Patent Publication Number: US-2023156738-A1

Title: PDCCH RELIABILITY ENHANCEMENTS WITH MULTIPLE TRPs

Description:
RELATED APPLICATIONS 
     This application claims the benefit of provisional patent application serial number 62/970,492, filed Feb. 5, 2020, the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to transmission of a Physical Downlink Control Channel (PDCCH) in a Radio Access Network (RAN) of a cellular communications system. 
     BACKGROUND 
     NR Frame Structure and Resource Grid 
     Third Generation Partnership Project (3GPP) New Radio (NR) uses Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) in both downlink (i.e., from a network node, NR base station (gNB), or base station, to a User Equipment (UE)) and uplink (i.e., from UE to gNB). Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) is also supported in the uplink. In the time domain, NR downlink and uplink are organized into equally-sized subframes of 1 millisecond (ms) each. A subframe is further divided into multiple slots of equal duration. The slot length depends on subcarrier spacing. For subcarrier spacing of Δƒ = 15 kHz, there is only one slot per subframe and each slot consists of fourteen (14) OFDM symbols. 
     Data scheduling in NR is typically on a slot basis. An example is shown in  FIG.  1    with a 14-symbol slot, where the first two symbols contain Physical Downlink Control Channel (PDCCH) and the rest contains physical shared data channel, either Physical Downlink Shared Channel (PDSCH) or Physical Uplink Shared Channel (PUSCH). 
     Different subcarrier spacing values are supported in NR. The supported subcarrier spacing values (also referred to as different numerologies) are given by Δƒ = (15 × 2 µ )kHz where ε 0,1,2,3,4 . Δƒ = 15 kHz is the basic subcarrier spacing. The slot durations at different subcarrier spacings is given  
     
       
         
           
             by 
             
               1 
               
                 
                   2 
                   μ 
                 
               
             
           
         
       
     
     ms. 
     In the frequency domain, a system bandwidth is divided into Resource Blocks (RBs), each corresponding to twelve (12) contiguous subcarriers. The RBs are numbered starting with zero (0) from one end of the system bandwidth. The basic NR physical time-frequency resource grid is illustrated in  FIG.  2   , where only one resource block (RB) within a 14-symbol slot is shown. One OFDM subcarrier during one OFDM symbol interval forms one resource element (RE). 
     Downlink transmissions are dynamically scheduled, i.e., in each slot the gNB transmits Downlink Control Information (DCI) over Physical Downlink Control Channel (PDCCH) about which UE data is to be transmitted to and which RBs in the current downlink slot the data is transmitted on. The UE data are carried on PDSCH. 
     There are three DCI formats defined for scheduling PDSCH in NR, i.e., DCI formats 1_0 ,1_1, and 1_2. DCI format 1_0 has a smaller size than DCI 1_1 and can be used when a UE is not fully connected to the network while DCI format 1_1 can be used for scheduling Multiple-Input-Multiple-Output (MIMO) transmissions with two Transport Blocks (TBs). DCI format 1_2 is further introduced in NR Release 16 for scheduling PDSCH with different priorities, in which a priority indicator is included. 
     QCL and TCI States 
     Several signals can be transmitted from different antenna ports of a same base station. These signals can have the same large-scale properties such as Doppler shift/spread, average delay spread, or average delay. These antenna ports are then said to be Quasi Co-Located (QCL). 
     If the UE knows that two antenna ports are QCL with respect to a certain parameter (e.g., Doppler spread), the UE can estimate that parameter based on one of the antenna ports and apply that estimate for receiving signal on the other antenna port. Typically, the first antenna port is represented by a measurement reference signal such as Channel State Information Reference Signal (CSI-RS) or Synchronization Signal Block (SSB) (known as source Reference Signal (RS)) and the second antenna port is a Demodulation Reference Signal (DMRS) (known as target RS). 
     For instance, if antenna ports A and B are QCL with respect to average delay, the UE can estimate the average delay from the signal received from antenna port A and assume that the signal received from antenna port B has the same average delay. This is useful for demodulation since the UE can know beforehand the properties of the channel, which for instance helps the UE in selecting an appropriate channel estimation filter. 
     Information about what assumptions can be made regarding QCL is signaled to the UE from the network. In NR, four types of QCL relations between a transmitted source RS and transmitted target RS were defined:
     Type A: {Doppler shift, Doppler spread, average delay, delay spread},   Type B: {Doppler shift, Doppler spread},   Type C: {average delay, Doppler shift}, and   Type D: {Spatial Rx parameter}.   

     QCL type D was introduced to facilitate beam management with analog beamforming and is known as spatial QCL. There is currently no strict definition of spatial QCL, but the understanding is that if two transmitted antenna ports are spatially QCL, the UE can use the same Rx beam to receive them. 
     For dynamic beam and Transmission/Reception Point (TRP) selection, a UE can be configured through Radio Resource Control (RRC) signaling with up to 128 Transmission Configuration Indicator (TCI) states for PDSCH in Frequency Range 2 (FR2) and up to 8 TCI states in Frequency Range 1 (FR1), depending on UE capability. 
     Each TCI state contains QCL information, i.e. one or two source downlink (DL) RSs, each source RS associated with a QCL type. For example, a TCI state contains a pair of reference signals, each associated with a QCL type, e.g. two different CSI-RSs {CSI-RS1, CSI-RS2} is configured in the TCI state as {qcl-Type1,qcl-Type2} = {Type A, Type D}. This means the UE can derive Doppler shift, Doppler spread, average delay, delay spread from CSI-RS1 and Spatial Rx parameter (i.e., the RX beam to use) from CSI-RS2. 
     The list of TCI states can be interpreted as a list of possible beams transmitted from the network or a list of possible TRPs used by the network to communicate with the UE. 
     For PDSCH transmission, up to 8 TCI states or pairs of TCI states may be activated by a Medium Access Control (MAC) Control Element (CE), and a UE may be dynamically indicated by a TCI codepoint in DCI one or two of the activated TCI states for PDSCH reception. The UE uses the TCI-State according to the value of the ‘Transmission Configuration Indication’ field in the detected PDCCH with DCI for determining PDSCH antenna port quasi co-location. 
     If each of all the TCI codepoints is mapped to a single TCI state by a MAC CE and the offset between the reception of a DL DCI and the corresponding PDSCH is less than a threshold timeDurationForQCLconfigured by higher layers, the UE may assume that the DM-RS ports of PDSCH of a serving cell are quasi co-located with the RS(s) with respect to the QCL parameter(s) used for PDCCH quasi co-location indication of the CORESET associated with a monitored search space with the lowest CORESET-ID in the latest slot in which one or more CORESETs within the active bandwidth part (BWP) of the serving cell are monitored by the UE. 
     If the offset between the reception of the DL DCI and the corresponding PDSCH is less than the threshold timeDurationForQCL and at least one configured TCI states for the serving cell of scheduled PDSCH contains the ‘QCL-TypeD’, and at least one TCI codepoint indicates two TCI states, the UE may assume that the DM-RS ports of PDSCH of a serving cell are quasi co-located with the RS(s) with respect to the QCL parameter(s) associated with the TCI states corresponding to the lowest codepoint among the TCI codepoints containing two different TCI states. 
     CORESET and Search Space 
     A UE monitors a set of PDCCH candidates in one or more Control Resource Sets (CORESETs) on an active DL BWP on each activated serving cell configured with PDCCH monitoring according to corresponding search space sets, where monitoring implies decoding each PDCCH candidate according to the monitored DCI formats. A PDCCH candidate can occupy one or more Control-Channel Elements (CCEs), also referred to Aggregation Levels (ALs), as indicated in Table 1 below. A CCE consists of six (6) Resource-Element Groups (REGs), where a REG equals one RB during one OFDM symbol.  
     
       
         
          TABLE 1
           
               
               
             
               
                 NR supported PDCCH aggregation levels. 
               
               
                 Aggregation level 
                 Number of CCEs 
               
             
            
               
                 1 
                 1 
               
               
                 2 
                 2 
               
               
                 4 
                 4 
               
               
                 8 
                 8 
               
               
                 16 
                 16 
               
            
           
         
       
     
     A set of PDCCH candidates for a UE to monitor is defined in terms of PDCCH search space sets. A search space set can be a Common Search Space (CSS) set or a UE Specific Search Space (USS) set. A UE can be configured with up to ten (10) sets of search spaces per BWP for monitoring PDCCH candidates. 
     A search space set is defined over a CORESET. A CORESET consists of  
     
       
         
           
             
               N 
               
                 RB 
               
               
                 CORESET 
               
             
           
         
       
     
     resource blocks in the frequency domain and  
     
       
         
           
             
               N 
               
                 symb 
               
               
                 CORESET 
               
             
           
         
       
     
     ∈ {1,2,3} consecutive OFDM symbols in the time domain. For each DL BWP configured to a UE in a serving cell, a UE can be provided by higher layer signaling with P ≤ 5 CORESETs. For each CORESET, a UE is configured by RRC signaling with CORESET Information Element (IE), which includes the following information:
     a CORESET index p, 0 ≤ p &lt; 16;   a DM-RS scrambling sequence initialization value;   a precoder granularity for a number of resource element groups (REGs) in the frequency domain where the UE can assume use of a same DM-RS precoder;   a number of consecutive symbols;   a set of RBs;   CCE-to-REG mapping parameters;   a list of up to 64 TCI-States can be configured in a CORESET p. These TCI states are used to provide QCL relationships between the source DL RS(s) in one RS Set in the TCI State and the PDCCH DMRS ports (i.e., for DMRS ports for PDCCHs received in one of the search spaces defined over CORESET p). The source DL RS(s) can either be a CSI-RS or SSB;   an indication for a presence or absence of a transmission configuration indication (TCI) field for DCI format 1_1 transmitted by a PDCCH in CORESET p. This is done by the field ‘tci-PresentInDCI’. In the ‘tci-PresentInDCI’ field is absent in the CORESET IE corresponding to CORESET p, then the UE considers the TCI field to be absent/disabled when scheduling is done via DCI format 1_1. The corresponding field for indicating a presence or absence of a TCI field for DCI format 1_2 is given by ‘tci-PresentInDCI-ForDCIFormat1_2’.   

     For each CORESET, only one TCI state is activated by Medium Access Control (MAC) Control Element (CE). For each DL BWP configured to a UE in a serving cell, the UE is provided by higher layers with S ≤ 10 search space sets where, for each search space set from the S search space sets, the UE is provided the following by higher layers:
     a search space set index s, 0 ≤ s &lt; 40   an association between the search space set  s  and a CORESET p   a PDCCH monitoring periodicity of k s  slots and a PDCCH monitoring offset of o s  slots   a PDCCH monitoring pattern within a slot, indicating first symbol(s) of the CORESET within a slot for PDCCH monitoring   a duration of T s  &lt; k s  slots indicating a number of slots that the search space set s exists   a number of PDCCH candidates              M   s       L                 per CCE aggregation level L   an indication that search space set s is either a CSS set or a USS set   DCI formats to monitoring   

     For search space set s, the UE determines that a PDCCH monitoring occasion(s) exists in a slot with slot number  
     
       
         
           
             
               n 
               
                 s 
                   
                 , 
                 f 
               
               μ 
             
           
         
       
     
     in a frame with frame number n ƒ  if  
     
       
         
           
             
               
                 
                   n 
                   f 
                 
                   
                 ⋅ 
                   
                 
                   N 
                   
                     slot 
                   
                   
                     frame 
                     , 
                       
                     μ 
                   
                 
                   
                 + 
                   
                 
                   n 
                   
                     s 
                     , 
                       
                     f 
                   
                   μ 
                 
                   
                 − 
                   
                 
                   o 
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             m 
             o 
             d 
               
             
               k 
               s 
             
               
             = 
               
               
             0. 
               
           
         
       
     
     The UE monitors PDCCH for search space set s for T S  consecutive slots, starting from slot  
     
       
         
           
             
               n 
               
                 s 
                   
                 , 
                 f 
               
               μ 
             
             , 
           
         
       
     
     and does not monitor PDCCH for search space set s for the next k s  — T s  consecutive slots. 
     A UE first detects and decodes PDCCH and, if the decoding is successful, it then decodes the corresponding PDSCH based on the decoded control information in the PDCCH. 
     Uplink data transmissions are also dynamically scheduled using PDCCH. Similar to downlink, a UE first decodes uplink grants in PDCCH and then transmits data over PUSCH based the decoded control information in the uplink grant such as modulation order, coding rate, uplink resource allocation, etc. There are three DCI formats defined for scheduling PUSCH in NR, i.e., DCI formats 0_0 , 0_1, and 0_2. DCI format 0_0 has a smaller size than DCI 0_1 and can be used when a UE is not fully connected to the network. DCI format 1_2 is further introduced in NR Rel-16 for scheduling PUSCH with different priorities, in which a priority indicator is included. 
     NR HARQ ACK/NACK Feedback Over PUCCH 
     When receiving a PDSCH in the downlink from a serving gNB at slot n, a UE feeds back a Hybrid Automatic Repeat Request (HARQ) Acknowledgement (ACK) at slot n+kover a Physical Uplink Control Channel (PUCCH) resource in the uplink to the gNB if the PDSCH is decoded successfully. Otherwise, the UE sends a HARQ Negative ACK (NACK) at slot n+kto the gNB to indicate that the PDSCH is not decoded successfully. 
     In NR, up to four PUCCH resource sets can be configured to a UE. A PUCCH resource set with pucch-ResourceSetId=0 can have up to thirty-two (32) PUCCH resources while, for PUCCH resource sets with pucch-ResourceSetld=1 to 3, each set can have up to eight (8) PUCCH resources. A UE determines the PUCCH resource set in a slot based on the number of aggregated Uplink Control Information (UCI) bits to be sent in the slot. The UCI bits consist of HARQ ACK/NACK, Scheduling Request (SR), and Channel State Information (CSI) bits. 
     A 3-bit PUCCH resource Indicator (PRI) field in DCI maps to a PUCCH resource in a set of PUCCH resources with a maximum of eight PUCCH resources. For the first set of PUCCH resources with pucch-ResourceSetld = 0 and when the number of PUCCH resources, R PUCCH , in the set is larger than eight, the UE determines a PUCCH resource with index r pUCCH , 0 ≤ r PUCCH  ≤ R PUCCH  - 1, for carrying HARQ-ACK information in response to detecting a last DCI format 1_0 or DCI format 1_1 in a PDCCH reception, among DCI formats 1_0 or DCI formats 1_1 the UE received with a value of the PDSCH-to-HARQ_feedback timing indicator field indicating a same slot for the PUCCH transmission, as 
     
       
         
           
             
               r 
               
                 PUCCH 
               
             
               
             = 
               
             
               
                 
                   
                     
                       
                         
                           
                             
                               
                                 
                                   n 
                                   
                                     CCE 
                                     , 
                                       
                                     p 
                                       
                                   
                                 
                                 ⋅ 
                                 
                                   
                                     
                                       
                                         
                                           R 
                                           
                                             PUCCH 
                                           
                                         
                                       
                                       8 
                                     
                                   
                                 
                               
                               
                                 
                                   N 
                                   
                                     CCE 
                                     , 
                                     p 
                                   
                                 
                               
                             
                           
                         
                           
                         + 
                           
                         
                           Δ 
                           
                             PRI 
                           
                         
                           
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                                   R 
                                   
                                     PUCCH 
                                   
                                 
                               
                               8 
                             
                           
                         
                       
                     
                     
                       
                         If 
                           
                           
                         
                           Δ 
                           
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                           R 
                           
                             PUCCH 
                           
                         
                           
                         mod 
                           
                         8 
                           
                       
                     
                   
                   
                     
                       
                         
                           
                             
                               
                                 
                                   n 
                                   
                                     CCE 
                                     , 
                                       
                                     p 
                                       
                                   
                                 
                                 ⋅ 
                                 
                                   
                                     
                                       
                                         
                                           R 
                                           
                                             PUCCH 
                                           
                                         
                                       
                                       8 
                                     
                                   
                                 
                               
                               
                                 
                                   N 
                                   
                                     CCE 
                                     , 
                                     p 
                                   
                                 
                               
                             
                           
                         
                           
                         + 
                           
                         
                           Δ 
                           
                             PRI 
                           
                         
                           
                         ⋅ 
                           
                         
                           
                             
                               
                                 
                                   R 
                                   
                                     PUCCH 
                                   
                                 
                               
                               8 
                             
                           
                         
                           
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                           R 
                           
                             PUCCH 
                           
                         
                           
                         m 
                         o 
                         d 
                           
                         8 
                       
                     
                     
                       
                         if 
                           
                           
                         
                           Δ 
                           
                             PRI 
                           
                         
                           
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                           R 
                           
                             PUCCH 
                           
                         
                           
                         m 
                         o 
                         d 
                           
                         8 
                       
                     
                   
                 
                   
               
             
           
         
       
     
      where N CCE,p  is a number of CCEs in CORESET p of the PDCCH reception for the DCI format 1_0 or DCI format 1_1 as described in Subclause 10.1 of 3GPP TS 38.213 v15.4.0, n CCE,p  is the index of a first CCE for the PDCCH reception, and Δ PRI  is a value of the PUCCH resource indicator field in the DCI format 1_0 or DCI format 1_1. 
     Ultra-Reliable Low Latency (URLLC) Data Transmission Over Multiple Transmission Points 
     Reliable PDSCH transmission with multiple panels or TRPs has been introduced in 3GPP for NR Release 16, in which a transport block may be transmitted over multiple TRPs to achieve diversity. Reliability is achieved by transmitting different layers of an encoded codeword (CW) for the TB on the same resource over two TRPs (Scheme 1a), or different parts of a CW on different frequency resources over two TRPs (Scheme 2a), or by repeating the same TB over two TRPs in time (Schemes 3 and 4) or frequency domain (Scheme 2b). For this purpose, two TCI states are indicated in a DCI scheduling the PDSCH. 
     In NR Release 17, it has been proposed to further introduce PDCCH enhancement with multiple TRPs by repeating a PDCCH from different TRPs as shown in  FIG.  3   .  FIG.  3    shows an example of PDCCH transmission from multiple TRPs for increasing reliability. 
     Three methods were proposed in R1-1911184, “Enhancements on multi-TRP/panel transmission”, NTT DOCOMO, 3gpp RAN1#98bis, Chongqing, China, October 14th - 20th, 2019 and R1-1909423, “Preliminary results on PDCCH over multi-TRP for URLLC”, Ericsson, 3GPP RAN1#98, Prague, Czech Republic, 26th-30th August 2019. These three methods are:
     1. CCE interleaving: 
   a PDCCH with aggregation level L is mapped to two CORESETs each associated with one TRP with half of the PDCCH symbols mapped to the same L/2 CCEs in each of the two CORESETs   
   2. PDCCH repetition without soft combining 
   A PDCCH is repeated over two CORESETs each associated with one TRP, the PDCCH is considered successfully decoded if any one repetition is decoded successfully. No soft combining is performed at the UE   
   3. PDCCH repetition with soft combining 
   A PDCCH is repeated over two CORESETs each associated with one TRP, soft combining is performed before PDCCH decoding   
   

     It is shown in R1-1911184 and R1that, in the presence of channel blocking or deep fading, all three multi-TRP schemes provide better Block Error Rate (BLER) performance than single TRP. In absence of channel blocking or deep fading, CCE interleaving and PDCCH repetition with soft combining provide better BLER performance than single TRP while PDCCH repetition without soft combining performs similar as single TRP. 
     For DCI format 1_2 for URLLC PDSCH scheduling, it has been agreed in Release 16 to introduce a new reference point for the time domain resource allocation of PDSCH:
     For time domain resource allocation indication for PDSCH for Rel-16 URLLC in DCI format 1_2, using the starting symbol So of the PDCCH monitoring occasion in which the DL assignment is detected as the reference of the SLIV is supported. 
   ◯ A RRC parameter is used to enable the utilization of the new reference   ◯ When the RRC parameter enables the utilization of the new reference S 0 , the new reference S 0  is applied for TDRA entries with K 0 =0 (i.e., slot offset 0).   ◯ For other entries (if any) in the same TDRA table, the reference is slot boundary as in Rel-15.   
   

     PDSCH mapping type A is not supported with the new reference. In Rel.15, the reference point is the first symbol in the slot, while for this new DCI format, the reference point is instead the starting symbol of the PDCCH monitoring occasions, which can be different from the first symbol of the slot, especially for Type B scheduling, see Table 1. 
     SUMMARY 
     Systems and methods are disclosed herein for improving the reliability of a physical downlink control channel (PDCCH) transmission and reception. In one embodiment, a method performed by a wireless communication device for reception of PDCCH repetitions over multiple control resource sets (CORESETs) in a cellular communications system comprises receiving a configuration of a first CORESET and a second CORESET. The method further comprises receiving, from one or more network nodes, a first repetition of a PDCCH carrying downlink control information (DCI) in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. The method further comprises decoding the DCI based on the first repetition of the PDCCH and/or the second repetition of the PDCCH. In this manner, a way to link resources of two or more PDCCH repetitions is provided. 
     In one embodiment, the first and the second repetitions of the PDCCH are transmitted in first control channel elements (CCEs) of the first CORSET and second CCEs of the second CORESET, respectively. In one embodiment, the first and the second CCEs have a one-to-one mapping. In another embodiment, the first and the second CCEs have the same CCE indices. In another embodiment, the first and the second CCEs have different CCE indices. 
     In one embodiment, each of the first and the second CORESETs comprises a number of orthogonal frequency division multiplexing (OFDM) symbols in time domain and a number of resource blocks in frequency domain. 
     In one embodiment, the first and the second CORESETs are multiplexed either in time, frequency, or a combination of both time and frequency. 
     In one embodiment, receiving the first repetition of the PDCCH in the first CORESET and the second repetition of the PDCCH in the second CORESET comprises receiving the first repetition of the PDCCH in the first CORESET from a first network node and receiving the second repetition of the PDCCH in the second CORESET from a second network node. In one embodiment, the first CORESET is associated with a first TCI state, the second CORESET is associated with a second TCI state, and the first TCI state may be the same or different from the second TCI state. In one embodiment, the first and the second network nodes are associated with the first and the second TCI states, respectively. 
     In one embodiment, receiving the first repetition of the PDCCH in the first CORESET and the second repetition of the PDCCH in the second CORESET comprises receiving the first repetition of the PDCCH in the first CORESET and the second repetition of the PDCCH in the second CORESET on different beams from a single network node. In one embodiment, the first CORESET is associated with a first TCI state, the second CORESET is associated with a second TCI state, and the first TCI state may be the same or different from the second TCI state. 
     In one embodiment, either a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) is scheduled by the DCI. In one embodiment, the method further comprises determining a time offset between reception of the DCI and the scheduled PDSCH or PUSCH. In one embodiment, the time offset is between: (a) a last symbol in time from among all symbols of the first repetition of the PDCCH and the second repetition of the PDCCH and (b) a first symbol in time of the scheduled PDSCH or PUSCH. In one embodiment, the method further comprises determining a reference symbol from among the first repetition of the PDCCH and the second repetition of the PDCCH for the scheduled PDSCH or PUSCH. In one embodiment, the reference symbol is a first symbol of one of the first repetition of the PDCCH and the second repetition of the PDCCH that starts at a same time or later in time. In one embodiment, the reference symbol is a first symbol of one of the first repetition of the PDCCH and the second repetition of the PDCCH in one of the first and the second CORESETs having a lowest CORESET index. 
     In one embodiment, either a channel state information reference signal (CSI-RS) or a sounding reference signal (SRS) is triggered by the DCI. In one embodiment, the method further comprises determining a time offset between reception of the DCI and the triggered CSI-RS or SRS. In one embodiment, the time offset is between: (a) a last symbol in time from among all symbols of the first repetition of the PDCCH and the second repetition of the PDCCH and (b) the corresponding one of the CSI-RS or SRS. 
     In one embodiment, a PDSCH is scheduled by the DCI, and the method further comprises determining a physical uplink control channel (PUCCH) resource in a PUCCH resource set for carrying a Hybrid Automatic Repeat Request (HARQ) ACK or NACK associated with the scheduled PDSCH, wherein the PUCCH resource set has more than eight PUCCH resources. In one embodiment, determining the PUCCH resource comprises determining an index of a first CCE over which the first PDCCH or second PDCCH is transmitted and a total number of CCEs in the first CORESET or the second CORESET over which the first PDCCH or second PDCCH is transmitted. 
     In one embodiment, the first repetition of the PDCCH and the second repetition of the PDCCH are identical. In another embodiment, the first repetition of the PDCCH is different from the second repetition of the PDCCH. 
     In one embodiment, the DCI is one of one or more certain DCI formats for which PDCCH or DCI repetition is allowed to occur. 
     In one embodiment, a radio network temporary identifier (RNTI) associated to the DCI is one of one or more certain RNTIs for which PDCCH or DCI repetition is allowed to occur. 
     Corresponding embodiments of a wireless communication device are also provided. In one embodiment, a wireless communication device for reception of PDCCH repetitions over multiple CORESETs in a cellular communications system is adapted to receive a configuration of a first CORESET and a second CORESET. The wireless communication device is further adapted to receive, from one or more network nodes, a first repetition of a PDCCH carrying DCI in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. The wireless communication device is further adapted to decode the DCI based on the first repetition of the PDCCH and/or the second repetition of the PDCCH. 
     In one embodiment, a wireless communication device for reception of PDCCH repetitions over multiple CORESETs in a cellular communications system comprises one or more transmitters, one or more receivers, and processing circuitry associated with the one or more transmitters and the one or more receivers. The processing circuitry is configured to cause the wireless communication device to receive a configuration of a first CORESET and a second CORESET. The processing circuitry is further configured to cause the wireless communication device to receive, from one or more network nodes, a first repetition of a PDCCH carrying DCI in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. The processing circuitry is further configured to cause the wireless communication device to decode the DCI based on the first repetition of the PDCCH and/or the second repetition of the PDCCH. 
     Embodiments of a method performed by a network node are also disclosed. In one embodiment, a method performed by a network node for transmission of at least one of two or more PDCCH repetitions over multiple CORESETs in a cellular communications system comprises transmitting, to a wireless communication device, a configuration of a first CORESET and a second CORESET. The method further comprises transmitting, to the wireless communication device, at least one of a first repetition of a PDCCH carrying DCI in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. 
     In one embodiment, transmitting the at least one of the first repetition of the PDCCH in the first CORESET and the second repetition of the PDCCH in the second CORESET comprises transmitting the first repetition of the PDCCH in the first CORESET, wherein the second repetition of the PDCCH is transmitted in the second CORESET by a separate network node. 
     In one embodiment, transmitting the at least one of the first repetition of the PDCCH in the first CORESET and the second repetition of the PDCCH in the second CORESET comprises transmitting the first repetition of the PDCCH in the first CORESET on a first beam, wherein the second repetition of the PDCCH in the second CORESET is transmitted on a second beam. 
     In one embodiment, the first CORESET is associated with a first transmission configuration indicator (TCI) state and the second CORESET is associated with a second TCI state, wherein the first TCI state is either the same as or different from the second TCI state. In one embodiment, the first and the second network nodes or the first or second beams are associated with the first and the second TCI states, respectively. 
     In one embodiment, the first and the second repetitions of the PDCCH are transmitted in first control channel elements, CCEs, of the first CORESET and second CCEs of the second CORESET, respectively. In one embodiment, the first and the second CCEs have a one-to-one mapping. In one embodiment, the first and the second CCEs have the same CCE indices. In one embodiment, the first and the second CCEs have different CCE indices. 
     In one embodiment, each of the first and the second CORESETs comprises a number of OFDM symbols in time domain and a number of resource blocks in frequency domain. 
     In one embodiment, the first and the second CORESETs are multiplexed either in time, frequency, or a combination of both time and frequency. 
     In one embodiment, either a PDSCH or a PUSCH is scheduled by the DCI. In one embodiment, the method further comprises determining a time offset between the DCI and the scheduled PDSCH or PUSCH. In one embodiment, the time offset is between: (a) a last symbol in time from among all symbols of the first repetition of the PDCCH and the second repetition of the PDCCH and (b) a first symbol of the scheduled PDSCH or PUSCH. In one embodiment, the method further comprises determining a reference symbol from among the first and the second repetitions of the PDCCH for the scheduled PDSCH or PUSCH. In one embodiment, the reference symbol is a first symbol in time of one of the first repetition of the PDCCH and the second repetition of the PDCCH that starts at a same time or later in time. In one embodiment, the reference symbol is a first symbol in time of one of the first repetition of the PDCCH and the second repetition of the PDCCH in one of the first and the second CORESETs having a lowest CORESET index. 
     In one embodiment, either a CSI-RS or a SRS is triggered by the DCI. In one embodiment, the method further comprises determining a time offset between reception of the DCI and the triggered CSI-RS or SRS. In one embodiment, the time offset is between: (a) a last symbol in time from among all symbols of the first repetition of the PDCCH and the second repetition of the PDCCH and (b) the corresponding one of the CSI-RS or SRS. 
     In one embodiment, a PDSCH is scheduled by the DCI, and the method further comprises determining a PUCCH resource in a PUCCH resource set for carrying a HARQ ACK or NACK associated with the scheduled PDSCH, wherein the PUCCH resource set has more than eight PUCCH resources. In one embodiment, determining the PUCCH resource comprises determining an index of a first CCE over which the first repetition of the PDCCH or second repetition of the PDCCH is transmitted and a total number of CCEs in the first CORESET or the second CORESET over which the first repetition of the PDCCH or second repetition of the PDCCH is transmitted. 
     In one embodiment, the first and the second PDCCHs are identical. In another embodiment, the first PDCCH is different from the second PDCCH. 
     In one embodiment, the DCI is one of one or more certain DCI formats for which PDCCH or DCI repetition is allowed to occur. 
     In one embodiment, a RNTI associated to the DCI is one of one or more certain RNTIs for which PDCCH or DCI repetition is allowed to occur. 
     Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node for transmission of at least one of two or more PDCCH repetitions over multiple CORESETs in a cellular communications system is adapted to transmit, to a wireless communication device, a configuration of a first CORESET and a second CORESET. The network node is further adapted to transmit, to the wireless communication device, at least one of a first repetition of a PDCCH carrying a DCI in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. 
     In one embodiment, a network node for transmission of at least one of two or more PDCCH repetitions over multiple CORESETs in a cellular communications system comprises processing circuitry configured to cause the network node to transmit, to a wireless communication device, a configuration of a first CORESET and a second CORESET. The processing circuitry is further configured to cause the network node to transmit, to the wireless communication device, at least one of a first repetition of a PDCCH carrying a DCI in the first CORESET and a second repetition of the PDCCH carrying the same DCI in the second CORESET, wherein the first and second repetitions of the PDCCH have either: (a) different channel encoding or (b) a same channel encoding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure. 
         FIG.  1    illustrates an example of a slot in Third Generation Partnership Project (3GPP) New Radio (NR); 
         FIG.  2    illustrates the basic NR physical time-frequency resource grid; 
         FIG.  3    illustrates an example of Physical Downlink Control Channel (PDCCH) transmission from multiple Transmission/Reception Points (TRPs); 
         FIG.  4    illustrates one example of a cellular communications system  400  in which embodiments of the present disclosure may be implemented; 
         FIGS.  5  and  6    illustrate examples in accordance with embodiments of the present disclosure; 
         FIG.  7    illustrates the operation of two TRPs and a User Equipment (UE) in accordance embodiments of the present disclosure; 
         FIGS.  8  through  10    are schematic block diagrams of example embodiments of a radio access node; 
         FIGS.  11  and  12    are schematic block diagrams of example embodiments of a UE; 
         FIG.  13    illustrates an example embodiment of a communication system in which embodiments of the present disclosure may be implemented; 
         FIG.  14    illustrates example embodiments of the host computer, base station, and UE of  FIG.  13   ; and 
         FIGS.  15  through  18    are flow charts that illustrate example embodiments of methods implemented in a communication system such as that of  FIG.  13   . 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure. 
     Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. 
     Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description. 
     Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device. 
     Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gNB Central Unit (gNB-CU) or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node. Another example of a radio access node is a Transmission Reception Point (TRP). 
     Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing an Access and Mobility Function (AMF), a UPF, a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like. 
     Communication Device: As used herein, a “communication device” is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection. 
     Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (IoT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless connection. 
     Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network/system. 
     Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system. 
     Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams. 
     There currently exist certain challenge(s). For Physical Downlink Control Channel (PDCCH) repetition with soft combining, one issue is how a UE knows which two PDCCH candidates in two Control Resource Sets (CORESETs) carry the same Downlink Control Information (DCI) and thus can be soft combined. For PDCCH repetition with or without soft combining, since the two PDCCH transmission occasions can be in different symbols in a slot, another issue is how to define the time offset between the reception of the downlink (DL) DCI and the corresponding Physical Downlink Shared Channel (PDSCH) in case of PDCCH repetition, which is defined currently in NR Release 15 and Release 16 as the number of symbols between the last PDCCH symbol and its scheduled PDSCH. The issue occurs in this case since there may now be more than one PDCCH occasion transmitted and received with the same DCI. The offset is used to compare to a threshold and, depending on whether the offset exceeds the threshold, different assumptions are made on the Transmission Configuration Indictor (TCI) state(s) to assume for the PDSCH reception. A similar ambiguity exists in time offset between a PDCCH reception and its scheduled Physical Uplink Shared Channel (PUSCH), a triggered aperiodic Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS), or a triggered Sounding Reference Signal (SRS) transmission. 
     When a DL PDSCH is scheduled by a DCI carried by a PDCCH and a PUCCH resource set with more than eight (8) PUCCH resources is selected for Hybrid Automatic Repeat Request (HARQ) ACK/NACK (A/N) report for the PDSCH, PUCCH Resource Indicator (PRI) in the DCI is used together with the index of a first Control Channel Element (CCE) for the PDCCH reception for identifying a PUCCH resource for sending the HARQ A/N. In case of PDCCH repetition without combining, the first CCE for each of multiple PDCCH transmission occasions would be different. Depending on which PDCCH occasion is decoded successfully, different PUCCH resources could be selected by a UE and, since gNB then does not know in which of the PDCCH occasions the PDCCH was decoded successfully (or in case of soft combining of multiple PDCCHs, how to define the PDCCH to assume for this purpose), the gNB would need to blind decode in two or more PUCCH resources. If all PDCCH occasions were decoded successfully, which PUCCH resource to use would be an issue. 
     Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. Embodiments are disclosed herein for PDCCH repetition over multiple CORESETs in a wireless network. More specifically, embodiments of a method performed by a radio access node for PDCCH repetition over multiple CORESETs and corresponding embodiments of a radio access node are disclosed herein. In some embodiments, a method performed by a radio access node for PDCCH repetition over multiple CORESETs comprises configuring a UE with a search space set with more than one associated CORESET (e.g., a first CORESET and a second CORESET). In some embodiments, the first symbol of each CORESET in the search space set may be individually configured or a gap between the CORESETs is configured. The method further comprises transmitting a PDCCH transmission (e.g., a DCI or “DCI message”) in at least two of the CORESETs in the search space set. In some embodiments, if PDCCH repetition is configured or enabled, the PDCCH is repeated in the at least two CORESETs in the search space set on CCEs with the same indices. In some embodiments, the UE always tries to decode the PDCCH in the CCEs in the two or more CORESETs, either with or without soft combining. In some embodiments, the time offset between a PDCCH and its scheduled PDSCH or PUSCH is defined between the last symbol of the multiple PDCCH transmission occasions regardless of in which CORESET the PDCCH is successfully decoded. 
     Embodiments of a method performed by a UE for reception of two or more PDCCH repetitions (e.g., two or more DCI repetitions or “DCI message” repetitions) over multiple CORESETs and corresponding embodiments of a UE are also disclosed herein. In some embodiments, a method performed by a UE for reception of two or more PDCCH repetitions over multiple CORESETs comprises receiving (e.g., from a radio access node) one or more configurations that configure the UE with a search space set that includes more than one associated CORESET (e.g., a first CORESET and a second CORESET). In some embodiments, the first symbol of each CORESET in the search space set may be individually configured or a gap between the CORESETs is configured. The method further comprises receiving a PDCCH transmission (e.g., a DCI or “DCI message”) in at least two of the CORESETs in the search space set. In other words, the UE receives two or more repetitions of the PDCCH transmission (e.g., two or more repetitions of a DCI or “DCI message) in two or more respective CORESETs in the search space set. In some embodiments, if PDCCH repetition is configured or enabled, the PDCCH is repeated in the at least two CORESETs in the search space set on CCEs with the same indices. The method further comprises decoding the PDCCH transmission based on the received PDCCH transmissions in the at least two of the CORESETs in the search space set. 
     Certain embodiments may provide one or more of the following technical advantage(s). Embodiments disclosed herein provide a simple way to link resources of two or more PDCCH repetitions in a search space and ensure a unique PUCCH resource allocation, e.g., in case that there are more than eight (8) resources in a PUCCH resource set. Embodiments disclosed herein may also enable a UE to determine a unique time offset between a detected PDCCH and its scheduled PDSCH or PUSCH in case of PDCCH repetition regardless of where the PDCCH is successfully decoded. 
       FIG.  4    illustrates one example of a cellular communications system  400  in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communications system  400  is a 5G system (5GS) including a Next Generation RAN (NG-RAN) or an Evolved Packet System (EPS) including an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). In this example, the RAN includes base stations  402 - 1  and  402 - 2 , which in an NG-RAN are referred to gNBs (NR base stations) or ng-eNBs (i.e., eNBs connected to 5GC) and in E-UTRAN (i.e., LTE) are referred to as eNBs, controlling corresponding (macro) cells  404 - 1  and  404 - 2 . The base stations  402 - 1  and  402 - 2  are generally referred to herein collectively as base stations  402  and individually as base station  402 . Likewise, the (macro) cells  404 - 1  and  404 - 2  are generally referred to herein collectively as (macro) cells  404  and individually as (macro) cell  404 . The RAN may also include a number of low power nodes  406 - 1  through  406 - 4  controlling corresponding small cells  408 - 1  through  408 - 4 . The low power nodes  406 - 1  through  406 - 4  can be small base stations (such as pico or femto base stations) or Remote Radio Heads (RRHs), or the like. Notably, while not illustrated, one or more of the small cells  408 - 1  through  408 - 4  may alternatively be provided by the base stations  402 . The low power nodes  406 - 1  through  406 - 4  are generally referred to herein collectively as low power nodes  406  and individually as low power node  406 . Likewise, the small cells  408 - 1  through  408 - 4  are generally referred to herein collectively as small cells  408  and individually as small cell  408 . The cellular communications system  400  also includes a core network  410 , which in the 5GS is referred to as the 5G core (5GC). The base stations  402  (and optionally the low power nodes  406 ) are connected to the core network  410 . 
     The base stations  402  and the low power nodes  406  provide service to wireless communication devices  412 - 1  through  412 - 5  in the corresponding cells  404  and  408 . The wireless communication devices  412 - 1  through  412 - 5  are generally referred to herein collectively as wireless communication devices  412  and individually as wireless communication device  412 . In the following description, the wireless communication devices  412  are oftentimes UEs and as such sometimes referred to herein as UEs  412 , but the present disclosure is not limited thereto. 
     Embodiments are disclosed herein for PDCCH repetition over multiple CORESETs in a wireless network such as, e.g., the cellular communications system  400  of  FIG.  4   . Embodiments are described below for 3GPP systems and, as such, 3GPP terminology is used. However, the embodiments are not limited thereto. 
     In general, embodiments disclosed herein relate to linking PDCCH resources for multiple PDCCH transmission occasions. 
     In one embodiment, a search space set is defined to be associated with two or more CORESETs. Each CORESET is configured to be associated with an individual TCI state which allows them to be transmitted from different TRPs or different beams from the same TRP. The UE  412  may use the RS in the associated TCI state for time and/or frequency synchronization. 
     A PDCCH or a DCI (also referred to herein as a “DCI message”) is repeated in the CORESETs within a slot. Repeating a DCI means that the information content is the same while the channel encoding may be the same or different for each PDCCH transmitting this DCI. Thereby if different encodings are used, some coding diversity may be achieved. Repeating PDCCH means that the information content is the same and same encoding is used for each PDCCH (gain in signal to noise ratio can be achieved). 
     In both cases, when a PDCCH or a DCI is repeated in two or more CORESETs within a slot, the information content is the same. In one embodiment, in order to ensure the same payload size for the DCI repeated in the two or more CORESETs with DCI format 1_1, the ‘tci-PresentInDCI’ field should be either present/enabled in all of the two or more CORESETs within a slot or be absent/disabled in all of the two or more CORESETs within a slot. Similarly, in order to ensure the same payload size for the DCI repeated in the two or more CORESETs with DCI format 1_2, the ‘tci-PresentInDCI-ForDCIFormat1_2’ field should be either present/enabled in all of the two or more CORESETs within a slot or be absent/disabled in all of the two or more CORESETs within a slot. 
     The decoding of the PDCCH can be with or without soft combining. Whether the UE  412  uses soft combining of PDCCH can be indicated from the UE  412  to the network by higher layer signaling, e.g. as a UE capability or feature. 
     In one embodiment, the PDCCH may be repeated in CCEs with the same CCE indices in different CORESETs. With such configuration, a UE  412  is indicated from the network that PDCCH repetition may occur in the search space set, the UE  412  knows exactly what resources (i.e., CCEs) of a PDCCH that may be repeated, and the UE  412  knows this from either signaling by higher layers or from specification. Since the same CCE indices in different CORESETs are linked in this manner, the index for a first CCE in all PDCCH repetition occasions is the same and, consequently, they all point to the same PUCCH resource for HARQ A/N transmission associated with the PDSCH scheduling. 
     In another embodiment, the CCEs between any two CORESETs are linked in a one-to-one mapping. The CCE#i in a first CORESET is linked to CCE#k in a second CORESET where i is not equal to k, in general. The CORESET identifier p may be the same for these two CORESETs in the CORESET set and, hence, the CCEs are mapped identically to physical resources for these two CORESETs. A mapping rule, or hashing table, is specified or signaled to the UE  412 , where the mapping rule links the CCEs between any two CORESETs, i.e. translates i to k. The benefit of deviating from the i=k mapping is that frequency diversity is achieved in the PDCCH transmissions from different CORESETs, especially if the two CORESETs are linked to the same TCI state and are thus transmitted from the same transmission point. In this case, it is beneficial if the two PDCCH transmitted from different CORESETs use different CCEs as they are mapped to different time and/or frequency resources. One example method to define the hashing function is to determine k= (i+L/2)mod L where L is the number of CCEs in the CORESET. In this case, the first CCE of the first CORESET is linked to the “middle numbered” CCE of the second CORESET and so on. In this case, regardless in which CORESET(s) a PDCCH is successfully decoded, the first CCE and the number of CCEs in one of the CORESETs are always used in deriving the corresponding PUCCH resource if a PDSCH is scheduled. 
     In one embodiment, the number of CCEs is configured by the network to be the same for all the CORESETs associated to the search space set. In another embodiment, the number of CCEs of the CORESETs may be configured to be different. In this case, the number of CCEs of one of the CORESETs may be used in deriving a PUCCH resource when an associated PUCCH resource set has more than 8 PUCCH resources and a PDSCH is scheduled by the DCI. In one embodiment, the CORESET with the smallest (or the largest) number of CCEs may be the selected CORESET for the purpose of PUCCH resource determination. In another embodiment, the number of CCEs of a CORESET over which a PDCCH is correctly detected is used. In yet another embodiment, the first CCE and the number of CCEs to be used are associated with either the first or the second CORESET. 
     In the search space set configuration, a first symbol for each of the associated CORESETs within a slot is signaled by the network to the UE, e.g. using higher layer signaling such as RRC. The CORESETs may be either time division multiplexed (TDMed) or frequency division multiplexed (FDMed) in a slot. 
     When a DL DCI is carried by the PDCCH, the time offset between the reception of the DL DCI and the corresponding PDSCH is defined as the number of symbols between the last symbol of the multiple PDCCH transmit occasions and the first symbol of the PDSCH. If the DL DCI schedules multiple PDSCH transmission occasions, then the time offset is defined as the number of symbols between the last symbol of the multiple PDCCH transmit occasions and the first symbol of the first PDSCH transmission occasion. The PDSCH can be within the same slot as the PDCCHs or in a different slot. 
     When a UL DCI is carried by the PDCCH, the time offset between the reception of the UL DCI and the corresponding PUSCH is defined as the number of symbols between the last symbol of the multiple PDCCH transmit occasions and the first symbol of the PUSCH. If the UL DCI schedules multiple PUSCH transmission occasions, then the time offset is defined as the number of symbols between the last symbol of the multiple PDCCH transmit occasions and the first symbol of the first PUSCH transmission occasion. 
     Similarly, when an aperiodic channel state information reference signal (CSI-RS) or an aperiodic sounding reference signal (SRS) is triggered by a DCI carried by the PDCCH, the time offset between the reception of the DCI and the corresponding CSI-RS or SRS is defined as the number of symbols between the last symbol of the multiple PDCCH transmit occasions and the first symbol of the CSI-RS or SRS. 
     When the use of reference So is enabled via higher layer signaling, the starting symbol for a PDSCH scheduled by DCI format 1_2 with K 0 =0 (i.e., slot offset 0) is defined with respect to S o  where S 0  is the starting symbol of the PDCCH monitoring occasion in which the DL assignment is detected. If the PDSCH is scheduled with DCI format 1_2 via multiple PDCCH transmission occasions, then the reference So is defined as starting symbol of the latest PDCCH transmission occasion among the multiple PDCCH transmission occasions. In an alternative embodiment, the reference So is defined as starting symbol of the PDCCH transmission occasion corresponding to the lowest CORESET ID. 
     An example is shown in  FIG.  5   , where a search space is associated with two CORESETs. In this example, the two CORESETs are TDMed and each CORESET consists of one symbol. The first symbol of CORESET  0  starts at symbol 0 and the first symbol of CORESET  1  starts at symbol 1. A PDCCH with aggregation level 4 is repeated in the two CORESETs in CCEs #0 to 3 in both CORESETs. The time offset between the reception of the DL DCI and the corresponding PDSCH is 4 in this example, regardless of whether soft combining is used or not and in which CORESET the DCI is actually decoded. The two CORESETs may be associated with two TRPs by activating two TCI states each associated to one TRP, and in that case, the PDCCH would be repeated over the two TRP as shown in  FIG.  5   . 
       FIG.  6    shows an example of PDCCH repetition in a search space set associated with two CORESETs in an FDM manner. This could be used at lower carrier frequency (e.g., frequency range 1, FR1) where a UE  412  can receive from multiple TRPs simultaneously or the two CORESETs are associated with a single TRP but two different panels. 
     In one embodiment, applying the PDCCH repetition methods is dependent on the search spaces, CORESETs, the RNTIs, or DCI formats.
     E.g., it may only be applied to UE specific search spaces,   E.g., it may only be applied to certain group of CORESETs,   E.g., it may only be applied to PDCCH scrambled with CS-RNTI, C-RNTI, or MCS-C-RNTI, or   E.g., it may only be applied to DCI format 1_1, DCI 1_2, DCI 0_1, or DCI 0_2.   E.g., it may only be applied when the high priority indicator in DCI format 0_2 or DCI format 1_2 is set.   

     In one embodiment, the PDCCH repetition can be used to activate one uplink configured grant transmission or one downlink SPS reception. 
     In one embodiment, the PDCCH repetition can be used to deactivate uplink configured grant transmission or downlink SPS reception. 
       FIG.  7    illustrates the operation of two TRPs (TRP1  700 - 1  and TRP2  700 - 2 ) and a UE  412  in accordance with at least some aspects of the embodiments described above. Note that optional steps are represented by dashed lines/boxes. Further, any one or more of these steps may be performed in this method (i.e., not all steps are required). TRP1  700 - 1  and TRP2  700 - 2  may correspond to, for example, different base stations (e.g., base station  402 - 1  and base station  402 - 2  or base station  402 - 1  and low power node  406 - 1 ) and the UE  412  may be, e.g., the wireless communication device  412 - 1 . As another example, TRP1  700 - 1  and TRP2  700 - 2  may correspond to different beams from the same base station (e.g., base station  402 - 1 ). 
     As illustrated, the UE  412  is configured with a search space set that includes two or more CORESETs, as described above (step  701 ). In this example, the configuration is received from TRP1  700 - 1 , but is not limited thereto. As described above, TRP1  700 - 1  transmits a first PDCCH or DCI repetition in a first CORESET (step  702 ), and TRP2  700 - 2  transmits a second PDCCH or DCI repetition in a second CORSET (step  704 ). The first and second CORESETs are different ones of the two or more CORESETs included in the configured search space set. The details described above regarding the search space set, the PDCCH or DCI repetitions, the CORESETs, and the transmission of the PDCCH or DCI repetitions are equally applicable here. 
     At the UE  412 , the UE  412  receives the PDCCH or DCI repetitions in the first and second CORESETs and attempts to decode the PDCCH or DCI based on the received repetitions, as described above (step  706 ). 
     In some embodiments, the PDCCH or DCI is successfully decoded and schedules an associated PDSCH or PUSCH transmission for the UE  412 . In this case, the UE  412  may determine a time offset (e.g., expressed as a number of symbols) between the received PDCCH or DCI and the scheduled PDSCH or PUSCH transmission as described above (step  708 ). The UE  412  then receives/transmits the PDSCH/PUSCH in accordance with the determined time offset, as described above (step  710 ). Note that the details described above regarding determining the time offset and receiving/transmitting the scheduled PDSCH/PUSCH are equally applicable here. 
     In some embodiments, the PDCCH or DCI is successfully decoded and schedules an associated PDSCH transmission for the UE  412 . In this case, the UE  412  may determine a PUCCH resource for carrying a HARQ ACK/NACK associated with the scheduled PDSCH transmission as described above (step  712 ) and transmits a HARQ ACK/NACK for the scheduled PDSCH transmission using the determined PUCCH resource (step  714 ). In some embodiments, the PDCCH repetitions are repeated in the first and second CORESETs in CCEs with the same CCE indices. As discussed above, since the same CCE indices the first and second CORESETs are linked in this manner, they all point to the same PUCCH resource for HARQ ACK/NACK transmission associated with the PDSCH transmission scheduled by the PDCCH/DCI. In some other embodiments, the CCEs between the first and second CORESETs are linked in a one-to-one mapping (e.g., defined by a predefined or preconfigured mapping table or a predefined or preconfigured hashing function), and the first CCE and the number of CCEs in one of the first and second CORESETs is used to derive the corresponding PUCCH resource for carrying the HARQ ACK/NACK for the scheduled PDSCH transmission. Note that the details described above regarding determining the PUCCH resource for carrying the HARQ ACK/NACK for the scheduled PDSCH are equally applicable here. 
       FIG.  8    is a schematic block diagram of a radio access node  800  according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The radio access node  800  may be, for example, a base station  402  or  406  or a network node that implements all or part of the functionality of the base station  402 , eNB, gNB, or TRP described herein. As illustrated, the radio access node  800  includes a control system  802  that includes one or more processors  804  (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory  806 , and a network interface  808 . The one or more processors  804  are also referred to herein as processing circuitry. In addition, the radio access node  800  may include one or more radio units  810  that each includes one or more transmitters  812  and one or more receivers  814  coupled to one or more antennas  816 . The radio units  810  may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s)  810  is external to the control system  802  and connected to the control system  802  via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s)  810  and potentially the antenna(s)  816  are integrated together with the control system  802 . The one or more processors  804  operate to provide one or more functions of a radio access node  800  as described herein (e.g., one or more functions of a TRP as described herein, e.g., with respect to  FIG.  7   ). In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory  806  and executed by the one or more processors  804 . 
       FIG.  9    is a schematic block diagram that illustrates a virtualized embodiment of the radio access node  800  according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures. Again, optional features are represented by dashed boxes. 
     As used herein, a “virtualized” radio access node is an implementation of the radio access node  800  in which at least a portion of the functionality of the radio access node  800  is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node  800  may include the control system  802  and/or the one or more radio units  810 , as described above. The control system  802  may be connected to the radio unit(s)  810  via, for example, an optical cable or the like. The radio access node  800  includes one or more processing nodes  900  coupled to or included as part of a network(s)  902 . If present, the control system  802  or the radio unit(s) are connected to the processing node(s)  900  via the network  902 . Each processing node  900  includes one or more processors  904  (e.g., CPUs, ASICs, FPGAs, and/or the like), memory  906 , and a network interface  908 . 
     In this example, functions  910  of the radio access node  800  described herein (e.g., one or more functions of a TRP as described herein, e.g., with respect to  FIG.  7   ) are implemented at the one or more processing nodes  900  or distributed across the one or more processing nodes  900  and the control system  802  and/or the radio unit(s)  810  in any desired manner. In some particular embodiments, some or all of the functions  910  of the radio access node  800  described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s)  900 . As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s)  900  and the control system  802  is used in order to carry out at least some of the desired functions  910 . Notably, in some embodiments, the control system  802  may not be included, in which case the radio unit(s)  810  communicate directly with the processing node(s)  900  via an appropriate network interface(s). 
     In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node  800  or a node (e.g., a processing node  900 ) implementing one or more of the functions  910  of the radio access node  800  in a virtual environment according to any of the embodiments described herein (e.g., one or more functions of a TRP as described herein, e.g., with respect to  FIG.  7   ) is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory). 
       FIG.  10    is a schematic block diagram of the radio access node  800  according to some other embodiments of the present disclosure. The radio access node  800  includes one or more modules  1000 , each of which is implemented in software. The module(s)  1000  provide the functionality of the radio access node  800  described herein (e.g., one or more functions of a TRP as described herein, e.g., with respect to  FIG.  7   ). This discussion is equally applicable to the processing node  900  of  FIG.  9    where the modules  1000  may be implemented at one of the processing nodes  900  or distributed across multiple processing nodes  900  and/or distributed across the processing node(s)  900  and the control system  802 . 
       FIG.  11    is a schematic block diagram of a wireless communication device  1100  according to some embodiments of the present disclosure. As illustrated, the wireless communication device  1100  includes one or more processors  1102  (e.g., CPUs, ASICs, FPGAs, and/or the like), memory  1104 , and one or more transceivers  1106  each including one or more transmitters  1108  and one or more receivers  1110  coupled to one or more antennas  1112 . The transceiver(s)  1106  includes radio-front end circuitry connected to the antenna(s)  1112  that is configured to condition signals communicated between the antenna(s)  1112  and the processor(s)  1102 , as will be appreciated by on of ordinary skill in the art. The processors  1102  are also referred to herein as processing circuitry. The transceivers  1106  are also referred to herein as radio circuitry. In some embodiments, the functionality of the wireless communication device  1100  described above (e.g., one or more functions of a UE as described herein, e.g., with respect to  FIG.  7   ) may be fully or partially implemented in software that is, e.g., stored in the memory  1104  and executed by the processor(s)  1102 . Note that the wireless communication device  1100  may include additional components not illustrated in  FIG.  11    such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other components for allowing input of information into the wireless communication device  1100  and/or allowing output of information from the wireless communication device  1100 ), a power supply (e.g., a battery and associated power circuitry), etc. 
     In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device  1100  according to any of the embodiments described herein (e.g., one or more functions of a UE as described herein, e.g., with respect to  FIG.  7   ) is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory). 
       FIG.  12    is a schematic block diagram of the wireless communication device  1100  according to some other embodiments of the present disclosure. The wireless communication device  1100  includes one or more modules  1200 , each of which is implemented in software. The module(s)  1200  provide the functionality of the wireless communication device  1100  described herein (e.g., one or more functions of a UE as described herein, e.g., with respect to  FIG.  7   ). 
     With reference to  FIG.  13   , in accordance with an embodiment, a communication system includes a telecommunication network  1300 , such as a 3GPP-type cellular network, which comprises an access network  1302 , such as a RAN, and a core network  1304 . The access network  1302  comprises a plurality of base stations  1306 A,  1306 B,  1306 C, such as Node Bs, eNBs, gNBs, or other types of wireless Access Points (APs), each defining a corresponding coverage area  1308 A,  1308 B,  1308 C. Each base station  1306 A,  1306 B,  1306 C is connectable to the core network  1304  over a wired or wireless connection  1310 . A first UE  1312  located in coverage area  1308 C is configured to wirelessly connect to, or be paged by, the corresponding base station  1306 C. A second UE  1314  in coverage area  1308 A is wirelessly connectable to the corresponding base station  1306 A. While a plurality of UEs  1312 ,  1314  are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station  1306 . 
     The telecommunication network  1300  is itself connected to a host computer  1316 , which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer  1316  may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections  1318  and  1320  between the telecommunication network  1300  and the host computer  1316  may extend directly from the core network  1304  to the host computer  1316  or may go via an optional intermediate network  1322 . The intermediate network  1322  may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network  1322 , if any, may be a backbone network or the Internet; in particular, the intermediate network  1322  may comprise two or more sub-networks (not shown). 
     The communication system of  FIG.  13    as a whole enables connectivity between the connected UEs  1312 ,  1314  and the host computer  1316 . The connectivity may be described as an Over-the-Top (OTT) connection  1324 . The host computer  1316  and the connected UEs  1312 ,  1314  are configured to communicate data and/or signaling via the OTT connection  1324 , using the access network  1302 , the core network  1304 , any intermediate network  1322 , and possible further infrastructure (not shown) as intermediaries. The OTT connection  1324  may be transparent in the sense that the participating communication devices through which the OTT connection  1324  passes are unaware of routing of uplink and downlink communications. For example, the base station  1306  may not or need not be informed about the past routing of an incoming downlink communication with data originating from the host computer  1316  to be forwarded (e.g., handed over) to a connected UE  1312 . Similarly, the base station  1306  need not be aware of the future routing of an outgoing uplink communication originating from the UE  1312  towards the host computer  1316 . 
     Example implementations, in accordance with an embodiment, of the UE, base station, and host computer discussed in the preceding paragraphs will now be described with reference to  FIG.  14   . In a communication system  1400 , a host computer  1402  comprises hardware  1404  including a communication interface  1406  configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system  1400 . The host computer  1402  further comprises processing circuitry  1408 , which may have storage and/or processing capabilities. In particular, the processing circuitry  1408  may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The host computer  1402  further comprises software  1410 , which is stored in or accessible by the host computer  1402  and executable by the processing circuitry  1408 . The software  1410  includes a host application  1412 . The host application  1412  may be operable to provide a service to a remote user, such as a UE  1414  connecting via an OTT connection  1416  terminating at the UE  1414  and the host computer  1402 . In providing the service to the remote user, the host application  1412  may provide user data which is transmitted using the OTT connection  1416 . 
     The communication system  1400  further includes a base station  1418  provided in a telecommunication system and comprising hardware  1420  enabling it to communicate with the host computer  1402  and with the UE  1414 . The hardware  1420  may include a communication interface  1422  for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system  1400 , as well as a radio interface  1424  for setting up and maintaining at least a wireless connection  1426  with the UE  1414  located in a coverage area (not shown in  FIG.  14   ) served by the base station  1418 . The communication interface  1422  may be configured to facilitate a connection  1428  to the host computer  1402 . The connection  1428  may be direct or it may pass through a core network (not shown in  FIG.  14   ) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware  1420  of the base station  1418  further includes processing circuitry  1430 , which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The base station  1418  further has software  1432  stored internally or accessible via an external connection. 
     The communication system  1400  further includes the UE  1414  already referred to. The UE’s  1414  hardware  1434  may include a radio interface  1436  configured to set up and maintain a wireless connection  1426  with a base station serving a coverage area in which the UE  1414  is currently located. The hardware  1434  of the UE  1414  further includes processing circuitry  1438 , which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE  1414  further comprises software  1440 , which is stored in or accessible by the UE  1414  and executable by the processing circuitry  1438 . The software  1440  includes a client application  1442 . The client application  1442  may be operable to provide a service to a human or non-human user via the UE  1414 , with the support of the host computer  1402 . In the host computer  1402 , the executing host application  1412  may communicate with the executing client application  1442  via the OTT connection  1416  terminating at the UE  1414  and the host computer  1402 . In providing the service to the user, the client application  1442  may receive request data from the host application  1412  and provide user data in response to the request data. The OTT connection  1416  may transfer both the request data and the user data. The client application  1442  may interact with the user to generate the user data that it provides. 
     It is noted that the host computer  1402 , the base station  1418 , and the UE  1414  illustrated in  FIG.  14    may be similar or identical to the host computer  1316 , one of the base stations  1306 A,  1306 B,  1306 C, and one of the UEs  1312 ,  1314  of  FIG.  13   , respectively. This is to say, the inner workings of these entities may be as shown in  FIG.  14    and independently, the surrounding network topology may be that of  FIG.  13   . 
     In  FIG.  14   , the OTT connection  1416  has been drawn abstractly to illustrate the communication between the host computer  1402  and the UE  1414  via the base station  1418  without explicit reference to any intermediary devices and the precise routing of messages via these devices. The network infrastructure may determine the routing, which may be configured to hide from the UE  1414  or from the service provider operating the host computer  1402 , or both. While the OTT connection  1416  is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). 
     The wireless connection  1426  between the UE  1414  and the base station  1418  is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE  1414  using the OTT connection  1416 , in which the wireless connection  1426  forms the last segment. 
     A measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection  1416  between the host computer  1402  and the UE  1414 , in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection  1416  may be implemented in the software  1410  and the hardware  1404  of the host computer  1402  or in the software  1440  and the hardware  1434  of the UE  1414 , or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection  1416  passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software  1410 ,  1440  may compute or estimate the monitored quantities. The reconfiguring of the OTT connection  1416  may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station  1418 , and it may be unknown or imperceptible to the base station  1418 . Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 1402’s measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software  1410  and  1440  causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection  1416  while it monitors propagation times, errors, etc. 
       FIG.  15    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE which may be those described with reference to  FIGS.  13  and  14   . For simplicity of the present disclosure, only drawing references to  FIG.  15    will be included in this section. In step  1500 , the host computer provides user data. In sub-step  1502  (which may be optional) of step  1500 , the host computer provides the user data by executing a host application. In step  1504 , the host computer initiates a transmission carrying the user data to the UE. In step  1506  (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1508  (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. 
       FIG.  16    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE which may be those described with reference to  FIGS.  13  and  14   . For simplicity of the present disclosure, only drawing references to  FIG.  16    will be included in this section. In step  1600  of the method, the host computer provides user data. In an optional sub-step (not shown) the host computer provides the user data by executing a host application. In step  1602 , the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step  1604  (which may be optional), the UE receives the user data carried in the transmission. 
       FIG.  17    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE which may be those described with reference to  FIGS.  13  and  14   . For simplicity of the present disclosure, only drawing references to  FIG.  17    will be included in this section. In step  1700  (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step  1702 , the UE provides user data. In sub-step  1704  (which may be optional) of step  1700 , the UE provides the user data by executing a client application. In sub-step  1706  (which may be optional) of step  1702 , the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in sub-step  1708  (which may be optional), transmission of the user data to the host computer. In step  1710  of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure. 
       FIG.  18    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE which may be those described with reference to  FIGS.  13  and  14   . For simplicity of the present disclosure, only drawing references to  FIG.  18    will be included in this section. In step  1800  (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step  1802  (which may be optional), the base station initiates transmission of the received user data to the host computer. In step  1804  (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. 
     Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure. 
     While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.). 
     Some example embodiments of the present disclosure are as follows. 
     Embodiment 1: A method of PDCCH repetition over multiple CORESETs in a wireless network comprising one or more network nodes and a UE, the method comprising one or more of: configuring ( 701 ) the UE with a search space set comprising a first CORESET and a second CORESET; transmitting ( 702 ;  704 ), by the one or more network nodes, a DCI in a first PDCCH in the first CORESET and in a second PDCCH in the second CORESET; and decoding ( 706 ), by the UE, the DCI based on the first and the second PDCCH. 
     Embodiment 2: The method of embodiment 1, wherein the first and the second PDCCH are transmitted in CCEs of the first and the second CORESET having the same CCE indices. 
     Embodiment 3: The method of embodiment 1 or 2, wherein the first and the second CORESETs are multiplexed either in time, frequency, or a combination of both time and frequency. 
     Embodiment 4: The method of any one of embodiments 1 to 3, wherein the first CORESET is associated with a first TCI state, the second CORESET is associated with a second TCI state, and the first TCI state may be the same or different from the second TCI state. 
     Embodiment 5: The method of any one of embodiments 1 to 4, wherein the method further comprises scheduling a PDSCH or a PUSCH by the DCI. 
     Embodiment 6: The method of any one of embodiments 1 to 5, wherein the method further comprises determining ( 706 ) a time offset between reception of the DCI and the scheduled one of PDSCH or PUSCH and/or a time offset between reception of the DCI and CSI-RS and/or SRS. 
     Embodiment 7: The method of embodiment 6, wherein the time offset is between a last symbol of the first and the second PDCCH and the first symbol of the corresponding one of PDSCH, PUSCH, CSI-RS, and SRS. 
     Embodiment 8: The method of any one of embodiments 1 to 5, wherein a PDSCH is scheduled by the DCI, and the method further comprises determining ( 712 ) a PUCCH resource for carrying a HARQ A/N associated with the scheduled PDSCH. 
     Embodiment 9: The method of embodiment 8, wherein the determining ( 712 ) the PUCCH resource comprises determining an index of a first CCE over which the first (or second) PDCCH is transmitted and a total number of CCEs in the first or the second CORESET over which the first (or second) PDCCH is transmitted. 
     Embodiment 10: The method of any one of embodiments 1 to 9, wherein the first and the second PDCCH are identical. 
     Embodiment 11: The method of any one of embodiments 1 to 9, wherein the first PDCCH is different from the second PDCCH. 
     Embodiment 12: The method of any one of embodiments 1 to 11, wherein the PDCCH repetition may occur for certain DCI formats. 
     Embodiment 13: The method of any one of embodiments 1 to 11, wherein the PDCCH repetition may occur for certain RNTIs. 
     Embodiment 14: The method of any one of embodiments 1 to 11, wherein the PDCCH repetition may occur for certain UE specific search spaces. 
     Group A Embodiments 
     Embodiment 15: A method performed by a wireless communication device ( 412 ) for reception of PDCCH repetitions over multiple CORESETs in a cellular communications system ( 400 ), the method comprising one or more of: receiving ( 701 ) a configuration of a search space set comprising a first CORESET and a second CORESET; receiving ( 702 ;  704 ), from one or more network nodes, a first repetition of a PDCCH/DCI in the first CORESET and a second repetition of the PDCCH/DCI in the second CORESET, the first and second repetitions of the PDCCH/DCI being first and second repetitions of DCI on first and second PDCCHs having either: (a) different channel encoding or (b) a same channel encoding; decoding ( 706 ) the PDCCH or DCI based on the first and the second repetitions of the PDCCH or DCI. 
     Embodiment 16: The method of embodiment 15 wherein receiving ( 702 ;  704 ) the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET comprises: receiving ( 702 ) the first repetition of the PDCCH/DCI in the first CORESET from a first network node; and receiving ( 704 ) the second repetition of the PDCCH/DCI in the second CORESET from a second network node. 
     Embodiment 17: The method of embodiment 15 wherein receiving ( 702 ;  704 ) the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET comprises receiving ( 702 ;  704 ) the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET on different beams from a single network node. 
     Embodiment 18: The method of any one of embodiments 15 to 17, wherein the first and the second PDCCHs are transmitted in CCEs of the first and the second CORESETs having the same CCE indices. 
     Embodiment 19: The method of any one of embodiments 15 to 18, wherein the first and the second CORESETs are multiplexed either in time, frequency, or a combination of both time and frequency. 
     Embodiment 20: The methods of any one of embodiments 15 to 19, wherein the first CORESET is associated with a first TCI state, the second CORESET is associated with a second TCI state, and the first TCI state may be the same or different from the second TCI state. 
     Embodiment 21: The method of any one of embodiments 15 to 20, wherein either a PDSCH or a PUSCH is scheduled by the DCI. 
     Embodiment 22: The method embodiment 21, further comprising determining ( 706 ) a time offset between reception of the DCI and the scheduled PDSCH or PUSCH. 
     Embodiment 23: The method of any one of embodiments 15 to 22, further comprising determining a time offset between reception of the DCI and CSI-RS and/or SRS. 
     Embodiment 24: The method of embodiment 22 or 23, wherein the time offset is between a last symbol of the first and the second PDCCH and the first symbol of the corresponding one of PDSCH, PUSCH, CSI-RS, and SRS. 
     Embodiment 25: The method of any one of embodiments 15 to 24, wherein a PDSCH is scheduled by the DCI, and the method further comprises determining ( 712 ) a PUCCH resource for carrying a HARQ A/N associated with the scheduled PDSCH. 
     Embodiment 26: The method of embodiment 25, wherein determining ( 712 ) the PUCCH resource comprises determining an index of a first CCE over which the first (or second) PDCCH is transmitted and a total number of CCEs in the first or the second CORESET over which the first (or second) PDCCH is transmitted. 
     Embodiment 27: The method of any one of embodiments 15 to 26, wherein the first and the second PDCCHs are identical. 
     Embodiment 28: The method of any one of embodiments 15 to 26, wherein the first PDCCH is different from the second PDCCH. 
     Embodiment 29: The method of any one of embodiments 15 to 28, wherein PDCCH/DCI repetition may occur for certain DCI formats. 
     Embodiment 30: The method of any one of embodiments 15 to 28, wherein PDCCH/DCI repetition may occur for certain RNTIs. 
     Embodiment 31: The method of any one of embodiments 15 to 28, wherein PDCCH/DCI repetition may occur for certain UE specific search spaces. 
     Embodiment 32: The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to the base station. 
     Group B Embodiments 
     Embodiment 33: A method performed by one or more base stations for transmission of PDCCH repetitions over multiple CORESETs in a cellular communications system ( 400 ), the method comprising one or more of: transmitting ( 701 ), to a UE, a configuration of a search space set comprising a first CORESET and a second CORESET; transmitting ( 702 ;  704 ), to the UE, a first repetition of a PDCCH/DCI in the first CORESET and a second repetition of the PDCCH/DCI in the second CORESET, the first and second repetitions of the PDCCH/DCI being first and second repetitions of DCI on first and second PDCCHs having either: (a) different channel encoding or (b) a same channel encoding. 
     Embodiment 34: The method of embodiment 33 wherein transmitting ( 702 ;  704 ) the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET comprises: transmitting ( 702 ), by a first network node, the first repetition of the PDCCH/DCI in the first CORESET; and transmitting ( 704 ), by a second network node, the second repetition of the PDCCH/DCI in the second CORESET. 
     Embodiment 35: The method of embodiment 33 wherein transmitting ( 702 ;  704 ) the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET comprises transmitting ( 702 ;  704 ), by a single network node, the first repetition of the PDCCH/DCI in the first CORESET and the second repetition of the PDCCH/DCI in the second CORESET, on different beams. 
     Embodiment 36: The method of any one of embodiments 33 to 35, wherein the first and the second PDCCHs are transmitted in CCEs of the first and the second CORESETs having the same CCE indices. 
     Embodiment 37: The method of any one of embodiments 33 to 36, wherein the first and the second CORESETs are multiplexed either in time, frequency, or a combination of both time and frequency. 
     Embodiment 38: The methods of any one of embodiments 33 to 37, wherein the first CORESET is associated with a first TCI state, the second CORESET is associated with a second TCI state, and the first TCI state may be the same or different from the second TCI state. 
     Embodiment 39: The method of any one of embodiments 33 to 38, wherein either a PDSCH or a PUSCH is scheduled by the DCI. 
     Embodiment 40: The method of any one of embodiments 33 to 39, wherein the first and the second PDCCHs are identical. 
     Embodiment 41: The method of any one of embodiments 33 to 39, wherein the first PDCCH is different from the second PDCCH. 
     Embodiment 42: The method of any one of embodiments 33 to 41, wherein PDCCH/DCI repetition may occur for certain DCI formats. 
     Embodiment 43: The method of any one of embodiments 33 to 41, wherein PDCCH/DCI repetition may occur for certain RNTIs. 
     Embodiment 44: The method of any one of embodiments 33 to 41, wherein PDCCH/DCI repetition may occur for certain UE specific search spaces. 
     Embodiment 45: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a wireless device. 
     Group C Embodiments 
     Embodiment 46: A wireless device for reception of PDCCH repetitions over multiple CORESETs in a cellular communications system, the wireless device comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the wireless device. 
     Embodiment 47: A base station for PDCCH repetitions over multiple CORESETs in a cellular communications system, the base station comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; and power supply circuitry configured to supply power to the base station. 
     Embodiment 48: A User Equipment, UE, for reception of PDCCH repetitions over multiple CORESETs in a cellular communications system, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE. 
     Embodiment 49: A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a User Equipment, UE; wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments. 
     Embodiment 50: The communication system of the previous embodiment further including the base station. 
     Embodiment 51: The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station. 
     Embodiment 52: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application. 
     Embodiment 53: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group B embodiments. 
     Embodiment 54: The method of the previous embodiment, further comprising, at the base station, transmitting the user data. 
     Embodiment 55: The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application. 
     Embodiment 56: A User Equipment, UE, configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform the method of the previous 3 embodiments. 
     Embodiment 57: A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to a cellular network for transmission to a User Equipment, UE; wherein the UE comprises a radio interface and processing circuitry, the UE’s components configured to perform any of the steps of any of the Group A embodiments. 
     Embodiment 58: The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE. 
     Embodiment 59: The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE’s processing circuitry is configured to execute a client application associated with the host application. 
     Embodiment 60: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the Group A embodiments. 
     Embodiment 61: The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station. 
     Embodiment 62: A communication system including a host computer comprising: communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station; wherein the UE comprises a radio interface and processing circuitry, the UE’s processing circuitry configured to perform any of the steps of any of the Group A embodiments. 
     Embodiment 63: The communication system of the previous embodiment, further including the UE. 
     Embodiment 64: The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station. 
     Embodiment 65: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data. 
     Embodiment 66: The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data. 
     Embodiment 67: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments. 
     Embodiment 68: The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station. 
     Embodiment 69: The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application. 
     Embodiment 70: The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application; wherein the user data to be transmitted is provided by the client application in response to the input data. 
     Embodiment 71: A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments. 
     Embodiment 72: The communication system of the previous embodiment further including the base station. 
     Embodiment 73: The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station. 
     Embodiment 74: The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer. 
     Embodiment 75: A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments. 
     Embodiment 76: The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE. 
     Embodiment 77: The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer. 
     At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s). 
     
       
         
           
               
               
            
               
                 3GPP 
                 Third Generation Partnership Project 
               
               
                 5G 
                 Fifth Generation 
               
               
                 5GC 
                 Fifth Generation Core 
               
               
                 5GS 
                 Fifth Generation System 
               
               
                 AF 
                 Application Function 
               
               
                 AMF 
                 Access and Mobility Function 
               
               
                 AN 
                 Access Network 
               
               
                 AP 
                 Access Point 
               
               
                 ASIC 
                 Application Specific Integrated Circuit 
               
               
                 AUSF 
                 Authentication Server Function 
               
               
                 CPU 
                 Central Processing Unit 
               
               
                 DN 
                 Data Network 
               
               
                 DSP 
                 Digital Signal Processor 
               
               
                 eNB 
                 Enhanced or Evolved Node B 
               
               
                 EPS 
                 Evolved Packet System 
               
               
                 E-UTRA 
                 Evolved Universal Terrestrial Radio Access 
               
               
                 FPGA 
                 Field Programmable Gate Array 
               
               
                 gNB 
                 New Radio Base Station 
               
               
                 gNB-DU 
                 New Radio Base Station Distributed Unit 
               
               
                 HSS 
                 Home Subscriber Server 
               
               
                 IoT 
                 Internet of Things 
               
               
                 IP 
                 Internet Protocol 
               
               
                 LTE 
                 Long Term Evolution 
               
               
                 MME 
                 Mobility Management Entity 
               
               
                 MTC 
                 Machine Type Communication 
               
               
                 NEF 
                 Network Exposure Function 
               
               
                 NF 
                 Network Function 
               
               
                 NR 
                 New Radio 
               
               
                 NRF 
                 Network Function Repository Function 
               
               
                 NSSF 
                 Network Slice Selection Function 
               
               
                 OTT 
                 Over-the-Top 
               
            
           
           
               
               
            
               
                 PC 
                 Personal Computer 
               
               
                 PCF 
                 Policy Control Function 
               
               
                 P-GW 
                 Packet Data Network Gateway 
               
               
                 QoS 
                 Quality of Service 
               
               
                 RAM 
                 Random Access Memory 
               
               
                 RAN 
                 Radio Access Network 
               
               
                 ROM 
                 Read Only Memory 
               
               
                 RRH 
                 Remote Radio Head 
               
               
                 RTT 
                 Round Trip Time 
               
               
                 SCEF 
                 Service Capability Exposure Function 
               
               
                 SMF 
                 Session Management Function 
               
               
                 UDM 
                 Unified Data Management 
               
               
                 UE 
                 User Equipment 
               
               
                 UPF 
                 User Plane Function 
               
            
           
         
       
     
     Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.