Unified tci framework

Abstract

The present disclosure relates to a unified transmission configuration indicator framework. A user equipment (UE) is configured to receive a command for a transmission configuration indicator (TCI) state change for a joint TCI state including uplink (UL) and downlink (DL) signals; decode the joint TCI state command and perform measurements necessary for reception and transmission in the target TCI state, including path loss (PL) measurements for UL channels; and switch to reception of DL signals and transmission of UL signals in the target TCI state no later than a duration of a switching delay.

Description

BACKGROUND

[0001] A transmission configuration indicator (TCI) state contains parameters for configuring quasi co-location (QCL) relationships between one or more reference signals (RS) and corresponding antenna ports. For example, a demodulation reference signal (DMRS) port of a physical downlink shared channel (PDSCH), a DMRS port of a physical downlink control channel (PDCCH), or a channel state indicator reference signal (CSI-RS) port of a CSI-RS resource set can be associated with a QCL relationship. Two quasi co-located signals experience very similar channel conditions such that determining the channel properties of one signal will substantially aid in the determination of the channel properties of the other signal. A TCI state change can be implemented by a network and indicated to user equipment (UE) in the network. The UE expects to complete the switch from a previous (current) TCI state to a new (target) TCI state within a specified delay time. SUMMARY

[0002] Some example embodiments relate to a processor of a user equipment (UE) configured to perform operations. The operations include receiving a command for a transmission configuration indicator (TCI) state change for a joint TCI state including uplink (UL) and downlink (DL) signals, decoding the joint TCI state command and performing measurements necessary to receive and transmit in the target TCI state, the measurements including path loss (PL) measurements for UL channels, and switching to receive DL signals and transmit UL signals in the target TCI state no later than a duration of a switch delay.

[0003] Other example embodiments relate to a user equipment (UE) having a transceiver configured to communicate with a network and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include receiving a command for a transmission configuration indicator (TCI) state change for a joint TCI state including uplink (UL) and downlink (DL) signals, decoding the joint TCI state command and performing measurements necessary to receive and transmit in the target TCI state, the measurements including path loss (PL) measurements for UL channels, and switching to receive DL signals and transmit UL signals in the target TCI state no later than a duration of a switch delay.

[0004] Still further example embodiments are directed to a processor of a user equipment (UE) configured to perform operations. The operations include receiving a command for a transmission configuration indicator (TCI) state change for a separate uplink (UL) TCI state that includes UL signals and does not include downlink (DL) signals, decoding the separate UL TCI state command and performing measurements necessary for reception and transmission with a target TCI state, the measurements including path loss (PL) measurements for UL channels, and switching to transmission of UL signals with the target TCI state no later than a duration of a switching delay.

[0005] Further example embodiments are directed to a user equipment (UE) having a transceiver configured to communicate with a network and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include receiving a command for a transmission configuration indicator (TCI) state change for a separate uplink (UL) TCI state that includes UL signals and does not include downlink (DL) signals, decoding the separate UL TCI state command and performing measurements necessary for reception and transmission with a target TCI state, the measurements including path loss (PL) measurements for UL channels, and switching to transmission of UL signals with the target TCI state no later than a duration of a switching delay. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 A network arrangement is shown in accordance with various example embodiments.

[0007] Figure 2 An example UE is shown in accordance with various example embodiments.

[0008] Figure 3 An example network cell is shown in accordance with various example embodiments.

[0009] Figure 4 An example method of TCI state switching in a unified TCI framework is shown in accordance with various example embodiments described herein. DETAILED DESCRIPTION

[0010] The example embodiments can be further understood with reference to the following description and related drawings in which like elements are referred to with the same reference numerals. The example embodiments describe configurations of a user equipment (UE) in a 5G New Radio (NR) network related to allowed delay times for switching transmission configuration indicator (TCI) states. The delay times can be specified differently for various scenarios based on different considerations related to the respective scenarios, which are described in detail below.

[0011] In some embodiments, a joint TCI state switch of associations including uplink (UL) and downlink (DL) reference signals (RSs) can be configured. In other embodiments, a separate UL TCI state switch of associations including UL RSs is configured. In either of these scenarios, a TCI state switch from a current TCI state to a target TCI state can be indicated by a medium access control (MAC) control element (MAC-CE) and / or downlink control information (DCI). The delay time of the TCI state switch can be specified based on considerations such as a time duration for decoding the TCI state switch command, a time duration for beam refinement, a time duration for time and frequency tracking of the target TCI state, and a time duration for path loss measurement, which are described in detail below.

[0012] Exemplary embodiments are described with respect to a UE. However, the use of a UE is provided for illustrative purposes only. Exemplary embodiments can be used with any electronic component configured with hardware, software, and / or firmware for exchanging information (e.g., control information) and / or data with a network. Thus, a UE described herein is used to represent any suitable electronic device.

[0013] Exemplary embodiments are also described with respect to a 5G New Radio (NR) network. However, the reference to a 5G NR network is provided for illustrative purposes only. Exemplary embodiments can be used with any network that implements a similar TCI state architecture as described herein. Thus, a 5G NR network as described herein can represent any type of network that implements similar TCI state functionality as a 5G NR network.

[0014] Figure 1 An exemplary network arrangement 100 is shown in accordance with various exemplary embodiments. Exemplary network arrangement 100 includes a user equipment (UE) 110. Those skilled in the art will appreciate that a UE can be any type of electronic component configured to communicate via a network, such as a mobile phone, a tablet, a smart phone, a phablet, an embedded device, a wearable device, a Cat-M device, a Cat-Ml device, an MTC device, an eMTC device, other types of Internet of Things (IoT) devices, etc. It should also be appreciated that an actual network arrangement can include any number of UEs used by any number of users. Thus, only an example with a single UE 110 is provided for illustrative purposes.

[0015] The UE 110 can communicate directly with one or more networks. In the example of network arrangement 100, the networks with which the UE 110 can wirelessly communicate are a 5G NR radio access network (5G NR-RAN) 120, a LTE radio access network (LTE-RAN) 122, and a wireless local area network (WLAN) 124. Thus, the UE 110 can include a 5G NR chipset to communicate with the 5G NR-RAN 120, an LTE chipset to communicate with the LTE-RAN 122, and an ISM chipset to communicate with the WLAN 124. However, the UE 110 can also communicate with other types of networks (e.g., a legacy cellular network), and the UE 110 can also communicate with networks through a wired connection. With respect to the example embodiment, the UE 110 can establish a connection with the 5G NR RAN 122.

[0016] The 5G NR-RAN 120 and the LTE-RAN 122 can be part of a cellular network that can be deployed by a cellular provider (e.g., Verizon, AT&T, T-Mobile, etc.). These networks 120, 122 can include, for example, cells or base stations (NodeBs, eNodeBs, HeNBs, eNBS, gNBs, gNodeBs, macrocell base stations, microcell base stations, small cell base stations, femtocell base stations, etc.) configured to send and receive traffic from UEs equipped with the appropriate cellular chipset. The WLAN 124 can include any type of wireless local area network (WiFi, hotspots, IEEE 802. l lx networks, etc.).

[0017] The UE 110 can connect to the 5G NR-RAN via at least one of a next generation nodeB (gNB) 120A and / or a gNB 120B. The gNBs 120A, 120B can be configured with the necessary hardware (e.g., antenna arrays), software, and / or firmware to perform massive multiple input multiple output (MIMO) functionality. Massive MIMO can refer to a base station configured to generate multiple beams for multiple UEs. The reference to two gNBs 120A, 120B is for illustrative purposes only. The example embodiments can apply to any appropriate number of gNBs.

[0018] In addition to the networks 120, 122, and 124, the network arrangement 100 includes a cellular core network 130, the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network services backbone 160. The cellular core network 130 can be viewed as an interconnected set of components that manage the operation and traffic of the cellular network. The cellular core network 130 also manages traffic that flows between the cellular network and the Internet 140. The IMS 150 can generally be described as an architecture for delivering multimedia services to UEs 110 using IP protocols. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UEs 110. The network services backbone 160 communicates with the Internet 140 and the cellular core network 130, either directly or indirectly. The network services backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that can be used to extend the functionality of the UEs 110 in communicating with various networks.

[0019] Figure 2 An exemplary UE 110 is shown in accordance with various exemplary embodiments. The UE 110 will be described with reference to the network arrangement 100 of Figure 1 The UE 110 can represent any electronic device, and can include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 can include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, a sensor for detecting a condition of the UE 110, etc.

[0020] The processor 205 can be configured to execute a number of engines of the UE 110. For example, an engine can include a TCI state change delay engine 235. The TCI state change delay engine 235 can perform operations including determining a time span to continue using an old TCI state after receiving a TCI state change indicator from a network. The UE 110 can make such a determination based on various considerations involved in the TCI state change, including, for example, whether the TCI state change is for joint TCI state switching or for separate UL TCI state switching, and whether the TCI state change is indicated via a medium access control control element (MAC-CE) or a radio resource control (RRC) activation command that can have different command decoding times. The UE 110 can also consider whether additional time is needed for TX beam refinement, T / F tracking, or path loss measurement. Specific implementations of these various scenarios will be described in further detail below.

[0021] The above engines are exemplary only as applications (e.g., programs) executed by the processor 205. The functionality associated with the engines can also be represented as separate integrated components of the UE 110, or can be modular components coupled to the UE 110, e.g., integrated circuits with or without firmware. For example, the integrated circuits can include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines can also be embodied as one application or as multiple applications separate from one another. Further, in some UEs, the functionality described with respect to the processor 205 is split between two or more processors, such as a baseband processor and an application processor. The exemplary embodiments can be implemented in any of these or other configurations of the UE. The memory 210 can be a hardware component configured to store data related to operations performed by the UE 110.

[0022] The display device 215 can be a hardware component configured to display data to a user, and the I / O device 220 can be a hardware component that enables input by the user. The display device 215 and the I / O device 220 can be separate components or can be integrated together, such as a touchscreen. The transceiver 225 can be a hardware component configured to establish a connection with the 5G-NR RAN 120, the LTE RAN 122, etc. Thus, the transceiver 225 can operate on various different frequencies or channels (e.g., contiguous sets of frequencies).

[0023] Figure 3 An exemplary network cell, in this case a gNB 120A, is shown in accordance with various exemplary embodiments. As described above with respect to the UE 110, the gNB 120A can represent a serving cell for the UE 110. The gNB 120A can represent any access node of a 5G NR network through which the UE 110 can establish a connection and manage network operations. Figure 3 The gNB 120A shown can also represent the gNB 120B.

[0024] The gNB 120A can include a processor 305, a memory arrangement 310, input / output (I / O) devices 315, a transceiver 320, and other components 325. The other components 325 can include, for example, an audio input device, an audio output device, a battery, a data acquisition device, a port to electrically connect the gNB 120A to other electronic devices, etc.

[0025] The processor 305 can be configured to execute a number of engines of the gNB 120A. For example, the engines can include a TCI state change delay engine 330. The TCI state change delay engine 235 can perform operations including indicating a TCI state change to the UE 110, such as a joint TCI state change or a separate UL joint TCI state change. The TCI state change delay engine 330 can also determine a time span for which the UE 110 continues to use the old TCI state after receiving the TCI state change indicator. The gNB 120A can make such determinations based on various considerations involved in the TCI state change, including, for example, whether the TCI state change is for a joint TCI state switch or a separate UL TCI state switch, and whether the TCI state change is indicated via a medium access control control element (MAC-CE) or a radio resource control (RRC) activation command, which can have different command decoding times for the UE 110. The gNB 120A can also consider whether the UE 110 uses additional time for TX beam refinement, T / F tracking, or path loss measurement. Particular implementations of these various scenarios will be described in further detail below.

[0026] The above engines are each exemplary of an application (e.g., a program) executed by the processor 305. The functionality associated with the engines can also be represented as integral components of the gNB 120A, or can be modular components coupled to the gNB 120A, such as integrated circuits with or without firmware. For example, the integrated circuits can include input circuitry to receive signals and processing circuitry to process the signals and other information. Further, in some gNBs, the functionality described with respect to the processor 305 is split among multiple processors (e.g., a baseband processor, an application processor, etc.). The example embodiments can be implemented in accordance with any of these or other configurations of the gNB.

[0027] The memory 310 can be a hardware component configured to store data related to operations performed by the UE 110, 112. The I / O device 315 can be a hardware component or port that enables a user to interact with the gNB 120A. The transceiver 320 can be a hardware component configured to exchange data with the UE 110, 112 and any other UE in the network arrangement 100, for example, when the gNB 120A functions as a PCell or SCell of any of the UEs 110, 112 or both. The transceiver 320 can operate on a variety of different frequencies or channels (e.g., a set of contiguous frequencies). Accordingly, the transceiver 320 can include one or more components (e.g., radio components) to enable data exchange with a variety of networks and UEs.

[0028] A transmission configuration indicator (TCI) state contains parameters for configuring a quasi co-location (QCL) relationship between one or more reference signals (RSs) and a corresponding antenna port, e.g., a demodulation reference signal (DMRS) port of a physical downlink shared channel (PDSCH), a DMRS port of a physical downlink control channel (PDCCH), or a channel state indicator reference signal (CSI-RS) port of a CSI-RS resource set. Two quasi co-located signals experience very similar channel conditions, such that determining the channel properties of one signal will substantially aid the channel estimation of the other signal.

[0029] Existing QCL types defined in 3rd Generation Partnership (3GPP) TS 38.214 include QCL-TypeA, QCL-TypeB, QCL-TypeC, and QCL-TypeD. QCL-TypeA involves Doppler shift, Doppler spread, average delay, and delay spread. QCL-TypeB involves Doppler shift and Doppler spread. Measurements of Types A and B can be used, for example, to determine channel state information (CSI). QCL-TypeC involves Doppler shift and average delay, and measurements can be used, for example, to calculate reference signal received power (RSRP). Thus, QCL Types A-C involve timing and frequency error tracking information that is shared on the port corresponding to the QCLed signal. QCL-TypeD involves spatial Rx parameters and is used to support beamforming.

[0030] A TCI chain can be specified in the following way. A reference signal is considered to be QCLed with another reference signal if it is in the same TCI chain as the other reference signal, provided that the number of reference signals in the chain does not exceed 4. A single QCL type can be considered to exist per TCI chain. With respect to DL-only TCI chains, a TCI chain includes an SSB, and one or more CSI-RS resources, and the TCI state of each reference signal includes another reference signal in the same TCI chain. The DMRS of a PDCCH or PDSCH is QCLed with a reference signal in its active TCI state, and any other reference signal that is QCLed with the reference signal in the active TCI state based on the criteria described above.

[0031] A TCI chain can be configured to include UL components, including ports for UL RS (e.g., SRS) and / or UL channels (e.g., RACH, PUCCH, and PUSCH). A TCI chain can be configured with UL components only or in a mixed TCI chain that also includes DL components. A UE can use a Rx beam (QCL Type D) from one component in a QCL Type D TCI chain to another component in the same QCL Type D TCI chain for reception / transmission. A UE can also use T / F tracking information (QCL Type A / B / C) from one component in a QCL Type A / B / C TCI chain to another component in the same QCL Type A / B / C TCI chain for reception / transmission.

[0032] A UE can be configured with a list of up to M TCI state configurations within a higher layer parameter, e.g., M = 8, which can be transmitted from the network to the UE in a medium access layer (MAC) control element (CE), a DCI message, or a radio resource control (RRC) activation command.

[0033] A UE configured with one or more TCI state configurations on a serving cell shall complete the switch of active TCI state within a delay defined in, e.g., 3GPP TS 38.133 Section 8.10. If a set of conditions are met within the time span from the last transmission of RS resource for layer 1 receive signal reference power (L1-RSRP) measurement reporting for the target TCI state to the completion of the active TCI state switch, the UE considers the target TCI state as “known”. For example, if the UE has measured the target TCI state or any TCI state in its QCL chain within a certain duration before receiving the TCI state switch command. Otherwise, the TCI state can be considered as “unknown”.

[0034] In one example, for MAC-CE based TCI state switch, the delay for DL only TCI state is defined in 3GPP TS 38.133 Section 8.10.3 in the following manner. If the target TCI state is known, upon receiving the PDSCH carrying the MAC-CE activation command in slot n, the UE shall be able to receive PDCCH with the target TCI state of the serving cell on which the TCI state switch shall occur no later than in slot n + T HARQ + (3ms + TO k * (T first-SSB + T SSB-proc )) / NR slot length. The UE shall be able to receive PDCCH with the old TCI state until slot n + T HARQ + (3ms + TO k * (T first-SSB )) / NR slot length.

[0035] T HARQ denotes the timing between a DL data transmission and the corresponding acknowledgement as specified in 3GPP TS 38.213. T first-SSB denotes the timing between the MAC CE command being decoded by the UE and the first SSB transmission afterwards, where the SSB shall be QCL-TypeA or QCL-TypeC for the target TCI state. T SSB-proc = 2ms. If the target TCI state is not in the active TCI state list of PDSCH, TO k = 1, and if the target TCI state is in the active TCI state list of PDSCH, TO k = 0.

[0036] If the target TCI state is unknown, upon receiving the PDSCH carrying the MAC-CE activation command in slot n, the UE shall be able to receive PDCCH with the target TCI state of the serving cell on which the TCI state switch occurs no later than in slot n + T HARQ + (3ms + T L1-RSRP + TO uk * (T first-SSB + T SSB-proc )) / NR slot length. The UE shall be able to receive PDCCH with the old TCI state until slot n + T HARQ + (3ms + T L1-RSRP + TO uk * (T first-SSB )) / NR slot length. T L1-RSRP denotes the time for L1-RSRP measurement for Rx beam refinement and is defined as T L1-RSPR_Measurement_Period_SSB as specified in clause 9.5.4.1 for SSB, or T L1-RSRP_Measurement_Period_CSI-RS as specified in clause 9.5.4.2 for CSI-RS, subject to various other considerations as defined in 3GPP TS 38.133 clause 8.10.3. When the TCI state switch involves QCL-TypeD, TO UK = 1 for CSI-RS based L1-RSRP measurement, TO UK = 0 for SSB based L1-RSRP measurement. When the TCI state switch involves other QCL types, TO uk = 1.

[0037] To implement the unified TCI framework, TCI state switching delay requirements must be specified for joint TCI state switching as well as for separate UL TCI state switching. Joint TCI state refers to a TCI chain that includes both UL and DL signals, and separate UL TCI state refers to a TCI chain that includes only UL signals (although the source RS can be a DL signal). In addition, requirements for path loss reference signal (PL-RS) update under the unified TCI framework must be specified. In the following, the term “source RS” can refer to an RS that is measured by the UE such that channel properties of the channel carrying the RS can be determined, and the term “target RS” can refer to an RS that is directly associated with the source RS or in the TCI chain with the source RS.

[0038] According to some example embodiments, a TCI state switching delay time is determined for joint TCI state switching that includes both DL signals and UL signals. For joint TCI state that includes both UL and DL signals, the source RS should be a DL-RS. For example, the source RS can be an SSB or a CSI-RS. Joint TCI state switching can be indicated by a MAC CE and / or a DCI. For example, the TCI state switching can be a MAC-CE based joint TCI state switching, a DCI based joint TCI state switching, or a MAC-CE and DCI based joint TCI state switching, where the TCI state switching includes a two-part indication that includes both signals. In the two-part indication, the MAC CE can activate a subset or list of TCI states from a pool of RRC configured TCIs, and the DCI indicates the target TCI state from the list.

[0039] Considerations for defining the switching delay for joint TCI state switching can include the following. A first consideration relates to the duration for decoding the TCI state switching command. The duration for command decoding can depend on the type of switching indication, i.e., based on DCI or based on MAC-CE. For DCI based switching, the PDCCH / DCI resolution time is small relative to the other considerations discussed herein. Thus, for DCI based switching, the command decoding time can not be considered for the switching delay requirement. For MAC-CE based switching, the delay term for MAC-CE decoding time can be T HARQ + 3ms, where T HARQ represents the timing between the DL data transmission (PDSCH) carrying the MAC-CE and the corresponding acknowledgement, and 3ms represents the MAC-CE resolution time.

[0040] A second consideration factor relates to the duration for Rx beam refinement. According to the known / unknown definition defined in TS 38.133 8.10.1 discussed above, this duration only applies when the Rx beam of the target TCI state is unknown. The delay term for Rx beam refinement can be T L1-RSRP As defined in TS 38.133 8.10.3, where T L1-RSRP denotes the time for the UE to perform Rx beam sweeping to determine the best beam for receiving the RS.

[0041] A third consideration factor relates to the duration for time / frequency (T / F) offset tracking for the target TCI state. This duration only applies in the case that the UE needs additional time for fine time / frequency tracking of the DL signals of the target TCI state. For example, a UE configured with M active TCI states can track a certain number of states at the same time. If the UE is tracking all active TCI states, it will not be necessary to perform T / F tracking after the switch command. Otherwise, the UE needs a certain additional time to process the SSB of the target TCI state to determine the T / F offset. The term for T / F tracking can be T first-SSB + T SSB-proc As defined in TS 38.133 8.10.3.

[0042] A fourth consideration factor relates to the duration for path loss measurement. When a TCI state is switched, the path loss RS (PL-RS) of the UL channel can also change when the spatial relation information (QCL Type D) changes. Additional time for path loss measurement is only needed in the case that the UE does not maintain the PL-RS (e.g., SSB or CSI-RS). The UE can maintain a certain number of PL-RS, e.g., up to 4 PL-RS. When a new PL-RS is activated, the UE measures the PL with L3 filtered RSRP. The term for PL measurement can be 5*T target_PL-RS + 2 ms, as defined in TS 38.133 8.14.3, where T target_PL-RS denotes the periodicity of the target PL-RS, and 2 ms denotes the PL-RS processing time.

[0043] For a UE receiving a joint TCI state switch command, the starting point of the switching delay is the slot in which the UE receives the PDSCH (when the switch is indicated via MAC-CE) or PDCCH (when the switch is indicated via DCI) indicating the joint TCI state switch. The ending point of the switching delay is the slot in which the UE transmits the UL signal associated with the target TCI state or receives the DL signal associated with the target TCI state (whichever is later).

[0044] As discussed above, the UE can need additional time for UL transmission due to PL-RS measurement and / or for DL or UL grant. Thus, in view of the timing considerations discussed above, the switching delay for MAC CE based joint TCI state switching can be T HARQ + 3ms + UK* T L1-RSRP + TO* (T first-SSB + T SSB-proc ) + NM* (5*T target_PL-RS + 2ms), where UK = 1 if Rx beam is unknown, TO = 1 if additional time for T / F offset tracking is needed (when UE does not track target TCI state), and NM = 1 if UE does not maintain PL-RS. In alternative embodiments, L1-RSRP measurement for beam refinement and some of the PL-RS measurements can be performed on the same resource and in parallel, rather than sequentially. Thus, the switching delay can be THARQ + 3ms + TO* (Tfirst-SSB + TSSB-proc) + max(UK* TL1-RSRP, NM* (5*Ttarget_PL-RS + 2ms)).

[0045] The switching delay for DCI based joint TCI state switching can be [beam switching time] + UK*T L1-RSRP + TO* (T first-SSB + T SSB-proc ) + NM* (5*T target_PL-RS + 2ms), where the beam switching time can be defined by UE capability or indicated by the network. In alternative embodiments, similar to above, the switching delay can be [beam switching time] + TO* (Tfirst-SSB + TSSB-proc) + max(UK* TL1-RSRP, NM* (5*Ttarget_PL-RS + 2ms)).

[0046] According to other example embodiments, the TCI state switch delay time is determined for a separate TCI state switch that includes only UL signals. For a separate TCI state switch of only UL target RS, the source RS can be a DL-RS (SSB or CSI-RS, similar to above for joint TCI state switch) or an UL sounding reference signal (SRS). The separate UL TCI state switch can be indicated by a MAC CE and / or a DCI. For example, similar to above, the TCI state switch can be a MAC-CE based separate UL TCI state switch, a DCI based separate UL TCI state switch, or a MAC-CE and DCI based separate UL TCI state switch, where the TCI state switch includes a two-part indication.

[0047] Considerations for defining the switch delay for separate UL TCI state switch can include the following. These considerations can be similar in some aspects to the considerations discussed above with respect to joint TCI state switch, but with various identified differences as shown below.

[0048] A first consideration relates to the duration for decoding the TCI state switch command, similar to above for joint TCI state switch. The duration for command decoding can depend on the type of switch indication, i.e., based on DCI or based on MAC-CE. For DCI based switch, the PDCCH / DCI resolution time is small relative to the other considerations discussed herein. Thus, for DCI based switch, the command decoding time can not be considered for the switch delay requirement. For MAC-CE based switch, the delay term for MAC-CE decoding time can be T HARQ + 3ms.

[0049] A second consideration relates to the duration for Rx beam refinement. Similar to above, this duration only applies when the Rx beam of the target TCI state is unknown, according to the known / unknown definitions discussed above in TS 38.133 8.10.1. When the source RS of the target TCI state is a DL-RS, the delay term for Rx beam refinement can be T L1-RSRP as defined in TS 38.133 8.10.3. However, when the source RS of the target TCI state is an UL-RS (SRS), the delay term for Rx beam refinement is more difficult to quantify. Thus, in this case, there are different options available for use. In one option, the UE can utilize the target TCI state for transmission after Rx beam refinement. In another option, the UE can transmit with the best known beam without additional Rx beam refinement.

[0050] In the separate UL TCI state switch scenario, there are no considerations with respect to T / F offset tracking.

[0051] A third consideration relates to the duration for path loss measurement. Similar to the above, when a TCI state is switched, the path loss RS (PL-RS) for the UL channel can also change when the spatial relation information (QCL Type D) changes. Additional time for path loss measurement is only needed if the UE does not maintain the PL-RS. The term for PL measurement can be 5*T target_PL-RS + 2ms, as defined in TS 38.133 8.14.3.

[0052] For a UE receiving a separate UL TCI state switch command, the starting point of the switch delay is the slot in which the UE receives the PDSCH with MAC-CE or PDCCH with DCI indicating separate UL TCI state switch. The ending point of the switch delay is the slot in which the UE transmits the UL signal associated with the target TCI state.

[0053] In view of the timing considerations discussed above, the switch delay for separate UL TCI state switch based on MAC CE can be T HARQ + 3ms + UK* T L1-RSRP + NM* (5*T target_PL-RS + 2ms), where UK = 1 if the Rx beam is not known, and NM = 1 if the UE does not maintain the PL-RS. In an alternative implementation, similar to the above, the L1-RSRP measurement for beam refinement and some of the PL-RS measurement can be performed on the same resource and in parallel, rather than sequentially. Thus, the switch delay can be THARQ + max(UK* TL1-RSRP, NM* (5*Ttarget_PL-RS + 2ms)).

[0054] The switch delay for joint TCI state switch based on DCI can be [beam switch time] + UK*T L1-RSRP + NM* (5*T target_PL-RS + 2ms), where the beam switch time can be defined by UE capability or indicated by the network. In an alternative implementation, similar to the above, the switch delay can be [beam switch time] + max(UK* TL1-RSRP, NM* (5*Ttarget_PL-RS + 2ms)).

[0055] Figure 4 An exemplary method 400 of TCI state switching in a unified TCI framework is shown, in accordance with various exemplary embodiments described herein.

[0056] In 405, the UE receives a TCI state switch command. The TCI state switch command can be for joint TCI state switch or separate UL TCI state switch and can be indicated via MAC-CE or DCI.

[0057] In 410, the UE decodes the TCI state switch command and performs the measurements necessary for reception / transmission with the target TCI state. For example, depending on the type of TCI state switch command (based on MAC-CE or DCI, joint TCI or separate UL TCI), the UE can need time to decode the TCI state switch command or perform T / F tracking. In addition, the UE can need to perform Rx beam refinement or PL-RS measurements.

[0058] In 415, the UE switches from the current TCI state to the target TCI state no later than the switching delay needed for decoding the TCI state switch command and performing the necessary measurements. The UE can then transmit / receive with the target TCI state.

[0059] Those skilled in the art will understand that the exemplary embodiments described above can be implemented in any suitable software configuration or hardware configuration, or a combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments can include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, and the like. In other examples, the exemplary embodiments of the above-described methods can be embodied as a program including code lines stored on a non-transitory computer-readable storage medium, which, when compiled, can be executed on a processor or microprocessor.

[0060] While this patent application describes various combinations of various embodiments each having different features, those skilled in the art will appreciate that any feature of one embodiment can be combined with features of another embodiment or features that are not inconsistent with the operation or functioning of the devices of the embodiments disclosed or the functions described, in any manner not expressly disclosed, without necessarily being expressly disclosed.

[0061] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unintentional or unauthorized access or use of data, and every effort should be made to secure user's privacy while maintaining the integrity, availability and development of tools for enhancing or even robbing users' experience. In some embodiments, de-identified data or anonymized data can be used to improve the services and products without infringing on user privacy.

[0062] It will be apparent to those skilled in the art that various modifications can be made to the disclosed embodiments without departing from the spirit or scope of the disclosure. Thus, it is intended that the disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims

1. A processor of a user equipment (UE), the processor configured to perform operations comprising: receiving a beam switch time parameter from a network; receiving a command for a transmission configuration indicator (TCI) state change for a joint TCI state comprising uplink (UL) and downlink (DL) signals, wherein the command is transmitted via downlink control information (DCI); decoding the command and performing measurements necessary for reception and transmission with a target TCI state, the measurements comprising path loss (PL) measurements for a UL channel; and switching to reception of the DL signals and transmission of the UL signals with the target TCI state for a duration of a switch delay, wherein the duration is based on at least the beam switch time parameter.

2. The processor of claim 1, wherein the duration is further based on a time for Rx beam refinement when a reception (Rx) beam of the target TCI state is unknown.

3. The processor of claim 1, wherein the duration is further based on a time for time and frequency offset tracking of DL signals of the target TCI state when the target TCI state is not tracked by the UE.

4. The processor of claim 1, wherein the duration is further based on a time for performing the PL measurements when spatial relation information and associated PL reference signals (PL-RS) for the UL channel change with respect to a current TCI state for the target TCI state.

5. The processor of claim 4, wherein the PL measurements are performed with layer 3 filtered reference signal received power (RSRP).

6. The processor of claim 1, wherein the duration does not include a time for performing the PL measurements when the UE maintains a PL reference signal (PL-RS) at the time the command is received.

7. The processor of claim 1, wherein a source reference signal (RS) for the target TCI state is a synchronization signal block (SSB) or a channel state information (CSI) RS.

8. A user equipment (UE) comprising: a transceiver configured to communicate with a network; and a processor communicatively coupled to the transceiver and configured to perform operations comprising: receiving a beam switch time parameter from the network; receiving a command for a transmission configuration indicator (TCI) state change for a joint TCI state comprising uplink (UL) and downlink (DL) signals, wherein the command is transmitted via downlink control information (DCI); decoding the command and performing measurements necessary for reception and transmission with a target TCI state, the measurements comprising path loss (PL) measurements for a UL channel; and switching to reception of the DL signals and transmission of the UL signals with the target TCI state for a duration of a switch delay, wherein the duration is based on at least the beam switch time parameter.

9. A processor of a user equipment (UE), the processor configured to perform operations comprising: receiving a beam switch time parameter from a network; receiving a command for a transmission configuration indicator (TCI) state change for a separate uplink (UL) TCI state that includes UL signals and does not include downlink (DL) signals, wherein the command is transmitted via downlink control information (DCI); decoding the command and performing measurements necessary for reception and transmission with a target TCI state, the measurements including path loss (PL) measurements for UL channels; and switching to transmission of the UL signals with the target TCI state for a duration of a switch delay, wherein the duration is based at least on the beam switch time parameter.

10. The processor of claim 9, wherein when a receive (Rx) beam of the target TCI state is unknown and a source reference signal (RS) for the target TCI state is a DL RS, the duration is further based on a time for Rx beam refinement.

11. The processor of claim 9, wherein when a receive (Rx) beam of the target TCI state is unknown and a source reference signal (RS) for the target TCI state is a UL RS, the duration is not based on a time for Rx beam refinement, wherein the UE uses a best known beam without additional Rx beam refinement.

12. The processor of claim 9, wherein when spatial relation information and an associated PL reference signal (PL-RS) for the UL channels change for the target TCI state relative to a current TCI state, the duration is further based on a time for performing the PL measurements.

13. The processor of claim 12, wherein the PL measurements are performed with layer 3 filtered reference signal received power (RSRP).

14. The processor of claim 9, wherein when the UE maintains a PL reference signal (PL-RS) at the time the command is received, the duration does not include a time for performing the PL measurements.

15. The processor of claim 9, wherein a source reference signal (RS) for the target TCI state is a synchronization signal block (SSB), a channel state information (CSI) RS, or a sounding reference signal (SRS).

16. A user equipment (UE), comprising: a transceiver configured to communicate with a network; and a processor communicatively coupled to the transceiver and configured to perform operations comprising: receiving a beam switch time parameter from the network; receiving a command for a transmission configuration indicator (TCI) state change for a separate uplink (UL) TCI state that includes UL signals and does not include downlink (DL) signals, wherein the command is transmitted via downlink control information (DCI); decoding the command and performing measurements necessary for reception and transmission in the target TCI state, the measurements including path loss (PL) measurements for UL channels; and switching to transmission of the UL signal in the target TCI state for the duration of a switching delay, wherein the duration is based on at least the beam switching time parameter.

Images