 104, 106 can be up to four (4) . In some cases, the number of DL TCI states indicated in a TCI codepoint by the network entity can be up to four (4) . In some cases, the number of UL TCI states indicated in a TCI codepoint by the network entity can be up to four (4) .
As non-limiting examples, one or more of the following can be mapped to a TCI codepoint:
· one joint TCI state associated with the first TRP, one joint TCI state associated with the second TRP,
· one DL TCI state associated with the first TRP, one UL TCI state associated with the second TRP,
· one DL TCI state associated with the first TRP, one DL TCI state associated with the second TRP,
· one UL TCI state associated with the first TRP, one UL TCI state associated with the second TRP,
· one DL TCI state and one UL TCI state associated with the first TRP, one joint TCI state associated with the second TRP,
· one DL TCI state and one UL TCI state associated with the first TRP, one DL TCI state associated with the second TRP,
· one DL TCI state and one UL TCI state associated with the first TRP, one UL TCI state associated with the second TRP.
In some implementations, the network entity 104, 106 can transmit, and UE 102 can receive, a first DCI indicating one or more TCI states. The first DCI can indicate one or more TCI states by the TCI field in the first DCI. In response to receiving the first DCI, the UE 102 can transmit, to the network entity, a first acknowledgement signal via a PUCCH or PUSCH transmission. In response to transmitting the first acknowledgement signal, the UE 102 can apply or use the one or more TCI states activated/indicated by the first DCI for performing DL and/or UL transmission. In some cases, in response to transmitting the first acknowledgement signal, the UE 102 can apply or use the one or more TCI states activated/indicated by the first DCI for performing DL and/or UL transmission, after a first application time period. In some cases, the UE can apply or use the one or more TCI states activated/indicated by the first DCI for performing DL and/or UL transmission, starting from a first slot.
In some cases, the first slot can be the earliest slot that is at least the first application time period after the last symbol of the PUCCH or PUSCH transmission. In some cases, the earliest slot (for determining the first slot) and/or the first application time period can be determined based on the active bandwidth part (BWP) with the smallest subcarrier spacing (SCS) among the active BWP (s) of the carrier/serving cell (s) applying the one or more TCI states. In some cases, the first application time period can be in one of the following units: symbol, sub-slot, slot, sub-frame, frame, millisecond (ms) , or second. In some cases, the first application time period can be beamAppTime.
In other implementations, the UE 102 can receive the first MAC-CE indicating one or more TCI states. For example, the first MAC-CE might indicate one TCI state. For example, the first MAC-CE might indicate more than one TCI state, each of them can be associated with a different TRP or TRP identifier. For example, the first MAC-CE might indicate two TCI states, where one is associated with the first TRP (identifier) and the other is associated with the second TRP (identifier) . In such cases, the UE might not receive a DCI indicating one or more TCI states for applying for subsequent DL and/or UL transmission. In response to receiving the first MAC-CE, the UE 102 can transmit, to the network entity 104, 106, a second acknowledgement signal via a PUCCH or PUSCH transmission. In response to transmitting the second acknowledgement signal, the UE 102 can apply or use the one or more TCI states activated/indicated by the first MAC-CE for performing DL and/or UL transmission. In some cases, in response to transmitting the second acknowledgement signal, the UE 102 can apply or use the one or more TCI states activated/indicated by the first MAC-CE for performing DL and/or UL transmission, after a second application time period. In some cases, the UE can apply or use the one or more TCI states activated/indicated by the first MAC-CE for performing DL and/or UL transmission, starting from a second slot.
In some cases, the second slot can be the earliest slot that is at least the second application time period after the (last) slot of the PUCCH or PUSCH transmission. In some cases, the second application time period can beIn some cases, μ can be the SCS configuration for the PUCCH or PUSCH transmission; can be the subcarrier spacing configuration for k_max with a value of 0 for frequency range 1, and k_mac is provided by K-Mac or k_mac=0 if K-Mac is not provided.
In the example illustrated in Figure 1B, in addition to UE 102 and network entities 104, 106, wireless communication system 100 includes a core network (CN) 110. The network entities 104 and 106 can operate in a radio access network (RAN) 105 connected to the core network (CN) 110. The CN 110 can be implemented as an evolved packet core (EPC) 111 or a fifth generation (5G) core (5GC) 160, for example. The CN 110 can also be implemented as a sixth generation (6G) core in another example.
The network entity 104 can cover one or more cells (such as cells 124 and 125) with one or more transmit/receive points (TRPs) . Similarly, the network entity 106 can cover one or more cells (such as cell 126) with one or more TRPs. For example, the network entity 104 operates cell 124 with TRPs 107-1 and 107-2 and operates cell 125 with TRP 107-3. The network entity 106 operates cell 126 with TRPs 108-1 and 108-2. In some aspects, the cells 124 and 125 may be operated on the same carrier frequency or frequencies. In some aspects, the cell 126 can be operated on the same carrier frequency or frequencies as the cells 124 and 125. In some aspects, the cell 126 can be operated on different carrier frequency or frequencies from the cells 124 and 125. In some implementations, the network entity 104 connects each of the TRPs 107-1, 107-2 and 107-3 via a fiber connection or an Ethernet connection. If the network entity 104 is a gNB, the cells 124 and 125 can be 5G new radio (NR) cells. If the network entity 104 is an eNB, the cells 124 and 125 can be evolved universal terrestrial radio access (E-UTRA) cells. Similarly, if the network entity 106 is a gNB, the cell 126 can be an NR cell. If the network entity 106 is an (ng-) eNB, the cell 126 can be an E-UTRA cell. The cells 124, 125, and 126 can be in the same radio access network notification areas (RNAs) or different RNAs. In general, the RAN 105 can include any number of base stations, and each of the network entities can cover one, two, three, or any other suitable number of cells.
The UE 102 can support at least a 5G NR (or simply, “NR” ) or E-UTRA air interface to communicate with the network entity 104 via the TRP 107-1, TRP 107-2 and/or TRP-3. Similarly, the UE 102 can support at least a 5G NR (or simply, “NR” ) or E-UTRA air interface to communicate with the network entity 106 via the TRP 108-1 and/or TRP 108-2. Each of the network entities 104, 106 can connect to the CN 110 via an interface (such as an S1 or NG interface) . The network entities 104 and 106 also can be interconnected via an interface (such as an X2 or Xn interface) for interconnecting 5G next generation (NG) RAN nodes.
When a network entity 104, 106 transmits DL data via a TRP (such as the TRPs 107-1, TRP 107-2, TRP 107-3, TRP 108-1 or TRP 108-2) , the network entity 104 can generate a packet including the data transmit the packet to the TRP. For example, the packet can be a fronthaul transport protocol data unit. The TRP extracts the data from the packet and transmits the data. In some implementations, the network entity 104 can include control information for time-critical control and management information directly related to the data in the packet, and the TRP can transmit the data in accordance with the control information. In some implementations, the data includes in-phase and quadrature (IQ) data, a physical layer bit sequence, or a media access control (MAC) protocol data unit (PDU) . When the TRP receives data from a UE (such as UE 102) , the TRP generates a packet including the data and transmits the packet to the network entity 104, 106. In some implementations, the data includes IQ data, a physical layer bit sequence, or a MAC PDU.
Among other components, the EPC 111 of CN 110 can include a serving gateway (SGW) 112, a mobility management entity (MME) 114, and a packet data network gateway (PGW) 116. The SGW 112 in general is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., and the MME 114 is configured to manage authentication, registration, paging, and other management related functions. The PGW 116 provides connectivity from the UE 102 to one or more external packet data networks, for example, an Internet network and/or an Internet Protocol (IP) Multimedia Subsystem (IMS) network. The 5GC 160 includes a user plane function (UPF) 162, an access and mobility management function (AMF) 164, and/or session management function (SMF) 166. Generally, the UPF 162 is configured to transfer user-plane packets related to audio calls, video calls, Internet traffic, etc., the AMF 164 is configured to manage authentication, registration, paging, and other related functions, and the SMF 166 is configured to manage PDU sessions. AMF 164 may be a multicast/broadcast AMF (MB-AMF) . Similarly, SMF 166 may be a multicast/broadcast SMF (MB-SMF) .
As illustrated in Figure 1B, the network entity 104 supports cells 124 and 125, and the network entity 106 supports a cell 126. The cells 124, 125, and 126 can partially overlap, so that the UE 102 can select, reselect, or hand over from one of the cells 124, 125, and 126 to another cell. To directly exchange messages or information, the network entity 104 and network entity 106 can support an X2 or Xn interface. In general, the CN 110 can connect to any suitable number of network entities supporting cells (such as NR cells and/or E-UTRA cells) .
The network entity 104 is equipped with processing hardware 130 that can include one or more general-purpose processors (for example, CPUs) and a non-transitory computer-readable memory storing instructions that the one or more general-purpose processors execute. Additionally, or alternatively, the processing hardware 130 can include special-purpose processing units. The processing hardware 130 can include a TRP controller 132 configured to transmit data and control signals on physical DL channels and DL reference signals with one or more user devices (such as UE 102) via one or more TRPs (such as TRP 107-1, TRP 107-2 and/or TRP 107-3) . The TRP controller 132 is also configured to receive data and control signals on physical UL channels and/or UL reference signals with the one or more user devices via the one or more TRPs (such as TRP 107-1, TRP 107-2 and/or TRP 107-3) . The processing hardware 130 in an example implementation includes a MAC controller 134 configured to perform a random access (RA) procedure with one or more user devices, receive UL MAC PDUs from the one or more user devices, and transmit DL MAC PDUs to the one or more user devices. MAC controller 134 can include a TA controller 135 that manages UL timing advance for user devices (for example, UE 102) . The processing hardware 130 can further include an RRC controller 136 to implement procedures and messaging at the RRC sublayer of the protocol communication stack.
The network entity 106 can include processing hardware 140 that is similar to processing hardware 130. In particular, components 142, 144, 145, and 146 can be similar to the components 132, 134, 135, and 136, respectively.
The UE 102 is equipped with processing hardware 150 that can include one or more general-purpose processors such as CPUs and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and/or special-purpose processing units. The TRP controller 152 is also configured to receive data and control signals on physical DL channels and/or DL reference signals with the network entity 104 or 106 via one or more TRPs (such as TRP 107-1, TRP 107-2, TRP 107-3, TRP 108-1 and/or TRP 108-2) . The TRP controller 152 is also configured to transmit data and control signal on physical UL channels and/or UL reference signals with the network entity 104 or 106 via the one or more TRPs (such as TRP 107-1, TRP 107-2, TRP 107-3, TRP 108-1 and/or TRP 108-2) . The processing hardware 150 in an example implementation includes a MAC controller 154 configured to perform a random access procedure with network entity 104 or 106, transmit UL MAC PDUs to the network entity 104 or 106, and receive DL MAC PDUs from the network entity 104 or 106. MAC controller 154 can include a TA controller 155 that manages UL timing advance for UE 102. The processing hardware 150 can further include an RRC controller 156 to implement procedures and messaging at the RRC sublayer of the protocol communication stack.
Figure 1C depicts an example distributed or disaggregated implementation of one or both of the network entities 104, 106. In this implementation, each of the network entities 104 and/or 106 includes a central unit (CU) 172 and one or more distributed units (DUs) 174. The CU 172 includes processing hardware, such as one or more general-purpose processors (for example, CPUs) and a computer-readable memory storing machine-readable instructions executable on the general-purpose processor (s) , and/or special-purpose processing units. For example, the CU 172 can include a packet data convergence protocol (PDCP) controller (not shown in Figure 1C) , an RRC controller (such as RRC controller 136, 146 of Figure 1B) , and/or an RRC inactive controller (not shown in Figure 1C) . In some implementations, the CU 172 can include a radio link control (RLC) controller (not shown in Figure 1C) configured to manage or control one or more RLC operations or procedures. In other implementations, the CU 172 does not include an RLC controller.
Each of the DUs 174 also includes processing hardware that can include one or more general-purpose processors (for example, CPUs) and computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and/or special-purpose processing units. For example, the processing hardware can include a MAC controller (such as MAC controller 134, 144 of Figure 1B) configured to manage or control one or more MAC operations or procedures (for example, a random access procedure) , and/or an RLC controller configured to manage or control one or more RLC operations or procedures. The processing hardware can also include a physical layer controller configured to manage or control one or more physical layer operations or procedures.
In some implementations, the RAN 105 supports Integrated Access and Backhaul (IAB) functionality. In some implementations, the DU 174 operates as an (IAB) -node, and the CU 172 operates as an IAB-donor.
In some implementations, the CU 172 can include a logical node CU-control plane (CU-CP) 172A that hosts the control plane part of the PDCP protocol of the CU 172. The CU 172 can also include logical node (s) CU-user plane (CU-UP) 172B that hosts the user plane part of the PDCP protocol and/or service data adaptation protocol (SDAP) protocol of the CU 172. The CU-CP 172A can transmit control information (for example, RRC messages, F1 application protocol messages) , and the CU-UP 172B can transmit data packets (such as SDAP PDUs or IP packets) .
The CU-CP 172A can be connected to multiple CU-UPs 172B through an E1 interface. The CU-CP 172A selects the appropriate CU-UP 172B for the requested services for the UE 102. In some implementations, a single CU-UP 172B can be connected to multiple CU-CPs 172A through the E1 interface. If the CU-CP 172A and DU (s) 174 belong to a gNB, the CU-CP 172A can be connected to one or more DU 174 through an F1-C interface and/or an F1-U interface. If the CU-CP 172A and DU (s) 174 belong to an ng-eNB, the CU-CP 172A can be connected to DU (s) 174 through a W1-C interface and/or a W1-U interface. In some implementations, one DU 174 can be connected to multiple CU-UPs 172B under the control of the same CU-CP 172A. In such implementations, the connectivity between a CU-UP 172B and a DU 174 is established by the CU-CP 172A using bearer context management functions.
Figure 2A is a block diagram illustrating an example protocol stack according to which a UE can communicate with network entities. Figure 2A illustrates, in a simplified manner, an example protocol stack 200 according to which the UE 102 can communicate with a network entity (such as one or both of the network entities 104, 106) In the example shown in Figure 2A, network entities 104, 106 each may be an eNB/ng-eNB or a gNB.
In the example protocol stack 200, a physical layer (PHY) 202A of E-UTRA provides transport channels to the E-UTRA MAC sublayer 204A, which in turn provides logical channels to the E-UTRA RLC sublayer 206A. The E-UTRA RLC sublayer 206A in turn provides RLC channels to an E-UTRA PDCP sublayer 208 and, in some cases, to an NR PDCP sublayer 210. Similarly, the NR PHY 202B provides transport channels to the NR MAC sublayer 204B, which in turn provides logical channels to the NR RLC sublayer 206B. The NR RLC sublayer 206B in turn provides data transfer services to the NR PDCP sublayer 210. The NR PDCP sublayer 210 in turn can provide data transfer services to the SDAP sublayer 212 or an RRC sublayer (not shown in Figure 2A) . The UE 102, in some implementations, supports both the E-UTRA and the NR stack as shown in Figure 2A, to support handover between E-UTRA and NR network entities and/or to support dual connectivity (DC) over E-UTRA and NR interfaces. Further, as illustrated in Figure 2A, the UE 102 can support layering of NR PDCP 210 over E-UTRA RLC 206A, and SDAP sublayer 212 over the NR PDCP sublayer 210.
The E-UTRA PDCP sublayer 208 and the NR PDCP sublayer 210 receive packets (for example, from an IP layer, layered directly or indirectly over the PDCP layer 208 or 210) that can be referred to as service data units (SDUs) , and output packets (such as packets to the RLC layer 206A or 206B) that can be referred to as PDUs. Except where the difference between SDUs and PDUs is relevant, this disclosure for simplicity refers to both SDUs and PDUs as “packets. ”
On a control plane, the E-UTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide signaling radio bearers (SRBs) to the RRC sublayer (not shown in Figure 2A) to exchange RRC messages or non-access stratum (NAS) messages, for example. On a user plane, the E-UTRA PDCP sublayer 208 and the NR PDCP sublayer 210 can provide data radio bearers (DRBs) to support data exchange. Data exchanged on the NR PDCP sublayer 210 can be SDAP PDUs, IP packets, or Ethernet packets.
Figure 2B is a block diagram illustrating an example protocol stack according to which a UE can communicate with a DU and a CU of a distributed network entity. As shown in Figure 2B, it is possible to functionally split the radio protocol stack. The CU at one or both of the network entities 104, 106 can hold control and upper layer functionalities (such as RRC 214, SDAP 212, NR PDCP 210) , while the lower layer operations (such as NR RLC 206B, NR MAC 204B, and NR PHY 202B) can be delegated to the DU. To support connection to a 5GC, NR PDCP 210 provides SRBs to RRC 214, and NR PDCP 210 provides DRBs to SDAP 212 and SRBs to RRC 214.
Figures 3A-3D are sequence diagrams illustrating example communications between the UE 102 and the network entity 104 in example scenarios related to determining TA value or TAG applied for an UL transmission. In scenarios 300A to 300D of Figures 3A-3D, the network entity 104 can communicate with the UE 102 via TRP 107-1, 107-2 or 107-3. Similar communications sequences may take place between the UE 102 and network entity 106. Generally, events in Figures 3A-3D that can be the same are labeled with the same reference numbers.
Figure 3A is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA when spatial relation information is unavailable to the UE. In example scenario 300A of Figure 3A, at operation 310, the UE 102 can transmit or report UE capability (s) for supporting UL default beam and multiple TA (for example, 2TA) operation. In operation 320, the network entity 104 can transmit RRC configuration (s) for configuring an M-TRP mode of operation and multiple TA mode of operation. Optionally, at operation 330, the network entity 104 may transmit an RRC configuration for configuring one or more spatial relation (s) . At operation 340, the network entity 104 can transmit control signaling indicating scheduling information (such as an RRC configuration, MAC-CE configuration, or a downlink control information (DCI) ) for an UL transmission without providing a spatial relation. Additionally, or alternatively, UE 102 may not be configured with a source reference signal (RS) for deriving a spatial relation. Optionally, at operation 350, the UE 102 and/or the network entity 104 can determine or derive an UL default beam or spatial TX parameters for the UL transmission. As an example, the UE or network entity can determine a UL default beam using the UL beam of another UL channel. For example, UL default beam for a PUSCH can be the UL beam for transmitting a PUCCH, where the UL beam for transmitting the PUCCH could include information used by the UE to derive a TA parameter. At operation 360, the UE 102 can determine a TA value or a TAG to be applied for the UL transmission. Finally, at operation 370, the UE 102 can transmit the UL transmission with the TA value applied.
Figure 3B is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA when an UL channel/RS is not configured to share indicated joint/UL TCI. Example scenario 300B of Figure 3B is similar to the scenario 300A of Figure 3A. For example, operations 310, 320, 350, 360 and 370 are the same in both scenario 300A and scenario 300B. In scenario 300B, at operation 332, the network entity 104 can transmit RRC configuration information for configuring or indicating one or more joint/UL TCI state (s) . At operation 342, the network entity 104 can transmit scheduling information (such as an RRC configuration, MAC-CE configuration, or a DCI) for an UL transmission.
Figure 3C is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA after a beam failure recovery. Example scenario 300C of Figure 3C is similar to example scenario 300A of Figure 3A, with differences described below. For example, operations 310, 320, 330, 360 and 370 are the same in both scenario 300A and scenario 300C. In scenario 300C, at operation 322, the network entity 104 can transmit RRC configuration information for configuring beam failure recovery. At operation 342, the network entity 104 can transmit scheduling information (such as an RRC configuration, MAC-CE configuration, or a DCI) for an UL transmission. At operation 346, the UE 102 and/or the network entity 104 can perform a BFR procedure or a RA procedure for BFR. In some cases, the scheduling information of operation 340 can be transmitted after or during operation 346.
Figure 3D is a sequence diagram illustrating a communication flow between a UE and a network entity to establish a TA after a beam failure recovery and an UL channel/RS is not configured to share indicated joint/UL TCI. Example scenario 300D of Figure 3D is similar to example scenario 300C of Figure 3C, with differences described below. For example, operations 310, 320, 322, 330, 346, 350, 360 and 370 are the same in both example scenario 300C and example scenario 300D. In example scenario 300D, at operation 332, the network entity 104 can transmit RRC configuration information for configuring or indicating one or more joint/UL TCI state (s) . At operation 342, the network entity 104 can transmit scheduling information (such as an RRC configuration, MAC-CE configuration, or a DCI) for an UL transmission. In some cases, the scheduling information can be transmitted after or during operation 346.
Figure 4 is a flow chart illustrating operations of a method performed by a UE (for example, UE 102) for transmitting an uplink transmission in a multiple TA operation mode. At block 420, the UE receives, from a network entity, a configuration for a multiple TA operation mode. For example, the UE may receive one or more RRC configurations for configuring a multiple TA mode of operation.
At block 470, the UE transmits an UL transmission to a network entity using a TA parameter derived by the UE. Three scenarios where the UE derives a TA parameter and the techniques used in those scenarios will now be discussed below with reference to blocks 470A, 470B, and 470C.
Block 470A describes techniques for determining a TA or TAG to use for the transmission described at block 470 when an UL channel or RS is not configured/indicated with a spatial relation. In some aspects, the UE may not be configured/indicated with a spatial relation if the UE receives control signaling that lacks spatial relation information. In some aspects, the UE may not be configured/indicated with a spatial relation if the UE does not receive an RS from which the UE can derive spatial relation information.
In some implementations, the network entity can configure, to the UE, one or more spatial relations. In some cases, the one or more spatial relations can be configured in a serving cell or active bandwidth part (BWP) or UL active BWP. In some cases, the network entity can configure the one or more spatial relations for frequency range 2 (FR2) or when the UE is operating in FR2. In some cases, the network entity can also configure the one or more spatial relations for frequency range 1 (FR1) or when the UE is operating in FR1. The one or more spatial relations can include spatial relation (s) for PUCCH (for example, PUCCH-SpatialRelationInfo) and/or spatial relation (s) for SRS resource (for example, SRS-SpatialRelationInfo or SpatialRelationInfo-PDC) . The one or more spatial relations can also include one or more source RSs for deriving a UL beam or UL TX spatial parameters, such as a synchronization signal block (SSB) , CSI-RS or SRS.
In some implementations, the network entity can configure that a TAG or TAG ID is associated with or included in a spatial relation.
In some implementations, for a UL transmission with a spatial relation indicated or configured, the UE can determine which TA value to apply for transmitting the UL transmission based on the TAG or TAG ID associated with (or included in) the spatial relation.
However, as discussed above, a UL transmission may not have a spatial relation indicated or configured. Various techniques may be used to determine a TA value or TAG in such cases. As a first technique for a UL transmission at block 470 without a spatial relation indicated or configured, in some implementations, the UE can determine at block 470A which TA value or TAG to apply for transmitting the UL transmission based on a resource identifier. For example, the UE can determine a TA value or TAG based on a CORESETPoolIndex value of a CORESET with a PDCCH/DCI scheduling the UL transmission. In some examples, the UL transmission can be a PUSCH scheduled by a DCI format 0_0. If CORESETPoolIndex value of a CORESET with the DCI format 0_0 is index #0, the UE can apply the first TA value or the first TAG when transmitting the PUSCH. If CORESETPoolIndex value of a CORESET with the DCI format 0_0 is index #1, the UE can apply the second TA value or the second TAG when transmitting the PUSCH. The opposite case can also work. The DCI format 0_0 can be intended for a serving cell or UL BWP with PUCCH resource (s) , where at least one PUCCH resource is configured/indicated with spatial relation. Alternatively, the DCI format 0_0 can be intended for a serving cell or UL BWP without PUCCH resource (s) or without PUCCH resource (s) configured/indicated with spatial relation.
As a second technique for a UL transmission at block 470 without a spatial relation indicated or configured, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a fixed or pre-defined TAG or TA value. For example, in some aspects, the UE can transmit the UL transmission without a spatial relation indicated or configured by applying a first fixed TA value or a first fixed TAG. In some aspects, the UE can determine the TA parameter as a TA parameter associated with a TAG having an ID set to a fixed or predetermined value. Alternatively, the UE can transmit the UL transmission without a spatial relation indicated or configured by applying a second fixed TA value or a second fixed TAG.
As a third technique for a UL transmission at block 470 without a spatial relation indicated or configured, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a signal received from the network entity. The signal can be an RRC message, a MAC-CE or a DCI. In some cases, the signal can indicate to use the first TA value or the first TAG for such UL transmissions at block 470. In some other cases, the signal can indicate to use the second TA value or the second TAG for such UL transmissions at block 470.
As a fourth technique for a UL transmission at block 470 without a spatial relation indicated or configured, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a rule-based method. In some implementations, the UE can determine the TA value or the TAG based on the time and/or frequency resource location allocated/scheduled for the UL transmission. For example, the UE applies the first TA value or the TA for the first TAG if the index of a first symbol or first resource block (RB) of the UL transmission is odd; the UE applies the second TA value or the TA for the second TAG, otherwise. In some other implementations, the UE can determine the TA value or the TAG based on the time and/or frequency location of the PDCCH scheduling the UL transmission. For example, the UE applies the first TA value or the TA for the first TAG if the index of first symbol or first control channel element (CCE) of the PDCCH is odd; the UE applies the second TA value or the TA for the second TAG, otherwise.
As a fifth technique for a UL transmission at block 470 without a spatial relation indicated or configured, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a DL RS associated with the UL transmission. For example, the UL transmission can be an SRS for non-codebook based (NCB) UL. In some cases, the network entity can configure a CSI-RS to be associated with the SRS for NCB UL. The UE can determine which TA value or TAG to apply based on the CSI-RS.
If the CSI-RS is an aperiodic CSI-RS (AP CSI-RS) for a group-based beam report, it can be based on whether the CSI-RS is from resourcesForChannel or resourcesForChannel2. If resourcesForChannel, the UE can apply the first TA value or the first TAG when transmitting the SRS for NCB UL. If resourcesForChannel2, the UE can apply the second TA value or the second TAG when transmitting the SRS for NCB UL. The opposite case can also work.
If the CSI-RS is periodic or semi-persistent CSI-RS for group-based beam report, it can be based on whether the CSI-RS is from a CSI resource set with lower ID. If from a CSI resource set with lower ID, the UE can apply the first TA value or the first TAG when transmitting the SRS for NCB UL. Otherwise, the UE can apply the second TA value or the second TAG when transmitting the SRS for NCB UL.
In addition to, or instead of, the above described techniques, other techniques for deriving a TA for a UL transmission at block 470 without a spatial relation indicated or configured can be used. In some other implementations, the UE can determine the TA value or TAG for the UL transmission based on the downlink pathloss reference signal of the UL transmission, such as an SSB or CSI-RS, for uplink power control.
In such implementations, the UE receives the configuration of associated CORESET pool index, for example, CORESETPoolIndex, for the SSB or CSI-RS via RRC signaling, MAC-CE, or DCI. In some other implementations, the UE determines the associated CORESET pool index, for example, CORESETPoolIndex, for the CSI-RS, such as aperiodic CSI-RS, based on the scheduling PDCCH. The UE applies the TA value corresponding to one of the uplink signals in the same serving cell or bandwidth part or in another serving cell within the same band or band combination associated with the CORESETPoolIndex, such as a PUCCH resource or an SRS resource configured for other usage, such as codebook or antenna switching.
In some other implementations, the UE determines the TA value or TAG for the SRS based on the SRS resource set index. In one example, the UE applies the TA value for the first TAG for SRS resources in the first SRS resource set and the UE applies the TA value for the second TAG for SRS resources in the second SRS resource set. The network entity may refrain from configuring UL spatial relation or TCI state corresponding to different TAGs for SRS resources within a SRS resource set. The first SRS resource set can be an SRS resource set with lower resource set ID; the second SRS resource set can be an SRS resource set with higher resource set ID. The first and the second SRS resource set can be used or configured for PUSCH repetitions.
In some other implementations, the UE determines the TA value or TAG for the UL transmission based on the TAG associated with the first configured uplink spatial relation for PUCCH (such as PUCCH with the lowest resource ID) or the configured uplink spatial relation associated with the first SRS resource (such as an SRS with the lowest resource ID) .
In some implementations, a UL transmission without a spatial relation indicated or configured includes, but is not limited to, one or more of the following:
· A PUSCH scheduled by a DCI format 0_0, where the DCI format 0_0 is intended for or received from a serving cell or UL BWP with PUCCH resource (s) , in which at least one PUCCH resource is configured/indicated with spatial relation.
· A PUSCH scheduled by a DCI format 0_0, where the DCI format 0_0 is intended for or received from a serving cell or UL BWP without PUCCH resource (s) or without PUSCH resource (s) configured/indicated with spatial relation.
· A PUSCH scheduled by a DCI format 0_1 or 0_2 without SRS resource indicator (SRI) field.
· A PUSCH scheduled by random access response (RAR) or RAR grant.
· A PUSCH for MSGA transmission in 2-step random access procedure.
· A PUCCH without spatial relation configured/indicated.
· An SRS for codebook-based (CB) UL without spatial relation configured/indicated.
· An SRS for NCB UL without spatial relation configured/indicated.
· An SRS for beam management (BM) without spatial relation configured/indicated.
· An SRS for antenna switching without spatial relation configured/indicated.
· An SRS for positioning without spatial relation configured/indicated.
· A physical random access channel (PRACH) for a contention based random access procedure.
· A PRACH for a contention free random access procedure.
Block 470B describes techniques for determining a TA or TAG to use for the transmission described at block 470 when a UL channel or RS is not configured to share indicated joint/UL TCI (joint TCI or UL TCI) .
In some implementations, the network entity can configure, to the UE, one or more joint/UL TCI states. In some cases, the one or more joint/UL TCI states can be configured in a serving cell, active BWP, UL active BWP, or DL active BWP.
In some implementations, the network entity can configure that a TAG or TAG ID is associated with, or included in, a joint/UL TCI state.
In some implementations, for a UL transmission being able to share/follow indicated joint/UL TCI state, the UE can determine which TA value to apply for transmitting the UL transmission based on the TAG or TAG ID associated with (or included in) the indicated joint/UL TCI state applied for the UL transmission.
In some implementations, whether a UL transmission is able to share and/or follow indicated joint/UL TCI state can be configured by the network entity.
However, as discussed above, a UL transmission may be unable to or may not share and/or follow indicated joint/UL TCI state. In such cases, the transmission parameters of the joint/UL TCI are not applied for the UL transmission. In some implementations, whether a UL transmission is unable to or does not share and/or follow an indicated joint/UL TCI state can be configured by the network entity. For example, for some UL channels or RSs (e.g., SRS) , an RRC configuration indicates whether the UL channel can follow or share the indicated TCI state from a TCI field in DCI.
As a first technique for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on CORESETPoolIndex value of a CORESET with a PDCCH/DCI scheduling the UL transmission. If a CORESETPoolIndex value of a CORESET with the PDCCH/DCI scheduling the UL transmission is index #0, the UE can apply the first TA value or the first TAG when transmitting the UL transmission. If a CORESETPoolIndex value of a CORESET with the PDCCH/DCI scheduling the UL transmission is index #1, the UE can apply the second TA value or the second TAG when transmitting the UL transmission. The opposite case can also work.
As a second technique for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a fixed or pre-defined TAG or TA value. For example, the UE can transmit the UL transmission of block 470 by applying a first fixed TA value or a first fixed TAG. Alternatively, the UE can transmit the UL transmission of block 470 by applying a second fixed TA value or a second fixed TAG.
As a third technique for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission based on a signal received from the network entity. The signal can be an RRC message, a MAC-CE or a DCI. In some cases, the signal can instruct the UE to use the first TA value or the first TAG for the UL transmission of block 470. In some other cases, the signal can indicate to use the second TA value or the second TAG for the UL transmission of block 470.
As a fourth technique for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission of block 470 using a rule-based method. In some implementations, the UE can determine the TA value or the TAG based on the time and/or frequency resource location allocated/scheduled for the UL transmission. For example, the UE applies the first TA value or the TA for the first TAG if the index of first symbol or first RB of the UL transmission is odd; the UE applies the second TA value or the TA for the second TAG, otherwise. In some other implementations, the UE can determine the TA value or the TAG based on the time and/or frequency location of the PDCCH scheduling the UL transmission. For example, the UE applies the first TA value or the TA for the first TAG if the index of first symbol or first control channel element (CCE) of the PDCCH is odd; the UE applies the second TA value or the TA for the second TAG, otherwise.
As a fifth technique for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state, in some implementations, the UE can determine which TA value or TAG to apply for transmitting the UL transmission of block 470 based on a DL RS associated with the UL transmission. For example, the UL transmission can be an SRS for non-codebook based (NCB) UL. In some cases, the network entity can configure a CSI-RS to be associated with the SRS for NCB UL. The UE can determine which TA value or TAG to apply based on the CSI-RS.
If the CSI-RS is an AP CSI-RS for a group-based beam report, it can be based on whether the CSI-RS is from resourcesForChannel or resourcesForChannel2. If resourcesForChannel, the UE can apply the first TA value or the first TAG when transmitting the SRS for NCB UL. If resourcesForChannel2, the UE can apply the second TA value or the second TAG when transmitting the SRS for NCB UL. The opposite case can also work.
If the CSI-RS is periodic or semi-persistent CSI-RS for group-based beam report, it can be based on whether the CSI-RS is from a CSI resource set with lower ID. If from a CSI resource set with lower ID, the UE can apply the first TA value or the first TAG when transmitting the SRS for NCB UL. Otherwise, the UE can apply the second TA value or the second TAG when transmitting the SRS for NCB UL.
In addition to, or instead of, the above described techniques, other techniques for derive a TA for a UL transmission at block 470 when a UL transmission is unable to share and/or follow indicated joint/UL TCI state. In some other implementations, the UE can determine the TA value or TAG for the UL transmission based on the downlink pathloss reference signal of the UL transmission, such as an SSB or CSI-RS, for uplink power control.
In such implementations, the UE receives the configuration of associated CORESET pool index, for example, CORESETPoolIndex, for the SSB or CSI-RS via RRC signaling, MAC-CE, or DCI. In some other implementations, the UE determines the associated CORESET pool index, for example, CORESETPoolIndex, for the CSI-RS, such as aperiodic CSI-RS, based on the scheduling PDCCH. The UE applies the TA value corresponding to one of the uplink signals in the same serving cell or bandwidth part or in another serving cell within the same band or band combination associated with the CORESETPoolIndex, such as a PUCCH resource or an SRS resource configured for other usage, such as codebook or antenna switching.
In some implementations, the UE can determine the TA value or TAG for the SRS based on the SRS resource set index. In one example, the UE applies the TA value for the first TAG for SRS resources in the first SRS resource set and the UE applies the TA value for the second TAG for SRS resources in the second SRS resource set. The network entity may refrain from configuring UL spatial relation or TCI state corresponding to different TAGs for SRS resources within a SRS resource set. The first SRS resource set can be an SRS resource set with lower resource set ID; the second SRS resource set can be a SRS resource set with higher resource set ID. The first and the second SRS resource set can be used or configured for PUSCH repetitions.
In some implementations, the UE determines the TA value or TAG for the UL transmission based on the TAG associated with the first configured uplink spatial relation for PUCCH (such as PUCCH with the lowest resource ID) or the configured uplink spatial relation associated with the first SRS resource (such as an SRS with the lowest resource ID) .
In some implementations, a UL transmission being unable to share/follow indicated joint/UL TCI state includes, but is not limited to, one or more of the following:
· A PUSCH scheduled by a DCI format 0_0,
· A PUCCH.
· A PUSCH scheduled by a DCI format 0_1 or 0_2 without SRI field.
· A PUSCH scheduled by random access response (RAR) or RAR grant.
· A PUSCH for MSGA transmission in 2-step random access procedure.
· An SRS for CB UL without spatial relation configured/indicated.
· An SRS for NCB UL without spatial relation configured/indicated.
· An SRS for BM without spatial relation configured/indicated.
· A SRS for antenna switching without spatial relation configured/indicated.
· An SRS for positioning without spatial relation configured/indicated.
· A PRACH for a contention based random access procedure.
· A PRACH for a contention free random access procedure.
Block 470C describes techniques for determining a TA value or TAG to use for the transmission described at block 470 following beam failure recovery (BFR) . In some implementations, the network entity can configure, to the UE, RRC configuration (s) for BFR in a serving cell. The RRC configuration (s) for BFR can include cell-specific BFR and/or per-TRP BFR.
In some implementations, for cell-specific BFR, the UE can transmit a BFR request (BFRQ) , which can be a PRACH or PUCCH or a MAC-CE, to inform the network entity beam failure occurs. After the UE transmits the BFRQ, the UE can receive a BFR response. If the BFRQ is a PRACH, the BFR response can be a DCI scrambled by a radio network technology identifier (RNTI) such as a cell RNTI (C-RNTI) or modulation and coding scheme C-RNTI (MCS-C-RNTI) received on a search space (SS) with SS ID provided by recoverySearchSpaceId. If the BFRQ is a PRACH, the BFR response can also be a MSG4. If the BFRQ is a MAC-CE, the BFR response can be a UL grant with the same hybrid automatic repeat request (HARQ) process number as a PUSCH carrying the MAC-CE and having a toggled new data indicator (NDI) field value.
In some implementations, for cell-specific BFR for a special cell (SpCell) , after the UE receives the BFR response corresponding to a BFRQ as being a PRACH, the UE can perform at least one of the following:
· monitors PDCCH in all CORESETs, receives PDSCH and receives aperiodic CSI-RS resource in a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH, using the same antenna port quasi co-location parameters as the ones associated with a DL RS for transmitting the BFRQ, if any.
· transmits PUSCH, PUCCH and SRS that use the same spatial domain filter with same indicated TCI state as for the PUSCH and the PUCCH, using a same spatial domain filter as for the last PRACH transmission of BFRQ.
In some implementations, for cell-specific BFR for SCell, after the UE receives the BFR response corresponding to a BFRQ as being a MAC-CE (for example, BFR MAC-CE) , the UE can perform at least one of the following:
· monitor PDCCH in all CORESETs, receives PDSCH and receives aperiodic CSI-RS resource in a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH, using the same antenna port quasi co-location parameters as the ones associated with a DL RS indicated in the MAC-CE, if any
· transmit PUSCH, PUCCH and SRS that use the same spatial domain filter with same indicated TCI state as for the PUSCH and the PUCCH, using a same spatial domain filter for receiving the DL RS.
As a first technique for determining a TA for a UL transmission at block 470 following BFR, in some implementations, for cell-specific BFR, after the UE receives the BFR response, the UE can fallback from multiple TA (for example, 2TA) operation to single TA operation. For example, the UE can discard one of the first and the second TA value or TAG. The UE may not maintain one of the first and the second TAG until the UE receives MAC-CE or DCI for TCI indication, such as a TCI indication with more than one indicated joint/UL TCI states. In such implementations, the UE can use the first TA value or the first TAG for UL transmission (s) after receiving the BFR response. In such implementations, alternatively, the UE can use the second TA value or the second TAG for UL transmission (s) after receiving the BFR response. In such implementations, alternatively, the UE can use the TA value indicated in MSG2 or RAR for UL transmission (s) after receiving the BFR response, if the cell-specific BFR is for SpCell and is performed by a contention-based random access (CBRA) procedure. In some implementations, for SpCell BFR, the UE can apply the same TA value as the PRACH and the UE may update the TA value for the first and/or second TAG based on the TA value applied for the PRACH. In some other implementations, the network entity can configure the associated TAG for each candidate beam detection (CBD) RS. Then the UE applies the associated TAG for the UL channel/RS based on the CBD RS reported in the MAC-CE.
In some implementations, for per-TRP BFR, the UE can transmit a BFR request (BFRQ) , which can be a PUCCH or a MAC-CE, to inform the network entity beam failure of a TRP occurs or beam failure associated with a failure detection set occurs. After the UE transmits the BFRQ, the UE can receive a BFR response. The BFR response can be a UL grant with the same HARQ process number as a PUSCH carrying the MAC-CE and having a toggled NDI field value.
In some implementations, for per-TRP BFR, after the UE receives the BFR response corresponding to a BFRQ as being a MAC-CE (for example, BFR MAC-CE) , the UE can perform at least one of the following:
· monitor DL transmission (s) associated with the first TRP identifier, using the same antenna port quasi co-location parameters as the ones associated with a DL RS conveyed in the MAC-CE indicating failureDetectionSet1, if any. The DL transmission (s) can refer to PDCCH in all CORESETs, and PDSCH and aperiodic CSI-RS resource in a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH.
· monitor DL transmission (s) associated with the second TRP identifier, using the same antenna port quasi co-location parameters as the ones associated with a DL RS conveyed in the MAC-CE indicating failureDetectionSet2, if any. The DL transmission (s) can refer to PDCCH in all CORESETs, and PDSCH and aperiodic CSI-RS resource in a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH.
· transmit a first set of UL channel/RS, using a same spatial domain filter for receiving the DL RS conveyed in the MAC-CE indicating failureDetectionSet1. The first set of UL channel/RS can include UL channel/RS with indicated joint/UL TCI states associated with the first TRP identifier before performing the per-TRP BFR. The first set of UL channel/RS can include PUSCH, PUCCH and SRS that use the same spatial domain filter with same indicated TCI state as for the PUSCH and the PUCCH.
· transmit a second set of UL channel/RS, using a same spatial domain filter for receiving the DL RS conveyed in the MAC-CE indicating failureDetectionSet2. The second set of UL channel/RS can include UL channel/RS with indicated joint/UL TCI states associated with the second TRP identifier before performing the per-TRP BFR. The second set of UL channel/RS can include PUSCH, PUCCH and SRS that uses a same spatial domain filter with same indicated TCI state as for the PUSCH and the PUCCH.
As a second technique for a UL transmission at block 470 following BFR, in some implementations, for per-TRP BFR, after the UE receives the BFR response corresponding to a MAC-CE indicating failureDetectionSet1, the UE can apply the first TA value or the first TAG for transmitting the first set of UL channel/RS.
In some implementations, for per-TRP BFR, after the UE receives the BFR response corresponding to a MAC-CE indicating failureDetectionSet2, the UE can apply the second TA value or the second TAG for transmitting the second set of UL channel/RS.
In some other implementations, for per-TRP BFR, the UE receives the configuration of associated TAG for the first set and/or second set of UL channel/RS respectively based on the BFR response or a separate signaling, for example, MAC-CE. In one example, the configuration may indicate whether the UE continues using two TAGs or disabling one of the TAGs. In another example, the configuration may indicate the associated TAG for the UL channel/RS corresponding to the failure detection set.
In some other implementations, for per-TRP BFR, the network entity can configure the associated TAG for each CBD RS. Then the UE applies the associated TAG for the UL channel/RS corresponding to the failure detection set based on the CBD RS reported in the separate signaling.
For cell-specific BFR or per-TRP BFR, the UE can also apply techniques mentioned in with respect to blocks 470A and 470B for determining TA value or TAG after receiving BFR response or after BFR procedure is successfully completed. For example, the TA value or TAG can be based on CORESETPoolIndex of CORESET with scheduling PDCCH/DCI, or a fixed/pre-defined TAG, or a signal received from the network entity, or a rule-based method, or associated NZP CSI-RS, or DL pathloss RS, or SRS resource set, or PUCCH/SRS with lowest resource ID.
Figure 5 shows a block diagram of an example device that supports determination of a TA value according to some aspects of this disclosure. In some implementations, the device 500 can be an example of a device for use in a UE, such as the UE 102 described above with reference to Figures 1A-1C, 2A, 2B, 3A-3D, and 4. The device 500 is capable of transmitting (or outputting for transmission) and receiving wireless communications. In some implementations, the device 500 is an example of a network entity 104, 106.
The device 500 can be, or can include, a chip, system on chip (SoC) , chipset, package or device. The term “system-on-chip” (SoC) is used herein to refer to a set of interconnected electronic circuits typically, but not exclusively, including one or more processors, a memory, and a communication interface. The SoC might include a variety of different types of processors and processor cores, such as a general purpose processor, a central processing unit (CPU) , a digital signal processor (DSP) , a graphics processing unit (GPU) , an accelerated processing unit (APU) , a sub-system processor, an auxiliary processor, a single-core processor, and a multicore processor. The SoC might further include other hardware and hardware combinations, such as a field programmable gate array (FPGA) , a configuration and status register (CSR) , an application-specific integrated circuit (ASIC) , other programmable logic device, discrete gate logic, transistor logic, registers, performance monitoring hardware, watchdog hardware, counters, and time references. SoCs might be integrated circuits (ICs) configured such that the components of the IC reside on the same substrate, such as a single piece of semiconductor material (such as, for example, silicon) .
The term “system in a package” (SIP) is used herein to refer to a single module or package that might contain multiple resources, computational units, cores or processors on two or more IC chips, substrates, or SoCs. For example, a SIP might include a single substrate on which multiple IC chips or semiconductor dies are stacked in a vertical configuration. Similarly, the SIP might include one or more multi-chip modules (MCMs) on which multiple ICs or semiconductor dies are packaged into a unifying substrate. A SIP also might include multiple independent SoCs coupled together via high speed communication circuitry and packaged in close proximity, such as on a single motherboard or in a single mobile communication device. The proximity of the SoCs facilitates high speed communications and the sharing of memory and resources.
The term “multicore processor” is used herein to refer to a single IC chip or chip package that contains two or more independent processing cores (for example a CPU core, IP core, GPU core, among other examples) configured to read and execute program instructions. An SoC might include multiple multicore processors, and each processor in an SoC might be referred to as a core. The term “multiprocessor” may be used herein to refer to a system or device that includes two or more processing units configured to read and execute program instructions.
The device 500 might include one or more modems 502. In some implementations, the one or more modems 502 (collectively “the modem 502” ) might include a wireless wide area network (WWAN) modem (for example, a 3GPP 4G LTE or 5G compliant modem) . In some implementations, the device 500 also includes one or more radios (collectively “the radio 504” ) . In some implementations, the device 500 further includes one or more processors, processing blocks or processing elements (collectively “the processing system 506” ) and one or more memory blocks or elements (collectively “the memory 508” ) . In some implementations, the processing system 506 can include the memory 508.
The modem 502 can include an intelligent hardware block or device such as, for example, an application-specific integrated circuit (ASIC) among other possibilities. The modem 502 is generally configured to implement a PHY layer. For example, the modem 502 is configured to modulate packets and to output the modulated packets to the radio 504 for transmission over the wireless medium. The modem 502 is similarly configured to obtain modulated packets received by the radio 504 and to demodulate the packets to provide demodulated packets. In addition to a modulator and a demodulator, the modem 502 might further include digital signal processing (DSP) circuitry, automatic gain control (AGC) , a coder, a decoder, a multiplexer and a demultiplexer. For example, while in a transmission mode, data obtained from the processing system 506 is provided to a coder, which encodes the data to provide encoded bits. The encoded bits are mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols might be mapped to a number of spatial streams (NSS) or a number of space-time streams (NSTS) . The modulated symbols in the respective spatial or space- time streams might be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and subsequently provided to the DSP circuitry for Tx windowing and filtering. The digital signals might be provided to a digital-to-analog converter (DAC) . The resultant analog signals might be provided to a frequency upconverter, and ultimately, the radio 504. In implementations involving beamforming, the modulated symbols in the respective spatial streams are precoded via a steering matrix prior to their provision to the IFFT block.
While in a reception mode, digital signals received from the radio 504 are provided to the DSP circuitry, which is configured to acquire a received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offsets. The DSP circuitry is further configured to digitally condition the digital signals, for example, using channel (narrowband) filtering, analog impairment conditioning (such as correcting for IQ imbalance) , and applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuitry might be fed to the AGC, which is configured to use information extracted from the digital signals, for example, in one or more received training fields, to determine an appropriate gain. The output of the DSP circuitry also is coupled with the demodulator, which is configured to extract modulated symbols from the signal and, for example, compute the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled with the decoder, which might be configured to process the LLRs to provide decoded bits. The decoded bits from all of the spatial streams are fed to the demultiplexer for demultiplexing. The demultiplexed bits might be descrambled and provided to the MAC layer (the processing system 506) for processing, evaluation, or interpretation.
The radio 504 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain” ) and at least one RF receiver (or “receiver chain” ) , which might be combined into one or more transceivers. For example, the RF transmitters and receivers might include various DSP circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA) , respectively. The RF transmitters and receivers might, in turn, be coupled to one or more antennas. For example, in some implementations, the device 500 can include, or be coupled with, multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain) . The symbols output from the modem 502 are provided to the radio 504, which transmits the symbols via the coupled antennas. Similarly, symbols received via the antennas are obtained by the radio 504, which provides the symbols to the modem 502.
The processing system 506 can include an intelligent hardware block or device such as, for example, a processing core, a processing block, a central processing unit (CPU) , a microprocessor, a microcontroller, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a programmable logic device (PLD) such as a field programmable gate array (FPGA) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processing system 506 processes information received through the radio 504 and the modem 502, and processes information to be output through the modem 502 and the radio 504 for transmission through the wireless medium. In some implementations, the processing system 506 might generally control the modem 502 to cause the modem to perform various operations described herein. For example, the processing system 506, in conjunction with the modem 502, may implement any of the features described with reference to Figures 1A-1C, 2A, 2B, 3A-3D, and 4.
The memory 508 can include tangible storage media such as random-access memory (RAM) or read-only memory (ROM) , or combinations thereof. The memory 508 also can store non-transitory processor-or computer-executable software (SW) code containing instructions that, when executed by the processing system 506, cause the processor to perform various operations described herein for wireless communication, including the generation, transmission, reception and interpretation of MAC PDUs (MPDUs) , frames or packets. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein, can be implemented as one or more modules of one or more computer programs.
It is noted that throughout this disclosure, the UE may have one or more of the following attributes or behaviors. The following attributes or behaviors of the UE may also imply associated attributes or behaviors of a network entity:
· The UE may be configured with and/or served by the network entity in a serving cell.
· The UE may (be configured to) communicate with the network entity in the serving cell.
· The UE may be configured with one or more serving cells by the network entity, which may include the serving cell.
· The UE may be activated or be indicated, by the network entity, to activate one or more serving cells, which may include the serving cell.
· The UE may be configured and/or indicated, by the network entity, with one or more BWPs. The UE may be indicated and/or configured, by the network entity, with a BWP (in the serving cell) . In some cases, the BWP may be activated as an active BWP.
· In some cases, the BWP may be referred to an active BWP
· In some cases, the BWP may be an active DL BWP.
· In some cases, the BWP may be an active UL BWP.
· In some cases, the BWP may be an initial BWP.
· In some cases, the BWP may be a default BWP.
· In some cases, the BWP may be a dormant BWP.
· The UE may be in one of RRC_CONNECTED state, RRC_INACTIVE state or RRC_IDLE state.
It is noted that throughout this disclosure, a neighboring cell can be referred to or replaced with one or more of the following:
· Non-serving cell,
· A cell with physical cell identifier (PCI) different that of the serving cell, or
· A TRP associated with a PCI that is different from that of the serving cell.
It is noted that throughout this disclosure, the action time of a signal can mean the actual timing when the signal is applicable or takes effect, which can be later than the timing of receiving the signal.
It is noted that throughout this disclosure, for case (s) that a network entity configures or indicates the UE to operate with single TRP (S-TRP) mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with S-TRP mode, it can imply or be referred to be one or more of the following:
· No TRP identifier or no TRP-related index is configured or indicated, by the network entity, to any channel or RS in the serving cell or BWP, and/or
· (only) One TRP identifier or TRP-related index is configured or indicated, by the network entity, to any channel or RS in the serving cell or BWP, and/or
· When the UE or the network entity transmits/receives a transmission, (only) one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam/TCI state applied for the transmission.
It is noted that throughout this disclosure, for case (s) that a network entity configures or indicates the UE to operate with M-TRP mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with M-TRP mode, it can imply or be referred to be one or more of the following:
· More than one TRP identifier or TRP-related index is configured or indicated, by the network entity, to at least one channel or RS in the serving cell or BWP, and/or
· One TRP identifier or TRP-related index is configured or indicated, by the network entity, to one channel or RS in the serving cell or BWP; and the UE derives or determines another one TRP identifier or TRP-related index applied for or associated with at least one channel or RS in the serving cell or BWP, and/or
· When the UE or the network entity transmits/receives a transmission, more than one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam/TCI state applied for the transmission, and/or
· The network entity configures, to the UE, a higher layer parameter PDCCH-Config that contains two different values of coresetPoolIndex in ControlResourceSet in the serving cell or BWP, and/or
· The UE receives, from the network entity, a MAC-CE (such as PDSCH TCI activation MAC-CE) in the serving cell or BWP, which indicates that at least one TCI codepoint is mapped to two TCI states.
It is noted that throughout this disclosure, for case (s) that a network entity configures or indicates the UE to operate with (M-TRP) M-DCI mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with (M-TRP) M-DCI mode, it can imply or be referred to be one or more of the following:
· More than one TRP identifier or TRP-related index is configured or indicated, by the network entity, to at least one channel or RS in the serving cell or BWP, and/or
· One TRP identifier or TRP-related index is configured or indicated, by the network entity, to one channel or RS in the serving cell or BWP; and the UE derives or determines another one TRP identifier or TRP-related index applied for or associated with at least one channel or RS in the serving cell or BWP, and/or
· The network entity configures, to the UE, a higher layer parameter PDCCH-Config that contains two different values of coresetPoolIndex in ControlResourceSet in the serving cell or BWP.
It is noted that throughout this disclosure, for case (s) that a network entity configures or indicates the UE to operate with (M-TRP) single DCI (S-DCI) mode in a serving cell or a BWP, or for case (s) that a serving cell or a BWP is operated with (M-TRP) S-DCI mode, it can imply or be referred to be one or more of the following:
· When the UE or the network entity transmits/receives a transmission, more than one TRP identifier or TRP-related index is configured or indicated or involved to the transmission or the beam/TCI state applied for the transmission, and/or
· The UE receives, from the network entity, a MAC-CE (such as PDSCH TCI activation MAC-CE) in the serving cell or BWP, which indicates that at least one TCI codepoint is mapped to two TCI states.
It is noted that throughout this disclosure, a panel can mean that an antenna (port) group or an antenna (port) set. There may be more than one DL/UL beam associated with one panel. When one transmitting node (UE or NW) is performing a transmission via a panel, only one beam associated with the panel can be used to perform the transmission. For a transmitter comprising more than one panel (for example, two panels) , it may happen that two beams associated with the two panels respectively are used to perform a transmission.
It is noted that throughout this disclosure, a TRP identifier can mean or be referred to a (candidate) value of a TRP identifier. The first TRP identifier can be a first candidate value of a TRP identifier or a first TRP identifier value. The second TRP identifier can be a second candidate value of a TRP identifier or a second TRP identifier value.
It is noted that throughout this disclosure, a panel identifier can mean or be referred to a (candidate) value of a panel identifier. The first panel identifier can be a first candidate value of a panel identifier or a first panel identifier value. The second panel identifier can be a second candidate value of a panel identifier or a second panel identifier value.
It is noted that throughout this disclosure, when a procedure or description is related to a serving cell, it may mean the procedure or description is related to an active (DL/UL) BWP in the serving cell.
It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X or Y” . It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X and Y” . It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X and/or Y” . It is noted that throughout this disclosure, an expression of “ (A) B” or “B (A) ” may include concept of “only B” . It is noted that throughout this disclosure, an expression of “ (A) B” or “B (A) ” may include concept of “A+B” or “B+A” .
It is noted that some or all of the foregoing or the following implementations can be jointly combined or formed to be a new or another one implementation.
It is noted that the foregoing or the following techniques can be used to solve at least (but not limited to) the issue (s) or scenario (s) mentioned in this disclosure.
The following additional considerations may apply to the foregoing and the following discussions.
It is noted that any two or more than two of the foregoing or the following paragraphs, (sub) -bullets, points, actions, or claims described in each method/technique/implementation may be combined logically, reasonably, and properly to form a specific method.
It is noted that any sentence, paragraph, (sub) -bullet, point, action, or claim described in each of the foregoing or the following technique (s) /implementation (s) /concept (s) may be implemented independently and separately to form a specific method. Dependency, such as “based on” , “more specifically” , “where” or etc., in technique (s) /implementation (s) /concept (s) mentioned in this disclosure is just one possible implementation which would not restrict the specific method.
It is noted that, some or all of the following terminology and assumptions may be used herein:
· network entity: a network central unit or a network node in NR which is used to control one or multiple TRPs which are associated with one or multiple cells. Communication between network entity and TRP (s) is via fronthaul. network entity may be referred to as central unit (CU) , eNB, gNB, or NodeB.
· TRP: a transmit/receive point provides network coverage and directly communicates with UEs. TRP may be referred to as distributed unit (DU) or network node.
· Cell: a cell is composed of one or multiple associated TRPs, for example, coverage of the cell is composed of coverage of all associated TRP (s) . One cell is controlled by one network entity or a network entity. Cell may be referred to as TRP group (TRPG) .
· Serving beam: serving beam for a UE is a beam generated by a network node, such as a TRP, which is configured to be used to communicate with the UE, such as for transmission and/or reception.
· Candidate beam: candidate beam for a UE is a candidate of a serving beam. Serving beam may or may not be candidate beam.
Certain techniques are described in this disclosure as including logic or a number of components or modules. Modules may be software modules (such as code stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. A hardware module can comprise dedicated circuitry or logic that is permanently configured (such as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC) ) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (for example, as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry, or in temporarily configured circuitry (for example, configured by software) may be driven by cost and time considerations.
Figures 1A-1C, 2A, 2B, 3A-3D, 4, and 5 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations might include additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.
The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. While the aspects of the disclosure have been described in terms of various examples, any combination of aspects from any of the examples is also within the scope of the disclosure. The examples in this disclosure are provided for pedagogical purposes. Alternatively, or in addition to the other examples described herein, examples include any combination of the following implementation options (enumerated as clauses for clarity) .
CLAUSES
Clause 1. A method for wireless communication by a user equipment (UE) , the method including: receiving, from a network entity, a configuration for multiple timing advance (TA) operation; and transmitting, to the network entity, an uplink transmission based on a TA parameter associated with the multiple TA operation, the uplink transmission including at least one of: a first uplink transmission following reception of a beam failure recovery (BFR) response, a second uplink transmission without spatial relation information from the network entity, or a third uplink transmission without a joint or uplink transmission configuration indication (TCI) associated with the third uplink transmission.
Clause 2. The method of clause 1, further including: determining, by the UE, the TA parameter for the uplink transmission.
Clause 3. The method of clause 2, where the determining, by the UE, the TA parameter includes determining the TA parameter based on an index identifying a set of control resource sets.
Clause 4. The method of clause 2, where the determining, by the UE, the TA parameter includes determining the TA parameter associated with a timing advance group (TAG) having an ID set to a predetermined value.
Clause 5. The method of clause 2, where the determining, by the UE, the TA parameter includes configuring the TA parameter based on a one or more of a radio resource control (RRC) signal, a media access control (MAC) control element (CE) signal, or downlink control information (DCI) signal.
Clause 6. The method of clause 2, where the determining, by the UE, the TA parameter includes determining the TA parameter based on a rule.
Clause 7. The method of clause 2, where the determining, by the UE, the TA parameter includes determining the TA parameter based on non-zero power (NZP) channel state information reference signal (CSI-RS) .
Clause 8. The method of any one of clauses 1-7, where the second uplink transmission without the spatial relation information from the network entity is preceded by the UE receiving control signaling from the network entity that lacks an indication of the spatial relation information.
Clause 9. The method of any one of clauses 1-7, where the second uplink transmission without the spatial relation information from the network entity is preceded by the UE not being configured with a source reference signal enabling the UE to derive the spatial relation information.
Clause 10. The method of clause 1, where the BFR response is associated with a cell-specific BFR.
Clause 11. The method of clause 10, where the multiple TA operation utilizes a first TA parameter value and a second TA parameter value, and where the method further includes: switching from the multiple TA operation to single TA operation; receiving a signal from the network entity including a TCI indication indicating a plurality of TCI states; discarding the second TA parameter value; and retaining the first TA parameter value as the TA parameter.
Clause 12. The method of clause 10, where the method further includes: setting the TA parameter to an updated TA parameter determined using a random access (RA) procedure when the BFR response is associated with a primary cell (PCell) BFR.
Clause 13. The method of clause 10, further including retaining a previous TA parameter as the TA parameter.
Clause 14. The method of clause 1, where the BFR response is associated with a per-transmit/receive point (per-TRP) BFR.
Clause 15. The method of clause 14, further including at least one of: retaining a previous transmission TA parameter as the TA parameter, or setting the TA parameter based on a failure detection set identifier.
Clause 16. The method of any of clauses 1-15, where the TA parameter includes one of a TA value or a timing advance group (TAG) indicator.
Clause 17. The method of any of clauses 1-16, further including transmitting UE capability information to the network entity indicating that the UE supports the multiple TA operation.
Clause 18. A user equipment (UE) , including: a communication unit; and a processing system configured to control the communication unit to implement any one of the methods of clauses 1–17.
Another innovative aspect of the subject matter described in this disclosure can be implemented as a wireless communication device of a UE or a network entity. The wireless communication device may include at least one interface and a processing system communicatively coupled with the at least one interface. The processing system may be configured to implement any one of the above clauses.
Another innovative aspect of the subject matter described in this disclosure can be implemented as a portable electronic device including a wireless communication device, a plurality of antennas coupled to the at least one transceiver to wirelessly transmit signals output from the at least one transceiver and a housing that encompasses the wireless communication device, the at least one transceiver and at least a portion of the plurality of antennas. The wireless communication device may include at least one interface and a processing system communicatively coupled with the at least one interface. The processing system may be configured to implement any one of the above clauses.
Another innovative aspect of the subject matter described in this disclosure can be implemented as a machine-readable medium having processor-readable instructions stored therein that, when executed by a processing system of a UE, cause the UE to implement any one of the above clauses.
Another innovative aspect of the subject matter described in this disclosure can be implemented as an apparatus. The apparatus may include means for implementing any one of the above clauses.
As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”
Some aspects are described herein in connection with thresholds. As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.
As used herein, a phrase referring to “at least one of” or “one or more of” a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.
In this disclosure, the term "can" indicates a capability, or alternatively indicates a possible implementation option. The term "may" indicates a permission or a possible implementation option.
The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.
The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.
As described above, in some aspects implementations of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-or computer-executable instructions encoded on one or more tangible processor-or computer-readable storage media for execution by, or to control the operation of, data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media. When implemented in software, the techniques can be provided as part of the operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more special-purpose processors.
As used herein, the terms “user device” , “user equipment” (for example, UE 102) , “wireless communication device” , “mobile communication device” , “communication device” , or “mobile device” refer to any one or all of cellular telephones, smartphones, portable computing devices, personal or mobile multi-media players, laptop computers, tablet computers, smartbooks, Internet-of-Things (IoT) devices, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, wireless gaming controllers, display sub-systems, driver assistance systems, vehicle controllers, vehicle system controllers, vehicle communication system, infotainment systems, vehicle telematics systems or subsystems, vehicle display systems or subsystems, vehicle data controllers, point-of-sale (POS) terminals, health monitoring devices, drones, cameras, media-streaming dongles or another personal media devices, wearable devices such as smartwatches, wireless hotspots, femtocells, broadband routers or other types of routers, and similar electronic devices which include a programmable processor and memory and circuitry configured to perform operations as described herein. Further, the user device in some cases may be embedded in an electronic system such as the head unit of a vehicle or an advanced driver assistance system (ADAS) . Still further, a mobile-internet device (MID) . Depending on the type, the user device can include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.
Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.
Additionally, various features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

A method for wireless communication by a user equipment (UE) , the method comprising:

receiving, from a network entity, a configuration for multiple timing advance (TA) operation; and

transmitting, to the network entity, an uplink transmission based on a TA parameter associated with the multiple TA operation, the uplink transmission including at least one of:

a first uplink transmission following reception of a beam failure recovery (BFR) response,

a second uplink transmission without spatial relation information from the network entity, or

a third uplink transmission without a joint or uplink transmission configuration indication (TCI) associated with the third uplink transmission.
The method of claim 1, further comprising:

determining, by the UE, the TA parameter for the uplink transmission.
The method of claim 2, wherein the determining, by the UE, the TA parameter comprises determining the TA parameter based on an index identifying a set of control resource sets.
The method of claim 2, wherein the determining, by the UE, the TA parameter comprises determining the TA parameter associated with a timing advance group (TAG) having an ID set to a predetermined value.
The method of claim 2, wherein the determining, by the UE, the TA parameter comprises configuring the TA parameter based on a one or more of a radio resource control (RRC) signal, a media access control (MAC) control element (CE) signal, or downlink control information (DCI) signal.
The method of claim 2, wherein the determining, by the UE, the TA parameter comprises determining the TA parameter based on a rule.
The method of claim 2, wherein the determining, by the UE, the TA parameter comprises determining the TA parameter based on non-zero power (NZP) channel state information reference signal (CSI-RS) .
The method of any one of claims 1-7, wherein the second uplink transmission without the spatial relation information from the network entity is preceded by the UE receiving control signaling from the network entity that lacks an indication of the spatial relation information.
The method of any one of claims 1-7, wherein the second uplink transmission without the spatial relation information from the network entity is preceded by the UE not being configured with a source reference signal enabling the UE to derive the spatial relation information.
The method of claim 1, wherein the BFR response is associated with a cell-specific BFR.
The method of claim 10, wherein the multiple TA operation utilizes a first TA parameter value and a second TA parameter value, and wherein the method further comprises:

switching from the multiple TA operation to single TA operation;

receiving a signal from the network entity including a TCI indication indicating a plurality of TCI states;

discarding the second TA parameter value; and

retaining the first TA parameter value as the TA parameter.
The method of claim 10, wherein the method further comprises:

setting the TA parameter to an updated TA parameter determined using a random access (RA) procedure when the BFR response is associated with a primary cell (PCell) BFR.
The method of claim 10, further comprising retaining a previous TA parameter as the TA parameter.
The method of claim 1, wherein the BFR response is associated with a per-transmit/receive point (per-TRP) BFR.
The method of claim 14, further comprising at least one of:

retaining a previous transmission TA parameter as the TA parameter, or

setting the TA parameter based on a failure detection set identifier.
The method of any of claims 1-15, wherein the TA parameter comprises one of a TA value or a timing advance group (TAG) indicator.
The method of any of claims 1-16, further comprising transmitting UE capability information to the network entity indicating that the UE supports the multiple TA operation.
A user equipment (UE) , comprising:

a communication unit; and

a processing system configured to control the communication unit to implement any one of the methods of claims 1–17.