Patent Publication Number: US-2022231801-A1

Title: Apparatus and method for configuring application of tci state to component carriers

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 from U.S. Provisional Application No. 63/137,781, entitled “Common TCI Framework,” filed on Jan. 15, 2021, the subject matter of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosed embodiments relate generally to wireless communication, and, more particularly, to application of TCI state to component carriers. 
     BACKGROUND 
     In conventional network of 3rd generation partnership project (3GPP) 5G new radio (NR), the user equipment (UE) can be configured, by the base station (BS), with a plurality of transmission configuration indication (TCI) states for downlink (DL) transmission and uplink (UL) transmission. After being configured, the UE may apply one or more TCI states indicated by the beam indication downlink control information (DCI) in the first slot that is at least ‘Y’ symbols after the last symbol of the acknowledgment of the beam indication DCI. Regarding a set of component carriers (CCs), the UE may apply the one or more indicated TCI states to the set of the CCs. 
     However, because different CCs may have different sub-carrier spacings (SCSs), the TCI state switching timing may not be aligned if the UE determines the first slot and ‘Y’ symbols separately in each CC for beam application time, which is very inefficient and can cause heavier network load. 
     SUMMARY 
     Apparatus and methods are provided for configuring application of transmission configuration indication (TCI) state to component carriers (CCs). In one novel aspect, a user equipment (UE) may apply one or more TCI states to a set of CCs based on a slot of a reference CC. In particular, a base station (BS) can transmit an indication of one or more TCI states to a UE. The UE can receive the indication of the one or more TCI states from the BS. Then, the UE can apply the one or more TCI states to a set of CCs from a specific slot of a reference CC. The reference CC has a smallest sub-carrier space (SCS) among the set of CCs. 
     Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention. 
         FIG. 1  illustrates an exemplary 5G new radio network supporting application of TCI state activation to reference signal in accordance with embodiments of the current invention. 
         FIG. 2  is a simplified block diagram of the gNB and the UE in accordance with embodiments of the current invention. 
         FIG. 3A  illustrates one embodiment of message transmissions in accordance with embodiments of the current invention. 
         FIG. 3B  illustrates one embodiment of a set of CCs utilized by UE in accordance with embodiments of the current invention. 
         FIG. 4A  illustrates one embodiment of message transmissions in accordance with embodiments of the current invention. 
         FIG. 4B  illustrates one embodiment of a set of CCs utilized by UE in accordance with embodiments of the current invention. 
         FIG. 5  is a flow chart of a method of configuring application of TCI state to CCs in accordance with embodiments of the current invention. 
         FIGS. 6A and 6B  are flow charts of a method of configuring application of TCI state to CCs in accordance with embodiments of the current invention. 
         FIG. 7  is a flow chart of a method of configuring application of TCI state to CCs in accordance with embodiments of the current invention. 
         FIGS. 8A and 8B  are flow charts of a method of configuring application of TCI state to CCs in accordance with embodiments of the current invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
       FIG. 1  illustrates an exemplary 5G new radio (NR) network  100  supporting application of transmission configuration indication (TCI) state to component carriers (CCs) in accordance with aspects of the current invention. The 5G NR network  100  includes a user equipment (UE)  110  communicatively connected to a gNB  121  operating in a licensed band (e.g., 30 GHz-300 GHz for mmWave) of an access network  120  which provides radio access using a Radio Access Technology (RAT) (e.g., the 5G NR technology). The access network  120  is connected to a 5G core network  130  by means of the NG interface, more specifically to a User Plane Function (UPF) by means of the NG user-plane part (NG-u), and to a Mobility Management Function (AMF) by means of the NG control-plane part (NG-c). One gNB can be connected to multiple UPFs/AMFs for the purpose of load sharing and redundancy. The UE  110  may be a smart phone, a wearable device, an Internet of Things (IoT) device, and a tablet, etc. Alternatively, UE  110  may be a Notebook (NB) or Personal Computer (PC) inserted or installed with a data card which includes a modem and RF transceiver(s) to provide the functionality of wireless communication. 
     The gNB  121  may provide communication coverage for a geographic coverage area in which communications with the UE  110  is supported via a communication link  101 . The communication link  101  shown in the 5G NR network  100  may include uplink (UL) transmissions from the UE  110  to the gNB  121  (e.g., on the Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH)) or downlink (DL) transmissions from the gNB  121  to the UE  110  (e.g., on the Physical Downlink Control Channel (PDCCH) or Physical Downlink Shared Channel (PDSCH)). 
       FIG. 2  is a simplified block diagram of the gNB  121  and the UE  110  in accordance with embodiments of the present invention. For the gNB  121 , an antenna  197  transmits and receives radio signal. A radio frequency (RF) transceiver module  196 , coupled with the antenna, receives RF signals from the antenna, converts them to baseband signals and sends them to processor  193 . RF transceiver  196  also converts received baseband signals from the processor  193 , converts them to RF signals, and sends out to antenna  197 . Processor  193  processes the received baseband signals and invokes different functional modules and circuits to perform features in the gNB  121 . Memory  192  stores program instructions and data  190  to control the operations of the gNB  121 . 
     Similarly, for the UE  110 , antenna  177  transmits and receives RF signals. RF transceiver module  176 , coupled with the antenna, receives RF signals from the antenna, converts them to baseband signals and sends them to processor  173 . The RF transceiver  176  also converts received baseband signals from the processor  173 , converts them to RF signals, and sends out to antenna  177 . Processor  173  processes the received baseband signals and invokes different functional modules and circuits to perform features in the UE  110 . Memory  172  stores program instructions and data  170  to control the operations of the UE  110 . 
     The gNB  121  and the UE  110  also include several functional modules and circuits that can be implemented and configured to perform embodiments of the present invention. In the example of  FIG. 2 , the gNB  121  includes a set of control functional modules and circuit  180 . TCI handling circuit  182  handles TCI state(s) and associated network parameters for the UE  110 . Configuration and control circuit  181  provides different parameters to configure and control the UE  110 . The UE  110  includes a set of control functional modules and circuit  160 . TCI handling circuit  162  handles TCI state(s) and associated network parameters. Configuration and control circuit  161  handles configuration and control parameters from the gNB  121 . 
     Note that the different functional modules and circuits can be implemented and configured by software, firmware, hardware, and any combination thereof. The function modules and circuits, when executed by the processors  193  and  173  (e.g., via executing program codes  190  and  170 ), allow the gNB  121  and the UE  110  to perform embodiments of the present invention. 
       FIG. 3A  illustrates one embodiment of message transmissions in accordance with one novel aspect. In particular, the gNB  121  transmits a higher layer configuration  1210  to the UE  110 . The higher layer configuration  1210  configures the UE  110  a plurality of TCI states. The UE  110  receives the higher layer configuration  1210  from the gNB  121 . After the transmission of the higher layer configuration  1210 , the gNB  121  transmits a configuration  1212  to the UE  110 . The configuration  1212  includes an indication  1214  of one or more indicated TCI states of the configured plurality of TCI states. The UE  110  receives the configuration  1212 . In some embodiments, the higher layer configuration  1210  may include a radio resource control (RRC) configuration. In some embodiments, the configuration  1212  may include a downlink control information (DCI) so that the indication  1214  of one or more indicated TCI states is a DCI-based indication. 
     In some embodiments, after receiving the DCI-based indication  1214  of one or more indicated TCI states, the UE  110  can determine a reference CC from a set of CCs. The reference CC may have a smallest sub-carrier space (SCS) among the set of CCs. Then, the UE  110  can apply the one or more indicated TCI states to the set of CCs from a specific slot of the reference CC. In other words, after receiving the DCI-based indication  1214  of one or more indicated TCI states, the UE  110  can apply the one or more indicated TCI states to the set of CCs from the specific slot according to a reference SCS. The reference SCS is the smallest SCS among SCSs of the set of CCs. 
       FIG. 3B  illustrates one embodiment of a set of CCs utilized by the UE  110  in accordance with one novel aspect. For example, two CCs ‘A’, ‘B’ are utilized by the UE  110 . CC ‘A’ has SCS of 30 KHz. CC ‘B’ has SCS of 60 KHz. The UE  110  determines CC ‘A’ as a reference CC because the CC ‘A’ has the smallest SCS, which is 30 KHz, among the CCs ‘A’, ‘B’. Then, the UE  110  applies the one or more indicated TCI state to the CCs ‘A’, ‘B’ from a specific slot of the CC ‘A’. Accordingly, the one or more indicated TCI are applied to the CCs ‘A’, ‘B’ at the same switching timing. 
       FIG. 4A  illustrates one embodiment of message transmissions in accordance with one novel aspect. In particular, the gNB  121  transmits a higher layer configuration  1216  to the UE  110 . The higher layer configuration  1216  includes a number of symbols, configures the UE  110  a set of CCs and a plurality of TCI states. The UE  110  receives the higher layer configuration  1218  from the gNB  121 . After the transmission of the higher layer configuration  1216 , the gNB  121  transmits a configuration  1218  to the UE  110 . The configuration  1218  includes an indication  1220  of one or more indicated TCI states of the configured plurality of TCI states. The UE  110  receives the configuration  1218 . In some embodiments, the higher layer configuration  1216  may include an RRC configuration. In some embodiments, the configuration  1218  may include a DCI so that the indication  1220  of one or more indicated TCI states is a DCI-based indication. 
     In some embodiments, after receiving the DCI-based indication  1220  of one or more indicated TCI states, the UE  110  can determine a reference CC from the set of CCs. The reference CC may have a smallest SCS among the set of CCs. More specifically, an active bandwidth part (BWP) of the reference CC has the smallest SCS among active BWPs of the set of CCs. 
     In other words, after receiving the DCI-based indication  1220  of one or more indicated TCI states, the UE  110  can apply the one or more indicated TCI states to the set of CCs from the specific slot according to a reference SCS. The reference SCS is the smallest SCS among SCSs of the set of CCs. The SCSs are configured to the active BWPs of the set of CCs. 
     Next, the UE  110  transmits an acknowledgement  1222  in response to the configuration  1218  (i.e., in response to the DCI) to the gNB  121 . Then, the UE  110  can determine a specific slot and apply the one or more indicated TCI state to the set of CCs from the specific slot of the reference CC. The specific slot is the first slot of the reference CC after the number of symbols from a last symbol of transmitting the acknowledgment  1222  to the gNB  121 . In other words, the specific slot is the first slot after the number of symbols, according to the reference SCS, from the last symbol of transmitting the acknowledgment  1222  to the network. 
       FIG. 4B  illustrates one embodiment of a set of CCs utilized by the UE  110  in accordance with one novel aspect. For example, the number of symbols is ‘N’ and three CCs ‘X’, ‘Y’, ‘Z’ are utilized by the UE  110 . CC ‘X’ has SCS of 30 KHz. CC ‘Y’ has SCS of 60 KHz. CC ‘Z’ has SCS of 120 KHz. The UE  110  determines CC ‘X’ as a reference CC because the active BWP of the CC ‘X’ has the smallest SCS, which is 30 KHz, among active BWPs of the CCs ‘X’, ‘Y’, ‘Z’. The UE  110  determines the specific slot that is the first slot of the CC ‘X’ after ‘N’ symbols from a last symbol of transmitting the acknowledgment  1222 . Then, the UE  110  applies the one or more indicated TCI state to the CCs ‘X’, ‘Y’, ‘Z’ from the specific slot of the CC ‘X’. Accordingly, the one or more indicated TCI are applied to the CCs ‘X’, ‘Y’, ‘Z’ at the same switching timing. 
     In some embodiments, the gNB  121  can determine the number of symbols based on capability of the UE  110 . In particular, the UE  110  can transmit a capability report to the gNB  121 . The gNB  121  can determine the number of symbols according to the capability report of the UE  110  and transmit the number of symbols to the UE  110 . 
       FIG. 5  is a flow chart of a method of configuring application of TCI state to CCs in a 5G/NR network in accordance with one novel aspect. In step  501 , a UE receives an indication of one or more TCI states from a network. In step  502 , the UE applies the one or more TCI states to a set of CCs from a specific slot of a reference CC which has a smallest SCS among the set of CCs. 
       FIGS. 6A and 6B  ae flow charts of a method of configuring application of one or more TCI states to CCs in a 5G/NR network in accordance with one novel aspect. In step  601 , a UE receives a higher layer configuration from the network. The higher layer configuration includes a number of symbols, configures the UE a set of CCs and a plurality of TCI states. In step  602 , the UE receives a configuration (e.g., DCI) including an indication of one or more TCI states. In step  603 , the UE determines a reference CC from a set of CCs. An active BWP of the reference CC has the smallest SCS among active BWPs of the set of CCs. In step  604 , the UE transmits an acknowledgement to the network in response to the configuration (e.g., DCI). In step  605 , the UE applies the one or more TCI states to the set of CCs from a specific slot of the reference CC. The specific slot is the first slot of the reference CC after the number of symbols from a last symbol of transmitting the acknowledgment to the network. 
     In some embodiments, in an optional step  606 , the UE transmits a capability report to the network for the network to determine the number of the symbols. 
       FIG. 7  is a flow chart of a method of configuring application of TCI state to CCs in a 5G/NR network in accordance with one novel aspect. In step  701 , a UE receives an indication of one or more TCI states from a network. In step  702 , the UE applies the one or more TCI states to a set of CCs from a specific slot according to a reference SCS. The reference SCS is a smallest SCS among SCSs of the set of CCs. 
       FIGS. 8A and 8B  ae flow charts of a method of configuring application of TCI state to CCs in a 5G/NR network in accordance with one novel aspect. In step  801 , a UE receives a higher layer configuration from the network. The higher layer configuration includes a number of symbols, configures the UE a set of CCs and a plurality of TCI states. In step  802 , the UE receives a configuration (e.g., DCI) including an indication of one or more TCI states. In step  803 , the UE determines a reference SCS. The reference SCS is a smallest SCS among SCSs of the set of CCs. The SCSs are configured to active BWPs of the set of CCs. In step  804 , the UE transmits an acknowledgement to the network in response to the configuration (e.g., DCI). In step  805 , the UE applies the one or more TCI states to the set of CCs from a specific slot according to the reference SCS. The specific slot is the first slot after the number of symbols, according to the reference SCS, from a last symbol of transmitting the acknowledgment to the network. 
     In some embodiments, in an optional step  806 , the UE transmits a capability report to the network for the network to determine the number of the symbols. 
     Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.