PATENT DOCUMENT

Publication Number: US-12200699-B2
Application Number: US-202017593232-A
Country: US
Kind Code: B2

Title: Physical downlink control channel candidate resource mapping and transmission for multi-TRP operation

Abstract:
A base station maps physical downlink control channel (PDCCH) candidates and PDCCH transmissions for multi-transmission reception point (TRP) operation. The base station determines that a control resource set (CORESET) is to be shared by at least a first TRP and a second TRP corresponding to a cell of a network, performs resource element group (REG) bundle to virtual REG bundle mapping on a per TRP basis, wherein multiple REG bundles are indexed on the per TRP basis, performs virtual REG bundle interleaving across the first TRP and the second TRP, performs control channel element (CCE) to interleaved REG bundle mapping and transmits downlink control information (DCI) using the CORESET, wherein the CORESET is configured based on, at least, the CCE to interleaved REG bundle mapping.

Claims:
What is claimed: 
     
       1. A processor configured to perform operations comprising:
 determining that a control resource set (CORESET) is to be shared by at least a first transmission reception point (TRP) and a second TRP corresponding to a cell of a network; 
 performing resource element group (REG) bundle to virtual REG bundle mapping on a per TRP basis, wherein multiple REG bundles are indexed on the per TRP basis; 
 performing virtual REG bundle interleaving across the first TRP and the second TRP by
 determining a number of columns for a matrix based on, at least, a number of REG in the CORESET; 
 determining a number of rows for the matrix based on, at least, a number of TRPs sharing the CORESET; 
 inputting a first virtual REG bundle sequence into the matrix, and 
 generating a second virtual REG bundle sequence based on, at least, the matrix; 
 
 performing control channel element (CCE) to interleaved REG bundle mapping; and 
 transmitting downlink control information (DCI) using the CORESET, wherein the CORESET is configured based on, at least, the CCE to interleaved REG bundle mapping. 
 
     
     
       2. The processor of  claim 1 , wherein the first virtual REG bundle sequence is input into the matrix row by row in an increasing order of virtual REG bundle and TRP. 
     
     
       3. The processor of  claim 1 , wherein the operations further:
 determining whether an even CCE index or an odd CCE index is to be utilized; 
 when the even CCE index is to be utilized, the first virtual REG bundle sequence is input into the matrix row by row in an increasing order of virtual REG bundle starting from the first TRP; and 
 when the odd CCE index is to be utilized, the first virtual REG bundle sequence is input into the matrix row by row in an increasing order of virtual REG bundle starting from the second TRP. 
 
     
     
       4. The processor of  claim 1 , wherein the operations further comprise:
 shifting REG bundles in different TRPs when constructing a CCE based on a shifting parameter. 
 
     
     
       5. The processor of  claim 4 , wherein the shifting parameter is a function of a TRP index. 
     
     
       6. The processor of  claim 4 , wherein the shifting parameter is configured by higher layer signaling. 
     
     
       7. The processor of  claim 4 , wherein the shifting parameter is configured on a per CORESET basis. 
     
     
       8. A processor configured to perform operations comprising:
 monitoring a physical downlink control channel (PDCCH) for downlink control information (DCI) transmitted by a cell of a network;
 wherein monitoring the PDCCH includes identifying a set of PDCCH candidates that is based on a control channel element (CCE) bundle, 
 wherein the PDCCH includes the CCE bundle within a control resource set (CORESET) and the CCE bundle corresponds to a single transmission reception point (TRP), 
 wherein the CCE bundle is based on, at least, the single TRP and an aggregation level; 
 
 receiving the DCI carried by the PDCCH from the cell of the network; and 
 performing an operation in response to the DCI. 
 
     
     
       9. The processor of  claim 8 , wherein the CCE bundle is indexed is based on, at least, a TRP index and frequency. 
     
     
       10. The processor of  claim 8 , wherein the PDCCH includes the CCE bundle across CCEs of multiple transmission reception points (TRPS). 
     
     
       11. The processor of  claim 10 , wherein the CCE bundle includes multiple CCE pairs, wherein each CCE pair includes a first CCE for a first TRP and a second CCE for a second TRP. 
     
     
       12. The processor of  claim 10 , wherein the CCE bundle is indexed in increasing order of frequency. 
     
     
       13. The processor of  claim 8 , wherein the PDCCH includes a first control resource set (CORESET) corresponding to a first transmission reception point (TRP) and a second CORESET that is shared by the first TRP and a second TRP. 
     
     
       14. A cell, comprising:
 a communication interface configured to communicate with a user equipment (UE); and 
 a processor communicatively coupled to the communication interface and configured to perform operations comprising:
 determining that a control resource set (CORESET) is to be shared by at least a first transmission reception point (TRP) and a second TRP of the cell; 
 performing resource element group (REG) bundle to virtual REG bundle mapping on a per TRP basis, wherein multiple REG bundles are indexed on the per TRP basis; 
 performing virtual REG bundle interleaving across the first TRP and the second TRP by
 determining a number of columns for a matrix based on, at least, a number of REG in the CORESET; 
 determining a number of rows for the matrix based on, at least, a number of TRPs sharing the CORESET; 
 inputting a first virtual REG bundle sequence into the matrix, and 
 generating a second virtual REG bundle sequence based on, at least, the matrix; 
 
 performing control channel element (CCE) to interleaved REG bundle mapping; and 
 transmitting downlink control information (DCI) using the CORESET, wherein the CORESET is configured based on, at least, the CCE to interleaved REG bundle mapping. 
 
 
     
     
       15. The cell of  claim 14 , further comprising:
 shifting REG bundles in different TRPs when constructing a CCE based on a shifting parameter.

Description:
BACKGROUND 
     A cell of the network may be configured with multiple transmission reception points (TRPs). In a multi-TRP deployment scenario, a physical downlink control channel (PDCCH) may have downlink control information (DCI) repetition over different TRPs. For example, one control resource set (CORESET) may be shared by two TRPs. However, to adequately implement this type of functionality, there exists a need for mechanisms configured to perform PDCCH candidate mapping and PDCCH transmission for multi-TRP operation. 
     SUMMARY 
     Some exemplary embodiments are related to a processor configured to perform operations. The operations include determining that a control resource set (CORESET) is to be shared by at least a first transmission reception point (TRP) and a second TRP corresponding to a cell of a network, performing resource element group (REG) bundle to virtual REG bundle mapping on a per TRP basis, wherein multiple REG bundles are indexed on the per TRP basis, performing virtual REG bundle interleaving across the first TRP and the second TRP, performing control channel element (CCE) to interleaved REG bundle mapping and transmitting downlink control information (DCI) using the CORESET, wherein the CORESET is configured based on, at least, the CCE to interleaved REG bundle mapping. 
     Other exemplary embodiments are related to a processor configured to perform operations. The operations include monitoring a physical downlink control channel (PDCCH) for downlink control information (DCI) transmitted by a cell of a network, receiving the DCI carried by the PDCCH from the cell of the network and performing an operation in response to the DCI. 
     Still further exemplary embodiments are related to a cell including a communications interface configured to communicate with a user equipment (UE) and a processor communicatively coupled to the communications interface and configured to perform operations. The operations include determining that a control resource set (CORESET) is to be shared by at least a first transmission reception point (TRP) and a second TRP of the cell, performing resource element group (REG) bundle to virtual REG bundle mapping on a per TRP basis, wherein multiple REG bundles are indexed on the per TRP basis, performing virtual REG bundle interleaving across the first TRP and the second TRP, performing control channel element (CCE) to interleaved REG bundle mapping and transmitting downlink control information (DCI) using the CORESET, wherein the CORESET is configured based on, at least, the CCE to interleaved REG bundle mapping. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows an exemplary network arrangement according to various exemplary embodiments. 
         FIG.  2    shows an example of multiple transmission reception points (TRPs) deployed at different locations according to various exemplary embodiments. 
         FIG.  3    shows an exemplary user equipment (UE) according to various exemplary embodiments. 
         FIG.  4    shows a method for Multi-TRP physical downlink control channel (PDCCH) transmission according to various exemplary embodiments. 
         FIG.  5    illustrates an example of virtual resource element group (REG)-bundle interleaving across multiple TRPs according to various exemplary embodiments. 
         FIG.  6    illustrates an example of control channel element (CCE)-to-REG-bundle mapping with TRP-dependent REG-bundle shifting according to various exemplary embodiments. 
         FIG.  7    shows an example of REG-bundle based CCE-to virtual-REG bundle mapping for PDCCH transmission for multiple TRP operation according to various exemplary embodiments. 
         FIG.  8    illustrates an example of CCE bundles for different aggregation levels according to various exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments relate to multi-transmission reception point (TRP) deployment. As will be described below, the exemplary embodiments include techniques related to physical downlink control channel (PDCCH) candidate mapping and PDCCH transmission for multi-TRP operation. 
     The exemplary embodiments are described with regard to a user equipment (UE). However, reference to a UE is merely provided for illustrative purposes. The exemplary embodiments may be utilized with any electronic component that may establish a connection to a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any electronic component. 
     The exemplary embodiments are also described with regard to a 5G new radio (NR) network. However, reference to a 5G NR network is merely provided for illustrative purposes. The exemplary embodiments may be utilized with any network that is configured with multi-TRP capability. Therefore, the 5G NR network as described herein may represent any type of network that is configured with multi-TRP capability. 
     The 5G NR network may deploy a next generation node B (gNB) that is configured with multiple TRPs. Throughout this description, a TRP generally refers to a set of components configured to transmit and/or receive signals. In some embodiments, multiple TRPs may be deployed locally at the gNB. For example, the gNB may include multiple antenna arrays/panels that are each configured to generate a different beam. In other embodiments, multiple TRPs may be deployed at various different locations and connected to the gNB via a backhaul connection. For example, multiple small cells may be deployed at different locations and connected to the gNB. However, these examples are merely provided for illustrative purposes. Those skilled in the art will understand that TRPs are configured to be adaptable to a wide variety of different conditions and deployment scenarios. Thus, any reference to a TRP being a particular network component or multiple TRPs being deployed in a particular arrangement is merely provided for illustrative purposes. The TRPs described herein may represent any type of network component configured to transmit and/or receive a signal. 
     In a multi-TRP deployment scenario, a PDCCH may include downlink control information (DCI) repetition over different TRPs. For example, a control resource set (CORESET) may be shared by two TRPs with different transmission configuration indicator (TCI) states. In one example configuration, one PDCCH candidate in a given search space (SS) set may be associated with both TCI states of the CORESET. In another example configuration, two sets of PDCCH candidates in a given SS set may be associated with the two TCI states of the CORESET, respectively. In a third example configuration, two sets of PDCCH candidates may be associated with two corresponding SS sets, where both SS states are associated with the CORESET and each SS set is associated with only one TCI of the CORESET. Those skilled in the art will understand that a set of PDCCH candidates may contain one or more PDCCH candidates and a PDCCH candidate in a set corresponds to a repetition. However, to adequately implement this type of functionality, there exists a need for mechanisms configured to perform PDCCH candidate mapping and PDCCH transmission for multi-TRP operation. Specific examples of exemplary PDCCH candidate mapping and PDCCH transmission techniques for a multi-TRP deployment scenario will be described in more detail below. 
       FIG.  1    shows an exemplary network arrangement  100  according to various exemplary embodiments. The exemplary network arrangement  100  includes a UE  110 . Those skilled in the art will understand that the UE  110  may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, Internet of Things (IoT) devices, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of a single UE  110  is merely provided for illustrative purposes. 
     The UE  110  may be configured to communicate with one or more networks. In the example of the network configuration  100 , the network with which the UE  110  may wirelessly communicate is a 5G NR radio access network (RAN)  120 . However, the UE  110  may also communicate with other types of networks (e.g. 5G cloud RAN, a next generation RAN (NG-RAN), a long term evolution RAN, a legacy cellular network, a WLAN, etc.) and the UE  110  may also communicate with networks over a wired connection. With regard to the exemplary embodiments, the UE  110  may establish a connection with the 5G NR RAN  120 . Therefore, the UE  110  may have a 5G NR chipset to communicate with the NR RAN  120 . 
     The 5G NR RAN  120  may be a portion of a cellular network that may be deployed by a network carrier (e.g., Verizon, AT&amp;T, T-Mobile, etc.). The 5G NR RAN  120  may include, for example, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. 
     In network arrangement  100 , the 5G NR RAN  120  includes a cell  120 A that represents a gNB that is configured with multiple TRPs. Each TRP may represent one or more components configured to transmit and/or receive a signal. In some embodiments, multiple TRPs may be deployed locally at the cell  120 A. In other embodiments, multiple TRPs may be distributed at different locations and connected to the gNB. 
       FIG.  2    shows an example of multiple TRPs deployed at different locations. In this example, the gNB  205  is configured with a first TRP  210  via a backhaul connection  212  and a second TRP  220  via backhaul connection  222 . Each of the TRPs  210 ,  220  may transmit a signal to and/or receive a signal from the UE  110 . However, the gNB  205  may be configured to control the TRPs  210 ,  220  and perform operations such as, but not limited to, assigning resources, PDCCH candidate resource mapping, interleaving, etc. 
     The example shown in  FIG.  2    is not intended to limit the exemplary embodiments in any way. Those skilled in the art will understand that 5G NR TRPs are adaptable to a wide variety of different conditions and deployment scenarios. An actual network arrangement may include any number of different types of cells and/or TRPs being deployed by any number of RANs in any appropriate arrangement. Thus, the example of a single cell  120 A in  FIG.  1    and a single gNB  205  with two TRPs  210 ,  220  in  FIG.  2    is merely provided for illustrative purposes. 
     Returning to the network arrangement  100  of  FIG.  1   , the cell  120 A may include one or more communication interfaces to exchange data and/or information with UEs, the corresponding RAN, the cellular core network  130 , the internet  140 , etc. Further, the cell  120 A may include a processor configured to perform various operations. For example, the processor of the cell  120 A may be configured to perform operations related to PDCCH candidate mapping and PDCCH transmission. However, reference to a processor is merely for illustrative purposes. The operations of the cell  120 A may also be represented as a separate incorporated component of the cell  120 A or may be a modular component coupled to the cell  120 A, e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. In addition, in some examples, the functionality of the processor is split among two or more processors such as a baseband processor and an applications processor. The exemplary embodiments may be implemented in any of these or other configurations of a cell. 
     The UE  110  may connect to the 5G NR-RAN  120  via the cell  120 A. Those skilled in the art will understand that any association procedure may be performed for the UE  110  to connect to the 5G NR-RAN  120 . For example, as discussed above, the 5G NR-RAN  120  may be associated with a particular cellular provider where the UE  110  and/or the user thereof has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR-RAN  120 , the UE  110  may transmit the corresponding credential information to associate with the 5G NR-RAN  120 . More specifically, the UE  110  may associate with a specific cell (e.g., the cell  120 A). However, as mentioned above, reference to the 5G NR-RAN  120  is merely for illustrative purposes and any appropriate type of RAN may be used. 
     In addition to the 5G NR RAN  120 , the network arrangement  100  also 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  may be considered to be the interconnected set of components that manages the operation and traffic of the cellular network. The cellular core network  130  also manages the traffic that flows between the cellular network and the Internet  140 . The IMS  150  may be generally described as an architecture for delivering multimedia services to the UE  110  using the IP protocol. The IMS  150  may communicate with the cellular core network  130  and the Internet  140  to provide the multimedia services to the UE  110 . The network services backbone  160  is in communication either directly or indirectly with the Internet  140  and the cellular core network  130 . The network services backbone  160  may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE  110  in communication with the various networks. 
     As mentioned above, the exemplary embodiments include techniques related to physical downlink control channel (PDCCH) candidate mapping and PDCCH transmission for multi-TRP operations. From a UE  110  perspective, implementing these exemplary techniques may provide a performance benefit to operations related to PDCCH monitoring and/or PDCCH reception because these exemplary techniques improve the reliability and robustness of the PDCCH channel in a multi-TRP deployment scenario. 
       FIG.  3    shows an exemplary UE  110  according to various exemplary embodiments. The UE  110  will be described with regard to the network arrangement  100  of  FIG.  1   . The UE  110  may include a processor  305 , a memory arrangement  310 , a display device  315 , an input/output (I/O) device  320 , a transceiver  325  and other components  330 . The other components  330  may include, for example, an audio input device, an audio output device, a power supply, a data acquisition device, ports to electrically connect the UE  110  to other electronic devices, etc. 
     The processor  305  may be configured to execute a plurality of engines of the UE  110 . For example, the engines may include a multi-TRP PDCCH monitoring engine  335 . The multi-TRP PDCCH monitoring engine  335  may be configured to perform operations related to PDCCH monitoring and reception in a multi-TRP deployment scenario. For example, the multi-TRP PDCCH monitoring engine  335  may monitor the PDCCH for a CORESET shared by multiple TRPs. 
     The above referenced engine being an application (e.g., a program) executed by the processor  305  is only exemplary. The functionality associated with the engine may also be represented as a separate incorporated component of the UE  110  or may be a modular component coupled to the UE  110 , e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor  305  is split among two or more processors such as a baseband processor and an applications processor. The exemplary embodiments may be implemented in any of these or other configurations of a UE. 
     The memory arrangement  310  may be a hardware component configured to store data related to operations performed by the UE  110 . The display device  315  may be a hardware component configured to show data to a user while the I/O device  320  may be a hardware component that enables the user to enter inputs. The display device  315  and the I/O device  320  may be separate components or integrated together such as a touchscreen. The transceiver  325  may be a hardware component configured to establish a connection with the 5G NR-RAN  120 , an LTE-RAN (not pictured), a legacy RAN (not pictured), a WLAN (not pictured), etc. Accordingly, the transceiver  325  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). 
     As mentioned above, the exemplary embodiments relate to the PDCCH. The PDCCH may include a CORESET which refers to a set of time and frequency resources used to carry DCI. The resource elements (REs) of the CORESET may be characterized in RE groups (REGs) and REG bundles. Each REG may include multiple REs (e.g., 2, 6, 12, etc.) in one orthogonal frequency division multiplexing (OFDM) symbol and each REG bundle may include multiple REGs. 
     The PDCH may be carried by a particular number of control channel elements (CCEs). For example, the PDCCH may be carried by 1, 2, 4, 8, 16 or any other appropriate number of CCEs. Each CCE may include multiple REGs (e.g., 6 or any other appropriate amount). For PDCCH transmission, CCE-to-REG mapping may be performed. An example of CCE-to-REG mapping for multi-TRP PDCCH transmission will be provided in detail below. 
     On the UE  110  side, PDCCH reception may include monitoring PDCCH candidates. In some embodiments, this may include blindly decoding multiple PDCCH candidates in a search space. PDCCH monitoring and reception of CORESETs may require the UE  110  to take on a certain complexity and energy cost in exchange for scheduling flexibility and lower overhead on the network side. The exemplary techniques described herein improve both UE and network performance because these exemplary techniques improve the reliability and robustness of the PDCCH channel in a multi-TRP deployment scenario. 
       FIG.  4    shows a method  400  for Multi-TRP PDCCH transmission according to various exemplary embodiments. The method  400  will be described from the perspective of the cell  120 A of the network arrangement  100 . 
     A CORESET may be shared by multiple TRPs with different TCI states. The CCE-to-REG mapping for the shared CORESET may be interleaved or non-interleaved in units of REG bundles. The method  400  will describe different exemplary techniques for CCE-to-REG mapping for a CORESET shared by multiple TRPs. As will be described in more detail below, the exemplary techniques may achieve REG bundle interleaving across multiple TRPs and accordingly, improve PDCCH performance by leveraging the spatial diversity benefit. 
     In  405 , the cell  120 A may number multiple REG bundles on a per TRP basis. In this example, the REG-bundle defined in Rel-15 is reused and indexed on a per TRP basis. However, the exemplary embodiments are not limited to the REG-bundle defined in Rel-15 and may be applicable to any appropriate type of REG-bundle. 
     The numbering of the REG bundle per TRP may be represented as REGB (i)   m  which may be defined as {iL, iL+1, . . . , iL+L−1} where L is the REG bundle size, m is the TRP index, i is defined as {0, 1, . . . , N REGB   CORESET −1}, N REGB   CORESET =N REG   CORESET /L, and N REG   CORESET =N RB   CORESET N symb   CORESET  which represents the number of CORESETs in the shared CORESET of the TRP. 
     In  410 , the cell  120 A may perform REG-bundle to virtual REG-bundle mapping on a per TRP basis. This mapping may be represented by V_REGB (j)   m  which may be defined as 
             {       f   ⁡   (       6   ⁢   j     L     )     ,     f   ⁡   (         6   ⁢   j     L     +   1     )     ,   …        ,     f   ⁡   (         6   ⁢   j     L     +     6   L     -   1     )       }         
where f(.) is the interleaver defined in Rel-15 for CCE-to-REG mapping and j is the index of the virtual REG bundle.
 
     In  415 , the cell  120 A may perform virtual REG-bundle interleaving across multiple TRPs. As example of this is illustrated in  FIG.  5   . 
     The virtual REGs (V-REGs) input to the multi-TRP interleaver may be denoted by V_REGB (0)   m , V_REGB (1)   m , . . . , V_REGB (N     REGB       CORESET     −1 ) m . The output V-REG bundles from the multi-TRP interleaver may be derived as by assigning C REGB =N REGB   CORESET  be the number of columns of a matrix. The columns of the matrix may be numbered 0, 1, 2, . . . , C REGB −1 from left to right. The number of rows of the matrix may then be based on N TRP  which represents the number of TRPs sharing the CORESET. 
     Next, the V-REG bundle sequence (V_REGB (j)   m ) may be written into the matrix (C REGB ×N TRP ) row by row in an increasing order of V-REGB and TRP, starting from a first TRP (e.g., m=0). 
     The output of the V-REGB interleaver is the V-REGB sequence read out column by column from the matrix (C REGB ×N TRP ) which is denoted by V_REGB (0)   I , V_REGB (1)   I , . . . , V_REGB (K     Π     −1)   I  where K Π =N TRP ×N REGB   CORESET . 
     In  420 , the cell  120 A may perform CCE to interleaved virtual REG-bundle mapping. In this example, CCE j consists of interleaved virtual REG bundles (CCE-to-V-REGB) represented as {V_REGB (j)   I , V_REGB (j+1)   I , . . . , V REGB(j+5)   I }. 
     In  425 , the cell  120 A performs a PDCCH transmission to the UE  110 . For example, the cell  120 A may transmit DCI to the the UE  110  using a CORESET shared by a first TRP and a second different TRP. The CORESET is based on the CCE-to-virtual-REG-bundle mapping described above. The UE  110  may receive the DCI carried by the PDCCH and perform a subsequent operation (e.g., transmission, reception, etc.) in response to the DCI. The example provided above was described with regard to a first TRP and a second TRP sharing a single CORESET. However, the exemplary embodiments are not limited to two TRPs sharing a single CORESET. Those skilled in the art will understand how the exemplary techniques described herein may be applied to more than two TRPs. 
     In some embodiments, a parameter Δ shift   TRP  may be introduced in  415 - 420  of the method  400  to shift REG bundles in different TRPs when constructing a CCE. The value of Δ shift   m  is a function of the TRP index m. In one example, Δ shift   m =f(m)=m. In another example, Δ shift   m  may be configured by higher layer signaling, e.g., through system information block (SIB) information or dedicated signaling. 
       FIG.  6    illustrates an example of CCE-to-REGB mapping with TRP-dependent REG-bundle shifting according to various exemplary embodiments. In this example, when (V_REGB (j)   m ) is written into the matrix (C REGB ×N TRP ) row by row in an increasing order of V-REGB and TRP, it starts from a first TRP for an even CCE index 2 and the order is switched to start from the second TRP for an odd CCE index 2K+1. This may ensure that all PDCCH resources across all of the TRPs are utilized. 
     In some embodiments, Δ shift   m  may be configured on a per CORESET basis and a single value is shared for all TRPs for the corresponding CORESET. In this example, interference coordination of PDCCH across multiple TRP clusters is possible by assigning different shift values for different clusters but a single value for multiple TRPs within a cluster. 
     The exemplary techniques described above with regard to  FIGS.  4 - 6    may be extended to non-interleaved CCE-to-REG mapping by allowing REG bundle size to be configured with a smaller value than 6 (e.g., 2, 3, etc.). 
       FIG.  7    shows an example of REG-bundle based CCE to virtual-REG bundle mapping for PDCCH transmission on a shared CORESET for multiple TRP operation according to various exemplary embodiments. In this example, a CORESET duration is one OFDM symbol, the frequency domain resources include 24 physical resource blocks (PRBs), the REG bundle size is three and distributed CCE-to-REG mapping is performed. 
     Different approaches may be implemented to determine the CCEs across the TRPs. In some embodiments, a CCE-bundle is introduced for a PDCCH aggregation level L.  FIG.  8    illustrates an example of CCE bundles for different aggregation levels according to various exemplary embodiments.  FIG.  8    will be referenced below in the description of the different approaches that may be implemented to determine the CCEs across TRPs provided below. 
     One approach (e.g. option 1 of  FIG.  8   ) may include a CCE-bundle within a CORESET of a single TRP. The CCE bundle k may be defined as CCE{k*L,k*L+1, . . . , k*L+L−1} of a single TRP, where L represents the applicable aggregation level. In  FIG.  8   , three examples are provided. In the first example L=2, in the second example L=4 and in the third example L=8. However, in actual deployment scenario L may equal 1, 2, 4, 8 or any other appropriate value. In addition, as shown in option 1 of  FIG.  8   , numbering of the CCE bundle index is done in increasing order of first TRP then frequency. 
     Another approach (e.g., option 2 of  FIG.  8   ) may include a CCE-bundle across CCEs of different TRPs. The CCE bundle k may be defined as CCE pair {k,k+1, . . . , k+L/2} and each CCE pair k may include {CCEk in TRP #0,CCE k in TRP #1}. In addition, as shown in option 2 of  FIG.  8   , the numbering of the CCE bundle index is done in increasing order of frequency. 
     In some embodiments, different CORESETs may be configured with different CCE-bundle mapping based on different approaches (e.g., option 1 or 2 of  FIG.  8   ) to allow dynamic switching between single TRP transmission and multiple TRP transmission for PDCCH by transmitting PDCCH on different CORESETs with different CCE-bundle mapping approaches. 
     For PDCCH monitoring, the set of PDCCH candidates to monitor may be defined in terms of CCE bundles. For example, the CCE bundles corresponding to PDCCH candidate m with aggregation level L may be represented by 
                   (       (       Y     p   ,     n     s   ,   f     μ         +     ⌊         m     s   ,     n   CI         *     N     CCE   ,   p           L   *     M     s   ,   max       (   L   )           ⌋     +     n   CI       )     ⁢   mod   ⁢     ⌊       N     CCE   ,   p       /   L     ⌋       )     ⁢           m     s   ,     n   CI           =   0     ,   …        ,       M     s   ,     n   CI         (   L   )       -   1           
Here, the parameter N CCE,p  may be defined as the number of CCEs in a CORESET across all the TRPs. To provide an example, in  FIG.  8   , N CCE,p =8×2=16 and thus, 16 CCEs are shown in each example. m s,n     CI    may represent the number of PDCCH candidates the UE  110  is configured to monitor for aggregation level L of a search space s. Similarly, like the REG-bundle based approach, one offset Δ shift   m  may be introduced as a function of TRP index to shift the CCE-bundle location to ensure the CCE-bundles are frequency division multiplexed (FDM) across multiple TRPs to facilitate UE  110  PDCCH reception. In some embodiments, Δ shift   m  may be represented in units of CCE bundles.
 
     Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. The exemplary embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor. 
     Although this application described various embodiments each having different features in various combinations, those skilled in the art will understand that any of the features of one embodiment may be combined with the features of the other embodiments in any manner not specifically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed embodiments. 
     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 so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Metadata:
Filing Date: 20201014
Publication Date: 20250114
Grant Date: 20250114
Priority Date: 20201014
Inventors: HE, HONG
YAO, CHUNHAI
YE, CHUNXUAN
ZHANG, DAWEI
SUN, HAITONG
NIU, HUANING
OTERI, OGHENEKOME
FAKOORIAN, SEYED ALI AKBAR
YE, SIGEN
ZENG, WEI
YANG, WEIDONG
ZHANG, YUSHU
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W72/232", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/0453", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/0071", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0053", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0048", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0094", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0091", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1273", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L5/0035", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W72/232", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/0453", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/0071", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1273", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 81207556