Patent Publication Number: US-11647513-B2

Title: User equipment, a base station apparatus, a communication method of a user equipment and a communication method of a base station apparatus

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/267,773, entitled “USER EQUIPMENTS, BASE STATIONS AND METHODS FOR DOWNLINK SEMI-PERSISTENT SCHEDULING,” filed on Feb. 5, 2019, which is a continuation of PCT/US2019/016496, entitled “USER EQUIPMENTS, BASE STATIONS AND METHODS FOR DOWNLINK SEMI-PERSISTENT SCHEDULING,” filed on Feb. 4, 2019, and which is related to and claims priority from U.S. Provisional Patent Application No. 62/630,043, entitled “USER EQUIPMENTS, BASE STATIONS AND METHODS FOR DOWNLINK SEMI-PERSISTENT SCHEDULING,” filed on Feb. 13, 2018, which are all hereby incorporated by reference herein, in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to communication systems. More specifically, the present disclosure relates to user equipments, base stations and methods for downlink semi-persistent scheduling. 
     BACKGROUND 
     Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have become dependent upon wireless communication devices and have come to expect reliable service, expanded areas of coverage and increased functionality. A wireless communication system may provide communication for a number of wireless communication devices, each of which may be serviced by a base station. A base station may be a device that communicates with wireless communication devices. 
     As wireless communication devices have advanced, improvements in communication capacity, speed, flexibility and/or efficiency have been sought. However, improving communication capacity, speed, flexibility, and/or efficiency may present certain problems. 
     For example, wireless communication devices may communicate with one or more devices using a communication structure. However, the communication structure used may only offer limited flexibility and/or efficiency. As illustrated by this discussion, systems and methods that improve communication flexibility and/or efficiency may be beneficial. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram illustrating one implementation of one or more gNBs and one or more UEs in which systems and methods for downlink semi-persistent scheduling may be implemented; 
         FIG.  2    is an example illustrating downlink (DL) semi-persistent scheduling (SPS) procedures; 
         FIG.  3    is an example illustrating a DL SPS procedure for HARQ-ACK conflict; 
         FIG.  4    is an example illustrating a DL SPS procedure for repetitions and DL slot aggregation; 
         FIG.  5    is an example illustrating an approach for RV determination when DL repetition conflicts with UL by the slot format indication; 
         FIG.  6    is an example illustrating another approach for RV determination when DL repetition conflicts with UL by the slot format indication; 
         FIG.  7    is an example illustrating an approach for HARQ-ACK for repetitions in a DL SPS procedure; 
         FIG.  8    is an example illustrating another approach for HARQ-ACK for repetitions in a DL SPS procedure; 
         FIG.  9    is an example illustrating an approach for the condition for the termination of repetitions in a DL SPS procedure; 
         FIG.  10    is an example illustrating another approach for the condition for the termination of repetitions in a DL SPS procedure; 
         FIG.  11    is an example illustrating another approach for the condition for the termination of repetitions in a DL SPS procedure; 
         FIG.  12    is a diagram illustrating an example of a resource grid for the downlink; 
         FIG.  13    is a diagram illustrating one example of a resource grid for the uplink; 
         FIG.  14    shows examples of several numerologies; 
         FIG.  15    shows examples of subframe structures for the numerologies that are shown in  FIG.  14   ; 
         FIG.  16    shows examples of slots and sub-slots; 
         FIG.  17    shows examples of scheduling timelines; 
         FIG.  18    shows examples of DL control channel monitoring regions; 
         FIG.  19    shows examples of DL control channel which includes more than one control channel elements; 
         FIG.  20    shows examples of UL control channel structures; 
         FIG.  21    is a block diagram illustrating one implementation of a gNB; 
         FIG.  22    is a block diagram illustrating one implementation of a UE; 
         FIG.  23    illustrates various components that may be utilized in a UE; 
         FIG.  24    illustrates various components that may be utilized in a gNB; 
         FIG.  25    is a block diagram illustrating one implementation of a UE in which systems and methods for downlink semi-persistent scheduling may be implemented; 
         FIG.  26    is a block diagram illustrating one implementation of a gNB in which systems and methods for downlink semi-persistent scheduling may be implemented; 
         FIG.  27    is a flow diagram illustrating a communication method of a user equipment; and 
         FIG.  28    is a flow diagram illustrating a communication method of a base station apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     A user equipment (UE) is described. The UE includes receiving circuitry configured to receive system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The receiving circuitry is configured to receive a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The receiving circuitry is also configured to perform, based on a detection of a physical downlink control channel (PDCCH), the PDSCH reception according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment may override the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment may be used for the PDSCH reception. 
     In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is not configured, the first information of the first time domain resource assignment may be used for the PDSCH reception. In a case that the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment may be used for the PDSCH reception. 
     The system information may be remaining minimum system information. The PDCCH may be used for receiving downlink control information with cyclic redundancy check (CRC) scrambled by a configured scheduling radio network temporary identifier (CS-RNTI). 
     The first information of the first time domain resource assignment my comprise a first set of timing information for the PDSCH reception. The second information of the second time domain resource assignment may comprise a second set of timing information for the PDSCH reception. In a case that the first information of the first time domain resource assignment is used for the PDSCH reception, the PDCCH may be used for indicating one timing information among the first set. In a case that the first information of the first time domain resource assignment is used for the PDSCH reception, the PDCCH may be used for indicating one timing information among the second set. 
     A base station apparatus is also described. The base station includes transmitting circuitry configured to transmit system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The transmitting circuitry is configured to transmit a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The transmitting circuitry is configured to perform, based on a transmission of a physical downlink control channel (PDCCH), the PDSCH transmission according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment overrides the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment is used for the PDSCH transmission. 
     In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is not configured, the first information of the first time domain resource assignment may be used for the PDSCH transmission. In a case that the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment may be used for the PDSCH transmission. 
     The system information may be remaining minimum system information. The PDCCH may be used for transmitting downlink control information with cyclic redundancy check (CRC) scrambled by a configured scheduling radio network temporary identifier (CS-RNTI). 
     The first information of the first time domain resource assignment may comprise a first set of timing information for the PDSCH transmission. The second information of the second time domain resource assignment may comprise a second set of timing information for the PDSCH transmission. In a case that the first information of the first time domain resource assignment is used for the PDSCH transmission, the PDCCH may be used for indicating one timing information among the first set. In a case that the first information of the first time domain resource assignment is used for the PDSCH transmission, the PDCCH may be used for indicating one timing information among the second set. 
     A communication method of a user equipment is also described. The communication method includes receiving system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The communication method also includes receiving a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The communication method also includes performing, based on a detection of a physical downlink control channel (PDCCH), the PDSCH reception according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment overrides the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment is used for the PDSCH reception. 
     In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is not configured, the first information of the first time domain resource assignment may be used for the PDSCH reception. In a case that the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment may be used for the PDSCH reception. 
     The first information of the first time domain resource assignment may comprise a first set of timing information for the PDSCH reception. The second information of the second time domain resource assignment may comprise a second set of timing information for the PDSCH reception. In a case that the first information of the first time domain resource assignment is used for the PDSCH reception, the PDCCH may be used for indicating one timing information among the first set. In a case that the first information of the first time domain resource assignment is used for the PDSCH reception, the PDCCH may be used for indicating one timing information among the second set. 
     A communication method of a base station apparatus is also described. The communication method includes transmitting system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The communication method also includes transmitting a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The communication method also includes performing, based on a transmission of a physical downlink control channel (PDCCH), the PDSCH transmission according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment overrides the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment is used for the PDSCH transmission. 
     In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is not configured, the first information of the first time domain resource assignment may be used for the PDSCH transmission. In a case that the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment may be used for the PDSCH transmission. 
     The first information of the first time domain resource assignment may comprise a first set of timing information for the PDSCH transmission. The second information of the second time domain resource assignment may comprise a second set of timing information for the PDSCH transmission. In a case that the first information of the first time domain resource assignment is used for the PDSCH transmission, the PDCCH may be used for indicating one timing information among the first set. In a case that the first information of the first time domain resource assignment is used for the PDSCH transmission, the PDCCH may be used for indicating one timing information among the second set. 
     The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third and fourth generation wireless communication systems. The 3GPP may define specifications for next generation mobile networks, systems and devices. 
     3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN). 
     At least some aspects of the systems and methods disclosed herein may be described in relation to the 3GPP LTE, LTE-Advanced (LTE-A) and other standards (e.g., 3GPP Releases 8, 9, 10, 11 and/or 12). However, the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems. 
     A wireless communication device may be an electronic device used to communicate voice and/or data to a base station, which in turn may communicate with a network of devices (e.g., public switched telephone network (PSTN), the Internet, etc.). In describing systems and methods herein, a wireless communication device may alternatively be referred to as a mobile station, a UE, an access terminal, a subscriber station, a mobile terminal, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, etc. Examples of wireless communication devices include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, etc. In 3GPP specifications, a wireless communication device is typically referred to as a UE. However, as the scope of the present disclosure should not be limited to the 3GPP standards, the terms “UE” and “wireless communication device” may be used interchangeably herein to mean the more general term “wireless communication device.” A UE may also be more generally referred to as a terminal device. 
     In 3GPP specifications, a base station is typically referred to as a Node B, an evolved Node B (eNB), a home enhanced or evolved Node B (HeNB) or some other similar terminology. As the scope of the disclosure should not be limited to 3GPP standards, the terms “base station,” “Node B,” “eNB,” “gNB” and/or “HeNB” may be used interchangeably herein to mean the more general term “base station.” Furthermore, the term “base station” may be used to denote an access point. An access point may be an electronic device that provides access to a network (e.g., Local Area Network (LAN), the Internet, etc.) for wireless communication devices. The term “communication device” may be used to denote both a wireless communication device and/or a base station. An eNB may also be more generally referred to as a base station device. 
     It should be noted that as used herein, a “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (IMT-Advanced) and all of it or a subset of it may be adopted by 3GPP as licensed bands (e.g., frequency bands) to be used for communication between an eNB and a UE. It should also be noted that in E-UTRA and E-UTRAN overall description, as used herein, a “cell” may be defined as “combination of downlink and optionally uplink resources.” The linking between the carrier frequency of the downlink resources and the carrier frequency of the uplink resources may be indicated in the system information transmitted on the downlink resources. 
     “Configured cells” are those cells of which the UE is aware and is allowed by an eNB to transmit or receive information. “Configured cell(s)” may be serving cell(s). The UE may receive system information and perform the required measurements on all configured cells. “Configured cell(s)” for a radio connection may include a primary cell and/or no, one, or more secondary cell(s). “Activated cells” are those configured cells on which the UE is transmitting and receiving. That is, activated cells are those cells for which the UE monitors the physical downlink control channel (PDCCH) and in the case of a downlink transmission, those cells for which the UE decodes a physical downlink shared channel (PDSCH). “Deactivated cells” are those configured cells that the UE is not monitoring the transmission PDCCH. It should be noted that a “cell” may be described in terms of differing dimensions. For example, a “cell” may have temporal, spatial (e.g., geographical) and frequency characteristics. 
     Fifth generation (5G) cellular communications (also referred to as “New Radio,” “New Radio Access Technology” or “NR” by 3GPP) envisions the use of time/frequency/space resources to allow for enhanced mobile broadband (eMBB) communication and ultra-reliable low-latency communication (URLLC) services, as well as massive machine type communication (MMTC) like services. A new radio (NR) base station may be referred to as a gNB. A gNB may also be more generally referred to as a base station device. 
     Some configurations of the systems and methods described herein teach approaches for URLLC transmission/retransmission management to meet the latency/reliability requirement. Some requirements for URLLC relate to user (U)-plane latency and reliability. For URLLC, the target user plane latency is 0.5 milliseconds (ms) each way for both UL and DL. The target reliability is 1-10 −5  for X bytes within 1 milliseconds (ms). 
     These URLLC-specific constraints make the hybrid automatic repeat request (HARD) and retransmission mechanism design difficult. For example, the receiver must reply with a quick acknowledgement (ACK) or negative acknowledgement (NACK) or an uplink grant to meet the latency requirement, or the transmitter can retransmit immediately without waiting for ACK/NACK to enhance the reliability. On the other, grant-based or grant-free repetitions are supported to further enhance the reliability. How to terminate the repetitions is also an important issue. The described systems and methods teach URLLC HARQ/retransmission design in different cases. 
     Various examples of the systems and methods disclosed herein are now described with reference to the Figures, where like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different implementations. Thus, the following more detailed description of several implementations, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods. 
       FIG.  1    is a block diagram illustrating one implementation of one or more gNBs  160  and one or more UEs  102  in which systems and methods for downlink semi-persistent scheduling may be implemented. The one or more UEs  102  communicate with one or more gNBs  160  using one or more antennas  122   a - n . For example, a UE  102  transmits electromagnetic signals to the gNB  160  and receives electromagnetic signals from the gNB  160  using the one or more antennas  122   a - n . The gNB  160  communicates with the UE  102  using one or more antennas  180   a - n.    
     The UE  102  and the gNB  160  may use one or more channels  119 ,  121  to communicate with each other. For example, a UE  102  may transmit information or data to the gNB  160  using one or more uplink channels  121 . Examples of uplink channels  121  include a PUCCH (Physical Uplink Control Channel) and a PUSCH (Physical Uplink Shared Channel), PRACH (Physical Random Access Channel), etc. For example, uplink channels  121  (e.g., PUSCH) may be used for transmitting UL data (i.e., Transport Block(s), MAC PDU, and/or UL-SCH (Uplink-Shared Channel)). 
     Here, UL data may include URLLC data. The URLLC data may be UL-SCH data. Here, URLLC-PUSCH (i.e., a different Physical Uplink Shared Channel from PUSCH) may be defined for transmitting the URLLC data. For the sake of simple description, the term “PUSCH” may mean any of (1) only PUSCH (e.g., regular PUSCH, non-URLLC-PUSCH, etc.), (2) PUSCH or URLLC-PUSCH, (3) PUSCH and URLLC-PUSCH, or (4) only URLLC-PUSCH (e.g., not regular PUSCH). 
     Also, for example, uplink channels  121  may be used for transmitting Hybrid Automatic Repeat Request-ACK (HARQ-ACK), Channel State Information (CSI), and/or Scheduling Request (SR). The HARQ-ACK may include information indicating a positive acknowledgment (ACK) or a negative acknowledgment (NACK) for DL data (i.e., Transport Block(s), Medium Access Control Protocol Data Unit (MAC PDU), and/or DL-SCH (Downlink-Shared Channel)). 
     The CSI may include information indicating a channel quality of downlink. The SR may be used for requesting UL-SCH (Uplink-Shared Channel) resources for new transmission and/or retransmission. Namely, the SR may be used for requesting UL resources for transmitting UL data. 
     The one or more gNBs  160  may also transmit information or data to the one or more UEs  102  using one or more downlink channels  119 , for instance. Examples of downlink channels  119  include a PDCCH, a PDSCH, etc. Other kinds of channels may be used. The PDCCH may be used for transmitting Downlink Control Information (DCI). 
     Each of the one or more UEs  102  may include one or more transceivers  118 , one or more demodulators  114 , one or more decoders  108 , one or more encoders  150 , one or more modulators  154 , a data buffer  104  and a UE operations module  124 . For example, one or more reception and/or transmission paths may be implemented in the UE  102 . For convenience, only a single transceiver  118 , decoder  108 , demodulator  114 , encoder  150  and modulator  154  are illustrated in the UE  102 , though multiple parallel elements (e.g., transceivers  118 , decoders  108 , demodulators  114 , encoders  150  and modulators  154 ) may be implemented. 
     The transceiver  118  may include one or more receivers  120  and one or more transmitters  158 . The one or more receivers  120  may receive signals from the gNB  160  using one or more antennas  122   a - n . For example, the receiver  120  may receive and downconvert signals to produce one or more received signals  116 . The one or more received signals  116  may be provided to a demodulator  114 . The one or more transmitters  158  may transmit signals to the gNB  160  using one or more antennas  122   a - n . For example, the one or more transmitters  158  may upconvert and transmit one or more modulated signals  156 . 
     The demodulator  114  may demodulate the one or more received signals  116  to produce one or more demodulated signals  112 . The one or more demodulated signals  112  may be provided to the decoder  108 . The UE  102  may use the decoder  108  to decode signals. The decoder  108  may produce decoded signals  110 , which may include a UE-decoded signal  106  (also referred to as a first UE-decoded signal  106 ). For example, the first UE-decoded signal  106  may comprise received payload data, which may be stored in a data buffer  104 . Another signal included in the decoded signals  110  (also referred to as a second UE-decoded signal  110 ) may comprise overhead data and/or control data. For example, the second UE-decoded signal  110  may provide data that may be used by the UE operations module  124  to perform one or more operations. 
     In general, the UE operations module  124  may enable the UE  102  to communicate with the one or more gNB s  160 . The UE operations module  124  may include a UE scheduling module  126 . 
     The UE scheduling module  126  may perform downlink (DL) semi-persistent scheduling (SPS). DL SPS with or without repetitions is described herein. Furthermore, a hybrid automatic repeat request (HARD) mechanism design for the DL SPS is also described herein. 
     In a first aspect, for DL SPS in new radio (NR), there may be several basic procedures: radio resource control (RRC) configuration (e.g., a RRC message, a RRC signal), activation, DL transmission and deactivation, which are described in connection with  FIG.  2   . An example for DL SPS RRC configuration is shown in Listing 1. 
     
       
         
           
               
             
               
                   
               
               
                 Listing-1 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 -- ASN1START  
               
               
                 -- TAG-SPS-CONFIG-START  
               
               
                 -- SPS may be configured on the PCell as well as on SCells. But it shall 
               
               
                 not be configured for more than one serving cell of a cell group at once. 
               
               
                 SPS-Config ::=      SEQUENCE { 
               
               
                  downlink      SEQUENCE { 
               
               
                   -- RNTI for DL SPS. Corresponds to L1 parameter ‘SPS C-RNTI’ 
               
               
                   sps-RNTI       RNTI-Value  
               
               
                   -- Periodicity for DL SPS  
               
               
                   -- Corresponds to L1 parameter ‘semiPersistSchedIntervalDL’ 
               
               
                   periodicity        ENUMERATED {ms10, ms20, ms32,  
               
               
                 ms40, ms64, ms80, ms128, ms160, ms320, ms640,  
               
               
                                     spare6, spare5, spare4,  
               
               
                 spare3, spare2, spare1}     OPTIONAL,  
               
               
                   -- Number of configured HARQ processes for SPS DL. 
               
               
                   nrofHARQ-Processes     INTEGER (1..8)  
               
               
                   n1PUCCH-AN       CHOICE { 
               
               
                     format0         PUCCH-resource-config-PF0, -- 
               
               
                     format1         PUCCH-resource-config-PF1 -- 
               
               
                   } 
               
               
                  }, 
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     The physical downlink control channel (PDCCH) may be used to activate the DL SPS transmissions. The timing of the PDCCH (e.g., timing information in PDCCH) may indicate the start timing of DL SPS transmission (e.g., a value of K0). A gNB  160  may send the UE  102  a PDCCH scrambled by SPS C-RNTI at slot n-K0 to activate the DL SPS transmission. Here, the SPS C-RNTI described herein may be assumed to be CS-RNTI (Configured Scheduling RNTI) for sake of clear descriptions. Then the gNB  160  may start SPS PDSCH transmission at slot n. Namely, the UE  102  may receive the PDCCH used for activate the DL SPS transmission at slot n-K0. The value of K0 for DL SPS may be a fixed value (e.g., a default value, e.g., specified by the specification), configured by RRC and/or indicated by PDCCH (DCI) for activation. In a case that K0 timing field is not present or the timing field is 0-bit in DCI for activation, a different DCI field (e.g., HARQ process number, modulation and coding scheme, redundancy version, downlink assignment index, and/or new data indicator, etc.) can be used to indicate K0 (e.g., RV field set as ‘01’ indicates K0=1). Namely, for the DCI format used to activate the DL SPS transmissions, one or more DCI fields (e.g., one or more predetermined fields) included in the DCI format may be used for indicating the timing information (e.g., the value of K0). In yet another example, Remaining Minimum System Information (RMSI) may be used for carrying (e.g., configuring) K0 timing information (e.g., the value of K0). Also, a dedicated RRC message may be used for carrying (e.g., configuring) K0 timing information (e.g., the value of K0). For example, in a case that K0 timing information is configured by using the dedicated RRC message, the K0 timing information configured by using the dedicated RRC message may be used. Namely, even if K0 timing information is configured by the RMSI, K0 timing information configured by using the dedicated RRC message may override K0 information configured by using the RMSI. Namely, in a case that no value of K0 timing information is configured by using the dedicated RRC message, K0 timing information configured by using the RMSI may be used. Also, in a case that no value of K0 timing information is configured by using the dedicated RRC message, the fixed value for K0 may be used. In yet another example, the first value in a configured set may be used for K0, or any predefined value may be used for K0. 
     The PDCCH for activation may include time domain resource assignment which may indicate a starting symbol and a length (e.g., the stating symbol in a lot and a length from the staring symbol). Here, the timing information described above may be the time domain resource assignment information. In a case that the time domain resource assignment field is not present or the time domain resource assignment field is 0-bit in DCI for activation, a different DCI field (e.g., HARQ process number, modulation and coding scheme, redundancy version, downlink assignment index, and/or new data indicator, etc.) can be used to indicate time domain resource assignment. Namely, for the DCI format used to activate the DL SPS transmissions, one or more DCI fields (e.g., one or more predetermined fields) may be used for indicating the time domain resource assignment information. In yet another example, Remaining Minimum System Information (RMSI) may be used for carrying the time domain resource assignment information. Also, a dedicated RRC message may be used for carrying (e.g., configuring) the time domain resource assignment information. For example, in a case that the time domain resource assignment information is configured by using the dedicated RRC message, the time domain resource assignment information configured by using the dedicated RRC message may be used. Namely, even if the time domain resource assignment information is configured by the RMSI, the time domain resource assignment information configured by using the dedicated RRC message may override the time domain resource assignment information configured by using the RMSI. Namely, in a case that no value of the time domain resource assignment information is configured by using the dedicated RRC message, the time domain resource assignment information configured by using the RMSI may be used. Also, in a case that no value of the time domain resource assignment information is configured by using the dedicated RRC message, the fixed value for the time domain resource assignment may be used. In yet another example, any predefined time domain resource assignment may be used. 
     Upon detection of a DL SPS PDSCH in slot n, the UE  102  may transmit HARQ-ACK in slot n+K1. The value of K1 for DL SPS may be a fixed value (e.g., a default value, e.g., specified by the specification), configured by RRC and/or indicated by PDCCH (DCI) for activation. In a case that K1 timing field is not present or the timing field is 0-bit in DCI for activation, a different DCI field (e.g., HARQ process number, modulation and coding scheme, redundancy version, downlink assignment index, and/or new data indicator, etc.) can be used to indicate K1 (e.g., RV field set as ‘11’ indicates K1=4). Namely, for the DCI format used to activate the DL SPS transmissions, one or more DCI fields (e.g., one or more predetermined fields) included in the DCI format may be used for indicating the timing information (e.g., the value of K1). In yet another example, Remaining Minimum System Information (RMSI) may be used for carrying (e.g., configuring) K1 timing information (e.g., the value of K1). Also, a dedicated RRC message may be used for carrying (e.g., configuring) K1 timing information (e.g., the value of K1). For example, in a case that K1 timing information is configured by using the dedicated RRC message, the K1 timing information configured by using the dedicated RRC message may be used. Namely, even if K1 timing information is configured by the RMSI, K1 timing information configured by using the dedicated RRC message may override K1 information configured by using the RMSI. Namely, in a case that no value of K1 timing information is configured by using the dedicated RRC message, K1 timing information configured by using the RMSI may be used. Also, in a case that no value of K1 timing information is configured by using the dedicated RRC message, the fixed value for K1 may be used. In yet another example, a first value in a configured set may be used for K1, or any predefined value may be used for K1. 
     For the HARQ-ACK in slot n+K1, there may be a case where at least one semi-statically configured DL symbol overlaps with the symbol(s) carrying HARQ-ACK in slot n+K1, or a case where the symbol(s) carrying HARQ-ACK in slot n+K1 conflicts with (e.g., collides with) DL symbol(s) indicated by dynamic slot format indicator (SFI) (e.g., based on a slot format). Here, the one semi-statically configured DL symbol may be a DL symbols(s) determined based on the slot format configured by using system information (e.g., and/or the dedicated RRC message). Also, SFI may be included in DCI format with CRC (e.g., Cyclic Redundancy Check) scrambled by SFI-RNTI. Namely, the DCI format to which CRC parity bits scrambled by the SFI-RNTI are attached may be used for indicating the slot format (e.g., DL symbol(s), UL symbols(s) in a slot). Namely, for example, an UL slot n+K1 (e.g., and/or an UL symbol) in which HARQ-ACK for PDSCH transmission is transmitted may collide with a DL symbol(s) determined based on the slot format configured (e.g., indicated). 
     The UE  102  may use a backup value (K1_0) of timing for HARQ-ACK transmission for the PDSCH. The UE  102  may keep more than one values of timing for HARQ-ACK transmission for the PDSCH. One is the original or primary timing value, and other(s) are back up values. Namely, in a case that HARQ-ACK transmission for PDSCH in slot n+K1 collides with the DL symbol(s) (e.g., and/or the DL slot(s)) determined based on the slot format, the UE  102  may perform HARQ-ACK transmission for the PDSCH in slot n+K1_0. The value of K1_0 for DL SPS may be a fixed value (e.g., a default value, e.g., specified by the specification), configured by RRC and/or indicated by PDCCH (DCI) for activation. In a case that K1_0 timing field is not present or the timing field is 0-bit in DCI for activation, a different DCI field (e.g., HARQ process number, modulation and coding scheme, redundancy version, downlink assignment index, and/or new data indicator, etc.) can be used to indicate K1_0 (e.g., RV field set as ‘10’ indicates K1_0=3). Namely, for the DCI format used to activate the DL SPS transmissions, one or more DCI fields (e.g., one or more predetermined fields) included in the DCI format may be used for indicating the timing information (e.g., the value of K1_0). In yet another example, Remaining Minimum System Information (RMSI) may be used for carrying (e.g., configuring) K1_0 timing information (e.g., the value of K0). Also, a dedicated RRC message may be used for carrying (e.g., configuring) K1_0 timing information (e.g., the value of K1_0). For example, in a case that K1_0 timing information is configured by using the dedicated RRC message, the K1_0 timing information configured by using the dedicated RRC message may be used. Namely, even if K1_0 timing information is configured by the RMSI, K1_0 timing information configured by using the dedicated RRC message may override K0 information configured by using the RMSI. Namely, in a case that no value of K1_0 timing information is configured by using the dedicated RRC message, K1_0 timing information configured by using the RMSI may be used. Also, in a case that no value of K1_0 timing information is configured by using the dedicated RRC message, the fixed value for K0 may be used. In yet another example, a second value in a configured set may be used for K1_0, or any predefined value may be used for K1_0. 
     In yet another design, the gNB  160  may indicate a dynamic change of K1. To avoid the HARQ-ACK conflict, the gNB  160  may indicate a new K1 by PDCCH (e.g., DCI, DL grant), or the gNB  160  may change the value of K1 through PDCCH (re)activation. For example, as described above, the DCI format with CRC scrambled by the CS-RNTI may be used for activating SPS PDSCH transmission. Namely, the DCI format to which CRC parity bits scrambled by the CS-RNTI are attached may be used for activating SPS PDSCH transmission. And, based on the detection of the DCI format with CRC scrambled by the CS-RNTI in a slot n, the UE  102  may transmit in a slot n+kl, HARQ-ACK for the SPS PDSCH transmission. Here, as described above, the value of K1 may be indicated by using the RRC message (e.g., the RMSI and/or the dedicated RRC message) and/or DCI included in the DCI format with CRC scrambled by the CS-RNTI. Here, the DCI format with CRC scrambled by the CS-RNTI may be used for indicating retransmission(s) of SPS PDSCH transmission. Namely, the CS-RNTI may be used for indicating SPS PDSCH activation and/or SPS PDSCH retransmission. Here, the DCI format with CRC scrambled by the CS-RNTI used for indicating SPS PDSCH retransmission may include K1 timing information (e.g., the value of K1). Namely, based on the detection of the DCI format with CRC scrambled by the CS-RNTI used for indicating SPS PDSCH retransmission, the UE  102  may change (e.g., switch, update, overwide) the value of K1 to transmit HARQ-ACK. 
     In yet another design, the UE  102  may drop the HARQ-ACK or NACK is assumed by the gNB  160 . Then, the gNB  160  may retransmit to the UE  102 . 
     When the UE  102  is configured with aggregation-factor-DL&gt;1 (e.g., the number of PDSCH transmission (e.g., and/or PDSCH reception), and/or the number of slots for PDSCH transmission (e.g., and/or PDSCH reception)), the same symbol allocation may be applied across the aggregation-factor-DL consecutive slots not defined as UL by the slot format indication. The UE  102  may repeat PDSCH transmissions for the same TB in these aggregated slots. Namely, the UE  102  may perform PDSCH reception in a consecutive slots, based on the number determined from the aggregation-factor-DL. Namely, the number of PDSCH reception configured by using the aggregation-factor-DL may be the number of consecutive PDSCH reception. Also, the number of slots for PDSCH reception configured by using the aggregation-factor-DL may be the number of consecutive slots for PDSCH reception. 
     A RV sequence may be applied to the repetitions. A RV sequence may include a single value or multiple values. A RV sequence may be configured by RRC for DL repetitions. In yet another example, the RV sequence may be the same as UL transmission without grant or UL SPS. UL and DL may share the same RV sequence, or the RV sequence may be commonly configured for both UL and DL. The RV sequence may be separately configured for UL and DL. UL and DL may share the same set of RV sequences. UL and DL may use different sets of RV sequences. In yet another example, the RV sequence may be fixed or the same as the RV sequence determined by channel coding. The RV values in a RV sequence may be used cyclically if the number of repetitions is larger than the length of the RV sequence. 
     When DL repetition conflicts with (e.g., collide with) UL by the slot format indication, the UE  102  may skip the conflicted slot(s) and may continue to use the RV order from the next available aggregated slot. For example, the RV sequence is configured as {RV0, RV1, RV2, RV3} and the gNB  160  repeats PDSCH transmissions for the same TB in slot n, n+1, n+2 and n+3 with RV0, RV1, RV2 and RV3, respectively, if there is no SFI conflict. If slot n+3 is determined as UL by the slot format indication, then the UE  102  skips slot n+3 and repeat PDSCH transmission in slot n+4 by using RV3 if there is no SFI conflict in slot n+4. 
     In yet another design, the UE  102  may assume the RV value(s) in the RV sequence applied to the conflicted slot(s) although there is no PDSCH transmission. The DL PDSCH may be skipped but the RV counting in the RV sequence may be kept. Equivalently, the UE  102  may use the RV sequence corresponding to the slot index. For example, the RV sequence is configured as {RV0, RV1, RV2, RV3} and the gNB  160  repeats PDSCH transmissions for the same TB in slot n, n+1, n+2 and n+3 with RV0, RV1, RV2 and RV3, respectively, if there is no SFI conflict. If slot n+2 is determined as UL by the slot format indication, then the UE  102  skips slot n+2 and repeat PDSCH transmission in slot n+3 and n+4 by using RV3 and RV0, respectively, if there is no SFI conflict in slot n+3 or n+4. 
     Whether to resume the RV sequence after the conflict(s) or not may be configurable. 
     The UE  102  may transmit HARQ-ACK for each repetition. Namely, in a case that the aggregation-factor-DL (e.g., the aggregation-factor-DL&gt;1) is configured, HARQ-ACK may be transmitted for each PDSCH reception. In yet another design, the UE  102  may transmit HARQ-ACK only for the last repetition. Namely, in a case that the aggregation-factor-DL (e.g., the aggregation-factor-DL&gt;1) is configured, HARQ-ACK may be transmitted after the configured number (e.g., and/or the configured number of slots) of PDSCH reception is performed. Namely, for example, the UE  102  may transmit a positive acknowledgment (e.g., ACK) in a case that the configured number (e.g., and/or the configured number of slots) of PDSCH is received (e.g., in a case that the PDSCH reception based on the aggregation-factor-DL is terminated). Also, the UE  102  may transmit a negative acknowledgment (e.g., NACK) in a case that the configured number (e.g., and/or the configured number of slots) of PDSCH is not received. Whether to transmit HARQ-ACK for each repetition or the last repetition only may be configurable. Namely, the gNB  160  may transmit the RRC message, whether to transmit HARQ-ACK for each PDSCH reception or to transmit HARQ-ACK after the configured number (e.g., and/or the configured number of slots) of PDSCH reception is performed. 
     When the number of repetitions reaches the DL aggregation factor K, the gNB  160  may terminate the repetitions. When the gNB  160  receives ACK corresponding to a repetition, the gNB  160  may terminate the remaining repetitions for the same TB. In yet another example, the gNB  160  may keep transmitting the remaining repetitions. 
     The gNB  160  may transmit PDCCH (DCI, DL grant) to the UE  102  and terminate the repetitions or slot aggregations. The PDCCH may be used for scheduling the same TB or a new TB. 
     At the boundary of the period or at the beginning of the consecutive SPS time resource, if the gNB  160  does not finish K repetitions, it may stop the remaining repetitions. 
     For all the HARQ-ACK for repetitions, methods mentioned herein may be applied to handle the HARQ-ACK conflicts. In yet another design, HARQ-ACK for repetitions except the last one may be dropped when a conflict happens for these HARQ-ACK. 
     The UE operations module  124  may provide information  148  to the one or more receivers  120 . For example, the UE operations module  124  may inform the receiver(s)  120  when to receive retransmissions. 
     The UE operations module  124  may provide information  138  to the demodulator  114 . For example, the UE operations module  124  may inform the demodulator  114  of a modulation pattern anticipated for transmissions from the gNB  160 . 
     The UE operations module  124  may provide information  136  to the decoder  108 . For example, the UE operations module  124  may inform the decoder  108  of an anticipated encoding for transmissions from the gNB  160 . 
     The UE operations module  124  may provide information  142  to the encoder  150 . The information  142  may include data to be encoded and/or instructions for encoding. For example, the UE operations module  124  may instruct the encoder  150  to encode transmission data  146  and/or other information  142 . The other information  142  may include PDSCH HARQ-ACK information. 
     The encoder  150  may encode transmission data  146  and/or other information  142  provided by the UE operations module  124 . For example, encoding the data  146  and/or other information  142  may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder  150  may provide encoded data  152  to the modulator  154 . 
     The UE operations module  124  may provide information  144  to the modulator  154 . For example, the UE operations module  124  may inform the modulator  154  of a modulation type (e.g., constellation mapping) to be used for transmissions to the gNB  160 . The modulator  154  may modulate the encoded data  152  to provide one or more modulated signals  156  to the one or more transmitters  158 . 
     The UE operations module  124  may provide information  140  to the one or more transmitters  158 . This information  140  may include instructions for the one or more transmitters  158 . For example, the UE operations module  124  may instruct the one or more transmitters  158  when to transmit a signal to the gNB  160 . For instance, the one or more transmitters  158  may transmit during a UL subframe. The one or more transmitters  158  may upconvert and transmit the modulated signal(s)  156  to one or more gNBs  160 . 
     Each of the one or more gNBs  160  may include one or more transceivers  176 , one or more demodulators  172 , one or more decoders  166 , one or more encoders  109 , one or more modulators  113 , a data buffer  162  and a gNB operations module  182 . For example, one or more reception and/or transmission paths may be implemented in a gNB  160 . For convenience, only a single transceiver  176 , decoder  166 , demodulator  172 , encoder  109  and modulator  113  are illustrated in the gNB  160 , though multiple parallel elements (e.g., transceivers  176 , decoders  166 , demodulators  172 , encoders  109  and modulators  113 ) may be implemented. 
     The transceiver  176  may include one or more receivers  178  and one or more transmitters  117 . The one or more receivers  178  may receive signals from the UE  102  using one or more antennas  180   a - n . For example, the receiver  178  may receive and downconvert signals to produce one or more received signals  174 . The one or more received signals  174  may be provided to a demodulator  172 . The one or more transmitters  117  may transmit signals to the UE  102  using one or more antennas  180   a - n . For example, the one or more transmitters  117  may upconvert and transmit one or more modulated signals  115 . 
     The demodulator  172  may demodulate the one or more received signals  174  to produce one or more demodulated signals  170 . The one or more demodulated signals  170  may be provided to the decoder  166 . The gNB  160  may use the decoder  166  to decode signals. The decoder  166  may produce one or more decoded signals  164 ,  168 . For example, a first eNB-decoded signal  164  may comprise received payload data, which may be stored in a data buffer  162 . A second eNB-decoded signal  168  may comprise overhead data and/or control data. For example, the second eNB-decoded signal  168  may provide data (e.g., PDSCH HARQ-ACK information) that may be used by the gNB operations module  182  to perform one or more operations. 
     In general, the gNB operations module  182  may enable the gNB  160  to communicate with the one or more UEs  102 . The gNB operations module  182  may include a gNB scheduling module  194 . The gNB scheduling module  194  may perform downlink semi-persistent scheduling as described herein. 
     The gNB operations module  182  may provide information  188  to the demodulator  172 . For example, the gNB operations module  182  may inform the demodulator  172  of a modulation pattern anticipated for transmissions from the UE(s)  102 . 
     The gNB operations module  182  may provide information  186  to the decoder  166 . For example, the gNB operations module  182  may inform the decoder  166  of an anticipated encoding for transmissions from the UE(s)  102 . 
     The gNB operations module  182  may provide information  101  to the encoder  109 . The information  101  may include data to be encoded and/or instructions for encoding. For example, the gNB operations module  182  may instruct the encoder  109  to encode information  101 , including transmission data  105 . 
     The encoder  109  may encode transmission data  105  and/or other information included in the information  101  provided by the gNB operations module  182 . For example, encoding the data  105  and/or other information included in the information  101  may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder  109  may provide encoded data  111  to the modulator  113 . The transmission data  105  may include network data to be relayed to the UE  102 . 
     The gNB operations module  182  may provide information  103  to the modulator  113 . This information  103  may include instructions for the modulator  113 . For example, the gNB operations module  182  may inform the modulator  113  of a modulation type (e.g., constellation mapping) to be used for transmissions to the UE(s)  102 . The modulator  113  may modulate the encoded data  111  to provide one or more modulated signals  115  to the one or more transmitters  117 . 
     The gNB operations module  182  may provide information  192  to the one or more transmitters  117 . This information  192  may include instructions for the one or more transmitters  117 . For example, the gNB operations module  182  may instruct the one or more transmitters  117  when to (or when not to) transmit a signal to the UE(s)  102 . The one or more transmitters  117  may upconvert and transmit the modulated signal(s)  115  to one or more UEs  102 . 
     It should be noted that a DL subframe may be transmitted from the gNB  160  to one or more UEs  102  and that a UL subframe may be transmitted from one or more UEs  102  to the gNB  160 . Furthermore, both the gNB  160  and the one or more UEs  102  may transmit data in a standard special subframe. 
     It should also be noted that one or more of the elements or parts thereof included in the eNB(s)  160  and UE(s)  102  may be implemented in hardware. For example, one or more of these elements or parts thereof may be implemented as a chip, circuitry or hardware components, etc. It should also be noted that one or more of the functions or methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc. 
     URLLC may coexist with other services (e.g., eMBB). Due to the latency requirement, URLLC may have a highest priority in some approaches. Some examples of URLLC coexistence with other services are given herein (e.g., in one or more of the following Figure descriptions). 
       FIG.  2    is an example illustrating downlink (DL) semi-persistent scheduling (SPS) procedures. For DL SPS, there may be several basic procedures: radio resource control (RRC) configuration (e.g., a RRC message, a RRC signal), activation, DL transmission and deactivation. 
     DL assignment to DL data timing (PDCCH activation to first SPS DL data) may be referred to as K0. After RRC configuration, the gNB  160  may send the UE  102  a PDCCH scrambled by SPS RNTI at slot n-K0 to activate the DL SPS transmission. Then the gNB  160  may start SPS PDSCH transmission at slot n. For example, the UE  102  may receive on the PDCCH in a slot n-K0, the DCI format with CRC scrambled by the CS-RNTI used for indicating DL SPS activation. Also, based on the detection, in a slot n-K0 of the DCI format with CRC scrambled by the CS-RNTI used for indicating DL SPS activation, the UE  102  perform reception of DL SPS in slot n. There may be several ways to indicate the value of K0. 
     In a first approach, the value of K0 may be configured by using the RRC message. For example, the gNB  160  may transmit, by using the RMSI and/or the dedicated RRC message, information used for configuring the value of K0. 
     In a second approach, the value of K0 may be indicated by PDCCH (DCI) for activation of DL SPS (e.g., the DCI format used for indicating DL SPS activation). In an implementation, the value of K0 may be indicated by DCI format 1_0 (e.g., referred to as fallback DCI) for activation of DL SPS. In another implementation, the value of K0 may be indicated by DCI format 1_1 (e.g., referred to as non-fallback DCI) for activation of DL SPS. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K0 included in DCI format 1_0 may be applied. Namely, the DCI format 1_0 may be used for indicating DL SPS activation. Also, the DCI format 1_1 may be used for indicating DL SPS activation. And, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K0 indicated by using the DCI format 1_0 to perform DL SPS reception. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K0 included in DCI format 1_1 may be applied. Namely, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K0 indicated by using the DCI format 1_1 to perform DL SPS reception. Also, for example, the UE  102  may not be expected to receive DCI format 1_0 and DCI format 1_1 for DL SPS transmission (e.g., the single DL SPS reception). 
     In a third approach, the RMSI may be used for carrying (e.g., configuring) K0 timing information (e.g., the value of K0). Here, the value of K0 carried by the RMSI may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation is received, the UE  102  may use the value of K0 carried (e.g., configured) by using the RMSI to perform DL SPS reception. Here, for example, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K0 configured by using the dedicated RRC message to perform DL SPS reception. Also, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K0 indicated by using the DCI format 1_1 used for indicating DL SPS activation to perform DL SPS reception. 
     In a fourth approach, a set of values of K0 may be configured by the RRC message (e.g., the dedicated RRC message) and the choice (e.g., select) of K0 is indicated, among the set of values of K0, by PDCCH (DCI) for activation of DL SPS. 
     In a fifth approach, the value of K0 may be a fixed value or a default value (i.e., a predetermined value, e.g., specified by the specification). For example, in a case that the value of K0 is not explicitly indicated (e.g., by using the RRC message and/or by the PDCCH for activation of DL SPS), the default value (e.g., “0”) is applied. The default value of K0 may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation, the UE  102  may use the fixed value of K0 (e.g., the default value, e.g., “0”) to perform DL SPS reception. 
     In a sixth approach, if K0 timing field is not present or the timing field is 0-bit in DCI for activation of DL SPS (e.g., the presence of the timing field K0 may be configured by RRC, the timing field K0 is present only in DCI format 1_1 (i.e., non-fallback DCI) for activation of DL SPS, the timing field K0 is not present in DCI format 1_0 (i.e., fall back DCI) for activation of DL SPS), then how to indicate K0 may be implemented in one or more of the following ways: re-interpretation of DCI field (e.g., a different DCI field can be used to indicate K0); RMSI may be used for carrying K0 timing information; the first value in a configured set is used, or any predefined value is used. 
     The timing for a given PDSCH to the DL ACK may be referred to as K1. After receiving a SPS PDSCH at slot n, the UE  102  may send HARQ feedback at slot n+K1. There may be several ways to indicate the value of K1. For example, the UE  102  may perform, in a slot n, the DL SPS reception (e.g., SPS PDSCH reception). And, based on the reception, in the slot n, of the SPS PDSCH, the UE  102  may perform, in a slot n+K1, HARQ-ACK transmission for the SPS PDSCH. 
     In a first approach, the value of K1 may be configured by using the RRC message. For example, the gNB  160  may transmit, by using the RMSI and/or the dedicated RRC message, information used for configuring the value of K1. 
     In a second approach, the value of K1 may be indicated by PDCCH (DCI) for activation of DL SPS (e.g., the DCI format used for indicating DL SPS activation). In an implementation, the value of K1 may be indicated by DCI format 1_0 (e.g., referred to as fallback DCI) for activation of DL SPS. In another implementation, the value of K1 may be indicated by DCI format 1_1 (e.g., referred to as non-fallback DCI) for activation of DL SPS. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K1 included in DCI format 1_0 may be applied. Namely, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1 indicated by using the DCI format 1_0 to perform HARQ-ACK transmission. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K1 included in DCI format 1_1 may be applied. Namely, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1 indicated by using the DCI format 1_1 to perform HARQ-ACK transmission. Also, the UE  102  may not be expected to receive DCI format 1_0 and DCI format 1_1 for DL SPS transmission (e.g., the single DL SPS reception). 
     In a third approach, the RMSI may be used for carrying (e.g., configuring) K1 timing information (e.g., the value of K1). Here, the value of K1 carried by the RMSI may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation is received, the UE  102  may use the value of K1 carried (e.g., configured) by using the RMSI to perform HARQ-ACK transmission. Here, for example, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K1 configured by using the dedicated RRC message to perform HARQ-ACK transmission. Also, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K1 indicated by using the DCI format 1_1 used for indicating DL SPS activation to perform HARQ-ACK transmission. 
     In a fourth approach, a set of values of K1 may be configured by the RRC message (e.g., the dedicated RRC message) and the choice (e.g., select) of K1 is indicated, among the set of values of K1, by PDCCH (DCI) for activation. 
     In a fifth approach, the value of K1 may be a fixed value or a default value (i.e., a predetermined value, e.g., specified by the specification). For example, in a case that the value of K1 is not explicitly indicated (e.g., by using the RRC message and/or by the PDCCH for activation of DL SPS), the default value (e.g., “4”) may be applied. The default value of K1 may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation, the UE  102  may use the fixed value of K1 (e.g., the default value, e.g., “0”) to perform HARQ-ACK transmission. 
     In a sixth approach, if K1 timing field is not present or the timing field is 0-bit in DCI for activation of DL SPS (e.g., the presence of the timing field K1 may be configured by RRC, the timing field K1 is present only in DCI format 1_1 (i.e., non-fallback DCI) for activation of DL SPS, the timing field K1 is not present in DCI format 1_0 (i.e., fall back DCI) for activation of DL SPS), then how to indicate K1 may be implemented in one or more of the following ways: re-interpretation of DCI field (e.g., a different DCI field may be used to indicate K1); RMSI may be used for carrying K1 timing information; a first value in a configured set is used, or any predefined value is used. 
     Periodicity for DL SPS may be referred to as P. In examples of this disclosure, the periodicity of DL SPS is in a unit of slot for simplicity, but the periodicity of DL SPS may also use other units such as symbol and milliseconds (ms). In current specifications, the minimum periodicity is 10 ms, but in the future version it may be less than 10 ms (e.g., 5 ms, 2 ms, 1 ms, 0.5 ms, 7 symbols, 2 symbols, etc.). Periodicity may determine the interval between two adjacent transmission occasions or initial transmissions or repetitions. 
       FIG.  3    is an example illustrating a DL SPS procedure for HARQ-ACK conflict. As mentioned above, upon detection of a DL SPS PDSCH in slot n, UE is supposed to transmit HARQ-ACK in slot n+K1. However, there may be a case where at least one semi-statically configured DL symbol overlaps with the symbol(s) carrying HARQ-ACK in slot n+K1, or a case where the symbol(s) carrying HARQ-ACK in slot n+K1 conflicts with DL symbol(s) indicated by dynamic slot format indicator (SFI). 
     There may be several ways to handle the HARQ-ACK in cases of conflict. In an approach to handle HARQ-ACK conflict, the UE  102  may use a backup value (K1_0) of timing for given PDSCH to the DL ACK. The UE  102  may keep two or more values of timing for a given PDSCH to the DL ACK. One is the original or primary timing value, and other(s) are back up values. If HARQ-ACK conflict happens in slot n+K1, the UE  102  may try to HARQ-ACK in slot n+K1_0. There may several ways to indicate the backup value K1_0. 
     In a first approach, the value of K1_0 may be configured by using the RRC message. For example, the gNB  160  may transmit, by using the RMSI and/or the dedicated RRC message, information used for configuring the value of K0. 
     In a second approach, the value of K1_0 may be indicated by PDCCH (DCI) for activation of DL SPS (e.g., the DCI format used for indicating DL SPS activation). Here, the value of K1_0 may be indicated by DCI format 1_0 (e.g., referred to as fallback DCI) for activation of DL SPS. Also, the value of K1_0 may be indicated by DCI format 1_1 (e.g., referred to as non-fallback DCI) for activation of DL SPS. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K1_0 included in DCI format 1_0 may be applied. Namely, the DCI format 1_0 may be used for indicating DL SPS activation. Also, the DCI format 1_1 may be used for indicating DL SPS activation. And, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1_0 indicated by using the DCI format 1_0 to perform HARQ-ACK transmission. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K1_0 included in DCI format 1_1 may be applied. Namely, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1_0 indicated by using the DCI format 1_1 to perform HARQ-ACK transmission. Also, for example, the UE  102  may not be expected to receive DCI format 1_0 and DCI format 1_1 for DL SPS transmission (e.g., the single SL SPS transmission). 
     In a third approach, the RMSI may be used for carrying (e.g., configuring) K1_0 timing information (e.g., the value of K1_0). Here, the value of K1_0 carried by the RMSI may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation is received, the UE  102  may use the value of K1_0 carried (e.g., configured) by using the RMSI to perform HARQ_ACK transmission. Here, for example, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K1_0 configured by using the dedicated RRC message to perform HARQ-ACK transmission. Also, in a case that DCI format 1_1 used for indicating DL SPS activation is received, the UE  102  may use the value of K1_0 indicated by using the DCI format 1_1 used for indicating DL SPS activation to perform HARQ-ACK transmission. 
     In a fourth approach, a set of values of K1_0 may be configured by the RRC message and the choice (e.g., select) of K1_0 may be indicated, among the set of values of K1_0, by PDCCH (DCI) for activation of DL SPS. 
     In a fifth approach, the value of K1_0 may be a fixed value or a default value (i.e., a predetermined value, e.g. specified by specification). For example, in a case that the value of K1_0 is not explicitly indicated (e.g., by using the RRC message and/or by the PDCCH for indicating DL SPS activation), the default value (e.g., “4”) may be applied. The default value of K1_0 may be used for DL SPS activated by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation, the UE  102  may use the fixed value of K1_0 (e.g., the default value, e.g., “4”) to perform HARQ-ACK transmission. 
     In a sixth approach, if K1_0 timing field is not present or the timing field is 0-bit in DCI for activation of DL SPS (e.g., the presence of the timing field K1_0 may be configured by RRC, the timing field K1_0 is present only in DCI format 1_1 (i.e., non-fallback DCI) for activation of DL SPS, the timing field K1_0 is not present in DCI format 1_0 (i.e., fall back DCI) for activation of DL SPS), then how to indicate K1_0 may be implemented in one or more of the following ways: re-interpretation of DCI field (e.g., a different DCI field can be used to indicate K1_0); RMSI may be used for carrying K1_0 timing information; a second value in a configured set may be used, or any predefined value may be used. 
     In another approach to handle HARQ-ACK conflict, the gNB  160  indicates a dynamic change of K1. To avoid the HARQ-ACK conflict, the gNB  160  may indicate a new K1 (e.g., the value of K1_1) by PDCCH (DCI, DL grant), or the gNB  160  may change the value of K1 through PDCCH (re)activation. 
     In a first approach, the value of K1_1 may be configured by using the RRC message. For example, the gNB  160  may transmit, by using the RMSI and/or the dedicated RRC message, information used for configuring the value of K1_1. 
     In a second approach, the value of K1_1 may be indicated by PDCCH (DCI) for indicating DL SPS retransmission (e.g., the DCI format used for indicating DL SPS retransmission). In an implementation, the value of K1_1 may be indicated by DCI format 1_0 (e.g., referred to as fallback DCI) for DL SPS retransmission. In another implementation, the value of K1_1 may be indicated by DCI format 1_1 (e.g., referred to as non-fallback DCI) for DL SPS retransmission. Namely, the DCI format 1_0 may be used for indicating DL SPS activation and/or DL SPS retransmission. Also, the DCI format 1_1 may be used for indicating DL SPS activation and/or DL SPS retransmission. And, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1_1 indicated by using the DCI format 1_0 to perform HARQ-ACK transmission. If DCI format 1_0 and DCI format 1_1 are received for a DL SPS transmission, K1_1 included in DCI format 1_1 may be applied. Namely, in a case that the DCI format 1_0 and the DCI format 1_1 are received for DL SPS reception (e.g., a single DL SPS reception), the UE  102  may use the value of K1_1 indicated by using the DCI format 1_1 to perform HARQ-ACK transmission. Also, for example, the UE  102  may not be expected to receive DCI format 1_0 and DCI format 1_1 for DL SPS transmission (e.g., the single DL SPS reception). 
     In a third approach, the RMSI may be used for carrying (e.g., configuring) K1_1 timing information (e.g., the value of K1_1). Here, the value of K1_1 carried by the RMSI may be used for DL SPS activated and/or retransmitted by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation and/or DL SPS retransmission is received, the UE  102  may use the value of K1_1 carried (e.g., configured) by using the RMSI to perform HARQ-ACK transmission. Here, for example, in a case that DCI format 1_1 used for indicating DL SPS activation and/or DL SPS retransmission is received, the UE  102  may use the value of K1_1 configured by using the dedicated RRC message to perform HARQ-ACK transmission. Also, in a case that DCI format 1_1 used for indicating DL SPS activation and/or DL SPS retransmission is received, the UE  102  may use the value of K1_1 indicated by using the DCI format 1_1 used for indicating DL SPS activation and/or DL SPS retransmission to perform HARQ-ACK transmission. 
     In a fourth approach, a set of values of K1_1 may be configured by the RRC message (e.g., the dedicated RRC message) and the choice (e.g., select) of K1_1 is indicated, among the set of values of K0, by PDCCH (DCI) for activation of DL SPS. 
     In a fifth approach, the value of K1_1 may be a fixed value or a default value (i.e., a predetermined value, e.g., specified by the specification). For example, in a case that the value of K1_1 is not explicitly indicated (e.g., by using the RRC message and/or by the PDCCH for activation of DL SPS), the default value (e.g., “0”) is applied. The default value of K1_1 may be used for DL SPS activated and/or retransmitted by using DCI format 1_0 (i.e., fallback DCI). Namely, in a case that the DCI format 1_0 used for indicating DL SPS activation and/or DL SPS retransmission, the UE  102  may use the fixed value of K1_1 (e.g., the default value, e.g., “4”) to perform HARQ-ACK transmission. 
     In a sixth approach, if K1_1 timing field is not present or the timing field is 0-bit in DCI for activation of DL SPS (e.g., the presence of the timing field K1_1 may be configured by RRC, the timing field K1_1 is present only in DCI format 1_1 (i.e., non-fallback DCI) for activation of DL SPS, the timing field K1_1 is not present in DCI format 1_0 (i.e., fall back DCI) for activation of DL SPS), then how to indicate K1_1 may be implemented in one or more of the following ways: re-interpretation of DCI field (e.g., a different DCI field can be used to indicate K1_1); RMSI may be used for carrying K0 timing information; the first value in a configured set is used, or any predefined value is used. 
     In yet another approach to handle HARQ-ACK conflict, the UE  102  may drop the HARQ-ACK or NACK is assumed by the gNB  160 . In this case, the gNB  160  may retransmit to the UE  102 . 
       FIG.  4    is an example illustrating a DL SPS procedure for repetitions and DL slot aggregation. When the UE  102  is configured with DL slot aggregation factor K which is greater than 1, the same symbol allocation may be applied across the K consecutive slots not defined as UL by the slot format indication and the UE  102  may repeat PDSCH transmissions for the same TB. 
     For the case of repetitions or slot aggregations, the following issues should be addressed. One issue is Redundancy version (RV). A RV sequence may be applied to the repetitions. A RV sequence may include a single value or multiple values. There may be several ways to configure the RV sequence. 
     In one approach, an RV sequence may be configured by RRC for DL repetitions (slot aggregation). In another approach, the RV sequence is same as UL transmission without grant or UL SPS. In this approach, UL and DL share the same RV sequence. In yet another approach, the RV sequence is fixed or the same as the RV sequence determined by channel coding. 
     Another issue for the case of repetitions or slot aggregations is RV determination when DL repetition conflicts with UL by the slot format indication. In an approach, the UE  102  may resume the RV sequence after the conflict(s). The UE  102  may the skip the conflicted slot(s), continue to use the RV order from the next available aggregated slot.  FIG.  5    is an example illustrating this approach. In another approach, the UE  102  may assume the RV value(s) in the RV sequence applied to the conflicted slot(s) although there is no PDSCH transmission. The DL PDSCH may be skipped but the RV counting in the RV sequence is kept. Equivalently, the UE  102  may use the RV sequence corresponding to the slot index.  FIG.  6    is an example illustrating this approach. Whether to resume the RV sequence after the conflict(s) or not may be configurable. 
     Another issue for the case of repetitions or slot aggregations is HARQ-ACK for repetitions (i.e., DL SPS PDSCH repetition). In one approach, HARQ-ACK is fed back for each repetition. An example of this approach is illustrated in  FIG.  7   . In another approach, HARQ-ACK is fed back only for the last repetition. An example of this approach is illustrated in  FIG.  8   . Whether to transmit HARQ-ACK for each repetition or last repetition only is configurable (e.g., by RRC and/or by PDCCH for activation of DL SPS). 
     Another issue for the case of repetitions or slot aggregations is the condition for the termination of repetitions. In one approach for the termination of repetitions, the number of repetitions reaches the DL aggregation factor K. In another approach, ACK is received (e.g., information indicating ACK is transmitted from the UE  102  to the gNB  160  by using PUCCH and/or MAC CE). An example of this approach is illustrated in  FIG.  9   . In another approach, PDCCH is transmitted (e.g., a DL grant for the same TB or a new TB). An example of this approach is illustrated in  FIG.  10   . In yet another approach, a condition for the termination of repetitions may include a periodicity boundary is reached. An example of this approach is illustrated in  FIG.  11   . 
     Another issue for the case of repetitions or slot aggregations is HARQ-ACK handling for conflicts. In an approach, for all the HARQ-ACK to repetitions, the methods and approaches described in connection with  FIG.  3    may be applied. In another approach, HARQ-ACK for repetitions except the last one may be dropped. The methods and approaches described in connection with  FIG.  3    may be applied to the HARQ-ACK corresponding to the last repetition. 
     In another aspect, for each DL bandwidth part (BWP) of a serving cell where a UE  102  is configured to monitor PDCCH in a search space (e.g., common search space, and/or UE-specific search space), the UE  102  may be configured by one or more of the following higher layer parameter (e.g., information configured by RRC). 
     For the search space set s in the control resource set p, an indication that the search space set is a common search space set or a UE-specific search space set by higher layer parameter (e.g., information configured by RRC). If the search space is a common search space, an indication by higher layer parameter RNTI-monitoring to monitor PDCCH in the search space for DCI format 0_0 (e.g., DCI format used for scheduling of PUSCH, fallback DCI format for PUSCH scheduling) and DCI format 1_0 (e.g., DCI format used for scheduling of PUSCH, fallback DCI format for PDSCH scheduling). If the search space is a UE-specific search space, an indication by higher layer parameter USS-DCI format to monitor PDCCH in the search space either for DCI format 0_0 and DCI format 1_0, or for DCI format 0_1 (e.g., DCI format used for scheduling of PUSCH, non-fallback DCI format for PUSCH scheduling) and DCI format 1_1 (e.g., DCI format used for scheduling of PUSCH, non-fallback DCI format for PUSCH scheduling). A PDCCH monitoring periodicity of k p,s  slots by higher layer parameter (e.g., information configured by RRC). A PDCCH monitoring offset of o p,s  slots, where 0≤o p,s &lt;k p,s , by higher layer parameter (e.g., information configured by RRC). 
     A UE  102  may determine a PDCCH monitoring occasion from the PDCCH monitoring periodicity, the PDCCH monitoring offset, and the PDCCH monitoring pattern within a slot. 
     DCI formats for scheduling of PDSCH (e.g., DCI formats used for activation of DL SPS) are also described herein. Format 1_0 (e.g., fallback DCI) may be used for the scheduling of PDSCH in one DL cell. The following information may be transmitted by means of the DCI format 1_0: identifier for DCI formats (1 bits); frequency domain resource assignment (┌log 2 (N RB   UL,BWP (N RB   UL,BWP +1)/2)┐ bits); time domain resource assignment (e.g., timing information for K0) (X bits); VRB-to-PRB mapping (1 bit); modulation and coding scheme (5 bits); new data indicator (1 bit); redundancy version (2 bits); HARQ process number (4 bits); downlink assignment index (2 bits); TPC command for scheduled PUCCH (2 bits); PUCCH resource indicator (2 bits); and PDSCH-to-HARQ_feedback timing indicator (e.g., timing information for K1 and/or K1_0) (3 bits). 
     DCI format 1_1 may be used for the scheduling of PDSCH in one cell. The following information may be transmitted by means of the DCI format 1_1: 
     Carrier indicator (0 or 3 bits). 
     Identifier for DCI formats (1 bits). 
     Bandwidth part indicator (0, 1 or 2 bits). The bit-width for this field may be determined according to the higher layer parameter (e.g., information configured by RRC) for the PDSCH. 
     Frequency domain resource assignment (X bits). 
     Time domain resource assignment (e.g., timing information for K0) (1, 2, 3, or 4 bits). The bit-width for this field may be determined according to the higher layer parameter (e.g., information configured by RRC). 
     For transport block 1: Modulation and coding scheme (5 bits); a new data indicator (1 bit); and/or redundancy version (2 bits). 
     For transport block 2: Modulation and coding scheme (5 bits); a new data indicator (1 bit); and/or redundancy version (2 bits). 
     HARQ process number (4 bits). 
     Downlink assignment index (X bits). 
     TPC command for scheduled PUCCH (2 bits). 
     PUCCH resource indicator (2 bits). 
     PDSCH-to-HARQ_feedback timing indicator (e.g., timing information for K1 and/or K1_0) (3 bits). 
     SRS request (2 bits). 
     CBG transmission information (0, 2, 4, 6, or 8 bits), determined by higher layer parameter (e.g., information configured by RRC) for the PDSCH. 
     CBG flushing out information (0 or 1 bit), determined by higher layer parameter (e.g., information configured by RRC). 
     Regarding, PDCCH validation for semi-persistent scheduling (e.g., DCI setting for activation of DL SPS), a UE  102  may validate a Semi-Persistent Scheduling assignment PDCCH only if all the following conditions are met: the CRC parity bits obtained for the PDCCH payload are scrambled with the CS-RNTI (i.e., configured scheduling RNTI) and the new data indicator field is set to ‘0’. Validation is achieved if all the fields for the respective used DCI format are set according to Table 1, which includes special fields for semi-persistent scheduling activation PDCCH validation. If validation is achieved, the UE  102  may consider the received DCI information accordingly as a valid semi-persistent activation (e.g., DCI format for activation of Dl SPS). 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 DCI format 1_0 
                 DCI format 1_1 
               
               
                   
               
             
            
               
                 TPC command for 
                 set to ‘00’ 
                 N/A 
               
               
                 scheduled PUSCH 
                   
                   
               
               
                 Downlink assignment index 
                 set to ‘00’ 
                 N/A 
               
               
                 Modulation and coding 
                 MSB is set to ‘0’ 
                 N/A 
               
               
                 scheme 
                   
                   
               
               
                 HARQ process number 
                 N/A 
                 set to ‘000’ 
               
               
                 Modulation and coding 
                 N/A 
                 MSB is set to ‘0’ 
               
               
                 scheme 
                   
                   
               
               
                 Redundancy version 
                 N/A 
                 set to ‘00’ 
               
               
                   
               
            
           
         
       
     
       FIG.  5    is an example illustrating an approach for RV determination when DL repetition conflicts with UL by the slot format indication. In this approach, the UE  102  may the skip the conflicted slot(s), and may continue to use the RV order from the next available aggregated slot. 
       FIG.  6    is an example illustrating another approach for RV determination when DL repetition conflicts with UL by the slot format indication. In this approach, the UE  102  may assume the RV value(s) in the RV sequence applied to the conflicted slot(s) although there is no PDSCH transmission. The DL PDSCH may be skipped but the RV counting in the RV sequence is kept. Equivalently, the UE  102  may use the RV sequence corresponding to the slot index. 
       FIG.  7    is an example illustrating an approach for HARQ-ACK for repetitions in a DL SPS procedure. In this approach, HARQ-ACK is fed back for each repetition. 
       FIG.  8    is an example illustrating another approach for HARQ-ACK for repetitions in a DL SPS procedure. In this approach, HARQ-ACK is fed back only for the last repetition. 
       FIG.  9    is an example illustrating an approach for the condition for the termination of repetitions in a DL SPS procedure. In this approach, termination of repetitions occurs when ACK is received (e.g., information indicating ACK is transmitted from the UE  102  to the gNB  160  by using PUCCH and/or MAC CE). 
       FIG.  10    is an example illustrating another approach for the condition for the termination of repetitions in a DL SPS procedure. In this approach, termination of repetitions occurs when PDCCH is transmitted (e.g., a DL grant for the same TB or a new TB). 
       FIG.  11    is an example illustrating another approach for the condition for the termination of repetitions in a DL SPS procedure. In this approach, termination of repetitions occurs when a periodicity boundary is reached. 
       FIG.  12    is a diagram illustrating one example of a resource grid for the downlink. The resource grid illustrated in  FIG.  12    may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection with  FIG.  1   . 
     In  FIG.  12   , one downlink subframe  1269  may include two downlink slots  1283 . N DL   RB  is downlink bandwidth configuration of the serving cell, expressed in multiples of N RB   sc , where N RB   sc  is a resource block  1289  size in the frequency domain expressed as a number of subcarriers, and N DL   symb  is the number of OFDM symbols  1287  in a downlink slot  1283 . A resource block  1289  may include a number of resource elements (RE)  1291 . 
     For a PCell, N DL   RB  is broadcast as a part of system information. For an SCell (including an Licensed Assisted Access (LAA) SCell), N DL   RB  is configured by a RRC message dedicated to a UE  102 . For PDSCH mapping, the available RE  1291  may be the RE  1291  whose index l fulfils l≥l data,start  and/or l data,end ≥l in a subframe. 
     In the downlink, the OFDM access scheme with cyclic prefix (CP) may be employed, which may be also referred to as CP-OFDM. In the downlink, PDCCH, enhanced PDCCH (EPDCCH), PDSCH and the like may be transmitted. A downlink radio frame may include multiple pairs of downlink resource blocks (RBs) which is also referred to as physical resource blocks (PRBs). The downlink RB pair is a unit for assigning downlink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The downlink RB pair includes two downlink RBs that are continuous in the time domain. 
     The downlink RB includes twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM symbols in time domain. A region defined by one sub-carrier in frequency domain and one OFDM symbol in time domain is referred to as a resource element (RE) and is uniquely identified by the index pair (k,l) in a slot, where k and l are indices in the frequency and time domains, respectively. While downlink subframes in one component carrier (CC) are discussed herein, downlink subframes are defined for each CC and downlink subframes are substantially in synchronization with each other among CCs. 
       FIG.  13    is a diagram illustrating one example of a resource grid for the uplink. The resource grid illustrated in  FIG.  13    may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection with  FIG.  1   . 
     In  FIG.  13   , one uplink subframe  1369  may include two uplink slots  1383 . N UL   RB  is uplink bandwidth configuration of the serving cell, expressed in multiples of N RB   sc , where N RB   sc  is a resource block  1389  size in the frequency domain expressed as a number of subcarriers, and N UL   symb  is the number of SC-FDMA symbols  1393  in an uplink slot  1383 . A resource block  1389  may include a number of resource elements (RE)  1391 . 
     For a PCell, N UL   RB  is broadcast as a part of system information. For an SCell (including an LAA SCell), N UL   RB  is RB configured by a RRC message dedicated to a UE  102 . 
     In the uplink, in addition to CP-OFDM, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) access scheme may be employed, which is also referred to as Discrete Fourier Transform-Spreading OFDM (DFT-S-OFDM). In the uplink, PUCCH, PUSCH, PRACH and the like may be transmitted. An uplink radio frame may include multiple pairs of uplink resource blocks. The uplink RB pair is a unit for assigning uplink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The uplink RB pair includes two uplink RBs that are continuous in the time domain. 
     The uplink RB may include twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM/DFT-S-OFDM symbols in time domain. A region defined by one sub-carrier in the frequency domain and one OFDM/DFT-S-OFDM symbol in the time domain is referred to as a RE and is uniquely identified by the index pair (k, l) in a slot, where k and l are indices in the frequency and time domains respectively. While uplink subframes in one component carrier (CC) are discussed herein, uplink subframes are defined for each CC. 
       FIG.  14    shows examples of several numerologies  1401 . The numerology #1  1401   a  may be a basic numerology (e.g., a reference numerology). For example, a RE  1495   a  of the basic numerology  1401   a  may be defined with subcarrier spacing  1405   a  of 15 kHz in frequency domain and 2048 Ts+CP length (e.g., 160 Ts or 144 Ts) in time domain (i.e., symbol length #1  1403   a ), where Ts denotes a baseband sampling time unit defined as 1/(15000*2048) seconds. For the i-th numerology, the subcarrier spacing  1405  may be equal to 15*2 i  and the effective OFDM symbol length 2048*2 −i *Ts. It may cause the symbol length is 2048*2 −i *Ts+CP length (e.g., 160*2 −i *Ts or 144*2 −i *Ts). In other words, the subcarrier spacing of the i+l-th numerology is a double of the one for the i-th numerology, and the symbol length of the i+l-th numerology is a half of the one for the i-th numerology.  FIG.  14    shows four numerologies, but the system may support another number of numerologies. Furthermore, the system does not have to support all of the 0-th to the I-th numerologies, i=0, 1, . . . , I. 
     For example, the first UL transmission on the first SPS resource as above mentioned may be performed only on the numerology #1 (e.g., a subcarrier spacing of 15 kHz). Here, the UE  102  may acquire (detect) the numerology #1 based on a synchronization signal. Also, the UE  102  may receive a dedicated RRC signal including information (e.g., a handover command) configuring the numerology #1. The dedicated RRC signal may be a UE-specific signal. Here, the first UL transmission on the first SPS resource may be performed on the numerology #1, the numerology #2 (a subcarrier spacing of 30 kHz), and/or the numerology #3 (a subcarrier spacing of 60 kHz). 
     Also, the second UL transmission on the second SPS resource as above mentioned may be performed only on the numerology #3. Here, for example, the UE  102  may receive System Information (e.g., Master Information Block (MIB) and/or System Information Block (SIB)) including information configuring the numerology #2 and/or the numerology #3. 
     Also, the UE  102  may receive the dedicated RRC signal including information (e.g., the handover command) configuring the numerology #2 and/or the numerology #3. The System Information (e.g., MIB) may be transmitted on BCH (Broadcast Channel) and/or the dedicated RRC signal. The System Information (e.g., SIB) may contain information relevant when evaluating if a UE  102  is allowed to access a cell and/or defines the scheduling of other system information. The System Information (SIB) may contain radio resource configuration information that is common for multiple UEs  102 . Namely, the dedicated RRC signal may include each of multiple numerology configurations (the first numerology, the second numerology, and/or the third numerology) for each of UL transmissions (e.g., each of UL-SCH transmissions, each of PUSCH transmissions). Also, the dedicated RRC signal may include each of multiple numerology configurations (the first numerology, the second numerology, and/or the third numerology) for each of DL transmissions (each of PDCCH transmissions). 
       FIG.  15    shows examples of subframe structures for the numerologies  1501  that are shown in  FIG.  14   . Given that a slot  1283  includes N DL   symb  (or N UL   symb )=7 symbols, the slot length of the i+l-th numerology  1501  is a half of the one for the i-th numerology  1501 , and eventually the number of slots  1283  in a subframe (i.e., 1 ms) becomes double. It may be noted that a radio frame may include 10 subframes, and the radio frame length may be equal to 10 ms. 
       FIG.  16    shows examples of slots  1683  and sub-slots  1607 . If a sub-slot  1607  is not configured by higher layer, the UE  102  and the eNB/gNB  160  may only use a slot  1683  as a scheduling unit. More specifically, a given transport block may be allocated to a slot  1683 . If the sub-slot  1607  is configured by higher layer, the UE  102  and the eNB/gNB  160  may use the sub-slot  1607  as well as the slot  1683 . The sub-slot  1607  may include one or more OFDM symbols. The maximum number of OFDM symbols that constitute the sub-slot  1607  may be N DL   symb −1 (or N UL   symb −1). 
     The sub-slot length may be configured by higher layer signaling. Alternatively, the sub-slot length may be indicated by a physical layer control channel (e.g., by DCI format). 
     The sub-slot  1607  may start at any symbol within a slot  1683  unless it collides with a control channel. There could be restrictions of mini-slot length based on restrictions on starting position. For example, the sub-slot  1607  with the length of N DL   symb −1 (or N UL   symb −1) may start at the second symbol in a slot  1683 . The starting position of a sub-slot  1607  may be indicated by a physical layer control channel (e.g., by DCI format). Alternatively, the starting position of a sub-slot  1607  may be derived from information (e.g., search space index, blind decoding candidate index, frequency and/or time resource indices, PRB index, a control channel element index, control channel element aggregation level, an antenna port index, etc.) of the physical layer control channel which schedules the data in the concerned sub-slot  1607 . 
     In cases when the sub-slot  1607  is configured, a given transport block may be allocated to either a slot  1683 , a sub-slot  1607 , aggregated sub-slots  1607  or aggregated sub-slot(s)  1607  and slot  1683 . This unit may also be a unit for HARQ-ACK bit generation. 
       FIG.  17    shows examples of scheduling timelines  1709 . For a normal DL scheduling timeline  1709   a , DL control channels are mapped the initial part of a slot  1783   a . The DL control channels  1711  schedule DL shared channels  1713   a  in the same slot  1783   a . HARQ-ACKs for the DL shared channels  1713   a  (i.e., HARQ-ACKs each of which indicates whether or not transport block in each DL shared channel  1713   a  is detected successfully) are reported via UL control channels  1715   a  in a later slot  1783   b . In this instance, a given slot  1783  may contain either one of DL transmission and UL transmission. 
     For a normal UL scheduling timeline  1709   b , DL control channels  1711   b  are mapped the initial part of a slot  1783   c . The DL control channels  1711   b  schedule UL shared channels  1717   a  in a later slot  1783   d . For these cases, the association timing (time shift) between the DL slot  1783   c  and the UL slot  1783   d  may be fixed or configured by higher layer signaling. Alternatively, it may be indicated by a physical layer control channel (e.g., the DL assignment DCI format, the UL grant DCI format, or another DCI format such as UE-common signaling DCI format which may be monitored in common search space). 
     For a self-contained base DL scheduling timeline  1709   c , DL control channels  1711   c  are mapped to the initial part of a slot  1783   e . The DL control channels  1711   c  schedule DL shared channels  1713   b  in the same slot  1783   e . HARQ-ACKs for the DL shared channels  1713   b  are reported in UL control channels  1715   b , which are mapped at the ending part of the slot  1783   e.    
     For a self-contained base UL scheduling timeline  1709   d , DL control channels  1711   d  are mapped to the initial part of a slot  1783   f . The DL control channels  1711   d  schedule UL shared channels  1717   b  in the same slot  1783   f . For these cases, the slot  1783   f  may contain DL and UL portions, and there may be a guard period between the DL and UL transmissions. 
     The use of a self-contained slot may be upon a configuration of self-contained slot. Alternatively, the use of a self-contained slot may be upon a configuration of the sub-slot. Yet alternatively, the use of a self-contained slot may be upon a configuration of shortened physical channel (e.g., PDSCH, PUSCH, PUCCH, etc.). 
       FIG.  18    shows examples of DL control channel monitoring regions. One or more sets of PRB(s) may be configured for DL control channel monitoring. In other words, a control resource set is, in the frequency domain, a set of PRB s within which the UE  102  attempts to blindly decode downlink control information, where the PRBs may or may not be frequency contiguous, a UE  102  may have one or more control resource sets, and one DCI message may be located within one control resource set. In the frequency-domain, a PRB is the resource unit size (which may or may not include Demodulation reference signals (DM-RS)) for a control channel. A DL shared channel may start at a later OFDM symbol than the one(s) which carries the detected DL control channel. Alternatively, the DL shared channel may start at (or earlier than) an OFDM symbol than the last OFDM symbol which carries the detected DL control channel. In other words, dynamic reuse of at least part of resources in the control resource sets for data for the same or a different UE  102 , at least in the frequency domain may be supported. 
       FIG.  19    shows examples of DL control channel which includes more than one control channel elements. When the control resource set spans multiple OFDM symbols, a control channel candidate may be mapped to multiple OFDM symbols or may be mapped to a single OFDM symbol. One DL control channel element may be mapped on REs defined by a single PRB and a single OFDM symbol. If more than one DL control channel elements are used for a single DL control channel transmission, DL control channel element aggregation may be performed. 
     The number of aggregated DL control channel elements is referred to as DL control channel element aggregation level. The DL control channel element aggregation level may be 1 or 2 to the power of an integer. The gNB  160  may inform a UE  102  of which control channel candidates are mapped to each subset of OFDM symbols in the control resource set. If one DL control channel is mapped to a single OFDM symbol and does not span multiple OFDM symbols, the DL control channel element aggregation is performed within an OFDM symbol, namely multiple DL control channel elements within an OFDM symbol are aggregated. Otherwise, DL control channel elements in different OFDM symbols can be aggregated. 
       FIG.  20    shows examples of UL control channel structures. UL control channel may be mapped on REs which are defined a PRB and a slot in frequency and time domains, respectively. This UL control channel may be referred to as a long format (or just the 1st format). UL control channels may be mapped on REs on a limited OFDM symbols in time domain. This may be referred to as a short format (or just the 2nd format). The UL control channels with a short format may be mapped on REs within a single PRB. Alternatively, the UL control channels with a short format may be mapped on REs within multiple PRBs. For example, interlaced mapping may be applied, namely the UL control channel may be mapped to every N PRBs (e.g. 5 or 10) within a system bandwidth. 
       FIG.  21    is a block diagram illustrating one implementation of a gNB  2160 . The gNB  2160  may include a higher layer processor  2123 , a DL transmitter  2125 , a UL receiver  2133 , and one or more antenna  2131 . The DL transmitter  2125  may include a PDCCH transmitter  2127  and a PDSCH transmitter  2129 . The UL receiver  2133  may include a PUCCH receiver  2135  and a PUSCH receiver  2137 . 
     The higher layer processor  2123  may manage physical layer&#39;s behaviors (the DL transmitter&#39;s and the UL receiver&#39;s behaviors) and provide higher layer parameters to the physical layer. The higher layer processor  2123  may obtain transport blocks from the physical layer. The higher layer processor  2123  may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE&#39;s higher layer. The higher layer processor  2123  may provide the PDSCH transmitter transport blocks and provide the PDCCH transmitter transmission parameters related to the transport blocks. 
     The DL transmitter  2125  may multiplex downlink physical channels and downlink physical signals (including reservation signal) and transmit them via transmission antennas  2131 . The UL receiver  2133  may receive multiplexed uplink physical channels and uplink physical signals via receiving antennas  2131  and de-multiplex them. The PUCCH receiver  2135  may provide the higher layer processor  2123  UCI. The PUSCH receiver  2137  may provide the higher layer processor  2123  received transport blocks. 
       FIG.  22    is a block diagram illustrating one implementation of a UE  2202 . The UE  2202  may include a higher layer processor  2223 , a UL transmitter  2251 , a DL receiver  2243 , and one or more antenna  2231 . The UL transmitter  2251  may include a PUCCH transmitter  2253  and a PUSCH transmitter  2255 . The DL receiver  2243  may include a PDCCH receiver  2245  and a PDSCH receiver  2247 . 
     The higher layer processor  2223  may manage physical layer&#39;s behaviors (the UL transmitter&#39;s and the DL receiver&#39;s behaviors) and provide higher layer parameters to the physical layer. The higher layer processor  2223  may obtain transport blocks from the physical layer. The higher layer processor  2223  may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE&#39;s higher layer. The higher layer processor  2223  may provide the PUSCH transmitter transport blocks and provide the PUCCH transmitter  2253  UCI. 
     The DL receiver  2243  may receive multiplexed downlink physical channels and downlink physical signals via receiving antennas  2231  and de-multiplex them. The PDCCH receiver  2245  may provide the higher layer processor  2223  DCI. The PDSCH receiver  2247  may provide the higher layer processor  2223  received transport blocks. 
     It should be noted that names of physical channels described herein are examples. The other names such as “NRPDCCH, NRPDSCH, NRPUCCH and NRPUSCH”, “new Generation-(G)PDCCH, GPDSCH, GPUCCH and GPUSCH” or the like can be used. 
       FIG.  23    illustrates various components that may be utilized in a UE  2302 . The UE  2302  described in connection with  FIG.  23    may be implemented in accordance with the UE  102  described in connection with  FIG.  1   . The UE  2302  includes a processor  2303  that controls operation of the UE  2302 . The processor  2303  may also be referred to as a central processing unit (CPU). Memory  2305 , which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions  2307   a  and data  2309   a  to the processor  2303 . A portion of the memory  2305  may also include non-volatile random-access memory (NVRAM). Instructions  2307   b  and data  2309   b  may also reside in the processor  2303 . Instructions  2307   b  and/or data  2309   b  loaded into the processor  2303  may also include instructions  2307   a  and/or data  2309   a  from memory  2305  that were loaded for execution or processing by the processor  2303 . The instructions  2307   b  may be executed by the processor  2303  to implement the methods described above. 
     The UE  2302  may also include a housing that contains one or more transmitters  2358  and one or more receivers  2320  to allow transmission and reception of data. The transmitter(s)  2358  and receiver(s)  2320  may be combined into one or more transceivers  2318 . One or more antennas  2322   a - n  are attached to the housing and electrically coupled to the transceiver  2318 . 
     The various components of the UE  2302  are coupled together by a bus system  2311 , which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated in  FIG.  23    as the bus system  2311 . The UE  2302  may also include a digital signal processor (DSP)  2313  for use in processing signals. The UE  2302  may also include a communications interface  2315  that provides user access to the functions of the UE  2302 . The UE  2302  illustrated in  FIG.  23    is a functional block diagram rather than a listing of specific components. 
       FIG.  24    illustrates various components that may be utilized in a gNB  2460 . The gNB  2460  described in connection with  FIG.  24    may be implemented in accordance with the gNB  160  described in connection with  FIG.  1   . The gNB  2460  includes a processor  2403  that controls operation of the gNB  2460 . The processor  2403  may also be referred to as a central processing unit (CPU). Memory  2405 , which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions  2407   a  and data  2409   a  to the processor  2403 . A portion of the memory  2405  may also include non-volatile random-access memory (NVRAM). Instructions  2407   b  and data  2409   b  may also reside in the processor  2403 . Instructions  2407   b  and/or data  2409   b  loaded into the processor  2403  may also include instructions  2407   a  and/or data  2409   a  from memory  2405  that were loaded for execution or processing by the processor  2403 . The instructions  2407   b  may be executed by the processor  2403  to implement the methods described above. 
     The gNB  2460  may also include a housing that contains one or more transmitters  2417  and one or more receivers  2478  to allow transmission and reception of data. The transmitter(s)  2417  and receiver(s)  2478  may be combined into one or more transceivers  2476 . One or more antennas  2480   a - n  are attached to the housing and electrically coupled to the transceiver  2476 . 
     The various components of the gNB  2460  are coupled together by a bus system  2411 , which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated in  FIG.  24    as the bus system  2411 . The gNB  2460  may also include a digital signal processor (DSP)  2413  for use in processing signals. The gNB  2460  may also include a communications interface  2415  that provides user access to the functions of the gNB  2460 . The gNB  2460  illustrated in  FIG.  24    is a functional block diagram rather than a listing of specific components. 
       FIG.  25    is a block diagram illustrating one implementation of a UE  2502  in which systems and methods for downlink semi-persistent scheduling may be implemented. The UE  2502  includes transmit means  2558 , receive means  2520  and control means  2524 . The transmit means  2558 , receive means  2520  and control means  2524  may be configured to perform one or more of the functions described in connection with  FIG.  1    above.  FIG.  23    above illustrates one example of a concrete apparatus structure of  FIG.  25   . Other various structures may be implemented to realize one or more of the functions of  FIG.  1   . For example, a DSP may be realized by software. 
       FIG.  26    is a block diagram illustrating one implementation of a gNB  2660  in which systems and methods for downlink semi-persistent scheduling may be implemented. The gNB  2660  includes transmit means  2623 , receive means  2678  and control means  2682 . The transmit means  2623 , receive means  2678  and control means  2682  may be configured to perform one or more of the functions described in connection with  FIG.  1    above.  FIG.  24    above illustrates one example of a concrete apparatus structure of  FIG.  26   . Other various structures may be implemented to realize one or more of the functions of  FIG.  1   . For example, a DSP may be realized by software. 
       FIG.  27    is a flow diagram illustrating a communication method  2700  of a user equipment  102 . The communication method  2700  may include receiving  2702  system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The communication method  2700  may also include receiving  2704  a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The communication method  2700  may also include performing  2706 , based on a detection of a physical downlink control channel (PDCCH), the PDSCH reception according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment overrides the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment is used for the PDSCH reception. 
       FIG.  28    is a flow diagram illustrating a communication method  2800  of a base station apparatus  160 . The communication method  2800  may include transmitting  2802  system information comprising first information of first time domain resource assignment for a physical downlink shared channel (PDSCH). The communication method  2800  may also include transmitting  2804  a UE-specific radio resource control (RRC) signal comprising second information of second time domain resource assignment for a PDSCH. The communication method  2800  may also include performing  2806 , based on a transmission of a physical downlink control channel (PDCCH), the PDSCH transmission according to either the first information of the first time domain resource assignment or the second information of the second time domain resource assignment. In a case that the first information of the first time domain resource assignment is configured and the second information of the second time domain resource assignment is configured, the second information of the second time domain resource assignment overrides the first information of the first time domain resource assignment, and the second information of the second time domain resource assignment is used for the PDSCH transmission. 
     The term “computer-readable medium” refers to any available medium that can be accessed by a computer or a processor. The term “computer-readable medium,” as used herein, may denote a computer- and/or processor-readable medium that is non-transitory and tangible. By way of example, and not limitation, a computer-readable or processor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. 
     It should be noted that one or more of the methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc. 
     Each of the methods disclosed herein comprises one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another and/or combined into a single step without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. 
     It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the systems, methods, and apparatus described herein without departing from the scope of the claims. 
     A program running on the gNB  160  or the UE  102  according to the described systems and methods is a program (a program for causing a computer to operate) that controls a CPU and the like in such a manner as to realize the function according to the described systems and methods. Then, the information that is handled in these apparatuses is temporarily stored in a RAM while being processed. Thereafter, the information is stored in various ROMs or HDDs, and whenever necessary, is read by the CPU to be modified or written. As a recording medium on which the program is stored, among a semiconductor (for example, a ROM, a nonvolatile memory card, and the like), an optical storage medium (for example, a DVD, a MO, a MD, a CD, a BD, and the like), a magnetic storage medium (for example, a magnetic tape, a flexible disk, and the like), and the like, any one may be possible. Furthermore, in some cases, the function according to the described systems and methods described above is realized by running the loaded program, and in addition, the function according to the described systems and methods is realized in conjunction with an operating system or other application programs, based on an instruction from the program. 
     Furthermore, in a case where the programs are available on the market, the program stored on a portable recording medium can be distributed or the program can be transmitted to a server computer that connects through a network such as the Internet. In this case, a storage device in the server computer also is included. Furthermore, some or all of the gNB  160  and the UE  102  according to the systems and methods described above may be realized as an LSI that is a typical integrated circuit. Each functional block of the gNB  160  and the UE  102  may be individually built into a chip, and some or all functional blocks may be integrated into a chip. Furthermore, a technique of the integrated circuit is not limited to the LSI, and an integrated circuit for the functional block may be realized with a dedicated circuit or a general-purpose processor. Furthermore, if with advances in a semiconductor technology, a technology of an integrated circuit that substitutes for the LSI appears, it is also possible to use an integrated circuit to which the technology applies. 
     Moreover, each functional block or various features of the base station device and the terminal device used in each of the aforementioned implementations may be implemented or executed by a circuitry, which is typically an integrated circuit or a plurality of integrated circuits. The circuitry designed to execute the functions described in the present specification may comprise a general-purpose processor, a digital signal processor (DSP), an application specific or general application integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, or a discrete hardware component, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or may be configured by an analogue circuit. Further, when a technology of making into an integrated circuit superseding integrated circuits at the present time appears due to advancement of a semiconductor technology, the integrated circuit by this technology is also able to be used. 
     As used herein, the term “and/or” should be interpreted to mean one or more items. For example, the phrase “A, B and/or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C. As used herein, the phrase “at least one of” should be interpreted to mean one or more items. For example, the phrase “at least one of A, B and C” or the phrase “at least one of A, B or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C. As used herein, the phrase “one or more of” should be interpreted to mean one or more items. For example, the phrase “one or more of A, B and C” or the phrase “one or more of A, B or C” should be interpreted to mean any of: only A, only B, only C, A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C.